Pathogens

13 pages, 618 KiB

Open AccessArticle

Test Performance Study on qPCR Assays for Detection of Phyllosticta citricarpa

by Tjaša Jakomin, Janja Zajc Žunič and Polona Kogovšek

Pathogens 2025, 14(5), 413; https://doi.org/10.3390/pathogens14050413 - 24 Apr 2025

Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa, significantly affects citrus fruit marketability and can lead to premature fruit drop. Accurate and reliable detection of this quarantine pathogen is crucial, particularly for asymptomatic plant material. This study evaluated two qPCR [...] Read more.

Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa, significantly affects citrus fruit marketability and can lead to premature fruit drop. Accurate and reliable detection of this quarantine pathogen is crucial, particularly for asymptomatic plant material. This study evaluated two qPCR assays, the EPPO recommended assay PC and assay Pc-TEF1, based on TEF region, for detecting P. citricarpa through a collaborative test performance study (TPS). DNA from the isolates of Phyllosticta spp. and other fungi was spiked into citrus fruit peel extracts (lemon, orange, and pomelo) and distributed among 13 laboratories. Sample and qPCR assay stability under typical transport conditions was confirmed, although prolonged storage affected Pc-TEF1 assay performance. The assays were assessed based on sensitivity, specificity, reproducibility, and repeatability. Both assays demonstrated high performance, with repeatability and reproducibility exceeding 95%. The PC assay, as expected, detected different related Phyllosticta species, while Pc-TEF1 showed higher specificity for P. citricarpa included in the TPS alone. Additionally, inhibitory effects were observed specifically in the pomelo peel samples, suggesting matrix-dependent variability. This TPS confirms that both PC and Pc-TEF1 qPCR assays are robust. Further evaluation of the qPCR assays would support the selection of the most reliable assays for the detection of P. citricarpa, contributing to the effective management of CBS disease in citrus production and trade. Full article

(This article belongs to the Section Fungal Pathogens)

20 pages, 1442 KiB

Open AccessArticle

Inhibition of Biofilm Production and Determination of In Vitro Time-Kill Thymus vulgaris L. Essential Oil (TEO) for the Control of Mastitis in Small Ruminants

by Michela Galgano, Francesco Pellegrini, Daniela Mrenoshki, Luciana Addante, Alessio Sposato, Laura Del Sambro, Loredana Capozzi, Elisabetta Catalano, Marianna Solito, Francesco D’Amico, Davide Messina, Antonio Parisi, Annamaria Pratelli and Paolo Capozza

Pathogens 2025, 14(5), 412; https://doi.org/10.3390/pathogens14050412 - 24 Apr 2025

Abstract

Staphylococcus aureus and coagulase-negative staphylococci (CNS) are the main causative agents of mastitis in sheep. Their ability to form biofilms in vivo is considered an important virulence factor underlying mastitis outbreaks refractory to antibiotic treatments. Furthermore, pre- and postdipping immersion during milking in [...] Read more.

