Canadian journal of microbiology最新文献

{"title":"Osmotic stress tolerance and virulence of <i>Salmonella enterica</i> Tennessee and Serogroup B strains from low-moisture foods.","authors":"Adrián Gómez-Baltazar, Angélica Godínez-Oviedo, Ma Soledad Vázquez-Garcidueñas, Gerardo Vázquez-Marrufo, Montserrat Hernández-Iturriaga","doi":"10.1139/cjm-2025-0067","DOIUrl":"10.1139/cjm-2025-0067","url":null,"abstract":"<p><p><i>Salmonella enterica</i> is a major foodborne pathogen capable of surviving in low-water-activity (a_W) foods and retaining the ability to invade intestinal epithelial cells after environmental stress, such as exposure to high salt concentrations. Although multiple serotypes tolerate low a_W, Tennessee strains have been repeatedly linked to outbreaks in dry foods, suggesting specific adaptations. This study evaluated the effects of NaCl (1%, 4%, and 6%) on growth, biofilm formation, post-biofilm recovery, and internalization capacity (Caco-2 cell assays) of six <i>S. enterica</i> strains-four Tennessee and two serogroup B isolates-from peanuts, raisins, chocolate, and dehydrated tomatoes. Growth and biofilm formation were monitored over a 7-day exposure to NaCl; post-biofilm recovery and internalization were assessed afterward. While all strains showed reduced internalization after salt exposure, Tennessee isolates generally maintained higher growth and biofilm formation than the ATCC 14028 reference strain. Phenotypic responses varied by strain and NaCl concentration, indicating differences in osmotic stress adaptation. The persistence of internalization capacity, even at reduced levels, highlights a potential food safety risk in NaCl-preserved products. These findings emphasize the need to consider strain-specific traits when developing control measures for <i>Salmonella</i> in dry food environments.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-12"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211791","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":"Effect of cannabidiol (CBD), a cannabis plant derivative, against <i>Candida albicans</i> growth and biofilm formation.","authors":"Maryam Bahraminia, Shujun Cui, Ze Zhang, Abdelhabib Semlali, Étienne Le Roux, Kelly-Anne Giroux, Camille Lajoie, François Béland, Mahmoud Rouabhia","doi":"10.1139/cjm-2024-0034","DOIUrl":"10.1139/cjm-2024-0034","url":null,"abstract":"<p><strong>Highlights: </strong>Cannabidiol (CBD) decreases the growth of <i>C. albicans</i>. CBD inhibits the yeast-to-hyphae transition. CBD reduces biofilm formation by <i>C. albicans</i>. CBD induces <i>C. albicans</i> death through necrosis.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-13"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142458629","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":"Phenotypic and transcriptomic changes in <i>Acinetobacter baumannii</i> in rich and minimal growth mediums.","authors":"Vanessa Kornelsen, Dawn White, Ayush Kumar","doi":"10.1139/cjm-2024-0175","DOIUrl":"10.1139/cjm-2024-0175","url":null,"abstract":"<p><p><i>Acinetobacter baumannii</i> is an opportunistic pathogen that is often studied in commonly used rich media in laboratories worldwide. Due to the metabolic versatility of <i>A. baumannii</i>, it can be cultured in different growth mediums; however, this can lead to genotypic and phenotypic variations. In this study, we compared phenotypic and transcriptomic changes in <i>A. baumannii</i> ATCC17978-VU cultured in M9 minimal media supplemented with 20 mmol/L sodium succinate and rich lysogeny broth media. Phenotypically, growth was significantly slowed, virulence in <i>Galleria mellonella</i> was attenuated, and susceptibility to a variety of antibiotic classes was reduced when <i>A. baumannii</i> ATCC17978-VU was grown in minimal media versus rich media. Transcriptomic analysis showed differential regulation of >700 genes-including those associated with energy production and ribosomal function-when the two growth conditions were compared, with the majority of the upregulated genes seen in minimal media of unknown function. This study showed that culture media has a profound effect on the phenotype and cellular workings of a bacteria, highlighting the need for more studies of pathogens like <i>A. baumannii</i> ATCC17978-VU in minimal media.