Canadian journal of microbiology最新文献

{"title":"Variability in biofilm formation dynamics by <i>Salmonella enterica</i> isolated from animal-origin foods, plant-based foods, environment, clinical, and unspecified food sources: a 3-day in vitro study in tryptic soy broth at ambient temperature.","authors":"D E Mendoza-Barrón, M Hernández-Iturriaga, A Godínez-Oviedo","doi":"10.1139/cjm-2025-0020","DOIUrl":"10.1139/cjm-2025-0020","url":null,"abstract":"<p><p>Bacterial biofilm production is linked to its adaptive capacity to environments throughout its lifecycle. This study aimed to assess the variability in biofilm formation (BF) dynamic by <i>Salmonella enterica</i> and to explore the potential impact of the cell's prior history, primarily shaped by strain and its isolation source. In vitro BF of 141 <i>S. enterica</i> strains isolated from animal-origin foods, plant-based foods, unspecified food sources, the environment, and clinical cases, was evaluated using the crystal violet assay at 25 °C for up to 72 h. Kruskal-Wallis test was used to assess the effect of time, source, and strain. The Aryani method was used to characterize microbial response variability. The BF capacity of <i>S. enterica</i> strains ranged from 0.07 to 2.3, 0.07 to 2.7, and 0.06 to 2.7OD_595nm at 24, 48, and 72 h, respectively. At 24 h (66.0%; 93/141) and 48 h (56.0%; 79/141), most isolates were classified as nonbiofilm producers, while at 72 h, the majority were weak biofilm producers (39.7%; 56/141). Time, strain, and isolation source significantly influenced BF, with an overall increase in BF occurring over time, and clinical strains being the highest biofilm producers. Strain to strain variability was the highest contributor to the total variance ( <math><msubsup><mi>σ</mi> <mrow><mn>24</mn> <mi>h</mi></mrow> <mn>2</mn></msubsup> </math> = 0.18OD_595nm ², <math><msubsup><mi>σ</mi> <mrow><mn>48</mn> <mi>h</mi></mrow> <mn>2</mn></msubsup> </math> = 0.23OD_595nm ², <math><msubsup><mi>σ</mi> <mrow><mn>72</mn> <mi>h</mi></mrow> <mn>2</mn></msubsup> </math> = 0.26OD_595nm ²). Analysis of variability between and within isolation source groups revealed the highest variability among clinical isolates ( <math><msubsup><mi>σ</mi> <mrow><mn>24</mn> <mi>h</mi></mrow> <mn>2</mn></msubsup> </math> = 1.08OD_595nm ², <math><msubsup><mi>σ</mi> <mrow><mn>48</mn> <mi>h</mi></mrow> <mn>2</mn></msubsup> </math> = 1.36OD_595nm ², <math><msubsup><mi>σ</mi> <mrow><mn>72</mn> <mi>h</mi></mrow> <mn>2</mn></msubsup> </math> = 1.38OD_595nm ²). Although BF was statistically associated with the strain and its isolation source, the high variability observed within these factors suggests that they alone are insufficient to explain how the cell's prior history influences BF. A more comprehensive undertanding on BF will require considering additional intrinsic and extrinsic factors.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-8"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144882243","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":"<i>Morchella capensis</i> sp. nov., the Fynbos morel-the first description of an endemic <i>Morchella</i> species from Africa.","authors":"B Van der Merwe, J Williams, E Le Roux, A Van Staden, G Lawrence, K Jacobs","doi":"10.1139/cjm-2023-0224","DOIUrl":"10.1139/cjm-2023-0224","url":null,"abstract":"<p><p>A species of <i>Morchella</i> was observed growing in spring, under a vulnerable member of the <i>Proteaceae</i>, in the Cape Floristic Region of South Africa. These fungi shared many of the cryptic characteristics common in the genus <i>Morchella</i> and displayed a wide range of phenotypic expression. The unique ecology of these fungi and the fact that no endemic <i>Morchella</i> species have been described from Africa lead to suspicions that this could be a novel species. Sequencing of key genetic regions, phylogenetics, and morphological studies confirmed that this was indeed a previously unknown species of <i>Morchella</i>. Roots collected underneath the fruiting bodies displayed a range of root-associated activities, alluding to a possible relationship. Further, this <i>Morchella</i> species has a history of traditional use on the Cape Peninsula of South Africa. The traditional use of fungi is rarely recorded in Africa. In this study, we introduce <b><i>Morchella capensis</i> sp. nov.