Staphylococcus aureus and coagulase-negative staphylococci (CNS) are the main causative agents of mastitis in sheep. Their ability to form biofilms in vivo is considered an important virulence factor underlying mastitis outbreaks refractory to antibiotic treatments. Furthermore, pre- and postdipping immersion during milking in iodine substances could determine the presence of residues in milk and therefore represent a health risk factor for consumers. The aim of this study was to evaluate the antibacterial and biofilm inhibitory activity of Thymus vulgaris L. essential oil (TEO) against staphylococci strains isolated from ovine clinical mastitis. In particular, 3 reference strains (S. aureus 25923 and 11623 and S. epidermidis 12228) and 12 clinical isolates (6 S. aureus and 6 CNS) were used. TEO solutions, from a concentration of 1% (v/v) to 1.25% (v/v), corresponding to 9.28–2.32 mg/mL, were obtained after solubilization in 10% dimethyl sulfoxide (DMSO) and used to evaluate the bacterial time-kill compared to that of an iodine-based solution. Antibacterial efficacy was then assessed by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while biofilm inhibition was assessed by minimum biofilm inhibitory concentration (MBIC) using a spectrophotometer at a wavelength of 570 nm. Additionally, biofilm-associated genes (icaA and icaD) were evaluated in all tested strains by PCR. The tested TEO concentrations were able to significantly and prominently reduce bacterial growth compared to controls, as demonstrated by bacterial time-kills. The MIC value was obtained at a concentration of 0.50% (v/v) for a single coagulation-positive isolate (S. aureus (f)) and at a concentration of 0.25% (v/v) for all other isolates. TEO showed effective bactericidal action with a 99.9% reduction in CFU/mL of all isolates in the MBC test at a concentration of 0.25% (v/v) for most of the tested strains. Furthermore, a marked inhibition in biofilm formation at all tested concentrations was observed, with MBIC value of 0.25%. All S. aureus tested were biofilm-producing strains and positive for icaA and icaD genes, while two CNS biofilm-producing strains were negative for both genes. These preliminary results suggest that TEO could be a promising alternative as an udder disinfectant during milking practices. Although in vivo studies are needed to confirm the efficacy and safety of TEO as an adjuvant in the prevention and treatment of udder infections, TEO could help counteract the emergence of antimicrobial resistance and reduce the potential risk of iodine residues in milk. Full article

(This article belongs to the Section Bacterial Pathogens)

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15 pages, 587 KiB

Open AccessArticle

Seasonal Dynamics and Legionellosis-Associated Hospitalization in Spain: A Retrospective Study

by Enrique Gea-Izquierdo, Rossana Ruiz-Urbaez, Valentín Hernández-Barrera and Ángel Gil-de-Miguel

Pathogens 2025, 14(5), 411; https://doi.org/10.3390/pathogens14050411 - 24 Apr 2025

Abstract

Legionellosis is a serious respiratory disease with a high mortality rate, particularly if it is untreated or occurs in the immunocompromised. Legionellosis must be reported in the Spanish Epidemiological Surveillance System. To optimize the epidemiologic knowledge of legionellosis and improve prevention, we have [...] Read more.

Legionellosis is a serious respiratory disease with a high mortality rate, particularly if it is untreated or occurs in the immunocompromised. Legionellosis must be reported in the Spanish Epidemiological Surveillance System. To optimize the epidemiologic knowledge of legionellosis and improve prevention, we have investigated whether the disease is associated with seasonality. This study has described legionellosis cases, the temporal trend by seasonality, hospitalization rate, case fatality rate, and costs by autonomous community and season. We retrospectively reviewed cases of legionellosis, documented patient and clinical characteristics, diagnostics, and seasonality of infection. This study combined national legionellosis notification and hospital discharge data that were linked via the Spanish National Health Service to provide a dataset of hospitalized cases occurring between 2002 and 2021 in Spain. There was a significant increase in the number of legionellosis cases due to the season of the year in Spain. An association between legionellosis and factors related to seasonality is suggested. An increasing trend in case fatality rate, seasonality, and regionality and a decrease in legionellosis hospitalization in Spain were identified. The characterization of changes in legionellosis trend and seasonality and timely synchronization and harmonization of hospitalization records are essential to strengthen disease monitoring and inform potential interventions in an epidemiological way. Full article

(This article belongs to the Special Issue Legionella and Waterborne Disease)

16 pages, 1430 KiB

Open AccessArticle

Plasma-Activated Water Against Carbapenem-Resistant Klebsiella pneumoniae and Vancomycin-Resistant Enterococcus faecalis

by Dragana Vuković, Maja Miletić, Boško Toljić, Nikola Milojević, Olivera Jovanović, Jovana Kuzmanović Pfićer, Nikola Škoro and Nevena Puač

Pathogens 2025, 14(5), 410; https://doi.org/10.3390/pathogens14050410 - 24 Apr 2025

Abstract

The scope of the antibacterial effects of plasma-activated water (PAW) is not yet fully comprehended. We investigated the activity of PAW produced by the in-house 3-pin atmospheric pressure plasma jet against carbapenem-resistant Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecalis, with a focus on [...] Read more.

