Canadian journal of microbiology最新文献

{"title":"Bridging the gaps in antimicrobial resistance-from genomes to One Health.","authors":"Joseph B McPhee, Sandeep Tamber","doi":"10.1139/cjm-2026-0120","DOIUrl":"https://doi.org/10.1139/cjm-2026-0120","url":null,"abstract":"","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"72 ","pages":"1-3"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863632","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":"Deciphering the interrelation of gut microbiota and BMI in atherosclerosis: a metagenomic approach.","authors":"Hema Palanisamy, Subramanian Vidyalakshmi","doi":"10.1139/cjm-2025-0075","DOIUrl":"10.1139/cjm-2025-0075","url":null,"abstract":"<p><p>Atherosclerotic cardiovascular disease (ASCVD) is a global health concern, leading to higher rates of morbidity and mortality. Gut microbial dysbiosis significantly contributes to obesity related ASCVD. However, the interrelation of gut microbiome in driving obesity or overweight mediated ASCVD has not been sufficiently investigated. To unravel this complex interplay, we have compared the gut microbial shotgun metagenome data of ASCVD subjects across normal BMI (Body Mass Index) and overweight/obese (OW/OB) BMI categories. We identified a distinct gut microbial composition and function in normal and OW/OB ASCVD subjects. Using gut microbial abundance, a machine learning model was built to predict ASCVD in the normal and OW/OB samples. The gut microbiome-based signature for ASCVD discrimination was achieved with an AUC of 0.87 and 0.83 for distinguishing control and ASCVD in normal and OW/OB BMI groups, respectively. In addition, we have also identified that <i>Pseudoflavonifractor capillosus</i> could act as a prognostic organism in identifying OW/OB associated ASCVD. Therefore, an appropriate diet could modify the ASCVD contributing gut microbiome, hence minimizing the risk of ASCVD in OW/OB individuals.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-12"},"PeriodicalIF":1.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145630292","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":"Epinephrine and norepinephrine affect the cellular morphology, composition, and structure of <i>Gallibacterium anatis</i> biofilm.","authors":"Alicia N Aguilar-Fuentes, J Fernando Montes-García, Martha O Salcedo-Álvarez, Patricia Sánchez-Alonso, Candelario Vázquez-Cruz, Lourdes Rojas, Erika P Meneses-Romero, Erasmo Negrete-Abascal","doi":"10.1139/cjm-2025-0135","DOIUrl":"10.1139/cjm-2025-0135","url":null,"abstract":"<p><p><i>Gallibacterium anatis</i> is a Gram-negative bacterium that is a pathogen and part of the microbiome of both domestic and wild birds. It is also the cause of reproductive infections, primarily when birds are stressed. Its pathogenicity has been associated with the expression of virulence factors. The effect of epinephrine (Epi) and norepinephrine (NEpi) hormones on the composition and structure of <i>G. anatis</i> biofilms is evaluated here. Catecholamines induced compaction and fragmentation of biofilms at 24 h. Biofilm amount diminishes (50%) by NEpi. At 48 h, biofilm fragments are immersed in exopolymer material, and the control biofilm shows a high quantity of filamentous cells, not observed with hormones. Enzymatic digestion of biofilm polymers showed increased protein levels in the presence of Epi at 24 or 48 h and NEpi at 24 or 72 h. Epi increased carbohydrate quantity, but NEpi diminished, and DNA quantities diminished at 48 h by Epi. Epi diminishes the expression of proteins in the 70-200 kDa range but increases the expression of secreted proteins. NEpi induces proteolytic activity in the range of 20-110 kDa. A 55 kDa protease was induced at 72 h by both hormones. <i>Gallibacterium anatis</i> biofilm changes could be significant in its dispersion and pathogenesis.