Previous Article in Journal
Italian Version of the Hospital Aggressive Behaviour Scale-Users: Initial Psychometric Evaluation among Hospital Healthcare Professionals
Previous Article in Special Issue
Machine Learning-Based Prediction of Readmission Risk in Cardiovascular and Cerebrovascular Conditions Using Patient EMR Data
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Systematic Review

The State-of-the-Art of Mycobacterium chimaera Infections and the Causal Link with Health Settings: A Systematic Review

by
Vittorio Bolcato
1,*,
Matteo Bassetti
2,3,
Giuseppe Basile
4,5,
Luca Bianco Prevot
4,6,
Giuseppe Speziale
7,
Elena Tremoli
8,
Francesco Maffessanti
8 and
Livio Pietro Tronconi
8,9
1
Astolfi Associates Legal Firm, 20122 Milan, Italy
2
Department of Health Sciences (DISSAL), University of Genova, 16132 Genova, Italy
3
Infectious Diseases Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
4
IRCCS Orthopaedic Institute Galeazzi, 20157 Milan, Italy
5
Section of Legal and Forensic Medicine Clinical Institute San Siro, 20148 Milan, Italy
6
Residency Program in Orthopaedics and Traumatology, University of Milan, 20122 Milan, Italy
7
GVM Care and Research, Anthea Hospital, 70124 Bari, Italy
8
GVM Care and Research, Maria Cecilia Hospital, 49033 Cotignola, Italy
9
Department of Human Science, European University of Rome, 00163 Rome, Italy
*
Author to whom correspondence should be addressed.
Healthcare 2024, 12(17), 1788; https://doi.org/10.3390/healthcare12171788
Submission received: 29 July 2024 / Revised: 28 August 2024 / Accepted: 29 August 2024 / Published: 6 September 2024

Abstract

:
(1) Background. A definition of healthcare-associated infections is essential also for the attribution of the restorative burden to healthcare facilities in case of harm and for clinical risk management strategies. Regarding M. chimaera infections, there remains several issues on the ecosystem and pathogenesis. We aim to review the scientific evidence on M. chimaera beyond cardiac surgery, and thus discuss its relationship with healthcare facilities. (2) Methods. A systematic review was conducted on PubMed and Web of Science on 7 May 2024 according to PRISMA 2020 guidelines for reporting systematic reviews, including databases searches with the keyword “Mycobacterium chimaera”. Article screening was conducted by tree authors independently. The criterion for inclusion was cases that were not, or were improperly, consistent with the in-situ deposition of aerosolised M. chimaera. (3) Results. The search yielded 290 eligible articles. After screening, 34 articles (377 patients) were included. In five articles, patients had undergone cardiac surgery and showed musculoskeletal involvement or disseminated infection without cardiac manifestations. In 11 articles, respiratory specimen reanalyses showed M. chimaera. Moreover, 10 articles reported lung involvement, 1 reported meninges involvement, 1 reported skin involvement, 1 reported kidney involvement after transplantation, 1 reported tendon involvement, and 1 reported the involvement of a central venous catheter; 3 articles reported disseminated cases with one concomitant spinal osteomyelitis. (4) Conclusions. The scarce data on environmental prevalence, the recent studies on M. chimaera ecology, and the medicalised sample selection bias, as well as the infrequent use of robust ascertainment of sub-species, need to be weighed up. The in-house aerosolization, inhalation, and haematogenous spread deserve experimental study, as M. chimaera cardiac localisation could depend to transient bacteraemia. Each case deserves specific ascertainment before tracing back to the facility, even if M. chimaera represents a core area for healthcare facilities within a framework of infection prevention and control policies.

1. Introduction

A case report by Vendramin et al. describes the current upper extreme of Mycobacterium chimaera (M. chimaera) infection latency in a subject who underwent cardiac surgery 12 years earlier [1]. This interesting case poses the opportunity for an in-depth literature review oriented towards a causal assessment between M. chimaera infection and healthcare settings. The issue of defining an infection acquired in a healthcare setting, a so-called healthcare-associated infection (HAI), is of central significance from a medico-legal point of view. In the case of patient harm, in fact, it could derive the attribution of the restorative burden to the healthcare facility, and there is a growing interest in the implications in terms of the reliability and risk management strategies in healthcare systems [2,3,4,5,6,7]. The article mentioned above reported on M. chimaera infection from a clinical perspective and placed it in association with a previous cardiac surgery of an aortic dissection repair with graft replacement of the ascending aorta, based on a chronological and topographical criterion. But the farther apart two natural events are, the more other events can occur in between, and the more complex the causal reconstruction becomes [8]. The referenced scientific literature on M. chimaera is precisely limited to the M. chimaera outbreaks related to a lot of contaminated heater-cooler units, starting with the first case reported in the USA in 2013 and distinct cases in Italy between 2016 and 2019 [9,10,11,12]. That extreme case, however, does not describe any genetic ascertainment to be traced back at least to the group of strains most frequently identified in contaminated devices or in strains contaminating healthcare facilities [13,14,15,16,17,18]. And the same Italian Health Ministry Recommendations from 9 January 2019, starting from the European Centre for Disease Prevention and Control (ECDC) protocol and epidemiological criteria, refer to the temporal criterion: ‘performance of surgery that required cardiopulmonary bypass in the six years preceding the onset of symptoms of infection’ [19,20]. Nevertheless, this definition responds to epidemiological and clinical necessity, being biassed towards sensitivity. It was appropriately stated that M. chimaera infection poses significant difficulties for various reasons: (a) the time between infection and the manifestation of symptoms is extremely long and are not yet fully understood or described in the literature; (b) the characteristics of this particular mycobacterium and the route of infection are not widely recognised; (c) many diagnostic tests for M. chimaera are slow and of low sensitivity; (d) the healthcare infection route is very specific and occurs through routine processes employed within operating rooms; and (e) the elimination of M. chimaera biofilms from surfaces using routine disinfection procedures, both in healthcare settings and in communities, is challenging [21]. These considerations depend, and it is worth pointing this out, on the related scientific knowledge that, outside the perimeter of complications after cardiac surgery [22], still displays several unsolved challenges. Moreover, we are confronted with very recent microbiological acquisitions in terms of identification and pathogenic characteristics, being already relevant to the re-evaluation of cases previously attributed to Mycobacterium intracellular, or others from the avium complex group, and then traced back to chimaera [23,24]. Vendramin et al. themselves, indeed, emphasise the importance of punctual microbiological, histo-pathological, pathological-forensic, and genetic investigations, as well as the reporting and reviewing of cases with atypical clinical presentations during the follow-ups of patients who have undergone cardiac surgery [1]. The aim is precisely because it is only from robust and reliable data that is it possible to infer a clear causal relationship.
Therefore, the purpose of this systematic literature review, particularly in the face of such long latencies between healthcare interactions and clinical manifestations, is to summarise the scientific evidence on M. chimaera, which is not only restricted to cardiac surgery, to assess the possibility of alternative causes of transmission and infection besides the hypothesis of in situ deposition of aerosolised particles, and then to evaluate the role of healthcare settings.

2. Materials and Methods

A systematic literature review was conducted according to the PRISMA 2020 guidelines for reporting systematic reviews, including searches of databases and registers only [25]. The search was conducted on PubMed (PubMed.gov; US National Library of Medicine National Institute of Health) and Web of Science Core Collection (Clarivate) using the keyword “Mycobacterium chimaera” without any filter, any Boolean operator or limitation. PubMed query detail is “Mycobacterium chimaera” [Supplementary Concept] OR “Mycobacterium chimaera” [All Fields] OR “Mycobacterium chimaera” [All Fields]. Web of Science Core collection query detail is ALL = (MYCOBACTERIUM CHIMAERA). The literature survey was performed on 7 May 2024. The PRISMA 2020 flow diagram for systematic reviews was used for article screening, together with PRISMA checklist (Supplementary Materials Table S1). PROSPERO does not accept scoping reviews, literature reviews or mapping reviews. Not applicable. Duplicate articles were semi-automatically removed before screening by the first author (VB). Then, the articles were screened by the authors (VB, MB, LBP), who reviewed the title and abstract and excluded all not relevant articles, such as those incidentally referring to M. chimaera without any data on the pathogen, incomplete articles, meeting abstracts, and not available articles.
Articles deemed eligible for review were then independently re-screened by three authors (VB, MB, LBP) according to the following inclusion criteria: cases not or improperly consistent with in situ deposition of aerosolised M. chimaera particles during cardiac surgery, such as clinical manifestations not in the cardiac tissue/district after cardiac surgery or atypical clinical manifestations after other surgical intervention not using HCU, or in general cases of M. chimaera infections. Divergences were solved through discussion.
Included articles were discussed among all authors and summed in a table. The following items were considered: number of patients per each study, surgery if any, time lapse to presentation in case of surgery, Country, organ/tissue involved with complete diagnosis. The setting was reported distinguishing between not healthcare related (prevalent daily life, environmental contact and signs/symptoms presentation in community setting) or healthcare related because of frequent hospitalisation and/or pathologies requiring hospitalisation (underwent to surgery, possible frequent healthcare contact, possible healthcare contact).
The risk of bias assessment for the included articles was not applicable, as it was descriptive research. Articles reporting clinical cases that met the inclusion criteria were considered valid because they answer the study aim (qualitative data present or absent). The Limitations section contains further considerations.
M. chimaera characteristics and ecosystem, health devices and implants contamination, incubation period and clinical presentation, lung presence, transmission modality, detection and disinfection techniques were then discussed, comparing them with the findings of the considered articles, to finally argue on causal link with healthcare setting.

3. Results

Overall, the search yielded 256 articles on PubMed and 323 on Web of Science, reduced to 318 after removal of duplicates (Figure 1).
After the first screening, 28 articles were excluded because not relevant or non-retrievable, resulting in 290 distinct articles, including 26 review and 5 systematic reviews.
Among them, the most recent systematic review on M. chimaera infection after cardiac surgery was performed by Wetzstein et al., set at 15 June 2022, reporting 54 articles for a total of 180 cardiac surgery patients worldwide. The median period between the time of surgery and the occurrence of the first symptoms was 17 months (interquartile range 13–26 months), with 80% of the patients showing symptoms within 2 years. After that review, 49 articles were published on M. chimaera in general, without limitations to cardiac surgery. Eight articles (33 patients) were linked with cardiac surgery. Overall, to date, 62 articles (213 cardiac surgery patients) worldwide describing M. chimaera infection consistent with the hypothesis of in situ deposition after cardiac surgery were reported. The median incubation time in the most recent articles was in line with previously reported data.
The 290 eligible articles were deemed eligible and re-screened for inclusion. An established diagnosis of M. chimaera infection without clinical manifestations in the cardiac tissue/district after cardiac surgery or atypical clinical manifestations after other surgical intervention not using HCU or involvement of other organs or tissues not consistent with the hypothesis of in situ deposition of aerosolised M. chimaera particles, emerged in 34 articles (377 patients) (Table 1).
Out of these, in 5 articles, 12 patients had undergone cardiac surgery: 2 presenting symptomatology to be referred to the musculoskeletal district with a diagnosis of spinal osteomyelitis and discitis, 1 with a diagnosis of hand tenosynovitis with history of ipsilateral elbow wound, 4 with a disseminated presentation without endocarditis, and 5 patients with a disseminated presentation without endocarditis and hepatitis-like signs. Moreover, 1 patient showed urinary district M. chimaera infection after kidney transplantation with unknown infection source, concomitant Mycobacterium malmoense lung infection and lung fibro anthracosis.
The remaining 28 articles (364 patients) reported M. chimaera infections without evidence of cardiac signs or symptoms and/or without relation with any surgical approach or presence in operating room: 10 articles (10 patients) reported lung related signs and symptoms usually with various concomitant pathologies; of note, one of this article described the case of a healthcare worker reporting lung involvement, ten years after working as operating room nurse; 11 articles (346 patients) reported M. chimaera diagnosis after respiratory specimen reanalysis; in particular, 1 article reported data from genomic analysis of respiratory specimens in patients with cystic fibrosis to define cluster correlation to environmental samples in hospital outbreaks.
Three articles (3 patients) described disseminated infection in immunocompromised patients (2) and in presence of osteomyelitis (1). A single article (2 patients) described meningeal involvement. Finally, 1 patient showed hand tenosynovitis in rheumatoid arthritis, 1 patient a skin ulcer on the face (chin) with concomitant oral cavity periapical abscess, and 1 patient central venous catheter infection with recurrent M. chimaera blood and sputum positivity.