The scope of the antibacterial effects of plasma-activated water (PAW) is not yet fully comprehended. We investigated the activity of PAW produced by the in-house 3-pin atmospheric pressure plasma jet against carbapenem-resistant Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecalis, with a focus on PAW’s potential to promote susceptibility to conventional antibiotics in these bacteria. Bacterial inactivation was determined by the colony count after 15 and 60 min PAW treatments. Minimum inhibitory concentrations (MICs) measured following repeated exposures to PAW across multiple generations of bacteria enabled the assessment of changes in susceptibility to antibiotics. The PAW’s efficacy was also analyzed through the detection of intracellular reactive oxygen and nitrogen species in treated bacteria. Time-dependent significant inactivation efficiency against K. pneumoniae was observed (log reduction 6.92 ± 0.24 after 60 min exposure), while effects on E. faecalis were limited. PAW demonstrated potential to decrease the MICs of crucial antibiotics. Namely, a 50 to 62.5% decrease in the MICs of colistin against K. pneumoniae and a 25% reduction in the MICs of vancomycin against enterococci were recorded. We found a significant increase in the superoxide anion concentration in K. pneumoniae and E. faecalis cells after PAW treatments. This study indicates that PAW’s inactivating efficacy coupled with the capacity for the potentiation of antibiotic effects is a promising combination against multidrug-resistant bacteria. Full article

(This article belongs to the Section Bacterial Pathogens)

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15 pages, 2353 KiB

Open AccessArticle

Earthworms Significantly Alter the Composition, Diversity, Abundance and Pathogen Load of Fungal Communities in Sewage Sludge from Different Urban Wastewater Treatment Plants

by Manuel Aira, Ana Gómez-Roel and Jorge Domínguez

Pathogens 2025, 14(5), 409; https://doi.org/10.3390/pathogens14050409 - 24 Apr 2025

Abstract

Management of sewage sludge is of ongoing concern because this waste product is generated continuously and contains high levels of harmful constituents. Among these constituents, fungal pathogens are of increasing concern. Vermicomposting can reduce the amounts of bacterial pathogens in sewage sludge; however, [...] Read more.

Management of sewage sludge is of ongoing concern because this waste product is generated continuously and contains high levels of harmful constituents. Among these constituents, fungal pathogens are of increasing concern. Vermicomposting can reduce the amounts of bacterial pathogens in sewage sludge; however, information about the effects of earthworms on fungal pathogens is limited or non-existent. We therefore aimed to determine whether vermicomposting can control fungal pathogens present in sewage sludge. Using next-generation sequencing techniques, we characterized fungal communities in sewage sludge from eight wastewater treatment plants (WWTPs) and in casts (feces) of earthworms feeding on sewage sludge. Fungal communities in earthworm casts primarily included taxa that were absent from sewage sludges, indicating a significant change in fungal composition. Changes in fungal diversity depended on the source of sewage sludge (WWTP). All of the sewage sludges contained low levels of fungal pathogens, most of which were significantly reduced or eliminated by earthworms, such as Armillaria, Cystobasidium, Exophiala and Ophiosthoma. Moreover, earthworm gut transit enhanced beneficial (saprotrophic) fungi like Arthrobotrys, Aseroe, Crepidotus and Trichurus. Overall, digestion of sewage sludge by earthworms alone generated a mainly pathogen-free fungal community with a high proportion of saprotrophic taxa, which would enhance nutrient cycling rates. Full article

(This article belongs to the Section Fungal Pathogens)