</b>, the first endemic African morel.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"71 ","pages":"1-11"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514805","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":"BEVA2.0: modular assembly of golden gate-compatible vectors with expanded utility for genetic engineering.","authors":"Barney A Geddes, Riley Williamson, Jake Schumacher, Ahmad Ardi, Garrett Levin, Emily Červenka, Rui Huang, George C diCenzo","doi":"10.1139/cjm-2024-0246","DOIUrl":"10.1139/cjm-2024-0246","url":null,"abstract":"<p><p>This expansion for the modular vector assembly platform BEVA (Bacterial Expression Vector Archive) introduces 11 new BEVA parts including two new cloning site variants, two new antibiotic resistance modules, three new origins of replication, and four new accessary modules. As a result, the modular system is now doubled in size and expanded in its capacity to produce diverse replicating plasmids. Furthermore, it is now amenable to genetic engineering methods involving genome-manipulation of target strains through deletions or integrations. In addition to introducing the new modules, we provide several BEVA-derived Golden Gate cloning plasmids that are used to validate parts and that may be useful for genetic engineering of proteobacteria and other bacteria. We also introduce new parts to allow compatibility with the CIDAR MoClo parts libraries.</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":"143370450","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":"Survival of antimicrobial resistant <i>Salmonella</i> Heidelberg inoculated into microcosms of fresh pine wood shavings for broiler litter.","authors":"Adelumola Oladeinde, Kimberly Cook, Attiq Rehman, Catherine D Carrillo, Reed Woyda, Crystal Wiersma, Zaid Abdo, Jasmine Johnson, Anna Marie Bosch, Michael Rothrock, Moussa S Diarra","doi":"10.1139/cjm-2024-0088","DOIUrl":"10.1139/cjm-2024-0088","url":null,"abstract":"<p><strong>Highlights: </strong><i>S</i>. Heidelberg survived up to 21 days in PWS which is often used as broiler bedding. <i>S</i>. Heidelberg abundance and survival was correlated with the water activity of PWS. <i>S</i>. Heidelberg strains that carried higher copy numbers of small Col plasmids were the dominant strains isolated from PWS at later time points. <i>S</i>. Heidelberg strains harboring transmissible plasmid carrying AmpC-like beta-lactamase gene persisted longer in PWS without antibiotic pressures for AMR.</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":"142495599","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":"Tolerance mechanisms and molecular epidemiology of reduced susceptibility to chlorhexidine digluconate in different species of the <i>Acinetobacter baumannii</i> complex.","authors":"Liqiong Chen, Shixing Liu, Na Huang, Chunquan Xu, Cui Zhou, Lingbo Wang, Xiangkuo Zheng, Tieli Zhou, Pingting Yu","doi":"10.1139/cjm-2024-0174","DOIUrl":"10.1139/cjm-2024-0174","url":null,"abstract":"<p><p>The objective of this study was to compare chlorhexidine digluconate and other antibiotics susceptibility of four species of the<i>Acinetobacter baumannii</i> complex, and further investigate the chlorhexidine digluconate (CHG) tolerance mechanisms and molecular epidemic characteristics. Of 889 <i>A. baumannii</i> complex isolates, <i>A. baumannii, A. nosocomialis, A. pittii</i>, and <i>A. seifertii</i> accounted for 84.2%, 10.9%, 3.4%, and 1.5%. <i>Acinetobacter baumannii</i> was generally resistant to all tested antibiotics, while other three species were commonly more susceptible; 92.1% (313/340) CHG-tolerant <i>A. baumannii</i>, 19.6% (19/97) CHG-tolerant <i>A. nosocomialis</i>, 3.3% (1/30) CHG-tolerant <i>A. pittii</i>, and 15.4% (2/13) CHG-tolerant <i>A. seifertii</i> were identified. Furthermore, compared to <i>A. baumannii</i> ATCC 19606, upregulated expression was found in <i>qacE</i>_Δ1, <i>fabI</i>, and efflux pump encoding genes in CHG-tolerant <i>A. baumannii</i>, but the expression level of <i>oprD</i> was reduced. Additionally, only the expression level of <i>fabI</i> was increased in the CHG-tolerant <i>A. nosocomialis</i>, and the expression level of <i>adeG</i> was increased in the CHG-tolerant <i>A. pittii</i> and <i>A. seifertii</i>. Furthermore, CHG-tolerant <i>A. baumannii</i> may have a relatively high clonal correlation, the predominant sequence type of which was ST208 (90%, 36/40). It is rather necessary to identify specific species members among the <i>A. baumannii</i> complex for clinical treatment options and antibiotics resistance monitoring.