MicrobiologyOpen最新文献

{"title":"Of Commensals and Opportunists: Genomics of Coagulase-Negative Staphylococci During Sequential Ear and Eye Infections in a Healthy Adult","authors":"Soo Sum Lean,&nbsp;Chew Chieng Yeo,&nbsp;Zain Illyaaseen,&nbsp;Sargit Kaur,&nbsp;Yun Fong Ngeow,&nbsp;Stuart C. Clarke,&nbsp;Hien Fuh Ng","doi":"10.1002/mbo3.70277","DOIUrl":"10.1002/mbo3.70277","url":null,"abstract":"<p>Coagulase-negative staphylococci (CoNS) are ubiquitous skin commensals but can cause opportunistic infections and may serve as reservoirs for mobile genetic elements such as the staphylococcal cassette chromosome <i>mec</i> (SCC<i>mec</i>) associated with healthcare-adapted lineages. In this longitudinal, single-participant case study, we characterized CoNS isolates obtained over time from a healthy 32-year-old male who experienced two infection episodes 6 months apart (left ear, followed by the left eye), together with post-recovery sampling from additional body sites. Six CoNS isolates were recovered, tested for antimicrobial susceptibility and subjected to whole-genome sequencing. Genome-based identification showed that the ear and arm isolates were <i>Staphylococcus capitis</i> (subsp. <i>urealyticus</i> and subsp. <i>capitis</i>), whereas three isolates from the symptomatic left eye were <i>Staphylococcus epidermidis</i>. The three <i>S. capitis</i> isolates belonged to distinct sequence types (ST1, ST2, and ST10), while the three <i>S. epidermidis</i> isolates shared a novel sequence type, ST1284. A non-typable, mosaic SCC<i>mec</i> type IV element homologous to SCC<i>mec</i> IVa/IVn was identified in the multidrug-resistant <i>S. capitis</i> subsp. <i>urealyticus</i> ST1 isolate E_e2, recovered from the infected ear. Core-genome phylogeny and genomic signatures placed E_e2 within the proto-NRCS-A clade, indicating that a lineage closely related to hospital-associated outbreak strains can be encountered in a community-dwelling individual without known prior healthcare exposure. These findings provide a within-host genomic snapshot of CoNS dynamics across contiguous anatomical sites, and while the study does not establish causality for infection or permit population-level inference, it highlights the need for broader, systematic community surveillance of CoNS lineages and their mobile genetic elements.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70277","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147593110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Pilot Study on the Prevalence and Characterization of Multidrug-Resistant Gram-Negative Bacteria in Chicken and Pork Meat Around Kathmandu District, Nepal","authors":"Sushma Paudel,&nbsp;Sumitra Tamang,&nbsp;Preety Singh,&nbsp;Rishav Das,&nbsp;Sushmita Paudel,&nbsp;Astha Shakya","doi":"10.1002/mbo3.70275","DOIUrl":"10.1002/mbo3.70275","url":null,"abstract":"<p>The increasing trend of multidrug resistance in Gram-negative bacteria (MDR-GNB) has been a major concern for the healthcare settings in Nepal and globally. In Nepal, previous studies on antimicrobial resistance (AMR) have received limited attention to animal-sourced food, which represents a significant route for the zoonotic transmission of antibiotic-resistant pathogens. This study aimed to assess antibiotic resistance and multidrug resistance patterns of Gram-negative bacteria isolated from intestinal and gizzard samples of chicken and pork meat collected from five municipalities in Kathmandu. From 13 samples (11 chicken and 2 pork), a robust collection of 136 Gram-negative bacteria was isolated and subjected to susceptibility testing against 16 different antibiotics. The bacterial isolates, representing 11 distinct types, were successfully identified: <i>Escherichia coli</i> (33.82%) and <i>Shigella</i> spp. (11.76%) were the predominant bacteria, followed by <i>Yersinia</i> (8.8%), <i>Citrobacter</i> (8.8%), <i>Proteus</i> (8.8%), <i>Klebsiella</i> (5.1%), and <i>Plesiomonas</i> (5.1%), among others. Notably, the prevalence of multidrug-resistant bacteria was notably high, with half (50%) of the isolates exhibiting resistance to multiple classes of antibiotics. Additionally, 73.9% of <i>E. coli</i>, 14.28% of <i>Klebsiella</i>, 58.33% of <i>Yersinia</i>, and 41.67% of <i>Citrobacter</i> are found to be multidrug resistant. Thus, this study showed that the meat samples exhibited a high burden of MDR-GNB, indicating a high risk of food-borne illness and zoonotic transmission, calling for AMR monitoring and mitigation strategies.