{"title":"Microbial Primer: Bacterial metallophores - their role for metal homeostasis and social interactions.","authors":"Clémentine Laffont, Rolf Kümmerli","doi":"10.1099/mic.0.001688","DOIUrl":"https://doi.org/10.1099/mic.0.001688","url":null,"abstract":"<p><p>Metals are essential trace elements for almost all organisms including bacteria. Yet, metals are toxic at high concentrations, requiring fine-tuned regulatory mechanisms to steer metal homeostasis inside cells. In this primer, we explain how bacterial metallophores - small secreted secondary metabolites - act as gatekeepers by carefully orchestrating the scavenging and uptake of essential metals whilst preventing intracellular toxicity and keeping toxic metals outside the cell. We further introduce metallophore diversity together with main synthesis, secretion and uptake mechanisms. Finally, we show how secreted metallophores shape ecological interactions between bacteria and with eukaryotic organisms and how fundamental research on metallophores opens promising avenues for therapeutic and biotechnological applications.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 4","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13142891/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147845257","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}
Kiran-Kumar Shivaiah, Sabrina L Rosset, Robert A Quinn
{"title":"Microbe Profile: <i>Durusdinium trenchii</i>: a thermotolerant coral symbiont.","authors":"Kiran-Kumar Shivaiah, Sabrina L Rosset, Robert A Quinn","doi":"10.1099/mic.0.001679","DOIUrl":"10.1099/mic.0.001679","url":null,"abstract":"<p><p><i>Durusdinium trenchii</i> is a unicellular dinoflagellate in the family Symbiodiniaceae, a diverse group of photosynthetic microalgae known for forming symbiotic relationships with cnidarians and other reef organisms. Notably, this species displays exceptional tolerance to heat stress, enabling it to persist within the coral gastrodermis and often dominate symbiont communities under elevated temperatures. <i>D. trenchii</i> can confer increased thermal tolerance and reduced bleaching susceptibility to corals, though frequently with trade-offs in host growth and calcification. Its resilience has been linked to genome duplication, photoprotective mechanisms and characteristic lipid profiles. Its unique molecular traits, host generalist nature, ecological flexibility and increasing prevalence in warming oceans underscore the importance of this microbe in coral reef responses to climate change.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 5","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13152217/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147845295","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":"Insights into fungal communities in some benchmark agricultural soils of Alberta, Canada.","authors":"Nafsa Khazaei, M Derek MacKenzie, Brian Lanoil","doi":"10.1099/mic.0.001704","DOIUrl":"https://doi.org/10.1099/mic.0.001704","url":null,"abstract":"<p><p>Soil micro-organisms, including fungi, are integral to soil functions such as biogeochemical cycling, pollutant degradation and plant growth promotion. Soil fungi are influenced by environmental perturbations such as agricultural parameters and thus may be a potential soil health indicator. We hypothesized that tillage intensity, crop type and herbicide application would impose changes on soil fungal community composition and diversity and that these shifts would be associated with changes in soil physico-chemical properties. We examined the response of soil fungal communities to various agricultural parameters at a provincial scale from benchmark agricultural sites in Alberta. Surface soil samples from 26 farm locations were collected from benchmark sites across Alberta. Samples were grouped by crop type, tillage intensity and herbicide application. Physico-chemical properties of soil samples were measured. Following DNA extraction of soil samples, we used amplicon sequencing through primers for the ITS2 (internal transcribed spacer) region and analysed fungal community diversity, composition and predicted function. Multivariate analyses showed that ecoregion was the strongest environmental predictor of variation in fungal community composition. Amongst farming practices and soil properties, crop type was the most important identified driver of fungal community composition, followed by tillage intensity and soil pH. The genera <i>Mortierella</i>, <i>Pseudogymnoascus</i> and <i>Fusicolla</i>, as well as functional traits, including soil saprotrophs and mycoparasites, were responsive to variation in crop type, tillage levels and herbicide application. We observed minor changes in overall fungal diversity, but significant differences in species composition, in all farming treatments. The heterogeneity of samples also varied significantly by tillage intensity and crop type. No indicator species was strongly associated with crop type, tillage intensity or herbicide system. Bray-Curtis dissimilarity in the fungal community was positively correlated with soil pH and base saturation and negatively correlated with soil cation exchange capacity, organic matter and clay content. We conclude that management practices affect different attributes of soil fungal communities, and fungal community heterogeneity is a responsive attribute that could be used for soil health assessment in Alberta. The potential linkage we found between agricultural parameters, fungal community heterogeneity and soil parameters could be further investigated as a metric in soil health assessment.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 5","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13142292/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147845277","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}