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-11"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142869396","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":"Diversity and distribution characteristics of myxobacteria in the rhizosphere and nonrhizosphere soils of the halophyte <i>Haloxylon ammodendron</i> in the high saline-alkaline Ebinur Lake Wetland.","authors":"Xiaoyun Qi, Suhui Hou, Wenge Hu, Cheng Ding, Yang Li, Jie Xiong","doi":"10.1139/cjm-2024-0045","DOIUrl":"10.1139/cjm-2024-0045","url":null,"abstract":"<p><p>This study employed Illumina HiSeq high-throughput sequencing technology to analyze the V4-V5 regions of myxobacterial 16S rRNA in rhizosphere and nonrhizosphere soils of <i>Haloxylon ammodendron</i> in the saline-alkaline wetland of Ebinur Lake, with the aim of investigating the community structure and diversity of myxobacteria. Results indicated that myxobacterial communities in rhizosphere soils exhibited greater diversity and richness compared to nonrhizosphere soils. Soil physicochemical properties, particularly moisture content, were identified as key environmental factors influencing myxobacterial diversity. The halotolerant genus <i>Haliangium</i> was found to be predominant under saline-alkaline conditions. Additionally, myxobacteria demonstrated distinct ecological specificity and environmental adaptability between rhizosphere and nonrhizosphere soils. For example, the genus <i>Enhygromyxa</i> exhibited a negative correlation with soil moisture content in rhizosphere soils but a positive correlation with soil electrical conductivity in nonrhizosphere soils. Co-occurrence network analysis revealed complex interaction patterns among myxobacterial genera and other bacterial genera, with closer interactions observed in rhizosphere soils. This study highlights the importance of environmental factors in regulating microbial community structure and function in saline-alkaline wetlands, providing new insights into the ecological roles and interaction mechanisms of myxobacteria within the ecosystem.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"71 ","pages":"1-17"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143673369","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 ecology and evolution.","authors":"Rebecca T Doyle, Leanne A Grieves, Aleeza C Gerstein","doi":"10.1139/cjm-2024-0192","DOIUrl":"10.1139/cjm-2024-0192","url":null,"abstract":"","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-3"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142913596","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":"Rapid identification of <i>Fusarium</i> species causing head blight in Canada using MALDI-TOF mass spectrometry.","authors":"Shimosh Kurera, Bhaktiben Patel, Tehreem Ashfaq, Maria Eckhardt, Janice Bamforth, Niradha Withana Gamage, Gurcharn Singh Brar, Linda J Harris, Maria Antonia Henriquez, Rajagopal Subramaniam, Xiben Wang, Zamir Punja, Curtis Pozniak, Matthew G Bakker, Sean Walkowiak","doi":"10.1139/cjm-2025-0035","DOIUrl":"10.1139/cjm-2025-0035","url":null,"abstract":"<p><p>Fusarium head blight is a limitation to grain production and can be caused by several different <i>Fusarium</i> species. We evaluated the ability of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) to perform species identifications. The method generates a unique peptide mass fingerprint (PMF) for each sample that can be matched to a reference library. We first created a reference library of PMF profiles for <i>Fusarium</i> species from across Canada. Then, we tested the library to perform identifications using two validation panels. The