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14 pages, 1166 KiB

Open AccessArticle

Unravelling the Persistence of the Rare Serovar Salmonella Mikawasima in a Hospital Setting: A Whole-Genome Sequencing Study

by Ivana Ferencak, Ana Gveric Grginic, Tajana Juzbasic, Irena Tabain, Marija Tonkic, Ivana Goic-Barisic, Dragan Juric, Hrvojka Jankovic, Luka Katic and Anita Novak

Pathogens 2025, 14(5), 408; https://doi.org/10.3390/pathogens14050408 - 24 Apr 2025

Abstract

Salmonella Mikawasima is a rare, mainly environmental serovar. In 2020, an outbreak was observed in neonatal and maternal wards of the University Hospital of Split and was established as an endemic until the end of 2024. Using whole-genome sequencing, this study aimed to [...] Read more.

Salmonella Mikawasima is a rare, mainly environmental serovar. In 2020, an outbreak was observed in neonatal and maternal wards of the University Hospital of Split and was established as an endemic until the end of 2024. Using whole-genome sequencing, this study aimed to analyse the phenotypic and genotypic characteristics of S. Mikawasima isolates and to elaborate whether the spread of the same clone occurred. Sequenced isolates were classified as ST2030, with the presence of aminoglycoside and extended spectrum beta-lactam resistance genes. Ten percent of the sequenced isolates exhibit multi-drug resistance. Identified virulence factors that include biofilm formation genes suggest the potential persistence of S. Mikawasima in the hospital environment, while spatial and temporal analysis reveal clonal expansion and possible horizontal transmission between different hospital wards. This study provides a deep understanding of the genomic composition of S. Mikawasima and emphasises the need for more stringent infection prevention measures, especially in vulnerable neonatal and postpartum settings, to mitigate the risk of healthcare-associated infections, and it should be followed by further microbiological and epidemiological investigations to identify the source of infection. Full article

(This article belongs to the Special Issue Emerging and Neglected Pathogens in the Balkans)

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17 pages, 3572 KiB

Open AccessReview

The Relevance of the Predominant Clonal Evolution (PCE) Model for the Molecular Epidemiology and Subspecific Taxonomy of Trypanosoma cruzi

by Michel Tibayrenc

Pathogens 2025, 14(5), 407; https://doi.org/10.3390/pathogens14050407 - 24 Apr 2025

Abstract

The predominant clonal evolution (PCE) model is often misunderstood. Contrary to common belief, it is not restricted to strict mitotic clonality. Instead, it encompasses processes such as selfing, strong homogamy, and various forms of parthenogenesis, as widely acknowledged by researchers studying clonality. Moreover, [...] Read more.

The predominant clonal evolution (PCE) model is often misunderstood. Contrary to common belief, it is not restricted to strict mitotic clonality. Instead, it encompasses processes such as selfing, strong homogamy, and various forms of parthenogenesis, as widely acknowledged by researchers studying clonality. Moreover, the PCE model does not claim that genetic recombination is entirely absent or devoid of epidemiological and evolutionary significance. In this review, I will explore the reciprocal relationship between PCE and molecular epidemiology (strain typing) and discuss the implications of PCE for revising the subspecific nomenclature of Trypanosoma cruzi. Full article

(This article belongs to the Special Issue Chagas Disease: Celebrating the 115th Anniversary of the Discovery of Trypanosoma cruzi)

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14 pages, 1941 KiB

Open AccessArticle

Molecular Characterization of Clinical Isolates of Methicillin-Resistant Staphylococcus aureus from Chonburi, Thailand

by Patcharawalai Wassanarungroj, Panida Nobthai, Sirigade Ruekit, Apichai Srijan, Prawet Sukhchat, Oralak Serichantalergs, John M. Crawford, Brett E. Swierczewski, Sidhartha Chaudhury and Paphavee Lertsethtakarn

Pathogens 2025, 14(5), 406; https://doi.org/10.3390/pathogens14050406 - 24 Apr 2025

Abstract

Staphylococcus aureus (S. aureus), especially methicillin-resistant S. aureus (MRSA), remains a major public health concern. This study reports the antimicrobial resistance profiles and molecular characteristics of 31 S. aureus isolated during 2017–2018 from inpatient and outpatient clinical specimens from Queen Sirikit [...] Read more.