4. Discussion

4.1. Mycobacterium chimaera’s Characteristics and Ecosystem

Mycobacterium chimaera is a non-tuberculous mycobacterium (NTM), first described by Tortoli et al. in 2004, that belongs to the Mycobacterium avium complex (MAC). It is an opportunistic human pathogen, ubiquitous in the environment and water-borne, typically found in groundwater or tap water, soil, house dust, domestic and wild animals, and birds [59,60,61,62]. However, its prevalence in the environment is mostly unknown [9,63,64,65]. It is a slow-growing, non-pigmented, acid-fast positive, distinguished by non-motile and non-spore forming coccobacilli with a growth that takes up to 6–8 weeks [9]. The highly lipophilic cell wall, the low number of porins associated with a variety of efflux pumps, inducible resistance mechanisms and biofilm production confer an environmental resistance and a natural drug-resistance as well, similarly to other species belonging to the MAC group. The resistance against frequently used disinfectants, such as chlorines and ozone, could also explain their persistence in water systems. Indeed, water stagnation and high temperature, up to 40 °C, promote the formation of biofilms and create a more favourable environment for M. chimaera, while its growth is considerably slow at temperatures in the range of 25–35 °C [17,18]. In addition, MAC members and M. chimaera preferentially colonize warm water sources, and this might, at least partially, explain their propensity to aerosolize [9,63,66]. Moreover, the presence of NTM in dust collected from residences clearly suggests that some NTM species are desiccation tolerant, resulting in a further complexity, not restricting the survival to humid ecosystems [67]. Differences in water treatment, water heating systems, source water type, showerhead design, and characteristics of the water distribution systems, determine a lower presence of mycobacteria and M. chimaera in Europe than in the United States. In fact, U.S. households’ water had significantly higher chlorine and iron concentrations, but lower pH and nitrate levels than European households on municipal water [68]. Previous studies reported the presence of NTM and M. chimaera in domestic drinking water, showerheads and washing machines, with clear association with lung diseases and air diffusion [69,70,71,72]. Durnez et al. has demonstrated the presence of M. chimaera in small mammals in urban areas, highlighting their potential role as carriers of the pathogen [65].

4.2. Heater-Cooler Units, Medical Devices, Water, and Air-Conditioned Implants

An outbreak of M. chimaera infection following cardiac surgery has been reported, and the use of a specific heater-cooler units (HCU) model, clinically available since 2006 and contaminated in production, has been identified as the potential source. However, contamination of other HCU brands and hospital water systems has been observed and that suggests that the infectious risk might persist even after carefully controlling the single lot of devices contaminated in the production line [14]. The primary mode of transmission has been identified in the contaminated water tanks of HCUs, thermoregulatory components of Extra-Corporeal Membrane Oxygenation (ECMO), near the rotating fan, which can produce a contaminated aerosol within the operating room. The ECMO machines are air-tight and closed systems, unlike the HCUs used in cardiothoracic surgery, which may have precluded the release of infectious aerosols, in case of contamination, by those devices [73]. M. chimaera contamination of ECMO devices was reported by Trudzinki et al., but without the presence of air samples or other environmental samples in the surgery room. Nonetheless, transmission of M. chimaera from an ECMO device, in case of circuits damage during use, has been reported reported, due to haematic line failure, and this widens the problem to other devices sharing similar characteristics and use [74]. In fact, similar risks have been reported for infusion heating devices [75]. Also, as a consequence of Health Ministries’ campaigns held worldwide, which recommended the reporting of cases clinically attributed to the pathogen in the follow-up of patients undergone cardiac surgery, attention was focused in the first instance on the structural architecture of HCUs: some models, due to the proximity of fans and water tanks, have an easier and higher possibility to aerolize pathogens’ particles. Furthermore, their location in the operating theatre and the laminar air flow [76,77,78], the supply of water tanks [79], healthcare facilities’ water contamination and healthcare hand washing machines [80,81,82], overall operation time, the use of other medical equipment such endoscope reprocessing or haemodialysis systems, were reported as influencing factors that could predispose to M. chimaera contamination [14,75,83,84]. All these factors gradually extended the issue to the management of aeraulic systems in healthcare facilities, with the associated sampling. Delving into the subject, it was thus observed that mycobacterium could be almost widespread in the healthcare setting. Therefore, leaving aside for a moment whether an alternative transmission to the direct contamination of the surgical site is possible, apart from aerosolised particles, the healthcare facilities can be contaminated by M. chimaera and overall the so-called opportunistic premise plumbing pathogens (OPPP) depending on the replication of those natural ecosystems with certain ecological niches of choice, particularly warm water, where then can widely produce biofilms [63,85].

4.3. Incubation Period and Symptoms Presentation

The literature showed an extremely variable latency time, with extremes ranging between 6 weeks and 12 years, although 80% of the cases manifest symptoms within two years [11,86]. The clinical spectrum comprehends prosthetic valve endocarditis, grafts and prosthetic-related parts infection, sternotomy wound infection, pleuro-pericarditis and mediastinitis, usually with disseminated extrapulmonary infection. M. chimaera shows an ease of systemic dissemination, which results in a dismal prognosis, as only a 3-year survival from diagnosis of 40% has been observed. Embolic and immunologic sequela of disseminated infections have also been reported, such as splenomegaly, arthritis, spinal osteomyelitis, cytopenia due to bone marrow involvement, even without cardiac tissue involvement [11]. Specifically, on M. chimaera infective endocarditis, no natural cases have been described in the literature except ‘after’ cardiac surgery related to the outbreaks, but it must be considered that M. chimaera is a very recently defined pathogen among NMT which has only recently been included in the endocarditis diagnosis flow-chart, while even rarely other mycobacterial endocarditis are described [11]. For instance, a review has recently identified 20 cases reporting infective endocarditis caused by Mycobacterium abscessus [87]. Moreover, a wide range of infective endocarditis remains with a negative blood culture (i.e., with an undefined pathogen) with rates ranging from 7.7% to 66% (mean 10–20%). The variability in the observed incidence can be explained by several factors, most notably the lack of specific clinical syndromes related to M. chimaera infections [88,89], local variations in the early use of antibiotic therapy prior to obtaining blood cultures and the fact that mycobacterial cultures are not routinely pursued in clinical setting, but also differences in testing strategies and geographic variation of specific organisms [90,91]. Of course, it should also be considered how the same diagnostic challenge leads to an alteration of the natural history of the disease, for instance through empirical therapies. The same forensic investigations are not always feasible and/or possible within a reasonable—and so significant—timeframe for pathogens research, while histopathological assessment of removed prosthetic tissues must always be pursued.

4.4. Presence in the Lung System

Several article and patients reported lung system involvement, usually associated with cystic fibrosis, obstructive lung disease or pneumoconiosis, or, more in general, immunocompromising conditions. Pulmonary infection identical to that of other MAC infections have been reported [23]. Patients may suffer from chronic cough and breathlessness, with or without associated constitutional features such as fatigue, fever, night sweats and weight loss. Chest imaging may reveal nodules and hilar lymphadenopathy, and several patients have been erroneously diagnosed with sarcoidosis or pulmonary tuberculosis before the diagnosis of M. chimaera infection was made [92]. Mc can also cause pulmonary infection, like M. avium and M. intracellulare [23,33,42,93]. In the respiratory tract, Mc resulted more likely to be a colonizer and less likely to cause true infection, compared to the other MAC species, yet enhancing the difficulty of the prevalence assessment in the community. In fact, patients with symptomatic respiratory infection due to Mc were more likely to be immunosuppressed, suggesting an opportunistic pattern of the pathogen, aligned with the reported low virulence [17]. The prevalence of Mc has also been addressed in studies assessing whether the reservoir for M. intracellulare pulmonary disease was the patient’s household water system [17,33,94]. In a German cohort, Schweickert and colleagues, after genetic sequencing on 166 isolates that had been previously classified as M. intracellulare, found 86% (143/166) of these samples to be M. chimaera [95]. The discrepancy between Tortoli et al. high virulence and Schweickert et al. may be the result of a sampling bias, with patients suffering from a more severe disease in the former, as all their patients were hospitalised and underwent cardio-surgery. Low virulence, together with the indolent symptomatology and the ease of systemic dissemination resulted in an unfavourable prognosis. Numerous studies have commented on environmental exposures to water supplies, household and environmental, as a risk factor for MAC pulmonary infections [96].

