Canadian journal of microbiology最新文献

{"title":"Variation in plasmid conjugation among nontyphoidal <i>Salmonella enterica</i> serovars.","authors":"Anna Laidlaw, Madeleine Blondin-Brosseau, Julie A Shay, Forest Dussault, Mary Rao, Nicholas Petronella, Sandeep Tamber","doi":"10.1139/cjm-2024-0164","DOIUrl":"10.1139/cjm-2024-0164","url":null,"abstract":"<p><p>Conjugation is a complex phenomenon involving multiple plasmid, bacterial, and environmental factors. Here we describe an IncI1 plasmid encoding multidrug antibiotic resistance to aminoglycosides, sulfonamides, and third-generation cephalosporins. This plasmid is widespread geographically among animal, human, and environmental sectors. We present data on the transmissibility of this plasmid from <i>Salmonella</i> <i>enterica</i> ser. Kentucky into 40 strains of <i>S. enterica</i> (10 strains each from serovars Enteritidis, Heidelberg, Infantis, and Typhimurium). Thirty seven out of 40 strains were able to take up the plasmid. Rates of conjugation were variable between strains ranging from 10^-8 to 10^-4. Overall, serovars Enteritidis and Typhimurium demonstrated the highest rates of conjugation, followed by Heidelberg, and then Infantis. No relationships were observed between the recipient cell surface and rate of conjugation. Recipient cell numbers correlated positively with conjugation rate and strains with high conjugation rates had marginally but significantly higher growth parameters compared to strains that took up the plasmid at lower frequencies. Environmental conditions known to impact cell growth, such as temperature, nutrient availability, and the presence of antibiotics, had a modulating effect on conjugation. Collectively, these results will further understanding of plasmid transmission dynamics in <i>Salmonella</i>, which is a critical first step towards the development of mitigation strategies.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-14"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142853058","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":"Engineering conjugative plasmids for inducible horizontal DNA transfer.","authors":"Tahani Jaafar, Emily Carvalhais, Arina Shrestha, Ryan R Cochrane, Jordyn S Meaney, Stephanie L Brumwell, Samir Hamadache, Vida Nasrollahi, Bogumil J Karas","doi":"10.1139/cjm-2024-0241","DOIUrl":"10.1139/cjm-2024-0241","url":null,"abstract":"<p><p>Rapidly developing microbial resistance to existing antimicrobials poses a growing threat to public health and global food security. Current chemical-based treatments target cells by inhibiting growth or metabolic function, but their effectiveness is diminishing. To address the growing antimicrobial resistance crisis, there is an urgent need for innovative therapies. Conjugative plasmids, a natural mechanism of horizontal gene transfer in bacteria, have been repurposed to deliver toxic genetic cargo to recipient cells, showing promise as next-generation antimicrobial agents. However, the ecological risks posed by unintended gene transfer require robust biocontainment strategies. In this study, we developed inducible conjugative plasmids to solve these challenges. Utilizing an arabinose-inducible promoter, we evaluated 13 plasmids with single essential gene deletions, identifying trbC and trbF as strong candidates for stringent regulation. These plasmids demonstrated inducibility in both <i>cis</i> and <i>trans</i> configurations, with induction resulting in up to a 5-log increase in conjugation efficiency compared to uninduced conditions. Although challenges such as reduced conjugation efficiency and promoter leakiness persist, this work establishes a foundation for the controlled transfer of plasmids, paving the way for safer and more effective antimicrobial technologies.</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":"143762954","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":"Assessment of viable <i>Enterobacteriaceae</i> and <i>Enterococcus</i> spp. across the agro-ecosystem of an antibiotic-free swine farm.","authors":"Alexandra Langlois, Antony T Vincent, Renée M Petri, Karoline Lauzon, Dominic Poulin-Laprade","doi":"10.1139/cjm-2024-0173","DOIUrl":"10.1139/cjm-2024-0173","url":null,"abstract":"<p><p>Agricultural practices, specifically the use of antibiotics and other biocides, have repercussions on human, animal, and plant health. The aim of this study was to evaluate the levels of <i>Enterobacteriaceae</i> and <i>Enterococcus</i>, as antibiotic-resistant marker bacteria, in various matrices across the agro-ecosystem of an antibiotic-free swine farm in Quebec (Canada), namely pig feed, feces, manure, agricultural soil, water and sediment from a crossing stream, and soil from nearby forests. Samples were collected in fall 2022, spring and fall 2023, and spring 2024. All samples were subjected to counts of total, cefotaxime-, and ciprofloxacin-resistant <i>Enterobacteriaceae</i> as well as total and vancomycin-resistant <i>Enterococcus</i> spp. The frequency of total and cefotaxime-resistant <i>Enterobacteriaceae</i> along with the vancomycin-resistant <i>Enterococcus</i> decreased with age in pig feces, from weaning to the end of the fattening period. High proportions of the <i>Enterobacteriaceae</i> recovered from feces and environmental samples were resistant to cefotaxime. Application of manure on fields contributed a significant input of <i>Enterococcus</i>, but those resistant to vancomycin were under the detection limit. This study shows the prevalence of antibiotic-resistant bacteria in a farm agro-ecosystem even without the administration of antibiotics to the animals and highlights the complexity of components influencing antimicrobial resistance in the environment.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-14"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143064035","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":"Survey of fungal endophytes in barley under Fusarium head blight infection.","authors":"Denice Embrador, Zoe Quill, James R Tucker, Keval Shah, Ana Badea, Champa Wijekoon","doi":"10.1139/cjm-2024-0137","DOIUrl":"10.1139/cjm-2024-0137","url":null,"abstract":"<p><p>Fusarium head blight (FHB) is a devastating fungal disease caused by <i>Fusarium graminearum</i>, which affects barley (<i>Hordeum vulgare</i> L.) and other small cereal grains. Fungal endophytes are microorganisms that reside inside tissues and considered that they may have been involved in various roles of the plants. This study involved the comparison of fungal endophytes between \"non-infected/clean\" and \"FHB-infected\" barley genotypes in various tissues collected at different plant developmental stages and were grown under different conditions (i.e., greenhouse, research field, and FHB-field nursery). We hypothesized that fungal endophytes diversity and abundance may differ between plant tissues in various barley genotypes that were non-infected and FHB-infected. The 18S-internal transcribed spacer sequencing analysis revealed a greater number of fungal operational taxonomic units (OTUs) and endophyte species in FHB-infected barley compared to clean barley. A one-way ANOVA and Tukey's pairwise comparison test (<i>p</i> ≤ 0.05) were performed to test significant differences. Higher seed endophyte diversity was found in FHB-infected (120 OTUs) compared to non-infected (113 OTUs) harvested in 2021. The increase in diversity of endophytes that contributes to different roles in plant protection and defense, such as biocontrol agents, may prevent the growth of <i>Fusarium</i> species and decrease FHB-infection.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-16"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143784558","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":"Crossing the streams: improving data quality and integration across the One Health genomics continuum with data standards and implementation strategies.","authors":"Emma J Griffiths, Emil Jurga, Gabriel Wajnberg, Julie A Shay, Rhiannon Cameron, Charlie Barclay, Anoosha Sehar, Damion Dooley, Nithu Sara John, Andrew Scott, Lisa A Johnson, James Robertson, Justin Schonfeld, D Patrick Bastedo, Joshua Tang, Xianhua Yin, Attiq Rehman, Rhiannon L Wallace, Krysty Thomas, Shannon H C Eagle, Tim McAllister, Moussa S Diarra, John H E Nash, Ed Topp, Gary Van Domselaar, Eduardo Taboada, Sandeep Tamber, Tony Kess, Jordyn Broadbent, Dominic Poulin-Laprade, Derek D N Smith, Richard Reid-Smith, Rahat Zaheer, Chad R Laing, Catherine D Carrillo, William W L Hsiao","doi":"10.1139/cjm-2024-0203","DOIUrl":"10.1139/cjm-2024-0203","url":null,"abstract":"<p><p>The Canadian Genomics Research and Development Initiative for Antimicrobial Resistance (GRDI-AMR) uses a genomics-based approach to understand how health care, food production and the environment contribute to the development of antimicrobial resistance. Integrating genomics contextual data streams across the One Health continuum is challenging because of the diversity in data scope, content and structure. To better enable data harmonization for analyses, a contextual data standard was developed. However, development of standards does not guarantee their use. Implementation strategies are critical for putting standards into practice. This work focuses on the development of implementation strategies to better operationalize data standards across the Canadian federal genomics ecosystem. Results include improved understanding of complex data models that can create challenges for existing systems. Technical implementation strategies included spreadsheet-based solutions, new exchange formats, and direct standards integration into new databases. Data curation exercises highlighted common data collection and sharing issues, which informed improved practices and evaluation procedures. These new practices are contributing to improved data quality and sharing within the GRDI-AMR consortium as evidenced by publicly available datasets. The implementation strategies and lessons learned described in this work are generalizable for other standards and can be applied more broadly within other initiatives.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-14"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143000699","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":"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}