The Microbe最新文献

{"title":"The house that Kocuria built: A potential role for functional amyloid in the unique cube-based structure of K. varians biofilms","authors":"Daniel E. Otzen ,&nbsp;Gabriel Antonio S. Minero ,&nbsp;Henriette L. Røder ,&nbsp;Anders M. Torp ,&nbsp;Jakob Herschend ,&nbsp;Lotte G. Nielsen ,&nbsp;Olena Moshynets ,&nbsp;Janni Nielsen ,&nbsp;Rikke L. Meyer ,&nbsp;Morten K.D. Dueholm ,&nbsp;Mette Burmølle","doi":"10.1016/j.microb.2026.100676","DOIUrl":"10.1016/j.microb.2026.100676","url":null,"abstract":"<div><div>Biofilm is the dominant growth mode of microorganisms, providing protection, surface adhesion and synergy between co-habiting organisms. Many aspects of biofilm formation and architecture remain unknown and vary greatly among different species. Proteins that self-assemble into highly stable extracellular cross-β structures, known as amyloids, mechanically strengthen biofilm in various species, including <em>Escherichia coli</em> and <em>Pseudomonas</em> spp. Previously, we demonstrated that the microbial strain <em>Kocuria varians</em> G6, isolated from a food processing facility surface in a slaughterhouse, was able to engage in multi-species biofilms. Here we investigate the biofilm formation of <em>Kocuria varians</em> G6. We found that <em>K. varians</em> G6 forms a unique biofilm structure composed of unique cube-shaped clusters, which over time expand and at a specific time-point burst to release cells that then form a biofilm covering the surface. The cube surfaces bind Thioflavin T and Proteostat, suggesting the presence of amyloid as structural components. Further support for this was obtained from (a) reduced cube size when these were exposed to epigallocatechin-3-gallate (EGCG), a compound known to prevent amyloid polymerization and (b) a dense network of thin fibrils surrounding individual cells which were sensitive to both EGCG and proteinase K. We were unable to identify the potential amyloid monomer by comparative proteome analysis of whole-cell lysates with and without traditional amyloid depolymerization, indicating that the amyloids are highly stable or simply not detected by our proteome approach. This work expands our understanding of biofilm structural diversity and indicates a previously unreported role for amyloids in spatially patterned bacterial architectures.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100676"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterization of the BK polyomavirus early coding region in kidney transplant recipients in Vietnam","authors":"Thi Thu Hang Dinh ,&nbsp;Thu Ha Hoang ,&nbsp;Xuan Su Hoang","doi":"10.1016/j.microb.2026.100693","DOIUrl":"10.1016/j.microb.2026.100693","url":null,"abstract":"<div><div>The early coding region of BK polyomavirus (BKV), encoding the regulatory small T antigen (STAg) and large T antigen (LTAg), has received considerably less attention than the late coding region VP1 capsid gene, which is traditionally employed for BKV genotyping. This study aimed to characterize genetic variation within the BKV early coding region among Vietnamese renal transplant patients and to assess its utility for genotype and subgroup assignment. A total of 42 urine specimens with viral loads ≥ 10⁴ copies/mL were screened, followed by amplification of full-length (∼5.1 kb) viral genomes using long-range PCR. Complete early coding region sequences were obtained from ten clinical samples through Sanger primer walking. Analysis identified 137 single nucleotide variants (SNVs), with 122 localized to LTAg and 15 to STAg. Among these, 95 (77.87%) and 11 (73.33%) SNVs were cluster-defining for LTAg and STAg, respectively. Only ten SNVs resulted in substitutions of amino acids, all of which were genotype-specific. Phylogenetic analyses of STAg, LTAg, and the concatenated early coding region consistently assigned samples to genotype I (subgroup Ib1; n = 7) or genotype IV (subgroups IVa1 and IVc1; n = 3). Genotype-level bootstrap support was high across the early coding region phylogenies (93%-100%), and the concatenated early coding region tree achieved subgroup-level resolution with greater bootstrap support than the full-length VP1 tree. In contrast, the 327-bp VP1 typing fragment resolved only genotype-level clusters. Phylogenies inferred from the early coding region were fully concordant with VP1-based genotyping, supporting its utility as a complementary marker for BKV molecular surveillance. This study provides the first characterization of BKV early coding region diversity in Vietnam and highlights the potential of this region for enhanced genotyping resolution.