4.5. Modality of Transmission

Most recent cases referring to M. chimaera infection, support a relation to the contamination of a heat exchanger by experimental investigations of the contamination of the machine’s water tanks, a water temperature favourable to proliferation, an air flow that favoured aerosolization of the pathogen from the water and its dispersion in the air of the operating theatre [97]. The aerosolised pathogen subsequently adheres to the exposed substrates causing mediastinitis, infection of the surgical site, endocarditis, pleuritis; the immune response capacity and the formation of biofilm on an inert substrate were other relevant predisposing factors. Interestingly, it is not a valve that is contaminated ab initio, but a valve, tissue, graft, device that has been contaminated in a later stage, as mentioned most often as a function of aerosolised particles released by HCUs during laparotomic operations with cardio-pulmonary bypass [11,98,99]. This is supported by the presence in the air in case of active devices, the reduction of the presence when the device is switched off, the orientation of the airflow on the operating table, as well as the association with longer operations [10,89,100]. Yet, patients showed higher risk of M. chimaera infection when the ECMO used for open surgery, than for respiratory failure, posing the role of the larger potential entry sites for the pathogen [9,83,89]. Literature has also described the similarity of the genetic trait of infection samples with those present in the machinery such as HCU, thus supporting a more stringent relationship between the use of machinery in healthcare and therefore assessing HAI definition [13,101]. Nevertheless, as said considering its distribution in the ecosystem and lung colonization/infection, the importance of this pathogen to human health is beyond the cardio-thoracic surgery related outbreak, as in general for the mycobacterium family. Our knowledge on this emerging pathogen relating population prevalence, mode of infection and virulence mechanism is still limited [102]. We reported evidence of complicated diagnoses that does not meet or meet improperly the topographical criterion with respect to aerosolization of the pathogen in the operating room and the subsequent direct deposition. In particular, Chand et al. reported three cases of late disseminated M. chimaera infection and one osteomyelitis after valvular surgery without endocarditis and/or other infections directly matching with M. chimaera aerosol deposition, additionally demonstrating high genetic similarity of the samples to HCU isolates [36]. These few cases seem consistent with an in-hospital source, but the presence in the blood stream at such long intervals needs still need an explanation, as it may be secondary to a subsequent care-related cause as well as an undiagnosed, but apparently non cardiac site, of dormant M. chimaera. As mentioned, although the modes of transmission have been poorly investigated, the presence, persistence and growth in household and outdoor plumbing, account for the need to weigh the risk between healthcare and community contexts [17,68,94]. Certainly, the presence of high-risk subjects in such care settings favours their detection, but the precise association and definition of risk must necessarily depend on a more precise analysis of exposure in community environmental subsystems, enlarging the sample to include non-hospitalised/medicalised subjects, thus avoiding any potential selection bias [33,103]. Lung infections and lung colonisations were found in non-hospital settings, supporting the hypothesis of community aerosolization [33], even if the healthcare worker with lung involvement could be linked with the contagion in operating room, even though this activity goes back 10 years, and no genetic assessment has been carried out [40]. In other words, just as for HCUs after outbreaks, because of atypical clinical pictures in patients undergoing major cardiac surgery, attention has been focused on a little-known mechanism of exposure and transmission accidentally occurring, so it will be necessary to ascertain the presence, exposure and mode of transmission in another context and in an immunologically healthy population [33,103]. The localisation in the choroid, in spinal vertebrae in the form of a discitis, in the bone marrow in the form of granulomas, in chronic wound ulcers, need to be explained according to aerosol contamination, rather than supporting the hypotheses of localization by a circulating pathogen or not health-related contagion [50]. Interestingly, Asadi et al. reported and discussed a case without valvular involvement and without abscess formation, but with the presence of colonization of the peri-graft tissue at histopathological examination. Similarly, paravalvular or peri-graft involvements as disseminated infection without valve endocarditis were reported by Kohler, Clemente and Natanti, Trauth and Shaeffer. Those authors stressed the need for histopathological examination, as further confirmation, and once again the role of haematogenous spread, granulomas formation, and the struggle of endocarditis diagnostic path [92,104,105,106,107]. The disseminated forms themselves support pathogen circulation and haematogenous spread, which is shared by the entire mycobacterial family, as well as with mechanisms of embolization and dissemination via the meningeal route [45,108]. Most important in explaining modes of transmission and possible community acquisition is the finding of M. chimaera infection in non-hospitalised individuals or in surgeries that do not use HCUs. To date, this systematic literature review reported rare data about systemic manifestations and tissues involvements not directly ascribable to a topographical criterion which complies with the health-related aerosolised pathogen’s deposition. Alternative transmission routes are however possible and described. Patient blood may have been contaminated by a leakage in the membrane in one of the heat exchange units, but this should be regarded as an exceptional event; alternatively, contamination or colonization of the prosthetic material due to intravenous catheter-related bacteraemia may be considered an alternative explanation [22]. In addition, lung and disseminated infections are possible outside the operating room, such as by inhalation of aerosols or ingestion of contaminated water in various setting, for instance from community showerheads [66]. While these cases have certainly been described less frequently, limited to single case reporting, they showed atypical cases that could also be explained by aerosol inhalation and subsequent spreading via bloodstream [22,59].

4.6. Detection

Detection of M. chimaera relies on multiple methods, including standard microscopy, proteomics, molecular assays and next-generation sequencing, with different advantages and pitfalls, both for clinical and environmental samples, as well as the microbiological basis of the process of linking a case of M. chimaera infection to an environmental exposure, partially as for other opportunistic premise plumbing pathogens [19,73,109,110]. The algorithm for sample processing and staining for clinical suspected M. chimaera infection follows the same techniques and principles in place for other NTM species, according to each laboratory standard operating procedure involving decontamination and staining with auramine fluorochrome stain, carbol fuchsin-based Ziehl-Neelsen or Kinyoun stains for direct microscopy in suitable samples. Of note, clinical samples for M. chimaera infection investigation can range from respiratory specimens, urine, hepatic biopsies, bone/soft tissue biopsies to prosthetic material/graft tissues sampling. The identification of M. chimaera isolates from clinical/environmental samples followed ECDC protocol released in 2015, aiming to the harmonization of samples and data collection in cardiothoracic setting, and the International Society of Cardiovascular Infectious Diseases Guidelines [19,111]. Those investigations were graphically summarized by Cannas et al. in 2023 [100]. Concentration of water samples can be performed with filtration or centrifugation methods; for M. chimaera, filtration has proven more sensitive than centrifugation. After concentration, water samples should undergo decontamination, preferably with cetylpyridinium chloride, which has proved superior to the more common standard solution of N-acetyl-L-cysteine sodium hydroxide (NALC-NaOH) or NaOH in recovering MAC from environmental samples. Air samples should be obtained with an environmental air impaction sampling device capable of sampling a certain volume of air in each period. Environmental samples are than directly inoculated into selective liquid and solid media for mycobacterial culture. Culturing and further characterization requires a dedicated level of expertise and laboratory resources which are usually located in mycobacteriology units processing M. tuberculosis complex samples. For NTMs in general, performance of both liquid and solid media is recommended for clinical samples. Using both media has shown to increase the sensitivity of NTM detection by 15%, although the choice on the preferred type of solid media (Middlebrook 7H11 or 7H10 or Löwenstein-Jensen agar) is less evident in terms of performance. As the other species of the MAC complex, M. chimaera optimally grows with temperature ranging in the 36–42 °C interval. For environmental sampling, in case of limited resources, solid media is the preferred option according to the ECDC protocol, although some evidences point to a greater sensitivity of MGIT in detecting M. chimaera from water samples [112]. As M. chimaera grows in 6–8 weeks, incubation at 35–37 °C for 8 weeks is recommended with weekly inspection for mycobacterial growth and colony counting.
Also, identification of M. chimaera is challenging and should be performed in reference laboratories equipped for molecular diagnostics of mycobacteria. Guidelines for species identification follow the general guidelines for NTM laboratories and include molecular -preferred- and proteomics techniques, although the latter do not perform optimally for M. chimaera identification. Nucleic acid sequencing of DNA regions among internal transcribed spacer (ITS), 16S rRNA, rpoB and hsp65 is currently the reference method to identify M. chimaera [113]. Another approach involves the use of commercial line probe assay INNO-LiPA Mycobacteria, which carries a specific probe -the internal transcribed spacer between gene 16S e 23S of the rRNA—to distinguish species among Mycobacteria [19]. Indeed, several commercial easy-to-use kits are available for mycobacterial identification, but their performance in identifying M. chimaera is variable [100]. A study comparing three molecular biology kits (INNO-LiPA Mycobacteria, GenoType bacterium CM and GenoType NTM-DR) and matrix-assisted desorption ionization–time of flight mass spectrometry (MALDI-ToF MS) against reference standard in M. chimaera identification found a high level of concordance of INNO-LiPA Mycobacteria and GenoType NTM-DR, while GenoType Mycobacterium CM and MALDI-ToF MS were not able to distinguish between M. chimaera and M. intracellulare, which are genetically similar [114]. Recently, high sensibility and sensitivity are reported for NTM detection with MALDI-ToF MS [115]. Whole-genome sequencing (WGS) is currently the gold standard for performing genomic typing and has been pivotal during the M. chimaera outbreak to track cases and to link clinical cases to environmental exposure. The ECDC supports its use in genetic analysis of M. chimaera by sharing sequences of isolates among laboratories and countries to help informing about the genomic diversity of M. chimaera across Europe. Studies on the global outbreak have shown that WGS can be used to link clinical samples to HCUs contamination, also describing phylogenetic tree and the more prevalent branches involved [14,101,116].

4.7. Disinfection

Often HCUs do not provide any technology to reduce bacterial or other contamination and maintenance instructions for the HCU highlight the risk of oxygenator damage and of heat exchanger leakage with some corrosive disinfectant agents, with subsequent impair of the heat exchanger permeability and function. Changes in the overall structures of HCU models resulted efficacious in reducing at least the risk of aerosolization [117]. Disinfecting HCU is then very difficult [118]. Chemical agents or the combination of chemicals such as chlore derivative, chlorhexidine-alcohol, peracetic acid and sodium hydroxide [119,120,121,122] were reported, with partial or temporaneous efficacy or limited to colony forming units load reduction [123,124]. With water chlorination the paradoxical effect of increasing M. chimaera presence through amebae symbiosis was also reported [125]. The same water chlorination impact on M. chimaera presence in water was reported by Virdi et al. in U.S. and E.U. [94]. The European Centre for Disease Prevention and Control recommended the use of hydrogen peroxide in filtered water to fill heater-cooler unit tanks; however, heater-cooler units became heavily contaminated by opportunistic waterborne pathogens such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia [117,121]. Silver-ion cleaning also resulted insufficient, considering mainly resistant and structured biofilm formation [126]. As an alternative, or in support to chemical and thermal disinfection, filtration method resulted effective in the reduction of pathogen load [120,127]. Filters and UV disinfection have been evaluated for their ability to reduce numbers of waterborne non-NTM organisms from drinking water, but their efficacy in reducing NTM counts is not well-established [64]. Pradal et al. demonstrated Methylobacterium sp. extract efficacy in reducing biofilm of M. chimaera strain, while Foltan et al. suggested the use of electrolysis [128,129].

4.8. Causal Link Assessment

M. chimaera infection presents peculiar characteristics, common to the so-called opportunistic premise plumbing pathogens among which Legionella pneumophila. However, regarding M. chimaera, the overall environmental prevalence and transmission modality, together with the haematogenous spread, still deserve in-depth experimental studies to assess the possibility of tissue localisations starting from bacteraemia and further abscess formation [47,85,97]. For our purposes, i.e., the causal tracing of the infection back to the healthcare context, the data presented are useful to emphasise how even more with long latency periods, without long hospitalisations, and thus of main permanence in the living/social context, the probability of the subject being exposed to the pathogen has no specific or absolute prevalence. Therefore, a domestic contraction cannot be excluded a priori, and recent personal history must be investigated, as regarding Legionella pneumophila infections and hospital outbreaks. Senescent and poorly maintained water supply systems, poor environmental hygiene, extreme humidity or standing water, extreme branches of the water coiling system are significant factors also in residential settings, but even recent air travels could be relevant, as for Legionella [130,131,132]. Furthermore, the insufficiency of data on environmental and domestic prevalence, the recent studies on its ecology, the selection bias of the medicalised sample, as well as the infrequent use of robust ascertainment such as genetic and histopathological one, and not least the diagnostic complexity of endocarditis in general, severely limiting confirmation in developing countries, are further elements to be weighed up [104,133]. The same topographical criterion, i.e., the presence of contamination, up to abscess forms, at the site of previous surgery (valve replacements, vascular prostheses, suture, graft tissues, peri-prosthetic tissues and materials) must also be studied with respect to the presence of a foreign bodies interposed to the systemic flow in case of bacteraemia. This can easily be a colonisation site, escaping immunological control, and with the possibility of proliferating in a subtle and slow manner. This is even more than a possibility if one considers that the M. chimaera exploits the formation of biofilms and proliferates where the immune component is less competent and effective. As the phenomenon is frequently associated with the peculiarities of the healthcare setting and its contamination, due to the limitation of hospitalised population, each case must be studied individually and in detail, before tracing the cause directly to the facility. In fact, a hypothetical relationship between two naturalistic events could be the basis for a diagnostic hypothesis and then for an empirical therapy, but this cannot be the diagnosis from a law system perspective and for the purposes of possible compensation for health damages, since a tighter causal ascertainment is required. And as for endocarditis, even for early endocarditis occurring in the first year, the definition as healthcare-associated cannot be the same as other bacterial infections, as it does not matter that this occurs after having been hospitalised for more than 48 h, also from an epidemiological point of view [134]. Clinical data therefore must be integrated with the remaining criteria for causal ascertainment, namely the qualitative-quantitative suitability and the logical-scientific probability [135].
In the technical evaluation of each single case, the fact that contagion from M. chimaera is possible need to be in-depth discussed and the specific source of infection found out in that hospital, due to the use of contaminated HCUs or to other types of water/device contamination and having taken care to assess genotypic correlation with the healthcare fomites and finally exclude other possible causes. Hence the causal relationship with the healthcare setting and hence the definition of healthcare associated infection.