Staphylococcus aureus (S. aureus), especially methicillin-resistant S. aureus (MRSA), remains a major public health concern. This study reports the antimicrobial resistance profiles and molecular characteristics of 31 S. aureus isolated during 2017–2018 from inpatient and outpatient clinical specimens from Queen Sirikit Naval Hospital (QSH) in Chonburi province, Thailand. All isolates were tested for antimicrobial susceptibility. Staphylococcal cassette chromosome mec (SCCmec) typing, Panton–Valentine leukocidin (pvl) toxin, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and staphylococcal protein A (spa) typing were performed. Twenty-seven isolates were confirmed to be MRSA and exhibited resistance to up to seven antibiotics classes. The main MLST type was SCCmec type II (51.9%) and ST764 (55.6%). Five spa types were identified with t045 (55.6%) as the major type. All 31 S. aureus isolates were grouped into seven types using PFGE with the SCCmecII-ST764-t045 clone being the most prevalent. Overall, our findings reveal that the S. aureus isolates in this study differ from previous reports in Thailand, indicating a potential shift in local strains, highlighting the need for ongoing molecular surveillance of multidrug resistance patterns of MRSA in Southeast Asia. Full article

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12 pages, 228 KiB

Open AccessArticle

Determination of Minimum Inhibitory Concentrations of Selected Antibiotics Against Trueperella pyogenes Originated from Bovine Clinical Endometritis

by Ottó Szenci, Ákos Jerzsele, Zoltán Somogyi, Ádám Kerek, Attila Répási, Lea Lénárt and László Makrai

Pathogens 2025, 14(5), 405; https://doi.org/10.3390/pathogens14050405 - 24 Apr 2025

Abstract

Bacteriological examination of uterine secretions provides essential information for the prevalence of bovine uterine pathogens and their influence on fertility. The objective of the present study was to determine the uterine pathogens in cases of clinical endometritis in two Holstein-Friesian dairy farms between [...] Read more.

Bacteriological examination of uterine secretions provides essential information for the prevalence of bovine uterine pathogens and their influence on fertility. The objective of the present study was to determine the uterine pathogens in cases of clinical endometritis in two Holstein-Friesian dairy farms between 21 and 27 days after calving and the minimum inhibitory concentration (MIC) of 14 antimicrobials for Trueperella pyogenes (T. pyogenes). Overall, the prevalence of T. pyogenes (Farms A and B) was 46.3% and 22% (p < 0.01), respectively. In contrast, Farm B had significantly more cases (p < 0.001) of Escherichia coli, but the distribution of uterine pathogens was similar. Regarding the prevalence of any bacteria, Farm B also had significantly more bacteria (p < 0.001) than Farm A. T. pyogenes isolates were highly susceptible to amoxicillin, amoxicillin/clavulanic acid, tylosin, and cephalosporins, such as ceftiofur, cefquinome, and cephalexin with MIC₉₀ of ≤2 μg/mL. At the same time, MIC₉₀ of tulathromycin, lincomycin, and florfenicol were between 4 and 8 μg/mL and of doxycycline, enrofloxacin, oxytetracycline, and gentamicin, were between 16 and 32 μg/mL, respectively. Meanwhile, sulfamethoxazole/trimethoprim showed the highest MIC₉₀ (>32 μg/mL). In summary, T. pyogenes with high MIC₉₀ against oxytetracycline, gentamicin, and sulfamethoxazole/trimethoprim were found, which calls attention to the prudent use of antibiotics. Full article

(This article belongs to the Special Issue Current Progress on Bacterial Antimicrobial Resistance)