Carlos Valdivia, Callum O Rimmer, Jonathan C Thomas, David Negus, Pilar Domingo-Calap
{"title":"Isolation and characterization of broad-range <i>Staphylococcus epidermidis</i> sepunaviruses.","authors":"Carlos Valdivia, Callum O Rimmer, Jonathan C Thomas, David Negus, Pilar Domingo-Calap","doi":"10.1099/mic.0.001693","DOIUrl":"10.1099/mic.0.001693","url":null,"abstract":"<p><p><i>Staphylococcus epidermidis</i> is a major contributor to biofilm-associated infections, bacteraemia and sepsis in humans. Additionally, it is an important veterinary pathogen. The spread of multi-drug resistant <i>S. epidermidis</i> poses an even greater challenge, requiring the development of antibiotic-alternative approaches. Here, we isolated four new broad-range phages capable of infecting a large panel of 65 clinical and veterinary isolates of <i>S. epidermidis</i>. Phages with the broadest host range produced plaques on 37% of the hosts tested and halos on an additional 40%. These phages belonged to the <i>Sepunavirus</i> genus, as supported by their morphology and genome analysis. A genome-wide association study identified a significant correlation between resistance to phage lysis and the presence of the <i>ppl</i> defence system and the <i>ica</i> operon, highlighting the protective role of biofilms against the phages isolated in this study. Furthermore, distinct phage-encoded methyltransferases identified in the phage genomes may contribute to differences in host ranges. This study advances our knowledge on the diversity and characteristics of <i>S. epidermidis</i> phages, which could be considered as interesting tools for phage therapeutics.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 5","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13152194/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147845300","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}
John Leech, Yemisi D Obafemi, Samuel Breselge, Taiwo Aremu, Adewale Olusegun Obadina, Martins Ebunoluwa Itohan, Chibundu N Ezekiel, Charles Parkouda, Abel Tankoano, Korotimi Traoré, Kolawole Banwo, Angela Parry-Hanson Kunadu, Felix Kwashie Madilo, Abiodun I Sanni, Omotade Richard Ogunremi, Gbemisola Onipede, Damaris Achieng Odeny, Cynthia Otieno, Marcus J Claesson, Paul D Cotter
{"title":"Characterizing microbiomes of African fermented foods in a global context.","authors":"John Leech, Yemisi D Obafemi, Samuel Breselge, Taiwo Aremu, Adewale Olusegun Obadina, Martins Ebunoluwa Itohan, Chibundu N Ezekiel, Charles Parkouda, Abel Tankoano, Korotimi Traoré, Kolawole Banwo, Angela Parry-Hanson Kunadu, Felix Kwashie Madilo, Abiodun I Sanni, Omotade Richard Ogunremi, Gbemisola Onipede, Damaris Achieng Odeny, Cynthia Otieno, Marcus J Claesson, Paul D Cotter","doi":"10.1099/mic.0.001695","DOIUrl":"https://doi.org/10.1099/mic.0.001695","url":null,"abstract":"<p><p>Fermentation plays a vital role globally, shaping traditional diets and enhancing food preservation, nutrition and flavour. With over 5,000 varieties of fermented foods globally, the microbiomes of many of these have yet to be explored, particularly with respect to those produced in some regions of Africa. To begin to address this knowledge gap, we conducted a shotgun metagenomics-based analysis of 91 fermented foods produced in Burkina Faso, Ghana, Kenya and Nigeria and compared them to a larger, global curated Food Metagenomic Database (cFMD). As for other studies of fermented food microbiomes in general, the substrate that was fermented emerged as the primary determinant of microbial beta diversity within the current African dataset and between the broader cFMD dataset. However, it was notable that the newly studied samples showed a small but statistically significant geographic signal. The African samples also displayed more alpha diversity than the global dataset, with cassava-, seed- and grain-based samples having the highest alpha diversity among the African foods. We also characterized the functional and antimicrobial profiles of all food-derived metagenome-assembled genomes (MAGs), noting the prevalence of pathways associated with carbohydrate metabolism across both African and non-African MAGs and an absence of known antimicrobial resistance genes in numerous genera. These findings not only expand our fundamental understanding of Africa's under-studied fermented food microbiomes but also lay the foundation for starter culture development tailored to local substrates and conditions, fostering opportunities to enhance product safety, quality and scalability while retaining key characteristics associated with the original, artisanal product.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 5","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13142294/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147845266","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}
Elke Goethe, Martina Ackermann, Larissa Bulmann, Kristin Laarmann, Astrid Lewin, Janita Luehrs, Mathias Muesken, Ralph Goethe
{"title":"The accessory role of the outer membrane porin protein MspD in <i>Mycobacterium smegmatis</i> zinc homeostasis.","authors":"Elke Goethe, Martina Ackermann, Larissa Bulmann, Kristin Laarmann, Astrid Lewin, Janita Luehrs, Mathias Muesken, Ralph Goethe","doi":"10.1099/mic.0.001699","DOIUrl":"https://doi.org/10.1099/mic.0.001699","url":null,"abstract":"<p><p>Zinc is the second most abundant transition metal in living cells and is involved in numerous biological processes. Regulation of <i>Mycobacterium smegmatis</i> (MSMEG) zinc homeostasis and zinc-specific importers ZnuABC and ZnuABC2 in the mycobacterial cytoplasmic membrane are well described; however, transport across the outer membrane (OM) remained unexplored so far. MspD is a porin highly similar to MspA, the major and well-studied porin responsible for the uptake of several compounds. Unlike MspA and the paralogues MspB and MspC, MspD was found to be transcriptionally induced upon zinc starvation and deletion of the global Zinc Uptake Regulator ZUR. Our study aimed to investigate the role of <i>msp</i>D (<i>msmeg</i>_6057) in MSMEG zinc homeostasis as well as the regulation of MspD expression. In addition, by growth experiments, quantitative real-time PCR analyses, <i>in situ</i> gene tagging and electron microscopy, we successfully demonstrated the zinc-responsive expression of the MspD protein as well as its complex formation and incorporation into the OM. Overall, the results provided strong evidence for an involvement of the MspD protein in zinc homeostasis of MSMEG.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 4","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13098993/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147787316","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":"<i>In vitro</i> evaluation of the antimicrobial activity of chlorhexidine alone or in combination with ketoconazole or miconazole against clinical isolates of <i>Malassezia pachydermatis</i> and multidrug-resistant <i>Staphylococcus pseudintermedius</i>.","authors":"Gianna Goldman, Domenico Santoro","doi":"10.1099/mic.0.001701","DOIUrl":"10.1099/mic.0.001701","url":null,"abstract":"<p><p><b>Background.</b> <i>Staphylococcus pseudintermedius</i> (<i>SP</i>) and <i>Malassezia pachydermatis</i> (<i>MP</i>) are common causes of canine skin infections associated with increasing antimicrobial resistance. Topical products containing chlorhexidine and azoles have been utilized to treat these infections. However, a limited number of studies have assessed the interactions between chlorhexidine and azoles against <i>SP</i> and <i>MP</i>.<b>Hypothesis/Objectives.</b> To assess efficacy and potential additivity/synergy between chlorhexidine and azoles against clinical isolates of <i>MP</i> and multidrug-resistant <i>SP</i> (<i>MDR-SP</i>).<b>Materials and Methods.</b> A total of 30 <i>MDR-SP</i> and 30 <i>MP</i> isolates were tested using a modified broth microdilution method. Six twofold dilutions of 2% chlorhexidine gluconate, 1% miconazole nitrate and 0.15% ketoconazole were tested alone and in combination. Minimum inhibitory (MIC) and bactericidal/fungicidal (MBC/MFC) concentrations were recorded, and synergy, additivity or antagonism was calculated.<b>Result.</b> For <i>MDR-SP</i>, the combinations of chlorhexidine/miconazole (<i>P</i>=0.003) and chlorhexidine/ketoconazole (<i>P</i><0.0001) resulted in lower MICs than chlorhexidine alone. Only the chlorhexidine/ketoconazole combination had lower MBCs (<i>P</i>=0.0071) than chlorhexidine alone. For <i>MP</i>, only the chlorhexidine/ketoconazole combination had lower MICs (<i>P</i><0.0001) than chlorhexidine alone. Both combinations of chlorhexidine/miconazole (<i>P</i>=0.0028) and chlorhexidine/ketoconazole (<i>P</i><0.0001) resulted in lower MFCs than chlorhexidine alone. Chlorhexidine/miconazole combination showed synergy in three <i>MDR-SP</i> isolates, but in none of the <i>MP</i> isolates. Chlorhexidine/ketoconazole showed synergy for 1 out of 30 <i>MDR-SP</i> and 19 out of 30 <i>MP</i> isolates.<b>Conclusions and Clinical Relevance.</b> These results suggest that chlorhexidine/azole combinations are an effective topical treatment for <i>MDR-SP</i> and MP infections. Further studies should assess the efficacy of commercial products containing these compounds and their efficacy <i>in vivo</i>.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 4","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13128280/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147787058","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}
Chen-Yi Cheung, Imogen Samuels, Hannah R Klaus, Gregory M Cook, Matthew B McNeil
{"title":"Metabolic perturbation reduces antibiotic tolerance in <i>Mycobacterium tuberculosis</i>.","authors":"Chen-Yi Cheung, Imogen Samuels, Hannah R Klaus, Gregory M Cook, Matthew B McNeil","doi":"10.1099/mic.0.001697","DOIUrl":"https://doi.org/10.1099/mic.0.001697","url":null,"abstract":"<p><p><i>Mycobacterium tuberculosis</i> is tolerant to many antibiotics, leading to impaired antibiotic killing. Using CRISPR interference (CRISPRi) transcriptional knockdowns, we generated a panel of metabolically compromised strains to identify tolerance pathways for pursuing in therapeutic development. Disrupting the regulation of intracellular iron storage, amino acid biosynthesis and redox defence mechanisms potentiated the lethality of multiple drugs and translated to infected THP-1 macrophages. This work reinforces the role of metabolism as a major contributor to drug tolerance in <i>M. tuberculosis.</i></p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 4","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13102359/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147787341","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}
Valeria Trivellone, Francesca Canuto, Giulia Lucetti, Christopher H Dietrich, Luciana Galetto, Cristina Marzachì
{"title":"Tracking the early spatio-temporal dynamics of phytoplasma multiplication within its leafhopper vector.","authors":"Valeria Trivellone, Francesca Canuto, Giulia Lucetti, Christopher H Dietrich, Luciana Galetto, Cristina Marzachì","doi":"10.1099/mic.0.001700","DOIUrl":"10.1099/mic.0.001700","url":null,"abstract":"<p><p>Transmission of phytoplasmas, recalcitrant, yet-to-be-cultivated bacteria, by insect vectors depends on acquisition and subsequent pathogen multiplication within the insect body. However, the influence of acquisition duration on early colonization dynamics remains poorly understood. This study clarifies the spatio-temporal patterns of <i>Flavescence dorée</i> phytoplasma (16SrV-D) multiplication in its leafhopper vector <i>Euscelidius variegatus</i> during the early stages of infection when acquisition access period (AAP) is short. Insects were exposed to two acquisition conditions: a short 4-h AAP, simulating incidental feeding, and a 2-day AAP, considered the minimum threshold for effective acquisition. Phytoplasma load was quantified in the head and body over time, and these data were integrated with published data covering longer AAPs (7-14 days) and post-acquisition periods (up to 42 days). A Bayesian hurdle-lognormal model was used to describe temporal dynamics and estimate pathogen multiplication rates across studies. Very short AAPs led to significantly lower phytoplasma loads after an 8-day latent period compared to 2-day AAPs, highlighting the importance of feeding duration for efficient colonization. Model predictions indicated that phytoplasma load after short AAPs increases gradually and follows similar temporal trends to those observed for longer AAPs, but remained consistently lower across the 40-day post-acquisition period. Nevertheless, empirical and model-based estimates suggest that even brief feeding events, particularly 2 days, can yield pathogen loads approaching the minimum transmission threshold (10³-10⁴ genome units ng⁻¹ insect DNA) in some individuals, as suggested by upper CI bounds, with potential to sustain infection and facilitate transmission. These findings shed light on how acquisition duration shapes early phytoplasma dynamics in vectors and offer insights into transmission risk under natural conditions where incidental feeding events may occur.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 4","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13135482/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147787307","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":"Identification of an R1-type pyocin previously misannotated as a prophage in <i>Pseudomonas aeruginosa</i> ATCC 27853.","authors":"Rayhaan Gerard Pais, Mathias Müsken, Belinda Loh","doi":"10.1099/mic.0.001692","DOIUrl":"10.1099/mic.0.001692","url":null,"abstract":"<p><p>While <i>Pseudomonas aeruginosa</i> ATCC 27853 is a widely used reference strain with previously characterized prophage regions, our use of one of the latest prophage prediction tools, PHASTEST, helped reveal a critical misclassification in its genome. Using this tool, we initially identified six prophage regions, with four classified as intact; however, in-depth analysis demonstrated that one of these predicted intact prophages was, in fact, a functional pyocin-encoding region. Specifically, the region spanning 679,586-698,056 bp, initially annotated as an intact prophage, was definitively re-identified as a region harbouring an R1-type pyocin. The most recent literature regarding prophages in <i>P. aeruginosa</i> ATCC 27853 classifies the region spanning 683,173-696,044 bp as a prophage. This region falls entirely within the genomic region we describe and reclassify, further emphasizing the importance of the reclassification performed in this study. The identified R1-type pyocin was induced using mitomycin C, processed via tangential flow filtration, and its bactericidal activity was confirmed against a clinical <i>P. aeruginosa</i> isolate via spot-test killing assays and absorbance-based assays. Transmission electron microscopy revealed R-type pyocin particles averaging 133 nm in length. This misidentification of a pyocin as a prophage critically underscores the inherent limitations of current bioinformatic tools in accurately distinguishing between these distinct phage-derived elements, thereby highlighting the urgent need for more refined annotation methodologies. Accurate identification of such elements is essential, as they may influence experimental outcomes and provide new insights into bacterial defence mechanisms.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"172 4","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13075995/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147677970","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}