5. Limitations

Although the searches in PubMed and Web of Science were rigorously and widely conducted, it is possible that some cases that met the inclusion criteria were not found. However, the cross-reference analysis did not reveal any additional articles reporting clinical cases that were not included in this review. Publication bias must also be considered, as single or atypical clinical presentations, unrelated to cardiac surgery or surgery in general, may not have been described in the literature or only reported at conferences. This could be due to a greater focus on the association with cardiac surgery. In addition, the systematic review conducted is descriptive by nature, so it is not possible to determine the robustness of the article included, while the medico-legal perspective accounts for the wide heterogeneity of the included clinical case and overall cited literature. Independent and multidisciplinary screening and review of the literature could have partially weighed those limitations.

6. Conclusions

Mycobacterium chimaera infection is a recent scientific acquisition and presents peculiar characteristics, such as the ecosystem of proliferation, resistance strategies, transmission modality, high mortality and the initial relationship with a healthcare context that remains not fully elucidated. Further studies on the in-house water system prevalence and the hypothesis of haematogenous spread and rooting on the valve site are needed. Nonetheless, healthcare contamination represents a core and dedicated area for healthcare facilities within the framework of infection prevention and control policies and overall hospital ecosystem monitoring, looking methodically and with periodical monitoring at aeraulic implants, medical devices and surfaces hygiene.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/healthcare12171788/s1. Table S1: PRISMA 2020 Checklist.

Author Contributions

V.B., M.B. and L.B.P. Conceptualization; Data curation; Formal analysis; Methodology; Resources; Software; Validation; Visualization; Roles/Writing—original draft; and Writing—review & editing. G.B., G.S., E.T. and F.M. Conceptualization; Investigation; Project administration; Resources; Validation; and Writing—review & editing. L.P.T. Conceptualization; Methodology; Funding acquisition; Project administration; Supervision; Validation; Visualization; and Writing—review & editing. All authors have read and agreed to the published version of the manuscript.

Funding

This research was sustained by Fondazione GVM per la ricerca scientifica-O.N.L.U.S. Lugo, 48022, Italy.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

No new data were created or analysed in this study. Data sharing is not applicable to this article.

Conflicts of Interest

The authors declare no conflicts of interest.

Abbreviations

MAC mycobacterium avium complex
NTM non-tuberculosis mycobacterium
M. chimaeraMycobacterium chimaera
HCU heater-cooler units
OPPP opportunistic premise plumbing pathogens
ECMO extra-corporal mechanical oxygenation
HAI healthcare-associated infection