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70275","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147530775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacillus cereus Induces Necroptosis in Microglia via the RIPK1/3-MLKL Pathway","authors":"Jing Yang,&nbsp;Bianjin Sun,&nbsp;Huijing Xu,&nbsp;Yangyang Shen,&nbsp;Huili Ye,&nbsp;Qiheng Yuan,&nbsp;Siwen Chen,&nbsp;Meiqin Zheng","doi":"10.1002/mbo3.70276","DOIUrl":"10.1002/mbo3.70276","url":null,"abstract":"<p><i>Bacillus cereus</i> endophthalmitis is a rapidly progressing intraocular infection that often results in poor visual outcomes due to extensive retinal damage. Microglia are resident innate immune cells in the brain and retina that play critical roles in neurological and ocular diseases. To investigate the functional role and mechanisms of microglia during <i>B. cereus</i> infection, we established an in vitro microglial infection model using murine BV2 and human HMC3 cells. <i>B. cereus</i> infection reduced microglial viability and induced membrane rupture. Transcriptome analysis revealed enrichment of inflammatory and cell death. Flow cytometric screening identified that the RIPK1 inhibitor Nec-1 rescued cell death. Mechanistically, <i>B. cereus</i> increased phosphorylation of RIPK3 and MLKL, which was abolished by Nec-1. Moreover, Nec-1 suppressed <i>B. cereus</i>-induced secretion of IL-1β, IL-6, and TNF-α. In summary, this study demonstrates that <i>B. cereus</i> induces microglial necroptosis by activating the RIPK3/MLKL pathway, providing a new mechanism for neuroinflammation caused by related infections.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70276","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147521234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging Antimicrobial Resistance in Klebsiella pneumoniae: A Molecular and Antibiogram Insight From the Beef Value Chain in Bangladesh","authors":"Md Sodor Uddin,&nbsp;Fahmida Jahan Fahim,&nbsp;Sohel Rana,&nbsp;Abdullah Al Kafi,&nbsp;Jobaida Khanam,&nbsp;Md Nazim Uddin,&nbsp;Md Masudur Rahman,&nbsp;Monira Noor,&nbsp;Md Mukter Hossain,&nbsp;Md Mahfujur Rahman,&nbsp;Md Bashir Uddin,&nbsp;Ferdaus Mohd Altaf Hossain","doi":"10.1002/mbo3.70263","DOIUrl":"10.1002/mbo3.70263","url":null,"abstract":"<p><i>Klebsiella pneumoniae</i> is an opportunistic pathogen linked to rising antimicrobial resistance (AMR) globally. To assess the antimicrobial resistance pattern and biofilm-forming ability of <i>K. pneumoniae</i>, a total of 240 samples were collected from slaughterhouses, open butcher shops, wet market selling points, and high-grade, medium-grade, and poor-grade restaurants in Dhaka City Corporation (DCC) and Gazipur City Corporation (GCC). Among the samples, 132 (55%) samples were positive for <i>K. pneumoniae</i>, with the highest prevalence (60%) in raw beef from GCC. The antibiogram profile depicted diverse resistance patterns with the highest resistance pattern to ampicillin (100%), amoxicillin (100%), and cefoxitin (87.12%). All isolates exhibited a multiple antibiotic resistance index (MARI) value greater than 0.2, indicating contamination from high-risk sources. The antimicrobial resistance encoding genes were <i>bla</i>_<i>BIC</i> and <i>bla</i>_<i>IMP</i>, were 54% and 36%, respectively. Phenotypic characterization, utilizing Congo red agar and microtiter plate tests, identified 25 out of 132 (19%) isolates as biofilm producers, with 7 (28%) classified as strong producers, and 3 (12%) and 15 (60%) as intermediate and weak producers, respectively. This study addresses the alarming emergence of antimicrobial resistance within the beef value chain in Bangladesh, posing an alarming threat to food safety and public health associated with biofilm-producing foodborne pathogens, underscoring the necessity for improved hygiene practices to mitigate the public health risk posed by these pathogens.