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145660462","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":"Biochar alters microbial community structure in experimental treatment wetlands exposed to pesticides.","authors":"Charbel Hanna, Pierre-Luc Chagnon, Charles Jarry, Margit Kõiv-Vainik, Jacques Brisson, Stéphanie Pellerin","doi":"10.1139/cjm-2026-0019","DOIUrl":"https://doi.org/10.1139/cjm-2026-0019","url":null,"abstract":"<p><p>Treatment wetlands are increasingly used to treat agricultural wastewater. While plants and substrates contribute to pesticide immobilization and removal, most metabolic degradation is mediated by microorganisms. However, pesticides may negatively affect the microbial communities responsible for their degradation. This study aimed to assess whether biochar, an organic amendment commonly used in treatment wetlands, could mitigate the effects of pesticides on microbial communities. Six treatment wetland mesocosms planted with <i>Scirpus cyperinus</i> were sampled before and after exposure to a pesticide mixture (atrazine, glyphosate, and chlorantraniliprole) applied at three concentration levels. Half of the mesocosms were amended with biochar. Biochar did not impact microbial alpha diversity but altered community composition, particularly by modifying the relative abundance of bacterial taxa involved in nitrogen cycling. Pesticide concentration influenced root-associated fungal communities only. Eight taxa with known pesticide-degrading potential increased in relative abundance following pesticide application. Overall, our results suggest that biochar and pesticide exposure can shape microbial community composition in treatment wetlands, but without clear mitigation of pesticide impacts under the conditions tested. These findings highlight the importance of considering microbial community structure when designing treatment wetlands and underscore the need for temporally resolved studies to better understand microbial responses to pesticide exposure.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"72 ","pages":"1-12"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148535356","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":"A single-case foodborne botulism outbreak caused by <i>Clostridium botulinum</i> type A1(B5) in diced garlic in Newfoundland and Labrador, 2024.","authors":"Richard Harris, Annika Flint, Ryan Boone, Kelly Weedmark, Chris Nolan, Itai Malkin","doi":"10.1139/cjm-2026-0090","DOIUrl":"10.1139/cjm-2026-0090","url":null,"abstract":"<p><p>Foodborne botulism is a severe neuroparalytic disease caused by ingestion of foods containing botulinum neurotoxins, produced by <i>Clostridium botulinum</i>. In 2024, a 74-year-old woman from Newfoundland and Labrador with complete bilateral flaccid paralysis and respiratory distress was hospitalized and required intubation. From the broader differential diagnosis list, botulism was favoured prior to laboratory confirmation. Serum and feces samples initially tested negative for botulinum neurotoxins by mouse bioassay, yet viable <i>C. botulinum</i> type A was recovered from the feces. Food history investigation included some diced garlic in a repurposed coffee container that tested negative for botulinum neurotoxins by mouse bioassay, but viable <i>C. botulinum</i> type A was recovered from the sample. Both the fecal and garlic enrichment cultures were positive for <i>bont</i>/A and <i>bont/</i>B genes by real-time PCR. Whole genome sequencing revealed that both fecal and garlic isolates were highly similar with conserved gene synteny, including an intact bont/A1 gene and a disrupted (silent) bont/B5 gene encoded on the chromosome. This single-case foodborne botulism outbreak from Newfoundland and Labrador in 2024 was caused by <i>C. botulinum</i> type A1(B5) in diced garlic.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-8"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148599343","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":"Exploring the diversity of bacterial holdfast polar adhesins from Québec aquatic environments.","authors":"Cecile Berne, Marin Debidour, Matteo Paniconi, Nathaniel Danis, Emily D Sprowls, Kathryn Kavanagh, Laura Gilbert, Yves V Brun","doi":"10.1139/cjm-2025-0310","DOIUrl":"10.1139/cjm-2025-0310","url":null,"abstract":"<p><p>Biofilms are complex microbial communities that adhere to surfaces, often in response to their environment. Irreversible attachment in these biofilms is mediated by bacterial adhesins, and, in many Alphaproteobacteria, those adhesins are located at the cell pole. To examine the prevalence and natural variation of polar adhesins, 76 water samples were collected across Québec through a citizen science initiative. Environmental isolates were screened for their ability to form biofilms, and strains exhibiting polar attachment were selected. A subset of 21 representative strains was used for phenotypic assays and whole-genome sequencing. Phylogenetic analysis showed that most belonged to the order <i>Caulobacterales</i>, and microscopic characterization indicated variability in the polysaccharide composition of polar adhesins in these environmental strains. By integrating citizen science-driven sample collection, comparative genomics, and phenotypic assays, this work establishes a unique framework for linking microbial ecology to molecular mechanisms of adhesion. Our results highlight intra-order natural variations in polar adhesin structure and composition. Such variations may be signatures of adaptive adhesive performances across diverse environments. These findings not only advance the understanding of biofilm biology but also open avenues for bio-inspired applications, including the development of next-generation adhesives and anti-biofouling materials.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-16"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147484652","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":"Gulls as reservoirs and vectors of high-risk, multidrug-resistant <i>Escherichia coli</i> in Atlantic Canada: emergence of CMY-2-producing ST648.","authors":"Rym Ben Sallem, Oussama Bouallegue, Talia Quinlan, Micheline Theriault, Mohammadi Kaouass, Shawn Craik, Alex Wong","doi":"10.1139/cjm-2025-0240","DOIUrl":"10.1139/cjm-2025-0240","url":null,"abstract":"<p><p>Gulls (<i>Larus</i> spp.) are key reservoirs and vectors of antimicrobial resistance (AMR). We characterized extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC-producing <i>Escherichia coli</i> from Great Black-backed (<i>Larus marinus</i>) and American Herring (<i>Larus smithsonianus</i>) gulls in Nova Scotia, Canada. From 100 fecal samples collected from gulls visiting three fish-processing plants, 34 cefotaxime-resistant isolates were recovered: 29 ESBL and 5 AmpC producers. Detected β-lactamases included <i>bla</i>_CTX-M-1 (<i>n</i> = 12), <i>bla</i>_CTX-M-55 (<i>n</i> = 12), <i>bla</i>_CTX-M-15 (<i>n</i> = 2), <i>bla</i>_CMY-2 (<i>n</i> = 4), <i>bla</i>_CTX-M-15+ <i>bla</i>_TEM-1b (<i>n</i> = 1), <i>bla</i>_CTX-M-55+ <i>bla</i>_TEM-1b (<i>n</i> = 1), <i>bla</i>_CTX-M-55+ <i>bla</i>_TEM-1B+ <i>bla</i>_LAP-2 (<i>n</i> = 1), and <i>bla</i>_CMY-2+ <i>bla</i>_TEM-1c (<i>n</i> = 1). Additional resistance genes conferred resistance to sulfonamides (<i>sul2</i>/<i>sul3</i>), trimethoprim (<i>dfrA14</i>/<i>dfrA17</i>), tetracyclines (<i>tet</i>(<i>A</i>)/<i>tet</i>(<i>B</i>)), aminoglycosides, chloramphenicol (<i>floR</i>), macrolides (<i>mph</i>(<i>A</i>)), lincosamides (<i>lnu</i>(<i>F</i>)), and quinolones (<i>qnrS</i>), complemented by chromosomal mutations in <i>gyrA, parC</i>, and <i>parE</i>. The isolates represented phylogroups A (<i>n</i> = 9), B1 (<i>n</i> = 19), and D (<i>n</i> = 6), and high-risk sequence types including ST155 (<i>n</i> = 12), ST744 (<i>n</i> = 7), ST224 (<i>n</i> = 4), and ST648 (<i>n</i> = 3). Plasmid analysis revealed a high replicon burden (≥3 in 70.6% of isolates), primarily IncFIB (70.6%), Col (58.8%), and IncI (50.0%). Key virulence factors detected were <i>fimH</i> (97.1%), <i>lpfA</i> (73.5%), <i>fyuA</i> (47.1%), and <i>iss</i> (38.2%). These results demonstrate that synanthropic gulls in Atlantic Canada carry multidrug-resistant ESBL/AmpC <i>E. coli</i> from globally significant clones, underscoring the role of these birds in dissemination of antimicrobial resistance within a One Health context.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-14"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147762334","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":"Role of cold shock protein CspA in <i>Aeromonas salmonicida</i> subsp. <i>salmonicida</i> physiology and virulence.","authors":"Ahmed Hossain, Hajarooba Gnanagobal, Trung Cao, Ignacio Vasquez, Javier Santander","doi":"10.1139/cjm-2025-0118","DOIUrl":"10.1139/cjm-2025-0118","url":null,"abstract":"<p><p>Cold shock proteins are small, highly conserved nucleic acid-binding proteins that help bacteria adapt to stress conditions. <i>Aeromonas salmonicida</i> subspecies <i>salmonicida</i> is a psychotropic, Gram-negative intracellular fish pathogen that causes furunculosis in fish. The role of cold shock proteins in the stress response in marine pathogens like <i>A. salmonicida</i> is unknown. In this study, we reported the role of cold shock protein A (CspA) in <i>A. salmonicida</i> physiology, stress response, and virulence in lumpfish (<i>Cyclopterus lumpus</i>). <i>Aeromonas salmonicida</i> Δ<i>cspA</i> was characterized using phenotypic tests and transcriptomics. <i>Aeromonas salmonicida</i> Δ<i>cspA</i> showed a reduction in survival at low temperatures (0 and 4 °C) and in ox bile-containing (5%) conditions. Differential gene expression analysis showed 632 dysregulated genes in Δ<i>cspA.</i> Among these 632 differentially expressed genes (DEGs), 413 were upregulated, and 219 were downregulated. Most downregulated genes were related to the type III secretion system (T3SS). However, <i>A. salmonicida</i> Δ<i>cspA</i> was not fully attenuated in the lumpfish host but delayed fish mortality and reduced tissue colonization after systemic infection in contrast to the wild type strain. Overall, this study provides novel insight into the roles of CspA in virulence and the physiology of <i>A. salmonicida</i>.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-17"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147347297","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":"Mass mortalities caused by different genotypes of HPAIV H5N1 clade 2.3.4.4b in colony breeding Black-headed Gulls and Sandwich Terns in Denmark 2022 and 2023.","authors":"Charlotte Kristiane Hjulsager, Yuan Liang, Casper Thorup, Lars Erik Larsen, Tim Kåre Jensen, Solvej Breum, Thomas Bregnballe","doi":"10.1139/cjm-2025-0182","DOIUrl":"10.1139/cjm-2025-0182","url":null,"abstract":"<p><p>Unprecedented seabird mass mortality events (MMEs) were reported in multiple European countries in 2022 and 2023. These events were attributed to Clade 2.3.4.4b H5N1 high pathogenicity avian influenza viruses (HPAIVs). In Denmark, populations of Sandwich Terns (<i>Thalasseus sandvicensis</i>) and Black-headed Gulls (<i>Chroicocephalus ridibundus)</i> were significantly impacted. Sandwich Tern mortality occurred primarily between May and June of 2022 and was caused by the HPAIV genotype EA-AB. From 2022 to 2023, Danish Sandwich Tern populations decreased by 36%. Sandwich Terns commonly nest within Black-headed Gull colonies, allowing for direct contact between the species. Despite their proximity, in 2022, neither adults nor chicks of Black-headed Gulls exhibited morbidity associated with HPAIV. During the autumn of 2022 and the winter 2022/23 a novel clade 2.3.4.4b H5N1 HPAIV, genotype EA-BB, emerged in Black-headed Gulls. The new genotype caused the death of at least 3000 adult Black-headed Gulls in Denmark (i.e., >1.8% of the Danish breeding population) in the spring of 2023. Notably, in 2023 Sandwich Tern chicks, but not adults, in contact with Black-headed Gulls were affected by mass mortality. These observations suggest that adult Terns in 2023 were less susceptible to HPAIV infection, mitigating the impact of MMEs.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-10"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145948660","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":"Editorial: Advances in systems biology and bioinformatics for microbiology research.","authors":"Jennifer Geddes-McAlister, Arnaud Droit","doi":"10.1139/cjm-2026-0020","DOIUrl":"https://doi.org/10.1139/cjm-2026-0020","url":null,"abstract":"","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"72 ","pages":"1-3"},"PeriodicalIF":1.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249133","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}