first panel consisted of 820 fungal isolates from wheat (2021-2023 harvest years) and the second was 74 fungal isolates from oat and barley (2022 harvest year). The species identity of samples from the validation panels was confirmed with high-throughput quantitative PCR using species-specific DNA markers. The first validation panel was mostly <i>F. graminearum</i> and there was 95% overlap between the MALDI-TOF MS and DNA-based identifications. The second panel was mostly <i>F. poae</i> and the identifications from the two methods had 86% overlap. Our findings indicate that MALDI-TOF MS biotyping is sensitive enough to identify <i>Fusarium</i> strains to their species complexes and certain <i>Fusarium</i> strains to the species level.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-12"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143973324","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":"RNA-seq analysis of transcription patterns during infection of <i>Mesorhizobium japonicum</i> by phage Cp1R7A-A1.","authors":"K M Damitha Gunathilake, Kara D Loos, Christopher K Yost, Michael F Hynes","doi":"10.1139/cjm-2025-0061","DOIUrl":"10.1139/cjm-2025-0061","url":null,"abstract":"<p><p>RNA-Seq analysis of <i>Mesorhizobium japonicum</i> infected by phage Cp1R7A-A1 (full name vB_MloS_Cp1R7A-A1) revealed the transcription of all 237 putative phage genes, including 27 tRNA and 210 protein-encoding genes. All predicted protein-encoding genes of Cp1R7A_A1 showed expression. The phage tRNA genes also showed a notable expression, indicating a possible tRNA-dependant phage survival strategy. Host genes related to nutrient uptake and energy metabolism were significantly upregulated within 1-2 h post infection, likely reflecting the phage's metabolic demands. Notably, peptidoglycan-cleaving enzymes showed elevated expression after 3 h, suggesting host stress responses. These findings show the transcriptional interplay between phage Cp1R7A-A1 and <i>M. japonicum</i>, providing a foundation for future functional studies.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511600","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":"Influence of aquaculture and genomic surveillance techniques on antimicrobial resistance gene profiles and microbiota detected in marine and freshwater sediments.","authors":"Lisa A Johnson, Derek D N Smith, Renuka M Subasinghe, Monique R Raap, Robin Richter, David Huyben, Calvin H F Lau, Liam Brown, Jackson W F Chu, Olena P Khomenko, Anthony J Manning, Stewart C Johnson, Dounia Hamoutene","doi":"10.1139/cjm-2024-0206","DOIUrl":"10.1139/cjm-2024-0206","url":null,"abstract":"<p><p>Surveillance methods for antimicrobial resistance genes (ARGs) are needed to assess potential risk of antimicrobial resistance, especially in complex environmental samples with limited data on ARG distribution. This study employed target-enrichment metagenomics (bait-capture) and a Resistomap qPCR assay to assess the resistome in marine and freshwater sediments associated with active Canadian finfish aquaculture operations. Differences in resistome profiles were considered with distance to the net-pens, concentrations of three aquaculture-associated chemical residues, and microbial communities as detected with 16S rRNA gene amplicon sequencing. With bait-capture, a total of 194 ARGs and 41 replicon types were detected across the sediment samples. Differences due to aquaculture proximity were noted in the composition of the resistome, which was dominated by tetracycline resistance genes. With qPCR, 37 out of 51 ARGs targets were detected, and proximity to net-pens or region did not show changes in resistome composition. Co-occurrence networks revealed significant correlations among genera and the resistome detected with bait-capture, highlighting a potential influence of aquaculture on ARGs in the environment. This study demonstrates the utility of bait-capture and qPCR assays in detection of ARGs in both freshwater and marine sediments from aquaculture sites that will assist further ARG surveillance.</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":"144309555","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}