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100693"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147420162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extraction methods and essential oils properties from (Cinnamomum cassia) and (Syzygium aromaticum): A review","authors":"Hicham EL-BOUKHARY,&nbsp;Hamza EL KISSANY,&nbsp;Adelouahed HAJJAJI","doi":"10.1016/j.microb.2025.100638","DOIUrl":"10.1016/j.microb.2025.100638","url":null,"abstract":"<div><div>The potential of cinnamon and clove essential oils is examined in this article review, highlighting the rich chemical makeup of these essential oils and important components like eugenol and trans-cinnamaldehyde that support their capacity to counteract microbial drug resistance. The essential oils exhibit a broad biological activities, such as antiviral, antifungal, antibacterial, and anti-inflammatory qualities. As a result, they present an affordable and environmentally beneficial substitute for treating pathogens resistant to multiple drugs. Additionally, improvements in extraction methods, such as supercritical CO₂ extraction and microwave-assisted extraction, improve these essential oils' chemical composition and yield, making them attractive candidates for future study and use in the fight against resistant strains of bacteria, viruses, and fungi. This review aimed to highlight the importance of these essential oils and their compounds, the ideal techniques to extract them, and illustrate the biological benefits and drug-resistant pathogens.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100638"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association of Entamoeba gingivalis and Trichomonas tenax with Periodontitis in Hepatitis-C virus-Egyptian Infected Patients: A case-control study","authors":"Dina Sabry ,&nbsp;Marwa Abdallah Shaker ,&nbsp;Amira Hassouna ,&nbsp;Sahar ElRefai ,&nbsp;Nehal Diaa ,&nbsp;Ghada A. Saad ,&nbsp;Amany M. Tawfeik ,&nbsp;Haneya A.A. Anani ,&nbsp;Abdelrahman M. Attia ,&nbsp;Asmaa Rashad Ali ,&nbsp;Gena M. El-makromy ,&nbsp;Hala E. Shams El-Din","doi":"10.1016/j.microb.2026.100657","DOIUrl":"10.1016/j.microb.2026.100657","url":null,"abstract":"<div><div>An imbalance in the oral microbiota, known as oral dysbiosis, can lead to periodontitis. Hepatitis C virus (HCV) infections may impact oral health through immune function, diet, and lifestyle alterations, potentially contributing to periodontal disease development. The role of Protozoa in oral dysbiosis is still poorly understood. The contribution of oral Protozoa as <em>Entamoeba gingivalis</em> and <em>Trichomonas tenax</em> in periodontitis in HCV-infected patients has not been adequately invetigated. This research explored their prevalence and association with periodontitis in HCV-infected patients compared to healthy individuals without periodontitis (infected control). Venous blood samples were drawn to measure serum ALT, AST, albumin, urea, creatinine, iron, ferritin, transferrin, and sTfR. Serum and saliva samples were used to measure HCV RNA and detect the oral parasites <em>Entamoeba gingivalis</em> and <em>Trichomonas tenax</em> using polymerase chain reaction (PCR). A total of 242 participants were enrolled in the study, divided into the following groups: HCV patients with periodontitis (n = 73), HCV patients without periodontitis (n = 47), and healthy subjects (n = 122). AST, ALT, and urea were significantly elevated in HCV-infected patients compared to the control group(p &lt; 0.05). However, no significant differences were observed in albumin and creatinine