References

  1. Vendramin, I.; Peghin, M.; Tascini, C.; Livi, U. Longest Incubation Period of Mycobacterium chimaera Infection after Cardiac Surgery. Eur. J. Cardio-Thoracic Surg. 2021, 59, 506–508. [Google Scholar] [CrossRef] [PubMed]
  2. Biswas, M.; Rahaman, S.; Biswas, T.K.; Haque, Z.; Ibrahim, B. Association of Sex, Age, and Comorbidities with Mortality in COVID-19 Patients: A Systematic Review and Meta-Analysis. Intervirology 2020, 64, 36–47. [Google Scholar] [CrossRef]
  3. Treglia, M.; Pallocci, M.; Passalacqua, P.; Sabatelli, G.; De Luca, L.; Zanovello, C.; Messineo, A.; Quintavalle, G.; Cisterna, A.M.; Marsella, L.T. Medico-Legal Aspects of Hospital-Acquired Infections: 5-Years of Judgements of the Civil Court of Rome. Healthcare 2022, 10, 1336. [Google Scholar] [CrossRef] [PubMed]
  4. Bolcato, V.; Tronconi, L.P.; Odone, A.; Blandi, L. Healthcare-Acquired Sars-Cov-2 Infection: A Viable Legal Category? Int. J. Risk Saf. Med. 2023, 34, 129–134. [Google Scholar] [CrossRef]
  5. Tattoli, L.; Dell’erba, A.; Ferorelli, D.; Gasbarro, A.; Solarino, B. Sepsis and Nosocomial Infections: The Role of Medico-Legal Experts in Italy. Antibiotics 2019, 8, 199. [Google Scholar] [CrossRef]
  6. Barranco, R.; Caristo, I.; Spigno, F.; Ponzano, M.; Trevisan, A.; Signori, A.; Di Biagio, A.; Ventura, F. Management of the Medico-Legal Dispute of Healthcare-Related SARS-CoV-2 Infections: Evaluation Criteria and Case Study in a Large University Hospital in Northwest Italy from 2020 to 2021. Int. J. Environ. Res. Public Health 2022, 19, 16764. [Google Scholar] [CrossRef]
  7. Goldenberg, S.D.; Volpé, H.; French, G.L. Clinical Negligence, Litigation and Healthcare-Associated Infections. J. Hosp. Infect. 2012, 81, 156–162. [Google Scholar] [CrossRef]
  8. Rizzo, N. La Causalità Civile; Jus Civile; Giappichelli Editore: Torino, Italy, 2022. [Google Scholar]
  9. Riccardi, N.; Monticelli, J.; Antonello, R.M.; Luzzati, R.; Gabrielli, M.; Ferrarese, M.; Codecasa, L.; Di Bella, S.; Giacobbe, D.R. Mycobacterium chimaera Infections: An Update. J. Infect. Chemother. 2020, 26, 199–205. [Google Scholar] [CrossRef] [PubMed]
  10. Natanti, A.; Palpacelli, M.; Valsecchi, M.; Tagliabracci, A.; Pesaresi, M. Mycobacterium chimaera: A Report of 2 New Cases and Literature Review. Int. J. Leg. Med. 2021, 135, 2667–2679. [Google Scholar] [CrossRef]
  11. Wetzstein, N.; Kohl, T.A.; Diricks, M.; Mas-Peiro, S.; Holubec, T.; Kessel, J.; Graf, C.; Koch, B.; Herrmann, E.; Vehreschild, M.J.G.T.; et al. Clinical Characteristics and Outcome of Mycobacterium chimaera Infections after Cardiac Surgery: Systematic Review and Meta-Analysis of 180 Heater-Cooler Unit-Associated Cases. Clin. Microbiol. Infect. 2023, 29, 1008–1014. [Google Scholar] [CrossRef]
  12. Desai, A.N.; Hurtado, R.M. Infections and Outbreaks of Nontuberculous Mycobacteria in Hospital Settings. Curr. Treat. Options Infect. Dis. 2018, 10, 169–181. [Google Scholar] [CrossRef]
  13. van Ingen, J.; Kohl, T.A.; Kranzer, K.; Hasse, B.; Keller, P.M.; Katarzyna Szafrańska, A.; Hillemann, D.; Chand, M.; Schreiber, P.W.; Sommerstein, R.; et al. Global Outbreak of Severe Mycobacterium chimaera Disease after Cardiac Surgery: A Molecular Epidemiological Study. Lancet Infect. Dis. 2017, 17, 1033–1041. [Google Scholar] [CrossRef] [PubMed]
  14. Bisognin, F.; Messina, F.; Butera, O.; Nisii, C.; Mazzarelli, A.; Cristino, S.; Pascale, M.R.; Lombardi, G.; Cannas, A.; Dal Monte, P. Investigating the Origin of Mycobacterium chimaera Contamination in Heater-Cooler Units: Integrated Analysis with Fourier Transform Infrared Spectroscopy and Whole-Genome Sequencing. Microbiol. Spectr. 2022, 10, e0289322. [Google Scholar] [CrossRef] [PubMed]
  15. Pinzauti, D.; De Giorgi, S.; Fox, V.; Lazzeri, E.; Messina, G.; Santoro, F.; Iannelli, F.; Ricci, S.; Pozzi, G. Complete Genome Sequences of Mycobacterium chimaera Strains 850 and 852, Isolated from Heater-Cooler Unit Water. Microbiol. Resour. Announc. 2022, 11, e0102121. [Google Scholar] [CrossRef] [PubMed]
  16. Hasan, N.A.; Warren, R.L.; Elaine Epperson, L.; Malecha, A.; Alexander, D.C.; Turenne, C.Y.; MacMillan, D.; Birol, I.; Pleasance, S.; Coope, R.; et al. Complete Genome Sequence of Mycobacterium chimaera SJ42, a Nonoutbreak Strain from an Immunocompromised Patient with Pulmonary Disease. Genome Announc. 2017, 5, e00963-17. [Google Scholar] [CrossRef]
  17. Wallace, R.J.; Iakhiaeva, E.; Williams, M.D.; Brown-Elliott, B.A.; Vasireddy, S.; Vasireddy, R.; Lande, L.; Peterson, D.D.; Sawicki, J.; Kwait, R.; et al. Absence of Mycobacterium Intracellulare and Presence of Mycobacterium chimaera in Household Water and Biofilm Samples of Patients in the United States with Mycobacterium avium Complex Respiratory Disease. J. Clin. Microbiol. 2013, 51, 1747–1752. [Google Scholar] [CrossRef]
  18. Falkinham, J.O.; Hilborn, E.D.; Arduino, M.J.; Pruden, A.; Edwards, M.A. Epidemiology and Ecology of Opportunistic Premise Plumbing Pathogens: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa. Environ. Health Perspect. 2015, 123, 749–758. [Google Scholar] [CrossRef]
  19. European Centre for Disease Prevention and Control. EU Protocol for Testing of M. chimaera Infections Potentially Associated with Heater-Cooler Units Environmental Microbiology Investigations; Technical Document; European Centre for Disease Prevention and Control: Solna, Sweden, 2015. [Google Scholar]
  20. Ministero della Salute. Raccomandazioni per Il Controllo Dell’infezione da Mycobacterium chimaera in Italia; Ministero della Salute: Roma, Italy, 2019.
  21. Bolcato, M.; Rodriguez, D.; Aprile, A. Risk Management in the New Frontier of Professional Liability for Nosocomial Infection: Review of the Literature on Mycobacterium chimaera. Int. J. Environ. Res. Public Health 2020, 17, 7328. [Google Scholar] [CrossRef]
  22. Achermann, Y.; Rössle, M.; Hoffmann, M.; Deggim, V.; Kuster, S.; Zimmermann, D.R.; Bloemberg, G.; Hombach, M.; Hasse, B. Prosthetic Valve Endocarditis and Bloodstream Infection Due to Mycobacterium chimaera. J. Clin. Microbiol. 2013, 51, 1769–1773. [Google Scholar] [CrossRef]
  23. Zabost, A.T.; Szturmowicz, M.; Brzezińska, S.A.; Klatt, M.D.; Augustynowicz-Kopeć, E.M. Mycobacterium chimaera as an Underestimated Cause of NTM Lung Diseases in Patients Hospitalized in Pulmonary Wards. Pol. J. Microbiol. 2021, 70, 315–320. [Google Scholar] [CrossRef]
  24. Truden, S.; Žolnir-Dovč, M.; Sodja, E.; Starčič Erjavec, M. Nationwide Analysis of Mycobacterium chimaera and Mycobacterium intracellulare Isolates: Frequency, Clinical Importance, and Molecular and Phenotypic Resistance Profiles. Infect. Genet. Evol. 2020, 82, 104311. [Google Scholar] [CrossRef] [PubMed]
  25. Page, M.J.; McKenzie, J.E.; Bossuyt, P.M.; Boutron, I.; Hoffmann, T.C.; Mulrow, C.D.; Shamseer, L.; Tetzlaff, J.M.; Akl, E.A.; Brennan, S.E.; et al. The PRISMA 2020 Statement: An Updated Guideline for Reporting Systematic Reviews. BMJ 2021, 372, 71. [Google Scholar] [CrossRef] [PubMed]
  26. Bills, N.D.; Hinrichs, S.H.; Aden, T.A.; Wickert, R.S.; Iwen, P.C. Molecular Identification of Mycobacterium chimaera as a Cause of Infection in a Patient with Chronic Obstructive Pulmonary Disease. Diagn. Microbiol. Infect. Dis. 2009, 63, 292–295. [Google Scholar] [CrossRef]
  27. Cohen-Bacrie, S.; David, M.; Stremler, N.; Dubus, J.-C.; Rolain, J.-M.; Drancourt, M. Mycobacterium chimaera Pulmonary Infection Complicating Cystic Fibrosis: A Case Report. J. Med. Case Rep. 2011, 5, 473. [Google Scholar] [CrossRef] [PubMed]
  28. Alhanna, J.; Purucker, M.; Steppert, C.; Grigull-Daborn, A.; Schiffel, G.; Gruber, H.; Borgmann, S. Mycobacterium chimaera Causes Tuberculosis-like Infection in a Male Patient with Anorexia Nervosa. Int. J. Eat. Disord. 2012, 45, 450–452. [Google Scholar] [CrossRef]
  29. Gunaydin, M.; Yanik, K.; Eroglu, C.; Sanic, A.; Ceyhan, I.; Erturan, Z.; Durmaz, R. Distribution of Nontuberculous Mycobacteria Strains. Ann. Clin. Microbiol. Antimicrob. 2013, 12, 33. [Google Scholar] [CrossRef]
  30. Boyle, D.P.; Zembower, T.R.; Reddy, S.; Qi, C. Comparison of Clinical Features, Virulence, and Relapse among Mycobacterium avium Complex Species. Am. J. Respir. Crit. Care Med. 2015, 191, 1310–1317. [Google Scholar] [CrossRef]
  31. Mwikuma, G.; Kwenda, G.; Hang’ombe, B.M.; Simulundu, E.; Kaile, T.; Nzala, S.; Siziya, S.; Suzuki, Y. Molecular Identification of Non-Tuberculous Mycobacteria Isolated from Clinical Specimens in Zambia. Ann. Clin. Microbiol. Antimicrob. 2015, 14, 1. [Google Scholar] [CrossRef]
  32. Moon, S.M.; Kim, S.Y.; Jhun, B.W.; Lee, H.; Park, H.Y.; Jeon, K.; Huh, H.J.; Ki, C.S.; Lee, N.Y.; Shin, S.J.; et al. Clinical Characteristics and Treatment Outcomes of Pulmonary Disease Caused by Mycobacterium chimaera. Diagn. Microbiol. Infect. Dis. 2016, 86, 382–384. [Google Scholar] [CrossRef]
  33. Moutsoglou, D.M.; Merritt, F.; Cumbler, E. Disseminated Mycobacterium chimaera Presenting as Vertebral Osteomyelitis. Case Rep. Infect. Dis. 2017, 2017, 9893743. [Google Scholar] [CrossRef]
  34. Bursle, E.; Playford, E.G.; Coulter, C.; Griffin, P. First Australian Case of Disseminated Mycobacterium chimaera Infection Post-Cardiothoracic Surgery. Infect. Dis. Health 2017, 22, 1–5. [Google Scholar] [CrossRef]
  35. Kim, S.-Y.; Shin, S.H.; Moon, S.M.; Yang, B.; Kim, H.; Kwon, O.J.; Huh, H.J.; Ki, C.-S.; Lee, N.Y.; Shin, S.J.; et al. Distribution and Clinical Significance of Mycobacterium avium Complex Species Isolated from Respiratory Specimens. Diagn. Microbiol. Infect. Dis. 2017, 88, 125–137. [Google Scholar] [CrossRef] [PubMed]
  36. Chand, M.; Lamagni, T.; Kranzer, K.; Hedge, J.; Moore, G.; Parks, S.; Collins, S.; Del Ojo Elias, C.; Ahmed, N.; Brown, T.; et al. Insidious Risk of Severe Mycobacterium chimaera Infection in Cardiac Surgery Patients. Clin. Infect. Dis. 2017, 64, 335–342. [Google Scholar] [CrossRef] [PubMed]
  37. Truden, S.; Žolnir-Dovč, M.; Sodja, E.; Starčič Erjavec, M. Retrospective Analysis of Slovenian Mycobacterium avium Complex and Mycobacterium abscessus Complex Isolates and Molecular Resistance Profile. Russ. J. Infect. Immun. 2018, 8, 447–451. [Google Scholar] [CrossRef]
  38. Larcher, R.; Lounnas, M.; Dumont, Y.; Michon, A.L.; Bonzon, L.; Chiron, R.; Carriere, C.; Klouche, K.; Godreuil, S. Mycobacterium chimaera Pulmonary Disease in Cystic Fibrosis Patients, France, 2010–2017. Emerg. Infect. Dis. 2019, 25, 611–613. [Google Scholar] [CrossRef]
  39. Shafizadeh, N.; Hale, G.; Bhatnagar, J.; Alshak, N.S.; Nomura, J. Mycobacterium chimaera Hepatitis: A New Disease Entity. Am. J. Surg. Pathol. 2019, 43, 244–250. [Google Scholar] [CrossRef]
