Search Results (236)

Bacteriological control strains with known characteristics ensure consistency and reproducibility of assay performance across different laboratories and are an important cornerstone of quality control in the microbiology laboratory. Ideally, control strains should be representative of the assay target and be widely available from reputable sources. However, for work involving antibiotic resistance most controls come from human and veterinary clinical sources and are not optimized for work in agriculturally impacted environments or not widely available. The objective of this work was to identify and make widely available two E. coli isolates sourced from agricultural production settings that could be used as external controls supporting method development, research and environmental monitoring for extended spectrum β-lactamase producing (ESBL) and tetracycline resistant Escherichia coli. Previously collected E. coli suspects were screened based on antimicrobial susceptibility testing data, then confirmed as E. coli and characterized both phenotypically and genotypically. The positive control strain, ARS-C301 was ESBL positive and contained the CTX-M-55 and tet(A) genes, and the negative control strain, ARS-C101 was negative for both targets. Here we introduce two agriculturally sourced, fully characterized, and genetically sequenced control strains for use as laboratory controls in research involving extended-spectrum β-lactamase producing (ESBL) and tetracycline-resistant Escherichia coli isolated from the environment, available via publicly accessible culture collections, and commercially as a quantitative pellet. Full article

This pilot study investigated the presence of potentially zoonotic microorganisms in bat species from Kopaonik National Park, Serbia. A total of 40 individuals from 12 bat species were sampled and screened using microbiological and molecular methods. Salmonella spp., Chlamydia spp., Coxiella burnetii, Francisella tularensis, Leptospira spp., Lyssavirus, Filoviridae, henipaviruses, and SARS-CoV-2 were not detected in any bats. Coronavirus genomes were confirmed in four bats—one Myotis brandtii, two Myotis daubentonii, and one Myotis cf. mystacinus. Sequence analysis identified the presence of alphacoronavirus genomes with high similarity to strains previously found in Europe. Mycoplasma spp. genomes were found in 18 bats (45%), and Rickettsia spp. were detected in five bats (12.5%), although species-level identification was not possible. The findings highlight the presence of certain bacteria and viruses in bats that could have implications for public health, especially in areas with close human–wildlife interaction. Although no direct evidence of high-risk pathogens was found, the results support the importance of continued surveillance and ecological studies on bats, given their role as potential reservoirs. Monitoring bat-associated microorganisms is essential to better understand possible transmission routes and improve the prevention of emerging zoonotic diseases. Full article

Background/Objectives: Clinical laboratories are fundamental to healthcare systems, contributing to over 70% of clinical decisions while accounting for only 2–3% of hospital budgets. Among them, microbiology laboratories provide critical information that directly influences patient outcomes and satisfaction. This study presents a structured review of the current state of Lean Six Sigma (LSS) implementation in microbiology and comparable laboratory environments. The objective is to identify relevant contributions within the state of the art to highlight potential benefits applicable to microbiology laboratories and to detect persistent gaps and unresolved needs. Methods: A systematic literature review was performed across six databases (Web of Science, ScienceDirect, Scopus, ProQuest, PubMed, and Google Scholar) to identify studies published between 2012 and September 2024. After screening, 33 studies were selected for full-text analysis. Results: The selected literature was analyzed to assess the extent to which LSS methodologies have been applied in microbiology laboratories. Particular attention was given to the definition and use of key performance indicators (KPIs). While industry-adapted metrics such as cost reduction and turnaround time are commonly employed, clinical indicators, such as patient impact, satisfaction, and diagnostic accuracy, are underutilized. Additionally, the analysis revealed a frequent omission of the control phase in LSS projects, limiting long-term process monitoring. The review also identifies the most suitable LSS tools and evaluates how laboratories manage interruptions in routine workflows. Conclusions: Future research should prioritize the integration of clinical KPIs into LSS frameworks, establish robust control phases for sustained monitoring, and systematically address the impact of process interruptions on optimization efforts. Full article

Folate deficiency is a widespread nutritional issue, and biofortifying dairy products through lactic acid bacteria (LAB) is a promising strategy to enhance natural folate levels. This study aimed to develop a reliable method for selecting Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus strains with enhanced folate production for use as functional starter cultures. Initially, a traditional microbiological assay (MA) was used to measure folate production in 36 LAB strains isolated from fermented milks. Due to MA’s limitations, an untargeted and semi-quantitative method combining ultra-high-performance liquid chromatography (UHPLC) with high-resolution mass spectrometry (HRMS) was developed for a more comprehensive folate screening. The MA showed higher folate production in S. thermophilus strains (309–639 µg/L) compared to L. delbrueckii subsp. bulgaricus (up to 48 µg/L). Subsequently, nine selected LAB strains were further analyzed using the UHPLC-HRMS approach, which enabled the identification and semi-quantification of six folate metabolites, namely dihydrofolate, tetrahydrofolate (THF), 10-formyl-THF, 5,10-methenyl-THF, 5,10-methylene-THF, and 5-methyl-THF. Lab-scale yogurt production using the top-performing strains, as identified through the HRMS method, demonstrated an increase in folate content over a 14-day shelf life. These findings revealed the potential of UHPLC-HRMS as a high-throughput alternative method for folates detection, offering a promising tool for screening folate-enhanced LAB strains for biofortification. Full article