levels between the two groups (p &gt; 0.05). Iron-related parameters were significantly lower in HCV-infected patients compared to the control groups(p &lt; 0.05). The prevalence of <em>T. tenax</em> and <em>E. gingivalis</em> among the HCV patients with periodontitis was 34.2 % (n = 25) and 49.3 % (n = 36), respectively, with a high statistically significant difference compared to the control groups (p &lt; 0.001). While <em>T. tenax</em> positivity only demonstrated a statistically significant positive correlation with HCV copy number in saliva (p &lt; 0.05)., <em>E. gingivalis</em> positivity was significantly correlated with HCV copy number in both serum and saliva samples(p &lt; 0.05). Following HCV treatment, the prevalence of <em>E. gingivalis</em> and <em>T. tenax</em> decreased significantly, from 49.3 % and 34.2–11.0 % and 6.8 %, respectively (p &lt; 0.001). The results showed that HCV patients with periodontitis had a considerably higher prevalence of <em>E. gingivalis</em> and <em>T. tenax</em>, which significantly decreased after HCV treatment. Therefore, the conventional perception of <em>E. gingivalis</em> and <em>T. tenax</em> as harmless symbionts warrants reassessment, as their role in the pathophysiology of periodontal diseases cannot be disregarded.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100657"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the evaluation method on the assessment of the susceptibility of Listeria monocytogenes to quaternary ammonium compounds","authors":"Yarlenis Coello Delgado ,&nbsp;Adrián Gómez Baltazar ,&nbsp;Mauricio Redondo Solano ,&nbsp;Angélica Godínez Oviedo ,&nbsp;Juan Ramiro Pacheco Aguilar ,&nbsp;Montserrat Hernández Iturriaga","doi":"10.1016/j.microb.2025.100654","DOIUrl":"10.1016/j.microb.2025.100654","url":null,"abstract":"<div><div>Rapid and reliable methods are needed to evaluate <em>Listeria monocytogenes</em> resistance to disinfectants. The purpose of this study was to evaluate and compare the susceptibility of <em>L. monocytogenes</em> isolates from food-processing environments to quaternary ammonium compounds (QACs) using agar diffusion methods and suspension and surface challenge tests. <em>L. monocytogenes</em> strains isolated from frozen vegetables– (n = 23), broccoli- (1), cheese- (n = 3), and avocado- (n = 1) processing environments, and ATTC 19115 were used. Strains were characterized for antibiotic susceptibility and screened for <em>bcr</em>ABC and <em>qac</em>H resistance genes. The susceptibility to QACs (50, 200, 500, and 1000 ppm) was evaluated using agar diffusion methods. Growth inhibition zones were measured, and strains were categorized as resistant, intermediate, and sensitive to QACs (500 ppm). Strains were inoculated (10 log CFU/mL) in a QAC suspension (200 ppm/30 s) or on stainless steel (8.4 log CFU/cm²) and exposed to QACs (200 ppm/30 s and 2 min, 500 ppm/30 s and 2 min) and surviving microbial population was quantified. Strain characterization revealed heterogeneous antimicrobial and gene-resistance profiles among <em>L. monocytogenes</em> isolates. The agar well diffusion method showed higher sensitivity than the disc diffusion method (p &gt; 0.05). Based on the agar well diffusion method, isolates were classified as sensitive (≥ 21 mm), intermediate (16 mm ≤zone&lt; 21 mm), or resistant (&lt;16 mm). Regardless of the strain, the suspension method achieved complete inactivation of the microbial population (&gt;9 log CFU/mL), whereas bacterial reductions oscillated from 0.9 to 4.8 log CFU/cm² on stainless steel. A negative correlation (ρ= −0.4) was observed between the agar diffusion methods and the stainless steel surface assay. Agar diffusion methods can be used as rapid and reliable screening tools to assess the QAC susceptibility of <em>L. monocytogenes</em> isolates from food-production environments. The proposed classification based on inhibition zone diameters provides a practical and reproducible approach to interpret susceptibility data in the absence of standardized cut-offs for disinfectants. The stainless steel surface assay remains essential for evaluating disinfection effectiveness in food-processing environments.