13 pages, 3898 KiB

Open AccessArticle

Enhanced Biofilm Disruption in Methicillin-Resistant Staphylococcus aureus Using Rifampin and Fluoroquinolone Combinations

by Yu Ri Kang, Joo-Young Park, Doo Ryeon Chung, Minhee Kang, Jae-Hoon Ko, Kyungmin Huh, Sun Young Cho, Cheol-In Kang and Kyong Ran Peck

Pathogens 2025, 14(5), 404; https://doi.org/10.3390/pathogens14050404 - 23 Apr 2025

Abstract

Staphylococcus aureus biofilms complicate the treatment of device-related infections. We hypothesized that combining rifampin with fluoroquinolones could eradicate biofilms even in antimicrobial-resistant S. aureus strains. We determined the synergistic interactions of these combinations in a biofilm model. Thirty methicillin-resistant S. aureus (MRSA) isolates [...] Read more.

Staphylococcus aureus biofilms complicate the treatment of device-related infections. We hypothesized that combining rifampin with fluoroquinolones could eradicate biofilms even in antimicrobial-resistant S. aureus strains. We determined the synergistic interactions of these combinations in a biofilm model. Thirty methicillin-resistant S. aureus (MRSA) isolates with varying susceptibility profiles were evaluated. Minimum biofilm eradication concentrations (MBECs) were determined using the Calgary Biofilm Device, and the synergy was assessed using the fractional biofilm eradication concentration (FBEC) index. Scanning electron microscopy (SEM) was performed on one strain, and confocal laser scanning microscopy (CLSM) was conducted on four strains for visualizing and evaluating the biofilm viability. The MBEC₉₀ for rifampin and levofloxacin were 512 mg/L and 256 mg/L, respectively, and exceeded 1024 mg/L for ciprofloxacin. Synergy was observed in 56.7% of strains for both the rifampin + ciprofloxacin and rifampin + levofloxacin combinations, with no difference between the combinations. A higher ciprofloxacin MBEC (≥16 mg/L) increased the likelihood of synergy with rifampin by 18-fold. SEM and CLSM analyses in a subset of strains confirmed the enhanced biofilm disruption with rifampin + ciprofloxacin compared to ciprofloxacin alone. Our findings suggest that rifampin combined with ciprofloxacin or levofloxacin may synergistically eradicate MRSA biofilms, offering a potential treatment option for device-related infections when alternatives are limited. Full article

(This article belongs to the Special Issue Antibiotics, Antibiotic Alternatives, and Combination Antimicrobial Therapy (Volume 2))

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10 pages, 2019 KiB

Open AccessBrief Report

Molecular Differentiation and Detection of AMR Genes from Nosocomial Staphylococcus spp.

by Isabelle Carneiro, Wellington Luiz Pontes da Silva, Debora Ribeiro de Souza Santos and Ivano de Filippis

Pathogens 2025, 14(5), 403; https://doi.org/10.3390/pathogens14050403 (registering DOI) - 23 Apr 2025

Abstract

Staphylococcus spp. is a major nosocomial pathogen, particularly affecting immunocompromised patients and infants. It is associated with bacteremia, endocarditis, and co-infections. Methicillin-resistant Staphylococci (MRS) carry the mecA gene, encoding PBP2a, which confers resistance to beta-lactam antibiotics. The aim of this study is to [...] Read more.