Although ecotoxicology was emerging as a field through the 1970s, the incorporation of microbial indicators into the framework has been slower to evolve. The exploration of microbes as sensitive toxicity tests began in the late 70s and early 80s (with the emergence of Microtox^® and other simple tests). However, the applications have been limited, beyond water and wastewater screening. This opinion piece reflects my own perspective on the field—from my early excitement in the 1990s for its possibilities, to a sense of frustration at the slow pace of new development and applications in the field—despite the surge of “omics” options. While microbiology still fails to lead the field of ecotoxicology, the potential remains. Full article

This study aimed to evaluate the potential of lactic acid bacteria (LAB) isolated from organic acid whey as an alternative to nitrites in heat-treated organic sausages. Eleven LAB strains were screened for their ability to develop sensory characteristics similar to traditionally cured meat. Based on the results, Lactiplantibacillus plantarum S21 was selected for further experiments. Four sausage treatments were produced: control cured (C), salted (S), salted with L. plantarum S21 at 10⁷ CFU/g (LP), and salted with acid whey (AW). The pH value, oxidation-reduction potential (ORP), antioxidant activity of peptides (ABTS•+), thiobarbituric acid-reactive substance (TBARS), fatty acid profile, and microbiological quality were assessed post-production and after 14 days of cold storage. After production, the LP and AW sausages had a lower pH than the cured (C) and uncured (S) control samples. LP sausages exhibited a stable pink colour due to myoglobin conversion to nitrosylmyoglobin, comparable to the cured control. The LP sausages were similar in overall sensory quality to the cured (C) samples and were superior to the S and AW sausages after storage. The lowest ORP value was observed in treatment C after production, whereas after storage, no significant differences were found between the treatments. The highest antioxidant activity of peptides was observed in the LP sausages. It was shown that the LP and AW treatments had lower saturated fatty acid content and higher monounsaturated and polyunsaturated fatty acid content than the C and S treatments. Nevertheless, the C treatment had the lowest TBARS value. Lower total viable counts were found in the C and LP treatments than in the S and AW treatments after storage. Our research demonstrates the potential of L. plantarum S21 for producing heat-treated sausages without nitrites, assuming the implementation of additional anti-botulinum barriers. Nevertheless, further studies on the role of bacteria in meat oxidation processes are needed. Full article

Background: Neonatal sepsis is a major cause of infant mortality, and it accounts for a significant consumption of antimicrobials in paediatrics. This is the first comprehensive study on neonatal sepsis in Hong Kong. Methods: From 2014 to 2023, all neonates admitted to a single institution with culture-proven infections from the blood and/or cerebrospinal fluid were selected and reviewed retrospectively. The infecting organisms, their antibiotic nonsusceptibility pattern, and the concordance of empirical antimicrobial therapy with the microbiological profiles were described and were further compared between infants of normal/low birth weight (≥1.5 kg) and very low/extremely low birth weight (<1.5 kg), early-onset sepsis (<72 h), and late-onset sepsis (4–28 days), the first and the second 5-year periods (2014–2018 vs. 2019–2023). Results: After contaminants were excluded, there were 118 affected neonates with 125 organisms identified. Fifty-nine were male. Thirty-four were very low/extremely low birth weight infants, and twenty-eight infants had early-onset sepsis. Patient demographics and the microbiology findings did not differ between the first 5 years and the latter 5 years. However, the incidence of neonatal sepsis was significantly lower in the latter 5 years (3.23 vs. 1.61 per 1000 live births, p < 0.001), the period that coincided with the COVID-19 pandemic. Escherichia coli was the most common Gram-negative pathogen. Streptococcus agalactiae and Streptococcus bovis group infections were more common in early-onset sepsis, while coagulase-negative Staphylococcus and non-E. coli Gram-negative pathogens were more likely to occur in late-onset sepsis. In very low/extremely low birth weight infants, the rate of cefotaxime or ceftriaxone nonsusceptibility among Gram-negative isolates was higher (p = 0.01), and concordance of empirical antimicrobial therapy was lower (p = 0.006). Conclusions: Management of neonatal sepsis remains challenging, and there is a need for optimising antimicrobial therapy, especially in preterm patients. Antepartum screening with intrapartum antibiotic prophylaxis is effective in reducing the risk of early-onset sepsis associated with S. agalactiae, while stringent infection control measures are important for the prevention of late-onset sepsis. Full article