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100654"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petroleum hydrocarbon concentration as the primary driver of soil bacterial community dynamics during mycorrhizal fungi and rhizobacteria assisted phytoremediation","authors":"Prama Roy ,&nbsp;Daniele D. Silveira ,&nbsp;Jenika Hazell ,&nbsp;Barbara Zeeb","doi":"10.1016/j.microb.2026.100690","DOIUrl":"10.1016/j.microb.2026.100690","url":null,"abstract":"<div><div>Petroleum hydrocarbon (PHC) contamination poses widespread environmental risks in Canada, necessitating effective remediation strategies in the boreal ecozone due to the effects of the cold climate on soil nutrient cycling and weathering processes. This study analyzed rhizobacterial biodiversity and composition during phytoremediation of contaminated field soil (25,700 mg/kg total petroleum hydrocarbons - TPH) collected from a Canadian boreal site where PHCs had weathered in place for 25 + years. Additionally, a 1:1 contaminated: background (diluted) soil (12,600 mg/kg TPH), was used in conjunction with the field-contaminated soil, to investigate the effects on rhizobacterial community composition. In two-year greenhouse experiments, soils were planted with native or naturalized plant species and inoculated with i) arbuscular mycorrhizal fungi (AMF), ii) the biosurfactant-producing and plant-growth-promoting rhizobacterium (PGPR) - <em>Bacillus subtilis</em> ATCC 21332, or iii) both AMF and <em>B. subtilis</em>. PHC contamination exerted a dominant influence on rhizobacterial community composition. Alpha and beta diversity analyses revealed that neither plant species nor microbial inoculants significantly altered bacterial diversity or community structure beyond the overriding effect of PHC concentration. <em>Proteobacteria</em>, <em>Actinobacteriota</em>, <em>Acidobacteriota</em>, and <em>Chloroflexi</em> dominated across all soils, with hydrocarbon-degrading genera such as <em>KCM-B-112</em> and <em>Sphingomonas</em> highly abundant in the 25,700 mg/kg TPH soil. Exogenously introduced <em>B. subtilis</em> ATCC 21332 established only in the background soil, suggesting competitive dominance of indigenous PHC-degraders. These findings underscore the magnitude of PHC concentration as the primary driver of rhizobacterial dynamics during remediation.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100690"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147420164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impregnation of indwelling urinary catheter with promethazine: A strategy to combat catheter-associated urinary tract infections","authors":"Glaucia Morgana de Melo Guedes ,&nbsp;Francisco Ivanilsom Firmiano Gomes ,&nbsp;Bruno Rocha Amando ,&nbsp;Rodrigo Fonseca de Medeiros Guedes ,&nbsp;Alyne Soares Freitas ,&nbsp;Giovanna Barbosa Riello ,&nbsp;Carliane Alves Melgarejo ,&nbsp;Jaiane Alves Brasil ,&nbsp;Rodrigo Machado Pinheiro ,&nbsp;Paulo César Pereira de Sousa ,&nbsp;Rossana de Aguiar Cordeiro ,&nbsp;Marcos Fábio Gadelha Rocha ,&nbsp;José Júlio Costa Sidrim ,&nbsp;Débora de Souza Collares Maia Castelo-Branco","doi":"10.1016/j.microb.2026.100689","DOIUrl":"10.1016/j.microb.2026.100689","url":null,"abstract":"<div><div>Urinary tract infections (UTIs) associated with indwelling catheters pose a major clinical challenge due to the frequent association with bacterial biofilms, which contribute to antimicrobial resistance and persistent infections. This study aimed to evaluate the antimicrobial and antibiofilm effects of promethazine (PMZ) impregnated in catheter fragments against Gram-negative bacilli associated with UTIs. Twenty-three clinical isolates were tested, including <em>Escherichia coli</em> (n = 5), <em>Klebsiella pneumoniae</em> (n = 6), <em>Proteus mirabilis</em> (n = 6), and <em>Pseudomonas aeruginosa</em> (n = 6). The susceptibility of bacterial isolates to PMZ in planktonic and biofilm growth was assessed. Biofilm biomass reduction was evaluated using