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70263","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147513346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NCY-1 β-Lactamase Activity Correlates With Antimicrobial Susceptibility of a Clinical Strain of Nocardia cyriacigeorgica","authors":"Julie Couston,&nbsp;Athénaïs Le Marchand,&nbsp;Elisabeth Hodille,&nbsp;Charlotte Genestet,&nbsp;Brune Joannard,&nbsp;Jérôme Feuillard,&nbsp;Yvonne Benito,&nbsp;Oana Dumitrescu,&nbsp;Mickaël Blaise","doi":"10.1002/mbo3.70267","DOIUrl":"10.1002/mbo3.70267","url":null,"abstract":"<p>Nocardiosis is an infectious disease caused by several <i>Nocardia</i> species, among which <i>Nocardia cyriacigeorgica</i> is one of the most frequently isolated species in the clinic. Albeit most isolates of this species are susceptible to standard treatment combining trimethoprim and sulfamethoxazole, resistance has been reported, necessitating alternative or combination therapies. β-lactam antibiotics are of particular interest in this context. In this study, we aimed to address the β-lactam susceptibility profile of a clinical strain of <i>N. cyriacigeorgica</i> and assessed whether it correlated with the enzymatic activity of purified β-lactamase of the strain. We herein established that the strain is highly susceptible to imipenem and ceftriaxone, moderately susceptible to meropenem and resistant to amoxicillin. The resistance could be counteracted by β-lactamase inhibitors from two distinct chemical classes: vaborbactam, and avibactam while clavulanate was less potent. We demonstrated that the β-lactam susceptibility of the strain is in direct line with the enzymatic activity of purified NCY-1, a class A β-lactamase. NCY-1 was indeed only active with amoxicillin but displayed poor activity towards other classes of β-lactams. The NCY-1 activity could be inhibited <i>in vitro</i> by vaborbactam, clavulanate, and avibactam. We consolidated these data by determining the high-resolution structure of NCY-1 bound to avibactam. The structural analysis supported a conserved inhibitor binding site among other <i>Nocardia</i> class A β-lactamases strongly suggesting a broad inhibition spectrum of avibactam across <i>Nocardia</i> species.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70267","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147486527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-Genome Sequence Profiling of Listeria innocua From Different Sources: Implications for Public Health","authors":"Christ-Donald Kaptchouang Tchatchouang,&nbsp;Daniel Jesuwenu Ajose,&nbsp;Giulia Amagliani,&nbsp;Collins Njie Ateba","doi":"10.1002/mbo3.70274","DOIUrl":"10.1002/mbo3.70274","url":null,"abstract":"<p>Foodborne disease outbreaks, particularly those associated with antimicrobial-resistant (AMR) bacterial pathogens, have become an issue of severe public health concern owing to increased globalisation and active food trade among countries. These disease outbreaks include listeriosis, which can cause notable complications such as diarrhoea, headaches, and vomiting. The data generated during the South African foodborne outbreak caused by AMR <i>Listeria monocytogenes</i> led to the inclusion of listeriosis on the South African list of mandatory notifiable medical conditions. Prospective solution to managing the increasing threat caused by AMR foodborne pathogens to humans require frequent surveillance of food products using techniques with high throughput and discriminatory potential. Thus, this study assessed the virulome, resistome, and phylogenetics of two <i>Listeria innocua</i> strains (LIN_NWU_CNKT and LIN5_NWU_CNKT) previously isolated from food and water samples collected in the North-West Province, South Africa, using whole-genome sequencing (WGS). Based on WGS analysis, the isolates were confirmed as <i>L. innocua</i>, with genomes that are closely related to previously isolated human pathogens. The genomes of these two isolates harboured virulence genes, including those responsible for adherence (<i>fbpA</i>, <i>inlJ</i>), invasion (<i>aut</i>, <i>inlA</i>), and immune modulation (<i>inlC</i>, <i>lntA</i>). In addition, the genes encoding antibiotic resistance were found in the genomes. These genes confer resistance to antibiotics such as phosphonic acid (<i>fosX</i>), lincosamide (<i>lin</i>), tetracycline (<i>tetM</i>), and glycopeptide (<i>vanT</i>). These findings highlight a crucial need to enforce standard operating procedures in food processing to reduce the spread of AMR and foodborne outbreaks.