Edible and medicinal substances can be contaminated by fungi during harvesting, processing, and storage, leading to mycotoxin production and quality deterioration. The distribution of mycotoxigenic fungi in edible and medicinal substances was investigated in this study. Fungi and mycotoxins were detected in 163 commercially available edible and medicinal substances using standard microbiological techniques and high-performance liquid chromatography. A total of 92.0% of samples contained fungi (0.5–5.3 lg colony-forming units (CFU)·g⁻¹); 208 fungal strains belonging to 16 genera were identified, predominantly Aspergillus and Penicillium. Aspergillus section Nigri (30.3%) produced fumonisin B₂, which was distributed mainly in radix and rhizome samples. Thirteen samples had mycotoxins, of which ochratoxin A was the most common, followed by aflatoxins and zearalenone (ZEN). One Nelumbinis semen sample contained 10.75 μg·kg⁻¹ AFB₁, and one Raisin tree semen sample contained 484.30 μg·kg⁻¹ ZEN, which exceeded regulatory limits in Europe and China. These findings highlight the potential risks associated with fungal contamination and mycotoxins in edible and medicinal substances. Enhanced quality control measures are essential to reduce contamination during harvesting, processing, and storage. Expanded mycotoxin screening, improved preservation techniques, and stricter regulatory standards need to be implemented to ensure consumer safety. Full article

During an Antarctic expedition that took place in December 2010–January 2011 in the East Antarctic coastal region, soil samples were collected in aseptic conditions and stored for over a decade in freezers at −20 °C. Due to the shortly afterward passing of the Antarctic researcher in charge, Teodor Negoiță, the samples remained unintentionally frozen for a long period and were made available for research 13 years later. A chemical analysis of soil as well as screening for viable microbial presence was performed; soil analysis was conducted via inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier-transform infrared spectroscopy coupled with attenuated total reflection (FTIR-ATR). The presence of aerobic and facultative aerobic microbiotas was evaluated through a Biolog Ecoplates assay, and isolated strains were 16S sequenced for final taxonomic identification. The results obtained new insights into Antarctic soil characteristics from both chemical and microbiological aspects, even after over a decade of conservation. Full article

Background/Objectives: Long-term ventilation (LTV) is a widely used treatment for the management of patients with chronic respiratory failure. As use increases, it generates further questions about aspects of care. One issue is the potential risk of contamination within the device itself and the potential risk of respiratory tract infections in a subsequent user. Using an observational cross-sectional study design, the primary objective of this study was to identify whether airborne bacterial and fungal pathogens are present within a NIPPY 3+ (Breas Medical Ltd., Stratford Upon Avon, UK) room air ventilator following use in a community setting. Methods: Microbiological samples in the form of one single charcoal swab were taken from two specified areas of the device’s internal airflow pathway. Results: A total of 243 ventilators were sampled. A total of 215 ventilators with complete data collection were included in the study. A total of 84 (39%) were identified as having no growth and 131 (61%) were positive for bacterial and/or fungal growth. Overall, 307 organisms were grown from 131 ventilators ranging from 1 to 6 organisms per swab. Of the 215 ventilators screened, 15 (7%) grew organisms considered to be pathogenic. Well-established human pathogens were considered as ‘potentially pathogenic’ in this study due to the limitation of not obtaining patient-specific data, meaning host–pathogen interaction could not be determined. Of these, 14 grew one pathogenic organism and 1 grew four distinct pathogens. This is the largest study to date exploring the potential presence of airborne pathogens in room air ventilators. We have demonstrated that 61% of these devices were positive for bacterial or fungal growth and 7% were pathogenic. Pathogenic organisms included Pseudomonas aeruginosa, Staphylococcus aureus and Aspergillus sp. Although the growth of pathogenic organisms was relatively rare, there are important potential adverse clinical outcomes in patients with diseases commonly treated by LTV services. Conclusions: We have shown that the contamination of devices is rare, but, in 7%, there is contamination with potentially pathogenic organisms, which, if proven to be transferred between patients, could be a cause of worse patient outcomes. Full article

This paper explores various aspects of microbiology and immunology, with a particular focus on the epidemiology and molecular characterisation of infectious diseases in the Caribbean and South America. Key areas of investigation include tuberculosis (TB), experimental vaccines, and bloodborne pathogens. A retrospective study conducted in Jamaica highlights the significance of early HIV screening, timely diagnosis, and inte-grated care. The paper also examines the challenges posed by nosocomial infections, particularly those caused by antibiotic-resistant Gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), emphasising the critical importance of infection control measures. Additionally, it explores the regional microbiome, the global response to infectious diseases, and immune responses in patients with immunodeficiency disorders such as severe combined immunodeficiency (SCID) and chronic granulomatous disease (CGD), underscoring their heightened susceptibility to a wide range of infections. Full article