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-8"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143000709","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":"Microbial communities in the Hudson Strait amidst rapid environmental change.","authors":"Samantha J T Loutet, Alia Sanger, Kallie Strong, R Eric Collins, Nagissa Mahmoudi","doi":"10.1139/cjm-2024-0154","DOIUrl":"10.1139/cjm-2024-0154","url":null,"abstract":"<p><p>Climate change is rapidly altering Arctic marine environments, leading to warmer waters, increased river discharge, and accelerated sea ice melt. The Hudson Bay Marine System experiences the fastest rate of sea ice loss in the Canadian North resulting in a prolonged open water season during the summer months. We examined microbial communities in the Hudson Strait using high throughput 16s rRNA gene sequencing during the peak of summer, in which the bay was almost completely ice-free, and air temperatures were high. We found that salinity and temperature significantly affected the taxonomic composition among microbial communities across sites. We observed a higher relative abundance of specific <i>Polaribacter</i> sp. Amplicon sequence variants (ASVs) at more saline sites. Shannon diversity was not significantly impacted by salinity or temperature. These results contribute to our understanding of surface water microbial community composition in the Hudson Strait and shed light on how future salinity and temperature conditions may favour certain microbial populations.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-9"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027842","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 comprehensive guide to selecting the right modeling strategy for explanatory and predictive data analysis.","authors":"Maysa Niazy, Heather M Murphy, Khurram Nadeem, Nicole Ricker","doi":"10.1139/cjm-2025-0038","DOIUrl":"10.1139/cjm-2025-0038","url":null,"abstract":"<p><p>Declining costs of sequencing technology have catalyzed the widespread use of high-dimensional complex omics datasets in microbiology. While rich in information, these datasets present major analytical challenges, including sparsity, heterogeneity, and the need for robust statistical validation. Concerns about the reproducibility of findings across microbiological studies underscore the importance of standardized, transparent analytical approaches. Despite the availability of diverse statistical frameworks and machine learning methods, designing an appropriate statistical workflow (from method selection to model evaluation) remains challenging, particularly for researchers with limited advanced statistical training. Missteps in this process can lead to misinterpretation, irreproducibility, and flawed conclusions. This paper provides a structured, step-by-step framework to guide and validate the methodology of choosing the right statistical methods for both explanatory and predictive modeling in microbiology and translational research. We outline essential decision points spanning data preprocessing, feature selection, model assumptions, and model evaluation, and highlight common trade-offs and practical considerations. To demonstrate the guide's utility, we analyze a real-world COVID-19 dataset to identify cytokine biomarkers associated with disease severity. By aligning analytical strategies with microbiology inquiry, this guide aims to enhance reproducibility, empower data-informed decisions, and promote more rigorous, interpretable research in microbiology and public health.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-18"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144871605","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":"VeA is involved in anti-tumor activity by regulating adenylosuccinate lyase to mediate the synthesis of Acadesine in endophytic <i>Fusarium solani</i>.","authors":"Rongfei Liu, Wen Zheng, Lu Cai, Qing Xiao, Guihua Liu, Yuling Jiang, Zhangjiang He, Jichuan Kang","doi":"10.1139/cjm-2024-0073","DOIUrl":"https://doi.org/10.1139/cjm-2024-0073","url":null,"abstract":"<p><p>Acadesine (AICAR) is a promising candidate for new drugs in Phase III clinical trials. The purpose of this study is to analyse the steps in the biosynthesis pathway of AICAR. Our previous study found that overexpression of <i>veA</i>, a gene encoding a global regulator, significantly increased AICAR production of endophytic <i>Fusarium solani</i> HB1-J1 and the anti-tumor activity of its extracts. Transcriptome and metabolome analysis of FsveA^OE14, a <i>veA</i> overexpressing <i>F. solani</i> strain, revealed a 10-step AICAR synthesis pathway, with adenylosuccinate lyase PurB as a key enzyme. Generally, overexpressing <i>purB</i> (the gene encoding adenylosuccinate lyase) enhances AICAR synthesis. However, in FsveA^OE14, despite down-regulation of <i>purB</i>, AICAR content increased, which is contradictory. Further studies revealed that expression levels of <i>purB</i> homologs gene, <i>pro06469</i> and <i>pro10879</i>, were upregulated in FsveA^OE14. This suggests that although <i>veA</i> overexpression leads to <i>purB</i> down-regulation, their up-regulation may compensate for the reduction of <i>purB</i>, thus affecting AICAR synthesis. Additionally, compared to the wild type, overexpressing <i>purB</i> significantly enhances the inhibitory activity of the strain's extracts against the nonsmall-cell lung cancer cell line A549. Furthermore, it also increases the metabolic levels of other anti-tumor compounds, including 3-methyladenine, taurine, and others. These results indicate that VeA regulates AICAR biosynthesis via key enzymes like PurB, enhancing AICAR and other anti-tumor compound production, thus increasing the anti-tumor activity of <i>F. solani</i> extracts<i>.