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70274","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147486691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tn-seq of Thermus thermophilus Genome Reveals Unexpected Tolerance to Insertions in Bacterial Common Essential Genes","authors":"Cristina L. Gómez-Campo,&nbsp;Marc Gost,&nbsp;Bruna Fernanda Silva de Sousa,&nbsp;Laura Álvarez,&nbsp;José Berenguer,&nbsp;Modesto Redrejo-Rodríguez,&nbsp;Mario Mencía","doi":"10.1002/mbo3.70207","DOIUrl":"10.1002/mbo3.70207","url":null,"abstract":"<p>A large library based on a Tn<i>5</i> minitransposon carrying a thermostable kanamycin resistance gene was prepared using <i>Thermus thermophilus</i> HB27 genomic DNA as target. To increase the yield of transformants, DNA from the <i>in vitro</i> transposition reaction was amplified using isothermal multiple displacement amplification. The resulting product was first transformed into the high-transformation efficiency <i>addAB/ppol</i> strain and then into a wild-type HB27 strain. Tn-seq analysis of the libraries showed that almost all genes contained insertions and the distribution of the number of insertions per gene was unimodal, unlike the bimodal distribution reported in most Tn-seq analyzes, thus hindering the discrimination of required or essential genes. Upon comparing the Tn-seq results with gene conservation in pangenomic analysis from <i>Thermus thermophilus</i> to <i>Deiococcota</i> levels, as well as with available HB27 RNA-seq data, we observed a very low correlation between core genes or gene transcription levels and Tn-seq insertion frequency. Notably, many genes largely deemed part of the essential bacterial core, supporting critical cellular pathways, showed relatively high transposon insertion numbers. In the case of DNA repair routes, which are essential but somewhat redundant, our results align well with previously published essentiality data, indicating that many genes are dispensable and permissive to insertions. The analysis of these striking results in the context of <i>Thermus</i> biology suggests that the polyploidy of the <i>Thermus</i> genome and the differential stability of proteins may explain the apparent non-essentiality of key genes.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147481171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quercetin: A Light in the Fight Against MRSA","authors":"Maria Poliana Leite Galantini,&nbsp;Caroline Vieira Gonçalves,&nbsp;Amanda Kelle Santos Novaes,&nbsp;Caio Oliveira Lopes de Magalhães,&nbsp;Igor Pereira Ribeiro Muniz,&nbsp;Israel Souza Ribeiro,&nbsp;Paulo Henrique Bispo Lima,&nbsp;Maria Elisa Santos Flores,&nbsp;Artur Reis Carvalho,&nbsp;Luisa Carregosa Santos,&nbsp;Daiana Silva Lopes,&nbsp;Juliano Geraldo Amaral,&nbsp;Robson Amaro Augusto da Silva","doi":"10.1002/mbo3.70090","DOIUrl":"10.1002/mbo3.70090","url":null,"abstract":"<p>Antimicrobial photodynamic therapy (aPDT) for treating methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) infections has gained increasing attention in recent years. This study aimed to evaluate the potential of quercetin as a photosensitizer for aPDT. In vitro assays were conducted to assess the cytotoxicity and the antibacterial activity of quercetin photoactivated with blue LED light. In in vivo assays, and intradermal infection model was conducted in mice to evaluate the quercetin antimicrobial activity and cytokine production. The in vitro experiments showed low compound toxicity and antimicrobial activity accompanied by the generation of singlet oxygen. BALB/c mice infected with MRSA and treated with quercetin exhibited a reduced bacterial load in the draining lymph nodes and decreased recruitment of polymorphonuclear cells at the infection site. In response to infection, a strong interaction between the cytokines IL-12 and TNF-α was observed in the groups treated with quercetin. These observations support quercetin's anti-inflammatory and antimicrobial potential in infections with resistant strains of MRSA.