Staphylococcus spp. is a major nosocomial pathogen, particularly affecting immunocompromised patients and infants. It is associated with bacteremia, endocarditis, and co-infections. Methicillin-resistant Staphylococci (MRS) carry the mecA gene, encoding PBP2a, which confers resistance to beta-lactam antibiotics. The aim of this study is to investigate resistance profiles and develop a molecular method to identify nosocomial Staphylococcus spp. strains. A total of 64 strains from public hospitals in Rio de Janeiro were analyzed using phenotypic and molecular methods, with 17 classified as MDR. Different melting temperatures (Tm) were obtained through qPCR-HRM analysis, to identify S. aureus- (70.4 °C), S. haemolyticus- (79 °C), S. epidermidis- (74.1 °C) and mecA (70.5 °C)-positive strains (MRS). The mecA gene was detected in 51 strains, with 22 showing SCCmec type IV. The spread of MRSA and MDR Staphylococci, particularly MDR S. haemolyticus, is a growing concern. In our study, among 64 Staphylococci strains, only 11 were susceptible to methicillin, showing the continuous emergence of resistant strains. qPCR-HRM is a cost-effective, sensitive and fast method for rapid Staphylococcus spp. identification, aiding in nosocomial infection control. Full article

(This article belongs to the Special Issue Nosocomial Infections and Antimicrobial Resistance: Challenges and Solutions)

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19 pages, 3425 KiB

Open AccessArticle

Microbiological Risks to Health Associated with the Release of Antibiotic-Resistant Bacteria and β-Lactam Antibiotics Through Hospital Wastewater

by Andres E. Nolasco-Rojas, Eder Cruz-Del-Agua, Clemente Cruz-Cruz, Miguel Ángel Loyola-Cruz, Benjamín A. Ayil-Gutiérrez, María C. Tamayo-Ordóñez, Yahaira de J. Tamayo-Ordoñez, Araceli Rojas-Bernabé, Francisco A. Tamayo-Ordoñez, Emilio M. Durán-Manuel, Marianela Paredes-Mendoza, Laura M. Márquez-Valdelamar, Carlos A. Jiménez-Zamarripa, Esther Ocharan-Hernández, Paola B. Zárate-Segura, Omar García-Hernández, Oscar Sosa-Hernández, Enzo Vásquez-Jiménez, Claudia C. Calzada-Mendoza and Juan M. Bello-López

Pathogens 2025, 14(5), 402; https://doi.org/10.3390/pathogens14050402 - 23 Apr 2025

Abstract

Hospital wastewater (HWW) is a major source of microbiological contamination, often released into the municipal sewage system without prior treatment. This HWW may contain pathogens with antimicrobial resistance, posing risks to public health. The aim of this work was to assess the risks [...] Read more.

Hospital wastewater (HWW) is a major source of microbiological contamination, often released into the municipal sewage system without prior treatment. This HWW may contain pathogens with antimicrobial resistance, posing risks to public health. The aim of this work was to assess the risks associated with the seasonal release of ESKAPE bacteria resistant to β-lactam antibiotics and the release of carbapenems and cephalosporins through HWW of Hospital Juárez de México. The 12-month seasonal variation in β-lactam-resistant bacterial populations was assessed in the HWW of five discharge points. Resistant isolates were identified by mass spectrometry (MALDI-TOF) coupled with PCR assays to search for antimicrobial resistance genes, while β-lactamic antibiotics were detected using high-performance liquid chromatography (HPLC). Finally, a double-entry Vester matrix was constructed to classify the problems of HWW according to their degree of causality. Seasonal differences in bacterial loads were observed, with higher levels in warmer months. A wide variety of resistant pathogens were identified, including ESKAPE bacteria, as well as emerging bacteria carrying β-lactamase-encoding genes. The release of meropenem was detected most commonly, followed by cefepime and ceftazidime. The Vester matrix allowed the identification of critical clinical and environmental scenarios where two discharge points contribute significantly to the spread of microbiological contamination. This study highlights the importance of proper management of HWW and the need for stricter regulations to reduce the risks associated with the release of resistant pathogens with health impacts. Full article

(This article belongs to the Special Issue Nosocomial Infections and Antimicrobial Resistance: Challenges and Solutions)

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16 pages, 1077 KiB

Open AccessArticle

Antimicrobial Evaluation of Asphodelus microcephalus Extracts and Fine Powder of Dried Organs Against Fusarium and Oomycetes Responsible for Apple and Peach Decline Disease

by Sabrine Mannai and Naima Boughalleb-M’Hamdi

Pathogens 2025, 14(5), 401; https://doi.org/10.3390/pathogens14050401 - 22 Apr 2025

Abstract

Seedlings root and collar rot is an important disease that causes a reduction in plant production. The goal of this investigation was to evaluate the in vitro and in vivo efficiency of powdered preparation of dried Asphodelus microcephalus of fruits (PPDF), leaves (PPDL), [...] Read more.