PMZ at concentrations corresponding to the minimum inhibitory concentration (MIC), MIC/2, and MIC/4 for growing biofilms, and at the minimum biofilm eradication concentration (MBEC), MBEC/2, and 2 ×MBEC for mature biofilms. Foley catheter fragments were impregnated with PMZ at 390 μg/mL and 3900 μg/mL to assess its effect on biofilm formation by colony-forming unit (CFU) quantification. MICs ranged from 97.6 to 781.25 μg/mL, while MBECs varied from 390.6 to 3125 μg/mL. PMZ significantly reduced the biomass of growing biofilms by 37.3%, 41.5%, and 58.7% at MIC/4, MIC/2, and MIC, respectively (P &lt; 0.05). Catheter impregnation with 390 μg/mL PMZ did not significantly reduce overall CFU counts, but achieved 3-log reductions for <em>E. coli</em> and <em>P. mirabilis</em>. At 3900 μg/mL, PMZ significantly reduced CFU counts for all species, achieving reductions greater than 5-log, when compared to growth control. In addition, PMZ enhanced the antibiofilm activity of conventional antimicrobials. These findings suggest that PMZ is a potential alternative to prevent catheter-associated UTIs caused by Gram-negative bacilli.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100689"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147420165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Marine-derived probiotic microorganisms: A review of their therapeutic applications in human health","authors":"Sanjana Katariya ,&nbsp;Khushbu Khapandi ,&nbsp;Anjali Gadhiya ,&nbsp;Deviben Chhatrodiya","doi":"10.1016/j.microb.2026.100680","DOIUrl":"10.1016/j.microb.2026.100680","url":null,"abstract":"<div><div>This narrative review summarizes current knowledge on marine-derived probiotic microorganisms and their therapeutic applications in human health. Databases such as PubMed and Scopus were searched (2000–2025) using terms related to marine probiotics, bioactive compounds, and clinical or experimental evidence of health benefits. There has been an increasing interest in marine-derived probiotics and their potential applications to humans in health care. Probiotic microorganisms derived from marine environments include a spectrum of various species of bacteria including <em>Lactobacillus, Bacillus</em> and <em>Pseudomonas</em>, marine yeasts and microalgae. Marine microbes produce special bioactive compounds displaying unique antimicrobial, antioxidant and anti-inflammatory capacity that developed because of their adaptation to extreme oceanic conditions. While more research is needed in this area, evidence has shown that marine probiotics can alter gut microbiota, improve immune function, and exhibit bioactive functions including antimicrobial, anti-inflammatory, and antioxidant functions. Moreover, marine probiotics also have potential for prevention of gastrointestinal illnesses, improve cardiovascular function, and aid in metabolism. The purpose of this review is to summarize marine probiotics including, origins, cellular activity, and applications, including possible therapeutic functions as a new biotherapeutic approach to human health. However, comprehensive genomic and clinical studies are required to validate their safety and therapeutic efficacy</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100680"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147421000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into the riverine metaplasmidome: The role of anthropogenic factors in shaping microbial communities","authors":"Melany Calderón-Osorno ,&nbsp;Kenia Barrantes-Jiménez ,&nbsp;Franck Lejzerowicz ,&nbsp;Maria Arias-Andres ,&nbsp;Keilor Rojas-Jimenez","doi":"10.1016/j.microb.2025.100640","DOIUrl":"10.1016/j.microb.2025.100640","url":null,"abstract":"<div><div>The environmental plasmidome, encompassing the collective plasmids within an ecosystem, plays a key role in microbial adaptation and evolution. Plasmids, as mobile DNA molecules, enable the transfer of beneficial traits among bacteria, especially in response to environmental stresses. In this study, we developed a novel protocol combining PlasmidSafe DNase and REPLI-g amplification