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70090","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147468487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionomycin Exhibits Potent and Selective Bactericidal Activity Against Clostridioides difficile Through Calcium-Dependent Membrane Disruption","authors":"Ahmed A. Abouelkhair,&nbsp;Nader S. Abutaleb,&nbsp;Mohamed N. Seleem","doi":"10.1002/mbo3.70269","DOIUrl":"10.1002/mbo3.70269","url":null,"abstract":"<p><i>Clostridioides difficile</i> represents a critical global health concern due to its high morbidity, mortality, and recurrent infections associated with current therapeutic options. There is an urgent need for novel, selective anti-<i>C. difficile</i> therapeutic agents. Screening the microbial metabolite library against <i>C. difficile</i> identified ionomycin, a calcium ionophore produced by <i>Streptomyces conglobatus</i>, as a potent inhibitor for <i>C. difficile</i>. Ionomycin exhibited potent activity against 30 <i>C. difficile</i> isolates, with minimum inhibitory concentrations of 1 μg/mL and 2 μg/mL against 50% (MIC₅₀) and 90% (MIC₉₀) of isolates, respectively. Time-kill assays revealed rapid bactericidal activity, achieving a ≥ 3 log₁₀ reduction within 8 h, surpassing the efficacy of vancomycin and fidaxomicin. At subinhibitory concentrations, ionomycin markedly reduced toxin production (~20%) and spore formation (~3 log₁₀ CFU/mL). Moreover, ionomycin exerted a potent activity against <i>C. difficile</i> spore germination and significantly prevented the toxin production from the germinating <i>C. difficile</i> cells. Importantly, ionomycin displayed limited activity against representative gut microbiota strains, indicating a favorable selectivity profile. Mechanistic investigations revealed a calcium-dependent mode of action, as exogenous calcium enhanced ionomycin-mediated bactericidal activity, whereas calcium chelation attenuated its effects. Consistent with this mechanism, ionomycin disrupted <i>C. difficile</i> membrane potential, an effect that was further potentiated by calcium supplementation. Collectively, these findings identify ionomycin as a potent and selective anti-<i>C. difficile</i> agent with a distinct calcium-dependent mechanism of action, supporting its potential as a promising therapeutic candidate warranting further investigation.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147474453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Farm-Level Factors Associated With Multidrug-Resistant Escherichia coli and Klebsiella spp. in Bulk Tank Milk in Tigray, Northern Ethiopia","authors":"Goyitom Gebremedhn Gebru,&nbsp;Saravanan Muthupandian,&nbsp;Enquebaher Kassaye","doi":"10.1002/mbo3.70265","DOIUrl":"10.1002/mbo3.70265","url":null,"abstract":"<p>Raw milk is widely consumed unpasteurized in Ethiopia, posing food safety risks when contaminated with multidrug-resistant (MDR) bacteria. This study investigated farm-level factors associated with the occurrence of MDR <i>Escherichia coli</i> and <i>Klebsiella</i> spp. in bulk tank raw milk from dairy farms in the Tigray region, Northern Ethiopia. A cross-sectional study was conducted among 178 dairy farms, combining microbiological analysis of bulk tank milk with data on farm hygiene, animal health, and antimicrobial use (AMU) practices. A total of 119 isolates (70 <i>E. coli</i> and 49 <i>Klebsiella</i> spp.) were recovered, of which 32.8% were classified as MDR. Multivariable analysis showed that infrequent washing of milking utensils (once daily or less) was strongly associated with MDR-positive milk (adjusted odds ratio [AORs] = 7.41; 95% CI, 1.94–28.31). Self-administration of antimicrobials by farm owners (AOR = 3.73; 95% CI, 1.48–9.39) and a history of mastitis in the herd (AOR = 4.79; 95% CI, 1.39–16.52) were also independently associated with MDR occurrence, while herd size was not significantly associated. The presence of MDR <i>E. coli</i> and <i>Klebsiella</i> spp. in raw milk represents a significant food safety concern in smallholder dairy systems. Targeted interventions focusing on improved milking hygiene, responsible AMU under veterinary supervision, and effective mastitis management are essential to reduce the entry of resistant bacteria into the dairy value chain and limit consumer exposure.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 2","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70265","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147468549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}