Antimicrobial resistance is one of the most concerning public health issues in Vietnam due to antibiotic-resistant Gram-negative bacteria, including carbapenem-resistant organisms (CROs), which might appear in remote areas in Vietnam. At this center, we performed a cross-sectional study and collected fecal samples from humans (20 healthcare workers (HCWs) and 67 residents) and 175 environmental samples, with rectal and environment swabs, as data for this study, from September 2022 to December 2022. We conducted microbiological testing, including the MELAB Chromogenic CARBA agar plates, blood agar plates, and the BD PhoenixTM Automated Microbiology System to screen, isolate, and identify bacterial species and phenotypic tests for the antimicrobial susceptibility of carbapenem-resistant bacteria and the whole-genome sequencing for 12 CROs chosen to confirm the CRO transmission between HCWs and residents. The study findings showed that the prevalence and risk factors associated with CRO colonization were detected in HCWs, residents, and the environment in the Center of Care and Protection of Orphan Children. CRO transmission happened between HCWs and residents detected with WGS analysis. Whole-genome sequencing (WGS) plays a significant role in CRO control and prevention and reduces CRO transmission/colonization in this center and other healthcare settings. Full article

The presence of residues of antimicrobial substances in milk has been an important hygienic and technological parameter of raw milk quality since the 1960s. The presented review focuses on screening methods (microbiological inhibition methods and rapid specific tests) that are used in the control of antimicrobial residues in milk in the context of their historical development up to the present. We briefly explain the principles of the methods and discuss their pros and cons. The aim was to provide both the historical perspective on this topic and provide useful information on screening methods that are currently routinely used for the detection of residues of antimicrobials at farms, in the dairy industry, and in milk quality control laboratories. Full article

Background: Pott’s Puffy Tumor (PPT) in young-age patients is a rare clinical entity characterized by osteomyelitis of the frontal bone with a subperiosteal abscess collection. Previous reviews primarily consist of small, retrospective case series and anecdotal reports. This study aims to present the largest, most up-to-date systematic review of essential clinical findings, diagnostic modalities, microbiologic considerations, and treatment approaches for managing PPT in pediatric and adolescent populations. Methods: PubMed, Scopus, and Web of Science databases were systematically screened until 3 January 2024. The protocol of this investigation was registered on PROSPERO in January 2024, and the systematic review was performed according to the PRISMA statement. The study included 184 patients from 109 articles and an additional case from the authors’ institution. Results: PPT commonly stems from untreated rhinosinusitis, respectively, acute pansinusitis, frontal acute rhinosinusitis and chronic rhinosinusitis, and direct head trauma. Infections typically involve a polymicrobial anaerobe-predominant microbiome. Computed tomography and magnetic resonance imaging are routinely used for presurgical assessment and posttreatment surveillance. Intracranial complications were significantly associated with the type of surgical treatment (p value < 0.0001). Conclusions: PPT is a significant and relatively morbid disease often under-recognized and misdiagnosed due to its variable clinical presentation. Management includes both antimicrobial therapy and surgical intervention, emphasizing the importance of an interdisciplinary approach. Full article

Background: Pediatric osteoarticular tuberculosis (TB) remains a significant global health challenge, particularly in resource-limited settings, where delayed diagnosis and treatment frequently lead to severe long-term complications. Despite advancements in TB control, skeletal TB in children is often misdiagnosed due to its non-specific clinical presentation, contributing to poor outcomes such as joint deformities, growth disturbances, and chronic pain. The complexity of diagnosing osteoarticular TB is further exacerbated by the limited sensitivity of conventional diagnostic tools and the overlap with other musculoskeletal conditions. This study seeks to evaluate the impact of early detection and multidisciplinary management on treatment outcomes in pediatric patients with osteoarticular TB. Methods: A retrospective review was conducted at the Pediatric Orthopedics Department of the “Grigore Alexandrescu” Children’s Hospital in Romania from 2009 to 2023. Case data included clinical, imaging, and microbiological findings, and treatment outcomes in children aged 0–18 years diagnosed with tuberculous osteomyelitis. Results: The study identified varied clinical presentations, with delayed diagnosis often linked to misinterpretation of symptoms as non-TB infections. Multimodal diagnostic approaches combining imaging, microbiological testing, and histopathology improved diagnostic accuracy. Early surgical intervention alongside anti-TB therapy proved effective in reducing long-term complications. Conclusions: Timely, accurate diagnosis and multidisciplinary treatment are critical to improving outcomes in pediatric osteoarticular TB. Vaccination status and comprehensive diagnostic tools significantly influence disease progression and treatment success. The study underscores the need for enhanced screening and diagnostic methods to prevent delays in treatment. Full article