to selectively enrich and characterize plasmidic DNA from polluted environments. We applied this approach to the Virilla River (Costa Rica), a system heavily impacted by urban and industrial activities, analyzing water and sediment samples across seasons and pollution gradients. Our method enabled the recovery of longer, circular contigs confidently identified as plasmids through multiple independent tools, with 28,043 circular sequences primarily linked to Gammaproteobacteria. Contaminated sites, particularly during the rainy season, showed higher plasmid diversity and a marked increase in antibiotic resistance genes (ARGs). This heightened diversity in contaminated environments has implications for the dissemination of antibiotic and metal-resistance genes, as well as other adaptive traits within microbial communities. This research underscores the need to study plasmids in natural environments to better comprehend their ecological roles and potential risks in polluted ecosystems.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100640"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145705840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of abundance and diversity of extended-spectrum β-lactamase (ESBL)-producing bacteria in aquatic ecosystems of Foumbot, an agricultural area of Cameroon (Central Africa)","authors":"Issah Moifon Nji Mongou ,&nbsp;Fils Mamert Onana ,&nbsp;Ernest Koji ,&nbsp;Paul Fotseu ,&nbsp;William Mbouh Seko Fopa ,&nbsp;Awawou Manouore Njoya ,&nbsp;Jean Samuel Eheth ,&nbsp;Siméon Tchakonté ,&nbsp;Paul Alain Nana ,&nbsp;Antoine Tamsa Arfao ,&nbsp;Moise Nola","doi":"10.1016/j.microb.2026.100673","DOIUrl":"10.1016/j.microb.2026.100673","url":null,"abstract":"<div><div>Antimicrobial resistance is a major public health challenges of the 21st century with a rapid increase in strains producing extended-spectrum β-lactamases (ESBL). This study examined the abundance and diversity of ESBL-producing bacteria in the aquatic ecosystems of Foumbot, an agricultural region. Sixteen sampling points were chosen to collect wastewater, surface, well and spring water. ESBL-producing bacteria were isolated on Chromagar-ESBL culture medium using filtration membrane method and identified using API 20E systems while physicochemical parameters were measured using appropriate techniques. The bacterial diversity was assessed by calculating specific richness, Shannon and Weaver diversity index, Sorensen similitude index and Pielou equitability index. Statistical analysis were performed using PAST software 16.0. Results showed that abundance mean values varied from one sampling point to the other. They fluctuated from 20 × 10⁴–13 × 10⁵ CFU/100 mL in wastewater, 18 × 10²–13 × 10³ CFU/100 mL in surface water, 141–80 × 10² CFU/100 mL in well water and 14–366 CFU/100 mL in spring water. 37 ESBL-producing species were isolated with 22 belonging to the <em>Enterobacteriaceae</em> family (<em>Cedecea lapagei, Citrobacter braakiii, Citrobacter freundii, Enterobacter aerogenes, Enterobacter cloacae, Enterobacter gergoviae, Escherichia coli, Klebsiela oxytoca, Klebsiella pneumonia, Rahnella aquatilis, Raoultella ornithinolytica, Salmonella choleraesuis, Salmonella paratyphi A, Salmonella spp, Serratia ficaria, Serratia liquefaciens, Serratia marcescens, Serratia odorifera, Serratia phymuthyca, Serratia rubidaea, Shigella spp,</em> and <em>Yersinia pestis</em>). Surface water was the most diversified ecosystem whereas groundwater was the least. A high equitability (H’&gt;0.7) was recorded at almost all the sampling points and a high similarity (S&gt;0.7) of bacteria community was noted between surface, well and spring water. The bacterial abundance and species richness were significantly influenced by factors such as pH, nitrites, ammonia nitrogen (affecting only the abundance), phosphates, phosphorus, color, and turbidity. This study revealed the health risk for humans and aquatic environment of Foumbot.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"10 ","pages":"Article 100673"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}