  40. Rosero, C.I.; Shams, W.E. Mycobacterium chimaera Infection Masquerading as a Lung Mass in a Healthcare Worker. IDCases 2019, 15, e00526. [Google Scholar] [CrossRef]
  41. Watanabe, R.; Seino, H.; Taniuchi, S.; Igusa, R. Mycobacterium chimaera -Induced Tenosynovitis in a Patient with Rheumatoid Arthritis. BMJ Case Rep. 2020, 13, e233868. [Google Scholar] [CrossRef]
  42. Chen, L.C.; Huang, H.N.; Yu, C.J.; Chien, J.Y.; Hsueh, P.R. Clinical Features and Treatment Outcomes of Mycobacterium chimaera Lung Disease and Antimicrobial Susceptibility of the Mycobacterial Isolates. J. Infect. 2020, 80, 437–443. [Google Scholar] [CrossRef]
  43. Maalouly, C.; Devresse, A.; Martin, A.; Rodriguez-Villalobos, H.; Kanaan, N.; Belkhir, L. Coinfection of Mycobacterium malmoense and Mycobacterium chimaera in a Kidney Transplant Recipient: A Case Report and Review of the Literature. Transpl. Infect. Dis. 2020, 22, e13241. [Google Scholar] [CrossRef]
  44. de Melo Carvalho, R.; Nunes, A.L.; Sa, R.; Ramos, I.; Valente, C.; Saraiva da Cunha, J. Mycobacterium chimaera Disseminated Infection. J. Med. Cases 2020, 11, 35–36. [Google Scholar] [CrossRef]
  45. Sharma, K.; Sharma, M.; Modi, M.; Joshi, H.; Goyal, M.; Sharma, A.; Ray, P.; Rowlinson, M.C. Mycobacterium chimaera and Chronic Meningitis. QJM Int. J. Med. 2020, 113, 563–564. [Google Scholar] [CrossRef] [PubMed]
  46. Kim, M.J.; Kim, K.M.; Shin, J.I.; Ha, J.H.; Lee, D.H.; Choi, J.G.; Park, J.S.; Byun, J.H.; Yoo, J.W.; Eum, S.; et al. Identification of Nontuberculous Mycobacteria in Patients with Pulmonary Diseases in Gyeongnam, Korea, Using Multiplex PCR and Multigene Sequence-Based Analysis. Can. J. Infect. Dis. Med. Microbiol. 2021, 2021, 8844306. [Google Scholar] [CrossRef]
  47. Kavvalou, A.; Stehling, F.; Tschiedel, E.; Kehrmann, J.; Walkenfort, B.; Hasenberg, M.; Olivier, M.; Steindor, M. Biofilm Infection of a Central Venous Port-Catheter Caused by Mycobacterium avium Complex in an Immunocompetent Child with Cystic Fibrosis. BMC Infect. Dis. 2022, 22, 321. [Google Scholar] [CrossRef] [PubMed]
  48. Robinson, B.; Chaudhri, M.; Miskoff, J.A. A Case of Cavitary Mycobacterium chimaera. Cureus 2022, 14, e26984. [Google Scholar] [CrossRef]
  49. Ahmad, M.; Yousaf, A.; Khan, H.M.W.; Munir, A.; Chandran, A. Mycobacterium chimaera Lung Infection and Empyema in a Patient without Cardiopulmonary Bypass. Bayl. Univ. Med. Cent. Proc. 2022, 35, 817–819. [Google Scholar] [CrossRef] [PubMed]
  50. George, M.; Afra, T.P.; Santhosh, P.; Nandakumar, G.; Balagopalan, D.; Sreedharan, S. Ulcerating Nodules on the Face Due to Mycobacterium chimaera in a Patient with Diabetes. Clin. Exp. Dermatol. 2022, 47, 587–589. [Google Scholar] [CrossRef] [PubMed]
  51. Lin, Y.F.; Lee, T.F.; Wu, U.I.; Huang, C.F.; Cheng, A.; Lin, K.Y.; Hung, C.C. Disseminated Mycobacterium chimaera Infection in a Patient with Adult-Onset Immunodeficiency Syndrome: Case Report. BMC Infect. Dis. 2022, 22, 665. [Google Scholar] [CrossRef]
  52. Łyżwa, E.; Siemion-Szcześniak, I.; Sobiecka, M.; Lewandowska, K.; Zimna, K.; Bartosiewicz, M.; Jakubowska, L.; Augustynowicz-Kopeć, E.; Tomkowski, W. An Unfavorable Outcome of M. Chimaera Infection in Patient with Silicosis. Diagnostics 2022, 12, 1826. [Google Scholar] [CrossRef]
  53. McLaughlin, C.M.; Schade, M.; Cochran, E.; Taylor, K.F. A Case Report of a Novel Atypical Mycobacterial Infection: Mycobacterium chimaera Hand Tenosynovitis. JBJS Case Connect. 2022, 12, e22. [Google Scholar] [CrossRef]
  54. Gross, J.E.; Teneback, C.C.; Sweet, J.G.; Caceres, S.M.; Poch, K.R.; Hasan, N.A.; Jia, F.; Epperson, L.E.; Lipner, E.M.; Vang, C.K.; et al. Molecular Epidemiologic Investigation of Mycobacterium intracellulare Subspecies Chimaera Lung Infections at an Adult Cystic Fibrosis Program. Ann. Am. Thorac. Soc. 2023, 20, 677–686. [Google Scholar] [CrossRef]
  55. Azzarà, C.; Lombardi, A.; Gramegna, A.; Ori, M.; Gori, A.; Blasi, F.; Bandera, A. Non-Tuberculous Mycobacteria Lung Disease Due to Mycobacterium chimaera in a 67-Year-Old Man Treated with Immune Checkpoint Inhibitors for Lung Adenocarcinoma: Infection Due to Dysregulated Immunity? BMC Infect. Dis. 2023, 23, 573. [Google Scholar] [CrossRef]
  56. Pradhan, A.; Martinez, E.; Sintchenko, V.; Post, J.; Overton, K. Case of Mycobacterium chimaera Vertebral Osteomyelitis Diagnosed 7 Years after Cardiac Surgery. Intern. Med. J. 2023, 53, 150–151. [Google Scholar] [CrossRef] [PubMed]
  57. Garcia-Prieto, F.; Rodríguez Perojo, A.; Río Ramírez, M.T. Endobronchial Fibroanthracosis Associated with Mycobacterium chimaera Infection: An Exceptional Case. Open Respir. Arch. 2024, 6, 100309. [Google Scholar] [CrossRef] [PubMed]
  58. Paul, S.; MacNair, A.; Lostarakos, V.; Capstick, R. Non-Tuberculous Mycobacterial Pulmonary Infection Presenting in a Patient with Unilateral Pulmonary Artery Agenesis. BMJ Case Rep. 2024, 17, e259125. [Google Scholar] [CrossRef] [PubMed]
  59. Bittner, M.J.; Preheim, L.C. Other Slow-Growing Nontuberculous Mycobacteria. Microbiol. Spectr. 2016, 4, 767–776. [Google Scholar] [CrossRef]
  60. Tortoli, E.; Rindi, L.; Garcia, M.J.; Chiaradonna, P.; Dei, R.; Garzelli, C.; Kroppenstedt, R.M.; Lari, N.; Mattei, R.; Mariottini, A.; et al. Proposal to Elevate the Genetic Variant MAC-A Included in the Mycobacterium avium Complex, to Species Rank as Mycobacterium chimaera sp. nov. Int. J. Syst. Evol. Microbiol. 2004, 54, 1277–1285. [Google Scholar] [CrossRef]
  61. Turankar, R.P.; Singh, V.; Gupta, H.; Pathak, V.K.; Ahuja, M.; Singh, I.; Lavania, M.; Dinda, A.K.; Sengupta, U. Association of Non-Tuberculous Mycobacteria with Mycobacterium leprae in Environment of Leprosy Endemic Regions in India. Infect. Genet. Evol. 2019, 72, 191–198. [Google Scholar] [CrossRef]
  62. Makovcova, J.; Slany, M.; Babak, V.; Slana, I.; Kralik, P. The Water Environment as a Source of Potentially Pathogenic Mycobacteria. J. Water Health 2014, 12, 254–263. [Google Scholar] [CrossRef]
  63. Falkinham, J.O. Ecology of Nontuberculous Mycobacteria-Where Do Human Infections Come From? Semin. Respir. Crit. Care Med. 2013, 34, 95–102. [Google Scholar] [CrossRef]
  64. Norton, G.J.; Williams, M.; Falkinham, J.O., III; Honda, J.R. Physical Measures to Reduce Exposure to Tap Water-Associated Nontuberculous Mycobacteria. Front. Public Health 2020, 8, 190. [Google Scholar] [CrossRef] [PubMed]
  65. Durnez, L.; Eddyani, M.; Mgode, G.F.; Katakweba, A.; Katholi, C.R.; Machang’u, R.R.; Kazwala, R.R.; Portaels, F.; Leirs, H. First Detection of Mycobacteria in African Rodents and Insectivores, Using Stratified Pool Screening. Appl. Environ. Microbiol. 2008, 74, 768. [Google Scholar] [CrossRef]
  66. Sax, H.; Bloemberg, G.; Hasse, B.; Sommerstein, R.; Kohler, P.; Achermann, Y.; Rössle, M.; Falk, V.; Kuster, S.P.; Böttger, E.C.; et al. Prolonged Outbreak of Mycobacterium chimaera Infection after Open-Chest Heart Surgery. Clin. Infect. Dis. 2015, 61, 67–75. [Google Scholar] [CrossRef]
  67. Falkinham, J.O.; Williams, M.D. Desiccation-Tolerance of Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium chimaera, Mycobacterium abscessus and Mycobacterium chelonae. Pathogens 2022, 11, 463. [Google Scholar] [CrossRef] [PubMed]
  68. Gebert, M.J.; Delgado-Baquerizo, M.; Oliverio, A.M.; Webster, T.M.; Nichols, L.M.; Honda, J.R.; Chan, E.D.; Adjemian, J.; Dunn, R.R.; Fierer, N. Ecological Analyses of Mycobacteria in Showerhead Biofilms and Their Relevance to Human Health. mBio 2018, 9, e01614–e01618. [Google Scholar] [CrossRef] [PubMed]
  69. Cao, Y.; Yuan, S.; Pang, L.; Xie, J.; Gao, Y.; Zhang, J.; Zhao, Z.; Yao, S. Study on Microbial Diversity of Washing Machines. Biodegradation 2024, 1–13. [Google Scholar] [CrossRef]
  70. Liu, H.; Jiao, P.; Guan, L.; Wang, C.; Zhang, X.X.; Ma, L. Functional Traits and Health Implications of the Global Household Drinking-Water Microbiome Retrieved Using an Integrative Genome-Centric Approach. Water Res. 2024, 250, 121094. [Google Scholar] [CrossRef]
  71. Choi, J.Y.; Sim, B.R.; Park, Y.; Yong, S.H.; Shin, S.J.; Kang, Y.A. Identification of Nontuberculous Mycobacteria Isolated from Household Showerheads of Patients with Nontuberculous Mycobacteria. Sci. Rep. 2022, 12, 8648. [Google Scholar] [CrossRef]
  72. Shen, Y.; Haig, S.J.; Prussin, A.J.; Lipuma, J.J.; Marr, L.C.; Raskin, L. Shower Water Contributes Viable Nontuberculous Mycobacteria to Indoor Air. PNAS Nexus 2022, 1, pgac145. [Google Scholar] [CrossRef]
  73. Struelens, M.J.; Plachouras, D. Mycobacterium chimaera Infections Associated with Heater-Cooler Units (HCU): Closing Another Loophole in Patient Safety. Eurosurveillance 2016, 21, 30397. [Google Scholar] [CrossRef]
  74. Trudzinski, F.C.; Schlotthauer, U.; Kamp, A.; Hennemann, K.; Muellenbach, R.M.; Reischl, U.; Gärtner, B.; Wilkens, H.; Bals, R.; Herrmann, M.; et al. Clinical Implications of Mycobacterium chimaera Detection in Thermoregulatory Devices Used for Extracorporeal Membrane Oxygenation (ECMO), Germany, 2015 to 2016. Eurosurveillance 2016, 21, 30398. [Google Scholar] [CrossRef] [PubMed]
  75. Schnetzinger, M.; Heger, F.; Indra, A.; Kimberger, O. Bacterial Contamination of Water Used as Thermal Transfer Fluid in Fluid-Warming Devices. J. Hosp. Infect. 2023, 141, 49–54. [Google Scholar] [CrossRef] [PubMed]
  76. Barker, T.A.; Dandekar, U.; Fraser, N.; Dawkin, L.; Sweeney, P.; Heron, F.; Simmons, J.; Parmar, J. Minimising the Risk of Mycobacterium chimaera Infection during Cardiopulmonary Bypass by the Removal of Heater-Cooler Units from the Operating Room. Perfusion 2018, 33, 264–269. [Google Scholar] [CrossRef] [PubMed]
  77. Barnes, S.; Twomey, C.; Carrico, R.; Murphy, C.; Warye, K. OR Air Quality: Is It Time to Consider Adjunctive Air Cleaning Technology? AORN J. 2018, 108, 503–515. [Google Scholar] [CrossRef]
  78. Walker, J.T.; Lamagni, T.; Chand, M. Evidence That Mycobacterium chimaera Aerosols Penetrate Laminar Airflow and Result in Infections at the Surgical Field. Lancet Infect. Dis. 2017, 17, 1019. [Google Scholar] [CrossRef]
  79. Schlotthauer, U.; Hennemann, K.; Gärtner, B.C.; Schäfers, H.-J.; Becker, S.L. Microbiological Surveillance of Heater-Cooler Units Used in Cardiothoracic Surgery for Detection of Mycobacterium chimaera. Thorac. Cardiovasc. Surg. 2022, 72, 59–62. [Google Scholar] [CrossRef]
  80. Gross, J.E.; Caceres, S.; Poch, K.; Epperson, L.E.; Hasan, N.A.; Jia, F.; de Moura, V.C.N.; Strand, M.; Lipner, E.M.; Honda, J.R.; et al. Prospective Healthcare-Associated Links in Transmission of Nontuberculous Mycobacteria among People with Cystic Fibrosis (PHALT NTM) Study: Rationale and Study Design. PLoS ONE 2023, 18, e0291910. [Google Scholar] [CrossRef]