Seedlings root and collar rot is an important disease that causes a reduction in plant production. The goal of this investigation was to evaluate the in vitro and in vivo efficiency of powdered preparation of dried Asphodelus microcephalus of fruits (PPDF), leaves (PPDL), and roots (PPDR) against species of Fusarium and Pythiaceaes associated with this disease in Tunisian nurseries. The in vitro tests of methanolic and aqueous extracts of different Asphodelus organs showed their efficacy in reducing the pathogen mycelium growth. The in vivo assay of powdered preparation of this dried plant revealed that its effect depends on the pathogens, Asphodelus organs, and the period duration between the treatment and inoculation of seedlings. This study showed that this plant has some positive effects, such as disease severity reduction and plant growth stimulation. In fact, for Fusarium solani, the powder of different organs of Asphodelus was used one week before the plantation, and inoculation significantly improved the peach plant’s height. The treatments eight weeks before the inoculation enhanced the root weight of the plants. Meanwhile, the PPDL and PPDR were used eight weeks before the plantation, and inoculation induced the plant disease index. However, the A. microcephalus treatments also have some toxic effects on peach and apple seedlings, such as the improvement of root browning induced by some pathogens. Full article

(This article belongs to the Section Fungal Pathogens)

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8 pages, 2999 KiB

Open AccessCommunication

Diagnosis of Community-Acquired Pneumonia Due to Influenza or Respiratory Syncytial Virus: Evaluation of RT-PCR Sensitivity in Nasopharyngeal, Saliva, and Sputum Samples

by Julio Ramirez, Stephen Furmanek, Thomas Chandler, Ruth Carrico, Ashley Wilde, Alan Junkins and Anupama Raghuram

Pathogens 2025, 14(5), 400; https://doi.org/10.3390/pathogens14050400 - 22 Apr 2025

Abstract

Detection of viral RNA in nasopharyngeal (NP) samples by reverse transcription polymerase chain reaction (RT-PCR) is the standard diagnostic test for influenza or respiratory syncytial virus (RSV) in hospitalized patients with community-acquired pneumonia (CAP). This study compared the sensitivity of RT-PCR using NP [...] Read more.

Detection of viral RNA in nasopharyngeal (NP) samples by reverse transcription polymerase chain reaction (RT-PCR) is the standard diagnostic test for influenza or respiratory syncytial virus (RSV) in hospitalized patients with community-acquired pneumonia (CAP). This study compared the sensitivity of RT-PCR using NP swab, saliva, and sputum samples for the diagnosis of CAP due to influenza or RSV. A total of 60 patients were evaluated, of which 40 (67%) had influenza CAP, 19 (32%) had RSV CAP, and one patient (1%) had both RSV and influenza CAP. RT-PCR on NP swab, saliva, and sputum samples was performed using the Luminex ARIES platform. In patients with influenza CAP, the sensitivity was 34% for NP swabs, 68% for saliva, and 71% for sputum. In patients with RSV CAP, the sensitivity was 60% for NP swabs, 75% for saliva, and 85% for sputum. RT-PCR of nasopharyngeal swab samples was associated with a significant number of false negative results. A negative NP swab RT-PCR test should not be used to rule out CAP due to influenza or RSV. Saliva and sputum samples should be considered when performing a microbiological work-up in patients with suspected influenza or RSV CAP. Full article

(This article belongs to the Section Viral Pathogens)

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