</i></p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"71 ","pages":"1-13"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552317","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":"Disruption of MAPK signalling and amino acid biosynthesis underlies the antifungal biocontrol mechanism of <i>Coniochaeta velutina</i> against <i>Colletotrichum gloeosporioides</i>: a transcriptome and metabolome analysis.","authors":"Wei Zheng, Chunling Yang, Chengbo Zhou, Tianxiao Ma, Qingsong Zhu, Zhuoqi Li","doi":"10.1139/cjm-2023-0223","DOIUrl":"10.1139/cjm-2023-0223","url":null,"abstract":"<p><p><i>Colletotrichum gloeosporioides</i> is a destructive pathogen that causes significant economic and ecological losses in agricultural and forestry production. In search of effective biocontrol agents, this study isolated an endophytic fungus, <i>Coniochaeta velutina</i>, from healthy <i>Camellia oleifera</i> leaves and investigated its in vitro inhibitory mechanism on <i>Colletotrichum gloeosporioides</i> using transcriptomics and metabolomics analyses. These findings were used to evaluate the differences in gene expression and metabolite content between the treatment (<i>Coniochaeta velutina</i>-treated <i>Colletotrichum gloeosporioides</i>) and control (untreated <i>Colletotrichum gloeosporioides</i>) groups. The transcriptomic analysis detected a total of 15 310 expressed genes, with 3938 showing significant differential expression (<i>p</i> < 0.05) (2093 upregulated and 1845 downregulated genes). These genes were enriched primarily in the following pathways: mitogen-activated protein kinase (MAPK) signalling, antibiotic biosynthesis, amino acid metabolism, carbon metabolism, and peroxidase pathways. Metabolomic analysis revealed 452 metabolites in both groups, with 138 showing significant differences. These genes were enriched mainly in secondary metabolite biosynthesis, amino acid biosynthesis, and α-linolenic acid metabolism. Transcriptome and metabolome association analyses, along with qRT-PCR results, revealed that the levels of intracellular pectolinarigenin metabolites significantly increased in the treatment group, leading to disrupted MAPK signalling and reduced amino acid biosynthesis, which are essential for maintaining normal cell growth. Notably, the decrease in terpenoid compounds was the primary reason that <i>Colletotrichum gloeosporioides</i> was inhibited by the biocontrol fungus <i>Coniochaeta velutina.</i> Therefore, these findings provide valuable insights into the biocontrol mechanisms of <i>Coniochaeta velutina</i> against <i>Colletotrichum gloeosporioides</i> and offer a promising foundation for the development of new anthracnose prevention and control strategies.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-13"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144118842","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":"Isolation, identification, and community study of root fungal isolates from disturbed and undisturbed Arctic and alpine tundra habitats in Northern Quebec, Canada.","authors":"Léonie Côté, Godar Sene, Marie-Eve Beaulieu, Stéphane Boudreau, Damase P Khasa","doi":"10.1139/cjm-2024-0211","DOIUrl":"10.1139/cjm-2024-0211","url":null,"abstract":"<p><p>In northern ecosystems such as the subarctic tundra, mining activities increase stress to a point where actions are needed to promote site reclamation. Ecological restoration of these mining-impacted sites with beneficial microorganisms, such as mycorrhizal fungi, is considered necessary and useful for the growth and survival of their host plants, but also for their tolerance to poor and contaminated environments, such as mine tailings. Here, we are interested in root symbionts associated with plants from the Schefferville mining site in northern Quebec. Very few studies of root fungal communities have been conducted in such a northern environment. The spatial and host plant variation of root fungal isolates was investigated. A total of 456 culturable fungi were isolated, of which 376 were successfully identified and assigned to 106 taxa based on rDNA internal transcribed spacer analysis using ITSF-1 and ITS-4 primers. The most commonly isolated fungi belonged to three genetically related groups: the <i>Rhizoscyphus ericae</i> aggregate, the dark septate endophytes, and <i>Umbelopsis rammaniana</i> and <i>Mortierella</i> sp., which are known to be genetically very close and often misclassified as one another. These groups were present on both disturbed and natural sites, but it appears that plants from disturbed sites had a greater affinity for dark septate endophytes. This study is the first step in the development of a restoration plan for the Schefferville mining site, and the baseline data obtained open new avenues for future studies, including the use of indigenous mycorrhizal-based biofertilizers to implement ecological revegetation strategies.