  81. Nakamura, S.; Azuma, M.; Sato, M.; Fujiwara, N.; Nishino, S.; Wada, T.; Yoshida, S. Pseudo-Outbreak of Mycobacterium chimaera through Aerators of Hand-Washing Machines at a Hematopoietic Stem Cell Transplantation Center. Infect. Control Hosp. Epidemiol. 2019, 40, 1433–1435. [Google Scholar] [CrossRef]
  82. Kanamori, H.; Weber, D.J.; Rutala, W.A. Healthcare-Associated Mycobacterium chimaera Transmission and Infection Prevention Challenges: Role of Heater-Cooler Units as a Water Source in Cardiac Surgery. Clin. Infect. Dis. 2017, 64, 343–346. [Google Scholar] [CrossRef]
  83. Rao, M.; Silveira, F.P. Non-Tuberculous Mycobacterial Infections in Thoracic Transplant Candidates and Recipients. Curr. Infect. Dis. Rep. 2018, 20, 14. [Google Scholar] [CrossRef]
  84. Walker, J.; Moore, G.; Collins, S.; Parks, S.; Garvey, M.I.; Lamagni, T.; Smith, G.; Dawkin, L.; Goldenberg, S.; Chand, M. Microbiological Problems and Biofilms Associated with Mycobacterium chimaera in Heater–Cooler Units Used for Cardiopulmonary Bypass. J. Hosp. Infect. 2017, 96, 209–220. [Google Scholar] [CrossRef]
  85. Born, F.; Wieser, A.; Oberbach, A.; Oberbach, A.; Ellgass, R.; Peterss, S.; Kur, F.; Grabein, B.; Hagl, C. Five Years without Mycobacterium chimaera. Thorac. Cardiovasc. Surg. 2020, 68, S1–S72. [Google Scholar] [CrossRef]
  86. Scriven, J.E.; Scobie, A.; Verlander, N.Q.; Houston, A.; Collyns, T.; Cajic, V.; Kon, O.M.; Mitchell, T.; Rahama, O.; Robinson, A.; et al. Mycobacterium chimaera Infection Following Cardiac Surgery in the United Kingdom: Clinical Features and Outcome of the First 30 Cases. Clin. Microbiol. Infect. 2018, 24, 1164–1170. [Google Scholar] [CrossRef] [PubMed]
  87. Olatidoye, O.A.; Samat, S.H.; Yin, K.; Bates, M.J. Pulmonary Valve Infective Endocarditis Caused by Mycobacterium abscessus. J. Cardiothorac. Surg. 2023, 18, 221. [Google Scholar] [CrossRef]
  88. Ganatra, S.; Sharma, A.; D’Agostino, R.; Gage, T.; Kinnunen, P. Mycobacterium chimaera Mimicking Sarcoidosis. Methodist Debakey Cardiovasc. J. 2018, 14, 301–302. [Google Scholar] [CrossRef] [PubMed]
  89. Buchanan, R.; Agarwal, A.; Mathai, E.; Cherian, B. Mycobacterium chimaera: A Novel Pathogen with Potential Risk to Cardiac Surgical Patients. Natl. Med. J. India 2020, 33, 284–287. [Google Scholar] [CrossRef]
  90. McHugh, J.; Saleh, O.A. Updates in Culture-Negative Endocarditis. Pathogens 2023, 12, 1027. [Google Scholar] [CrossRef]
  91. Delgado, V.; Ajmone Marsan, N.; De Waha, S.; Bonaros, N.; Brida, M.; Burri, H.; Caselli, S.; Doenst, T.; Ederhy, S.; Erba, P.A.; et al. 2023 ESC Guidelines for the Management of Endocarditis. Eur. Heart J. 2023, 44, 3948–4042. [Google Scholar] [CrossRef]
  92. Kohler, P.; Kuster, S.P.; Bloemberg, G.; Schulthess, B.; Frank, M.; Tanner, F.C.; Rössle, M.; Böni, C.; Falk, V.; Wilhelm, M.J.; et al. Healthcare-Associated Prosthetic Heart Valve, Aortic Vascular Graft, and Disseminated Mycobacterium chimaera Infections Subsequent to Open Heart Surgery. Eur. Heart J. 2015, 36, 2745–2753. [Google Scholar] [CrossRef]
  93. Wyrostkiewicz, D.; Opoka, L.; Filipczak, D.; Jankowska, E.; Skorupa, W.; Augustynowicz-Kopeć, E.; Szturmowicz, M. Nontuberculous Mycobacterial Lung Disease in the Patients with Cystic Fibrosis—A Challenging Diagnostic Problem. Diagnostics 2022, 12, 1514. [Google Scholar] [CrossRef]
  94. Virdi, R.; Lowe, M.E.; Norton, G.J.; Dawrs, S.N.; Hasan, N.A.; Epperson, L.E.; Glickman, C.M.; Chan, E.D.; Strong, M.; Crooks, J.L.; et al. Lower Recovery of Nontuberculous Mycobacteria from Outdoor Hawai’i Environmental Water Biofilms Compared to Indoor Samples. Microorganisms 2021, 9, 224. [Google Scholar] [CrossRef]
  95. Schweickert, B.; Goldenberg, O.; Richter, E.; Göbel, U.B.; Petrich, A.; Buchholz, P.; Moter, A. Occurrence and Clinical Relevance of Mycobacterium chimaera sp. nov., Germany. Emerg. Infect. Dis. 2008, 14, 1443–1446. [Google Scholar] [CrossRef] [PubMed]
  96. Boyle, D.P.; Zembower, T.R.; Qi, C. Evaluation of Vitek MS for Rapid Classification of Clinical Isolates Belonging to Mycobacterium avium Complex. Diagn. Microbiol. Infect. Dis. 2015, 81, 41–43. [Google Scholar] [CrossRef]
  97. Sommerstein, R.; Rüegg, C.; Kohler, P.; Bloemberg, G.; Kuster, S.P.; Sax, H. Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System. Emerg. Infect. Dis. 2016, 22, 1008–1013. [Google Scholar] [CrossRef] [PubMed]
  98. Balsam, L.B.; Louie, E.; Hill, F.; Levine, J.; Phillips, M.S. Mycobacterium chimaera Left Ventricular Assist Device Infections. J. Card. Surg. 2017, 32, 402–404. [Google Scholar] [CrossRef] [PubMed]
  99. Sanchez-Nadales, A.; Diaz-Sierra, A.; Mocadie, M.; Asher, C.; Gordon, S.; Xu, B. Advanced Cardiovascular Imaging for the Diagnosis of Mycobacterium chimaera Prosthetic Valve Infective Endocarditis After Open-Heart Surgery: A Contemporary Systematic Review. Curr. Probl. Cardiol. 2022, 47, 101392. [Google Scholar] [CrossRef]
  100. Cannas, A.; Campanale, A.; Minella, D.; Messina, F.; Butera, O.; Nisii, C.; Mazzarelli, A.; Fontana, C.; Lispi, L.; Maraglino, F.; et al. Epidemiological and Molecular Investigation of the Heater–Cooler Unit (HCU)-Related Outbreak of Invasive Mycobacterium chimaera Infection Occurred in Italy. Microorganisms 2023, 11, 2251. [Google Scholar] [CrossRef]
  101. Schreiber, P.W.; Kohl, T.A.; Kuster, S.P.; Niemann, S.; Sax, H. The Global Outbreak of Mycobacterium chimaera Infections in Cardiac Surgery—A Systematic Review of Whole-Genome Sequencing Studies and Joint Analysis. Clin. Microbiol. Infect. 2021, 27, 1613–1620. [Google Scholar] [CrossRef]
  102. Rubinstein, M.; Grossman, R.; Nissan, I.; Schwaber, M.J.; Carmeli, Y.; Kaidar-Shwartz, H.; Dveyrin, Z.; Rorman, E. Mycobacterium intracellulare Subsp. Chimaera from Cardio Surgery Heating-Cooling Units and from Clinical Samples in Israel Are Genetically Unrelated. Pathogens 2021, 10, 1392. [Google Scholar] [CrossRef]
  103. Mercaldo, R.A.; Marshall, J.E.; Prevots, D.R.; Lipner, E.M.; French, J.P. Detecting Clusters of High Nontuberculous Mycobacteria Infection Risk for Persons with Cystic Fibrosis—An Analysis of U.S. Counties. Tuberculosis 2023, 138, 102296. [Google Scholar] [CrossRef]
  104. Asadi, T.; Mullin, K.; Roselli, E.; Johnston, D.; Tan, C.D.; Rodriguez, E.R.; Gordon, S. Disseminated Mycobacterium chimaera Infection Associated with Heater-Cooler Units after Aortic Valve Surgery without Endocarditis. J. Thorac. Cardiovasc. Surg. 2018, 155, 2369–2374. [Google Scholar] [CrossRef] [PubMed]
  105. Clemente, T.; Spagnuolo, V.; Bottanelli, M.; Ripa, M.; Del Forno, B.; Busnardo, E.; Di Lucca, G.; Castagna, A.; Danise, A. Disseminated Mycobacterium chimaera Infection Favoring the Development of Kaposi’s Sarcoma: A Case Report. Ann. Clin. Microbiol. Antimicrob. 2022, 21, 57. [Google Scholar] [CrossRef]
  106. Schaeffer, T.; Kuster, S.; Koechlin, L.; Khanna, N.; Eckstein, F.S.; Reuthebuch, O. Long-Term Follow-Up after Mycobacterium chimaera Infection Following Cardiac Surgery: Single-Center Experience. J. Clin. Med. 2023, 12, 948. [Google Scholar] [CrossRef] [PubMed]
  107. Trauth, J.; Matt, U.; Kohl, T.A.; Niemann, S.; Herold, S. Blind Spot in Endocarditis Guidelines: Mycobacterium chimaera Prosthetic Valve Endocarditis after Cardiac Surgery—A Case Series. Eur. Heart J. Case Rep. 2023, 7, ytad400. [Google Scholar] [CrossRef]
  108. Sanavio, M.; Anna, A.; Bolcato, M. Mycobacterium chimaera: Clinical and Medico-Legal Considerations Starting from a Case of Sudden Acoustic Damage. Leg. Med. 2020, 47, 101747. [Google Scholar] [CrossRef] [PubMed]
  109. van Ingen, J. Microbiological Diagnosis of Nontuberculous Mycobacterial Pulmonary Disease. Clin. Chest Med. 2015, 36, 43–54. [Google Scholar] [CrossRef] [PubMed]
  110. Wang, H.; Bédard, E.; Prévost, M.; Camper, A.K.; Hill, V.R.; Pruden, A. Methodological Approaches for Monitoring Opportunistic Pathogens in Premise Plumbing: A Review. Water Res. 2017, 117, 68–86. [Google Scholar] [CrossRef]
  111. Hasse, B.; Hannan, M.M.; Keller, P.M.; Maurer, F.P.; Sommerstein, R.; Mertz, D.; Wagner, D.; Fernández-Hidalgo, N.; Nomura, J.; Manfrin, V.; et al. International Society of Cardiovascular Infectious Diseases Guidelines for the Diagnosis, Treatment and Prevention of Disseminated Mycobacterium chimaera Infection Following Cardiac Surgery with Cardiopulmonary Bypass. J. Hosp. Infect. 2020, 104, 214–235. [Google Scholar] [CrossRef]
  112. Schreiber, P.W.; Köhler, N.; Cervera, R.; Hasse, B.; Sax, H.; Keller, P.M. Detection Limit of Mycobacterium chimaera in Water Samples for Monitoring Medical Device Safety: Insights from a Pilot Experimental Series. J. Hosp. Infect. 2018, 99, 284–289. [Google Scholar] [CrossRef]
  113. Daley, C.L.; Iaccarino, J.M.; Lange, C.; Cambau, E.; Wallace, R.J.; Andrejak, C.; Böttger, E.C.; Brozek, J.; Griffith, D.E.; Guglielmetti, L.; et al. Treatment of Nontuberculous Mycobacterial Pulmonary Disease: An Official ATS/ERS/ESCMID/IDSA Clinical Practice Guideline. Clin. Infect. Dis. 2020, 71, e1–e36. [Google Scholar] [CrossRef]
  114. Lecorche, E.; Haenn, S.; Mougari, F.; Kumanski, S.; Veziris, N.; Benmansour, H.; Raskine, L.; Moulin, L.; Cambau, E.; Aubry, A.; et al. Comparison of Methods Available for Identification of Mycobacterium chimaera. Clin. Microbiol. Infect. 2018, 24, 409–413. [Google Scholar] [CrossRef] [PubMed]
  115. Lyamin, A.V.; Ereshchenko, A.A.; Gusyakova, O.A.; Yanchenko, A.V.; Kozlov, A.V.; Khaliulin, A.V. Comparison of Laboratory Methods for Identifying Members of the Family Mycobacteriaceae. Int. J. Mycobacteriol 2023, 12, 129–134. [Google Scholar] [CrossRef]
  116. Togawa, A.; Chikamatsu, K.; Takaki, A.; Matsumoto, Y.; Yoshimura, M.; Tsuchiya, S.; Nakamura, S.; Mitarai, S. Multiple Mutations of Mycobacterium ntracellulare Subsp. Chimaera Causing False-Negative Reaction to the Transcription-Reverse Transcription Concerted Method for Pathogen Detection. Int. J. Infect. Dis. 2023, 133, 14–17. [Google Scholar] [CrossRef]
  117. Kuehl, R.; Banderet, F.; Egli, A.; Keller, P.M.; Frei, R.; Döbele, T.; Eckstein, F.; Widmer, A.F. Different Types of Heater-Cooler Units and Their Risk of Transmission of Mycobacterium chimaera during Open-Heart Surgery: Clues from Device Design. Infect. Control Hosp. Epidemiol. 2018, 39, 834–840. [Google Scholar] [CrossRef] [PubMed]
  118. Quintás Viqueira, A.; Pérez Romero, C.; Toro Rueda, C.; Sánchez Calles, A.M.; Blázquez González, J.A.; Alejandre Leyva, M. Mycobacterium chimaera in Heater-Cooler Devices: An Experience in a Tertiary Hospital in Spain. New Microbes New Infect. 2021, 39, 100757. [Google Scholar] [CrossRef] [PubMed]
  119. Falkinham, J.O., III. Disinfection and Cleaning of Heater-Cooler Units: Suspension- and Biofilm-Killing. J. Hosp. Infect. 2020, 105, 552–557. [Google Scholar] [CrossRef] [PubMed]
