Fems Microbiology Letters最新文献

{"title":"Phylogenetic support of pebS as a phage-exclusive auxiliary metabolic gene.","authors":"Nina Baeuerle, Nicole Frankenberg-Dinkel, Anne Kupczok","doi":"10.1093/femsle/fnag053","DOIUrl":"10.1093/femsle/fnag053","url":null,"abstract":"<p><p>Marine picocyanobacteria, including the genera Prochlorococcus and Synechococcus, are major contributors to oceanic photosynthesis and global primary production. Their populations are influenced by T4-like cyanophages, which frequently encode auxiliary metabolic genes (AMGs) capable of altering host metabolism during infection. One such AMG, pebS, encodes a ferredoxin-dependent bilin reductase (FDBR) phycoerythrobilin (PEB) synthase, which converts biliverdin IXα to PEB. In contrast, cyanobacteria perform a two-step reaction using the FDBR enzymes PebA (15,16-dihydrobiliverdin: ferredoxin oxidoreductase) and PebB (PEB:ferredoxin oxidoreductase), whereas pebS has not been reported in cyanobacterial genomes. Here, we re-evaluated whether pebS is truly restricted to cyanophages by searching the Ocean Gene Atlas (OGA) and all available cyanobacterial genomes at National Center for Biotechnology Information (NCBI) using a cyanophage-derived PebS sequence as query. Using protein phylogenies, we found that most search hits group with PebA or PebB, while few sequences from cyanobacterial genome assemblies were confirmed to belong to PebS based on phylogenetic placement. However, genomic context analysis of these pebS sequences revealed their phage origin, consistent with cyanophage infection at the time of sampling. In conclusion, our results support that pebS is absent in cyanobacterial genomes, raising questions about the evolutionary and biochemical causes for the two-step reduction of biliverdin IXα to PEB in these organisms.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13198022/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147766571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genotypic and phenotypic comparison of Neisseria meningitidis carriage and invasive disease isolates contemporaneously collected in the Netherlands.","authors":"Charles H Jones, Zhenghui Li, Li Hao, Arie van der Ende, Paul A Liberator, Annaliesa S Anderson, Ashlesh K Murthy","doi":"10.1093/femsle/fnaf140","DOIUrl":"10.1093/femsle/fnaf140","url":null,"abstract":"<p><p>Neisseria meningitidis (Nm), a commensal that colonizes the nasopharynx of 4.5%-24% of healthy humans, can cause invasive meningococcal disease (IMD). We hypothesized that distinct genotypic and/or phenotypic signatures might be found in carriage vs. invasive isolates. Carriage isolates were cultured from nasopharyngeal swabs (n = 267) collected from healthy students (aged 13-21 years) during the 2013 and 2014 school years in the Netherlands. Invasive isolates (n = 214) were cultured from all reported disease cases in the Netherlands from 2012 to 2014. Whole core genome sequences were determined for all isolates and comparisons of selected genotypic markers and phylogenomic associations between carriage and disease isolates were analyzed. While 30% of carriage isolates could not be assigned a genogroup, all the invasive isolates were successfully genogrouped. Genogroup B (MenB) predominated, representing 27% of carriage and 75% of IMD isolates. Sequence type (ST) complex diversity was dominated by four STs (ST-41/44, ST-213, ST-32, and ST-269) in both carriage and disease isolates. FHbp subfamily A variants were prevalent (79%) in carriage, whereas subfamily B variants were more frequent (69.6%) in disease. Carriage and IMD-causing Nm strains display similar ST and phylogenomic profiles; however, an increased FHbp subfamily B prevalence and an enhanced level of FHbp surface expression were noted in MenB disease-causing isolates.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12794619/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145762557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 comparative study on the effects of emulsification methods on the antimicrobial activity of essential oil emulsions.","authors":"Paul G Kamau, Paola Alzate, Malco Cruz-Romero, Michael A Morris, Joe P Kerry","doi":"10.1093/femsle/fnaf144","DOIUrl":"10.1093/femsle/fnaf144","url":null,"abstract":"<p><p>A 3 × 3 factorial design was used to systematically evaluate the impact of three widely used emulsification methods [ultrasonication (UT), high-shear homogenization (HSH), or vortex mixing (VM)] at three treatment times (30, 60, or 120 s) on the antimicrobial efficacy of sage (SEO) and garlic (GEO) essential oil emulsions. Independent of essential oil used, antimicrobial activity was significantly (P < 0.05) influenced by both emulsification method and treatment time, with Gram-negative bacteria showing greater resistance. From the tested methods, emulsions prepared by UT or HSH for at least 60 s exhibited significantly (P < 0.05) higher antimicrobial activity, which might be associated with their significantly (P < 0.05) smaller particle size and polydispersity index. Additionally, UT and HSH produced more stable SEO emulsions, while GEO required ≥60 s treatment for stability and VM led to rapid destabilization regardless of oil or time. This study highlights the importance of selecting an appropriate emulsification method for producing essential oil emulsions with enhanced antimicrobial activity, which is important not only for antimicrobial testing but also for the overall functional performance of the emulsion.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13017692/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147473078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DNA replication and cell division complexes remain physically associated throughout the cell cycle in Helicobacter pylori.","authors":"Priyanka Dubey, Anjali Yadav, Salman Khan, Fatima Akhtar, Mohammad Kamran, Inderjeet Kaur, Suman Kumar Dhar","doi":"10.1093/femsle/fnag037","DOIUrl":"10.1093/femsle/fnag037","url":null,"abstract":"<p><p>The occurrence of drug-resistant strains exacerbates the difficulty of treating stomach cancer caused by Helicobacter pylori. DNA replication and cell division offer attractive targets for the development of antibacterial therapies. Both DNA replication and cell division in H. pylori start at one of the poles and terminate at the middle of the cell. The absence of a SlmA homolog and the presence of a unique Min CDE system may explain polar divisome assembly in Helicobacter. We previously observed the co-localization of replisome and divisome proteins; however, it is unclear if they interact directly. We report, for the first time, the interaction between two complexes in vitro and in vivo. These results highlight the mechanistic aspects of the unique polar co-assembly of the replisome/divisome complex in Helicobacter, through interactions among members of each component, which might be useful for identifying new targets.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147632964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Galleria mellonella as a novel invertebrate model for studying Ehrlichia ruminantium pathogenesis and host-pathogen interactions.","authors":"Maëlle Bayet, Christina Nielsen-Leroux, Valérie Rodrigues, Damien F Meyer","doi":"10.1093/femsle/fnag113","DOIUrl":"10.1093/femsle/fnag113","url":null,"abstract":"<p><p>Ehrlichia ruminantium, the causative agent of heartwater disease, is an obligate intracellular bacterium that poses significant economic threats to livestock production in endemic regions. Current research models present substantial ethical, logistical, and economic constraints, particularly for studying host-pathogen interactions within arthropod vectors. Here, we establish Galleria mellonella larvae as a tractable invertebrate infection model for Ehrlichia ruminantium, enabling experimental investigation of pathogen persistence and host-pathogen interactions in an arthropod system. Following infection, G. mellonella proved susceptible to E. ruminantium with moderate mortality and remarkable bacterial persistence. Using rhodamine-labeled bacteria and fluorescence microscopy, we tracked bacterial dissemination from injection sites to systemic distribution in characteristic segmental patterns throughout the larval body. Rhodamine-labeled bacteria were consistently associated with hemocytes, the primary immune cells of G. mellonella, although widefield imaging cannot establish intracellular localization. Quantitative PCR revealed stable bacterial loads over the study period, and bacteria recovered from infected larvae remained viable and infectious for endothelial cells. These findings show that E. ruminantium persists in G. mellonella for at least two weeks without inducing a detectable melanization response. The fluorescence adopted a reproducible segmental distribution whose biological basis remains to be determined. This model offers significant advantages: ethical acceptability, cost-effectiveness, experimental tractability, and compatibility with high-throughput screening approaches. The G. mellonella system represents a valuable complement to existing mammalian models and provides a unique platform for investigating arthropod-specific aspects of E. ruminantium biology, screening antimicrobial compounds, and testing hypotheses of immune evasion that may inform strategies for heartwater disease control.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13656321/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149106384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-throughput microbiome profiling and co-occurrence with antibiotic-resistance genes in Lucilia sericata.","authors":"Arwa Shatta, Xavier Chavarria, Jun Ho Choi, Singeun Oh, Myungjun Kim, Dongjun Kang, Yoon Hee Cho, Du-Yeol Choi, Myung-Hee Yi, Ju Yeong Kim","doi":"10.1093/femsle/fnag063","DOIUrl":"10.1093/femsle/fnag063","url":null,"abstract":"<p><p>Blow flies such as Lucilia sericata (Diptera: Calliphoridae) serve important ecological functions as decomposers. However, due to their close association with decaying organic matter, they also play potential roles as reservoirs of pathogenic bacteria and antimicrobial resistance genes. In this study, we characterized the bacterial communities and targeted key antibacterial resistance markers of L. sericata specimens using 16S rRNA gene metabarcoding and targeted PCR screening. The microbiome was dominated by Dysgonomonas, Vagococcus, Pseudomonas, Ignatzschineria, and Providencia with geographic variation in community structure. Flies from Chungnam exhibited the lowest microbial diversity, while samples from Jeonnam and Gyeonggi showed greater richness and evenness. Beta diversity analyses confirmed geographic structuring of bacterial communities, with semi-urban and rural locations harboring more diverse taxa. Notably, opportunistic pathogens such as Proteus mirabilis and Providencia were detected alongside a range of ARGs (blaTEM, ermB, sul1, aac(6')-Ib-cr, cat and mecA) and integron elements (intI and intII), suggesting that L. sericata may act as a reservoir of clinically important microbes and resistance genes.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148041696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Involvement of the recA-dependent response in antibacterial activity of hesperetin in Escherichia coli.","authors":"Ji Hyun Park, Dong Gun Lee","doi":"10.1093/femsle/fnag087","DOIUrl":"10.1093/femsle/fnag087","url":null,"abstract":"<p><p>Hesperetin is a naturally occurring flavonoid with reported antimicrobial activity, but its antibacterial modes of action remain poorly understood. In this study, the antibacterial effects of hesperetin in Escherichia coli were investigated. Hesperetin treatment increased intracellular reactive oxygen species (ROS) levels, and scavenger-based experiments supported the contribution to downstream effects. Elevated ROS was associated with membrane depolarization and oxidative membrane damage, including lipid peroxidation, as indicated by increased malondialdehyde levels. Hesperetin treatment also increased DNA damage, including chromatin condensation and DNA fragmentation. Because recA is a key regulator of the SOS DNA repair response, a recA-deficient strain was used to assess the role of SOS-associated repair signaling; DNA damage was significantly greater in the recA-deficient strain than in the wild-type strain. In addition, programmed cell death-like features, including phosphatidylserine externalization detected by Annexin V/PI staining, were observed. Collectively, these findings indicate that the antibacterial activity of hesperetin involves ROS-associated membrane injury, oxidative DNA damage, and recA-dependent SOS-associated responses, together with programmed cell death-like features in E. coli.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148561239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collateral effects of antibiotic resistance in Campylobacter jejuni.","authors":"Hadiseh Zandrajabi, Wisse van Os, Wiep Klaas Smits, Seyed Ali Mortazavi, Farideh Tabatabaei-Yazdi, Johan G C van Hasselt","doi":"10.1093/femsle/fnag089","DOIUrl":"10.1093/femsle/fnag089","url":null,"abstract":"<p><p>Campylobacter jejuni is a leading cause of bacterial gastroenteritis worldwide, and resistance to major antibiotic classes is increasing. Exploiting collateral sensitivity (CS) may be an effective approach to optimize antibiotic use and mitigate the impact of resistance. In this study, we investigated CS and collateral resistance (CR) profiles in experimentally evolved C. jejuni mutants derived from ATCC 29428 resistant to ciprofloxacin, erythromycin, gentamicin, and tetracycline. Minimum inhibitory concentrations of thirteen antibiotics were determined in the wild-type and mutant strains to characterize collateral effects. Whole-genome sequencing was performed to identify mutations potentially underlying the observed collateral effects, and bacterial growth curves were used to evaluate the fitness of the mutants. Ciprofloxacin-resistant mutants exhibited CS most consistently to aminoglycosides, potentially explained by mutations in gyrA, parC, and parE. Gentamicin-resistant mutants showed CS to macrolides, fosfomycin, and amoxicillin. Erythromycin-resistant mutants displayed CS to aminoglycosides, albeit inconsistently across biological replicates. No CS was observed in tetracycline-resistant mutants, which showed CR to other ribosome-targeting antibiotics, potentially due to mutations in rpsJ. Consistent CR was observed among antibiotics of the same class. These findings demonstrate CS and CR patterns in C. jejuni, highlighting evolutionary trade-offs that could inform more effective treatment strategies against resistant C. jejuni infections.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13426002/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148591017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutrient enrichment and connectivity jointly shape bacterioplankton taxonomic and functional diversity.","authors":"Akhil Kholwadwala, Egor Katkov, Patrick Lypaczewski, Andrew Gonzalez, Rowan D H Barrett, B Jesse Shapiro","doi":"10.1093/femsle/fnag056","DOIUrl":"10.1093/femsle/fnag056","url":null,"abstract":"<p><p>It is increasingly important to understand the response of freshwater communities and ecosystems to fertilizers given their widespread usage and the propensity for these fertilizers to runoff into rivers and lakes. Dispersal, an important ecological factor mediated by landscape connectivity, could potentially counteract the impacts of anthropogenic stressors through the reintroduction of communities unperturbed by local stressors. However, this potential has not yet been studied in the context of nutrient stressed natural communities. Here, we investigate the impacts of nutrient enrichment and connectivity on freshwater bacterioplankton communities. We subjected mesocosms stocked with native bacterioplankton communities to different combinations of nutrient enrichment and connectivity (volumes of water transferred between mesocosms). We show that nutrient enrichment strongly structures the bacterioplankton community, favoring nutrient tolerant taxa and depressing taxonomic diversity. Connectivity, however, interacts with nutrient enrichment to restore functional diversity in communities subjected to the highest levels of nutrient stress. Despite the ameliorating effects of dispersal, nutrient enrichment leaves a consistent signature in communities, driving a shift from more heterotrophic to more phototrophic communities. Taken together, our results demonstrate that while nutrient enrichment significantly impacts freshwater bacterioplankton communities, connectivity can help restore functional diversity to a certain extent.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13185530/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147835761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fantastic microbes and where to find them: evaluating learning-by-doing outcomes in a crowdfunded metagenomics workshop.","authors":"Giulia Ghisleni, Ellen Dow, Teresa Iovino, Pamela Jael Colman-Vega, Alessia Dicesare, Emanuele Guanella, Yodit Maria Bacchi, Althea Colombo, Maristella Leccese, Matilde Marzucchi, Margherita Emma Gorla, Alessandra Caracciolo, Alessio Sala, Polina Makarycheva, Sharon Cristal Rubrica, Andrea Ferrier, Alice Armanni, Sara Fumagalli, Elisha Wood-Charlson, Antonia Bruno","doi":"10.1093/femsle/fnag093","DOIUrl":"10.1093/femsle/fnag093","url":null,"abstract":"<p><p>Metagenomics offers a powerful framework for authentic, interdisciplinary learning, yet it remains underrepresented in undergraduate education due to technical and infrastructural barriers. We hypothesized that a research-based, learning-by-doing metagenomics workshop supported by accessible bioinformatics tools could enhance students' perceived skills, self-efficacy, and conceptual understanding of metagenomic analysis. To test this hypothesis, we designed and evaluated a hybrid hands-on workshop in which undergraduate and postgraduate students analyzed real environmental shotgun metagenomic datasets generated from soil samples collected during a citizen science initiative. Using the graphical workflow platform KBase, participants completed an end-to-end metagenomic analysis, from quality control and assembly to genome reconstruction, taxonomic classification, functional annotation, and scientific presentation of results. Educational outcomes were assessed through validated retrospective pre-post questionnaires, self-efficacy scales, and an open-ended conceptual understanding task. Participants showed significant increases in perceived metagenomic skills and confidence in performing metagenomic analyses, while gains in perceived learning showed a positive trend. Conceptual understanding improved across educational levels, particularly among participants with limited prior experience. Together, these findings demonstrate that authentic, data-driven metagenomics activities can effectively lower barriers to computational biology and foster meaningful learning through hands-on research experiences.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501537/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148757441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}