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-13"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144274246","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":"Carvacrol, a monoterpenoid, binds quorum sensing proteins (LasI and LasR) and swarming motility protein BswR of <i>Pseudomonas aeruginosa,</i> resulting in loss of pathogenicity: an in silico approach.","authors":"Susmita Datta, Vishal Singh, Soma Nag, Dijendra Nath Roy","doi":"10.1139/cjm-2024-0155","DOIUrl":"10.1139/cjm-2024-0155","url":null,"abstract":"<p><p>The pathogenic <i>Pseudomonas aeruginosa</i> utilizes a quorum-sensing pathway for biofilm formation. The quorum-sensing proteins LasI and LasR of the Las system, alongside the swarming motility protein BswR, play a crucial role in the biofilm-mediated antibiotic resistance phenomenon. In this in silico study, LasI, LasR, and BswR were the prime targets for binding studies by promising drug candidates like linalool, ferutinin, citronellal, and carvacrol. These monoterpenoid compounds are carefully considered for this study due to their reported anti-microbial activity. Among all, carvacrol exhibited the highest binding energies with LasI (-5.932 kcal/mol), LasR (-7.469 kcal/mol), and BswR (-4.42 kcal/mol). Furthermore, the MMGBSA scores between carvacrol and LasI, LasR, and BswR individually are -33.14, -54.22, and -41.86 kcal/mol, which further corroborated the strong binding. During 100 ns of simulation, the ligand binds to the active sites of these proteins through the H-bonds at Ile107 of LasI, Tyr47 of LasR, and Leu57 of BswR. In addition, the root-mean-square deviation values of the ligand-protein complex are within the appropriate range of less than 5 Å. Absorption, Distribution, Metabolism, Excretion, and Toxicity analysis confirmed that carvacrol has the most negligible toxicity to mammalian cells. Hence, this finding is the first report to show that carvacrol can inhibit the <i>Pseudomonas aeruginosa</i> biofilms.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-15"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680845","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":"What in Earth? Analyses of Canadian soil populations of <i>Aspergillus fumigatus</i>.","authors":"Greg Korfanty, Arshia Kazerouni, Mykaelah Dixon, Micheala Trajkovski, Paola Gomez, Jianping Xu","doi":"10.1139/cjm-2024-0083","DOIUrl":"10.1139/cjm-2024-0083","url":null,"abstract":"<p><p><i>Aspergillus fumigatus</i> is a globally distributed mold and a major cause of opportunistic infections in humans. Because most infections are from environmental exposure, it is critical to understand environmental populations of <i>A. fumigatus</i>. Soil is a major ecological niche for <i>A. fumigatus</i>. Here, we analyzed 748 soil isolates from 21 locations in six provinces and one territory in Canada. All isolates were genotyped using nine microsatellite markers. Due to small sample size and/or close proximities for some local samples, these isolates were grouped into 16 local geographic and ecological populations. Our results indicated high allelic and genotypic diversities within most local and provincial populations. Interestingly, low but statistically significant genetic differentiations were found among geographic populations within Canada, with relatively similar proportions of strains and genotypes belonging to two large genetic clusters. In Hamilton, Ontario, and Vancouver, BC, where two and three ecological populations were analyzed, respectively, we found limited genetic difference among them. Most local and provincial populations showed evidence of both clonality and recombination, with no population showing random recombination. Of the 748 soil isolates analyzed here, two were resistant to triazole antifungals. We discuss the implications of our results to the evolution and epidemiology of <i>A. fumigatus</i>.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-13"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142458630","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}