  120. Hammer-Dedet, F.; Dupont, C.; Evrevin, M.; Jumas-Bilak, E.; Romano-Bertrand, S. Improved Detection of Non-Tuberculous Mycobacteria in Hospital Water Samples. Infect. Dis. Now 2021, 51, 488–491. [Google Scholar] [CrossRef]
  121. Romano-Bertrand, S.; Evrevin, M.; Dupont, C.; Frapier, J.M.; Sinquet, J.C.; Bousquet, E.; Albat, B.; Jumas-Bilak, E. Persistent Contamination of Heater-Cooler Units for Extracorporeal Circulation Cured by Chlorhexidine-Alcohol in Water Tanks. J. Hosp. Infect. 2018, 99, 290–294. [Google Scholar] [CrossRef]
  122. Colangelo, N.; Giambuzzi, I.; Moro, M.; Pasqualini, N.; Aina, A.; De Simone, F.; Blasio, A.; Alfieri, O.; Castiglioni, A.; De Bonis, M. Mycobacterium chimaera in Heater–Cooler Units: New Technical Approach for Treatment, Cleaning and Disinfection Protocol. Perfusion 2019, 34, 272–276. [Google Scholar] [CrossRef]
  123. Ditommaso, S.; Giacomuzzi, M.; Memoli, G.; Garlasco, J.; Curtoni, A.; Iannaccone, M.; Zotti, C.M. Chemical Susceptibility Testing of Non-Tuberculous Mycobacterium strains and Other Aquatic Bacteria: Results of a Study for the Development of a More Sensitive and Simple Method for the Detection of NTM in Environmental Samples. J. Microbiol. Methods 2022, 193, 106405. [Google Scholar] [CrossRef]
  124. Shrimpton, N.Y.R. Evaluation of Disinfection Processes for Water Heater Devices Used for Extracorporeal Life Support. Perfusion 2019, 34, 428–432. [Google Scholar] [CrossRef] [PubMed]
  125. Sarink, M.J.; van Cappellen, W.A.; Tielens, A.G.M.; van Dijk, A.; Bogers, A.J.J.C.; de Steenwinkel, J.E.M.; Vos, M.C.; Severin, J.A.; van Hellemond, J.J. Vermamoeba Vermiformis Resides in Water-Based Heater–Cooler Units and Can Enhance Mycobacterium chimaera Survival after Chlorine Exposure. J. Hosp. Infect. 2023, 132, 73–77. [Google Scholar] [CrossRef] [PubMed]
  126. Bengtsson, D.; Westerberg, M.; Nielsen, S.; Ridell, M.; Jönsson, B. Mycobacterium chimaera in Heater-Cooler Units Used during Cardiac Surgery–Growth and Decontamination. Infect. Dis. 2018, 50, 736–742. [Google Scholar] [CrossRef] [PubMed]
  127. Weitkemper, H.H.; Spilker, A.; Knobl, H.J.; Körfer, R. The Heater-Cooler Unit-A Conceivable Source of Infection. J. Extra Corpor. Technol. 2016, 48, 62–66. [Google Scholar] [CrossRef]
  128. Foltan, M.; Nikisch, A.; Dembianny, J.; Miano, A.L.; Heinze, J.; Klar, D.; Göbölös, L.; Lehle, K.; Schmid, C. A Solution for Global Hygienic Challenges Regarding the Application of Heater-Cooler Systems in Cardiac Surgery. Perfusion 2023, 38, 28–36. [Google Scholar] [CrossRef]
  129. Pradal, I.; Esteban, J.; Mediero, A.; García-Coca, M.; Aguilera-Correa, J.J. Contact Effect of a Methylobacterium sp. Extract on Biofilm of a Mycobacterium chimaera Strain Isolated from a 3T Heater-Cooler System. Antibiotics 2020, 9, 474. [Google Scholar] [CrossRef]
  130. Masaka, E.; Reed, S.; Davidson, M.; Oosthuizen, J. Opportunistic Premise Plumbing Pathogens. A Potential Health Risk in Water Mist Systems Used as a Cooling Intervention. Pathogens 2021, 10, 462. [Google Scholar] [CrossRef]
  131. Treglia, M.; Pallocci, M.; Ricciardi Tenore, G.; Castellani, P.; Pizzuti, F.; Bianco, G.; Passalacqua, P.; De Luca, L.; Zanovello, C.; Mazzuca, D.; et al. Legionella and Air Transport: A Study of Environmental Contamination. Int. J. Environ. Res. Public Health 2022, 19, 8069. [Google Scholar] [CrossRef]
  132. Glassmeyer, S.T.; Burns, E.E.; Focazio, M.J.; Furlong, E.T.; Gribble, M.O.; Jahne, M.A.; Keely, S.P.; Kennicutt, A.R.; Kolpin, D.W.; Medlock Kakaley, E.K.; et al. Water, Water Everywhere, but Every Drop Unique: Challenges in the Science to Understand the Role of Contaminants of Emerging Concern in the Management of Drinking Water Supplies. Geohealth 2023, 7, e2022GH000716. [Google Scholar] [CrossRef]
  133. Ortiz-Martínez, Y. Mycobacterium chimaera: An under-Diagnosed Pathogen in Developing Countries? J. Hosp. Infect. 2017, 97, 125–126. [Google Scholar] [CrossRef]
  134. Becker, J.B.; Moisés, V.A.; Guerra-Martín, M.D.; Barbosa, D.A. Epidemiological Differences, Clinical Aspects, and Short-Term Prognosis of Patients with Healthcare-Associated and Community-Acquired Infective Endocarditis. Infect. Prev. Pract. 2024, 6, 100343. [Google Scholar] [CrossRef]
  135. Ferrara, S.D.; Baccino, E.; Bajanowski, T.; Boscolo-Berto, R.; Castellano, M.; De Angel, R.; Pauliukevičius, A.; Ricci, P.; Vanezis, P.; Vieira, D.N.; et al. Malpractice and Medical Liability. European Guidelines on Methods of Ascertainment and Criteria of Evaluation. Int. J. Leg. Med. 2013, 127, 545–557. [Google Scholar] [CrossRef]
Figure 1. PRISMA 2020 flow diagram for systematic reviews which included searches of databases and registers only.
Figure 1. PRISMA 2020 flow diagram for systematic reviews which included searches of databases and registers only.
Healthcare 12 01788 g001
Table 1. List of references not or improperly consistent with in situ deposition of aerosolised M. chimaera particles during surgery.
Table 1. List of references not or improperly consistent with in situ deposition of aerosolised M. chimaera particles during surgery.
ReferencesAuthor, YearN. of Patients §SurgeryMean Time of Presentation If Previous SurgerySetting (Country)Organ and/or Tissue Involved
[26](Bills et al., 2009)1NoneNaNot healthcare (USA)Lung, nodules in chronic obstructive pulmonary disease
[27](Cohen-Bacrie et al., 2011)1NoneNaPossible frequent healthcare contact (Réunion Island, FR)Lung infections in cystic fibrosis
[28](Alhanna et al., 2012)1NoneNaNot healthcare (Germany)Lung infection
[29](Gunaydin et al., 2013)5 (of 90)NoneNaPossible healthcare contact (Turkey)Lung (reassessment of sputum specimens)
[30](Boyle et al., 2015)125 (of 448)NoneNaPossible healthcare contact (USA)Lung (reassessment of sputum specimens)
[31](Mwikuma et al., 2015)
1 (of 54) NoneNaNot healthcare (Zambia)Lung (reassessment of sputum specimens)
[32](Moon et al., 2016)11NoneNaNot healthcare (South Korea)Lung infection (reassessment of sputum specimens)
[33](Moutsoglou et al., 2017)1NoneNaNot healthcare (USA)Disseminated with spinal osteomyelitis and discitis
[34](Bursle et al., 2017)1Tricuspid valve repair and mitral annuloplasty13 monthsUnderwent surgery (Australia)Disseminated
[35]Kim et al., 20178 (of 91)NoneNaPossible healthcare contact (Korea)Lung (reassessment of sputum specimens)
[36](Chand et al., 2017) *4Valvular cardiac surgery 1.15 (0.25–5.1) yearsUnderwent surgery (UK)1 osteomyelitis and 3 disseminated
[37](Truden et al., 2018)49 (of 102)NoneNaPossible healthcare contact (Slovenia)Lung (reassessment of sputum specimens)
[38](Larcher et al., 2019) 4NoneNaPossible frequent healthcare contact (France)Lung (reassessment of sputum specimens in cystic fibrosis)
[39](Shafizadeh et al., 2019) *5Valvular cardiac surgery20.6 (14–29) monthsUnderwent surgery (USA)Disseminated with liver infection
[40](Rosero and Shams, 2019)1None but operating room nurse 10 years ago>10 yearsPossible frequent healthcare contact (USA)Lung infection
[41](Watanabe et al., 2020)1NoneNaNot healthcare (Japan)Tendons, hand tenosynovitis
[42](Chen et al., 2020)28NoneNaNot healthcare (Taiwan)Lung infection (reassessment of sputum specimens)
[43](Maalouly et al., 2020)1Kidney transplantationOne weekUnderwent surgery (Belgium)Kidney, urinary tract infection in a kidney transplant recipient with concomitant Mycobacterium malmoense lung infection and fibro anthracosis
[44](de Melo Carvalho et al., 2020)1NoneNaPossible healthcare contact (Portugal)Disseminated in B-cell lymphoma
[45](Sharma et al., 2020)2NoneNaNot healthcare (India)Meninges, meningitis
[23](Zabost et al., 2021)88 (of 200)NoneNaPossible healthcare contact (Poland)Lung infection (reassessment of sputum specimens)
[46](Kim et al., 2021)4 (of 320) NoneNaPossible healthcare contact (Korea) Lung infection (reassessment of sputum specimens)
[47](Kavvalou et al., 2022)1NoneNaPossible healthcare contact (Germany)Central venous catheter infection in cystic fibrosis
[48](Robinson et al., 2022)1NoneNaNot healthcare (USA)Lung infection in drug abuser
[49](Ahmad et al., 2022)1NoneNaNot healthcare (USA)Lung infection in sarcoidosis
[50](George et al., 2022)1NoneNaNot healthcare (India)Skin, periapical abscess with chin ulcer
[51](Lin et al., 2022)1NoneNaPossible frequent healthcare contact (Taiwan)Disseminated in adult-onset immunodeficiency syndrome
[52](Łyżwa et al., 2022)1NoneNaNot healthcare (Poland)Lung infection in silicosis
[53](McLaughlin et al., 2022)1Coronary artery bypass grafting1 yearUnderwent surgery (USA)Tendons, hand tenosynovitis in ipsilateral elbow wound in fisherman
[54](Gross et al., 2023)23NoneNaHealthcare (USA)Lung infections in cystic fibrosis (genomic analysis for cluster correlation to hospital outbreaks)
[55](Azzarà et al., 2023)1NoneNaPossible healthcare contact (Italy)Lung infection in lung adenocarcinoma treated with immune checkpoint inhibitors
[56](Pradhan et al., 2023)1Bioprosthetic mitral valve replacement7 yearsUnderwent surgery (Australia)Spinal osteomyelitis and discitis
[57](Garcia-Prieto et al., 2024)1NoneNaNot healthcare (Spain)Lung infection in fibro anthracosis
[58](Paul et al., 2024)1NoneNaPossible healthcare contact (UK)Lung infection in unilateral pulmonary artery agenesis on the right side
Legend: § in case of respiratory specimens’ reanalysis, the number reflects only those positive for M. chimaera (on the total one re-analysed); * The article reports also other cases with cardiac manifestations after cardiac surgery. Na: not applicable.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Bolcato, V.; Bassetti, M.; Basile, G.; Bianco Prevot, L.; Speziale, G.; Tremoli, E.; Maffessanti, F.; Tronconi, L.P. The State-of-the-Art of Mycobacterium chimaera Infections and the Causal Link with Health Settings: A Systematic Review. Healthcare 2024, 12, 1788. https://doi.org/10.3390/healthcare12171788

AMA Style

Bolcato V, Bassetti M, Basile G, Bianco Prevot L, Speziale G, Tremoli E, Maffessanti F, Tronconi LP. The State-of-the-Art of Mycobacterium chimaera Infections and the Causal Link with Health Settings: A Systematic Review. Healthcare. 2024; 12(17):1788. https://doi.org/10.3390/healthcare12171788

Chicago/Turabian Style

Bolcato, Vittorio, Matteo Bassetti, Giuseppe Basile, Luca Bianco Prevot, Giuseppe Speziale, Elena Tremoli, Francesco Maffessanti, and Livio Pietro Tronconi. 2024. "The State-of-the-Art of Mycobacterium chimaera Infections and the Causal Link with Health Settings: A Systematic Review" Healthcare 12, no. 17: 1788. https://doi.org/10.3390/healthcare12171788

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop