Canadian journal of microbiology最新文献

{"title":"Somatic coliphages as bioindicators of contamination in Lake Guamuez, Colombia.","authors":"Mario Andres Pantoja-España, Miller Cerón Gómez, Eddy Patricia López Molano, Raúl Mauricio Insuasty, Eduardo Ibarguen-Mondragón, María Alejandra Mármol Martínez, Deisy Lorena Guerrero-Ceballos, Jenny Dimelza Gómez Arrieta, Juan Camilo Paz García, Pablo Heyman Fernández Izquierdo, Arsenio Hidalgo Troya, Sandra Jaqueline Mena-Huertas, Noemi Nosomi Taniwaki, Gislene Mitsue Namiyama, Edith Mariela Burbano-Rosero","doi":"10.1139/cjm-2023-0147","DOIUrl":"10.1139/cjm-2023-0147","url":null,"abstract":"<p><p>Lake Guamuez is the second largest lake in Colombia and economically supports hundreds of families in the area. The main activities carried out in the region have focused on tourism, agriculture, livestock, and rainbow trout production; however, these activities have been associated with contamination of the lake. This research aimed to evaluate the water quality of Lake Guamuez using somatic coliphages (SCs) as bioindicators. For this purpose, periodic sampling was carried out for 6 months at nine strategic points of the lake. For the detection of SCs, the method described in 9211 D of the Standard Methods for the Examination of Water and Wastewater was used. The genomic variability and presence of virulence genes in the isolated SCs were determined. Water contamination in the lake is evident, and the SCs titer is greater in areas with a high flow of anthropogenic activities. An important degree of genetic diversity and a high prevalence of virulence genes could be observed among the SCs analyzed. The results when compared with guidelines and water quality standards from various countries showed concentrations of SCs higher than those allowed. The high prevalence of gastrointestinal diseases in the region suggests a link to water contamination.</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":"142495598","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":"Note of appreciation.","authors":"","doi":"10.1139/cjm-2024-0228","DOIUrl":"https://doi.org/10.1139/cjm-2024-0228","url":null,"abstract":"","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"71 ","pages":"1"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143000717","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":"Mechanisms and implications of phenotypic switching in bacterial pathogens.","authors":"Alexander Stephen Byrne, Nathalie Bissonnette, Kapil Tahlan","doi":"10.1139/cjm-2024-0116","DOIUrl":"10.1139/cjm-2024-0116","url":null,"abstract":"<p><p>Bacteria encounter various stressful conditions within a variety of dynamic environments, which they must overcome for survival. One way they achieve this is by developing phenotypic heterogeneity to introduce diversity within their population. Such distinct subpopulations can arise through endogenous fluctuations in regulatory components, wherein bacteria can express diverse phenotypes and switch between them, sometimes in a heritable and reversible manner. This switching may also lead to antigenic variation, enabling pathogenic bacteria to evade the host immune response. Therefore, phenotypic heterogeneity plays a significant role in microbial pathogenesis, immune evasion, antibiotic resistance, host niche tissue establishment, and environmental persistence. This heterogeneity can result from stochastic and responsive switches, as well as various genetic and epigenetic mechanisms. The development of phenotypic heterogeneity may create clonal populations that differ in their level of virulence, contribute to the formation of biofilms, and allow for antibiotic persistence within select morphological variants. This review delves into the current understanding of the molecular switching mechanisms underlying phenotypic heterogeneity, highlighting their roles in establishing infections caused by select bacterial pathogens.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-19"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370976","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":"Surveillance of <i>Clostridioides difficile</i> in Canadian retail meat and genomic linkages to community-associated human clinical infections in Canada.","authors":"Paula E Pidsadny, Tim Du, Romeo Hizon, Sean Ahmed, Derek Tan, George G Zhanel, Denice C Bay, Richard J Reid-Smith, Audrey Charlebois, George R Golding","doi":"10.1139/cjm-2024-0193","DOIUrl":"10.1139/cjm-2024-0193","url":null,"abstract":"<p><p>Community-associated <i>Clostridioides difficile</i> infections (CA-CDI) remain a concern in Canada, comprising a quarter of cases previously reported through the Canadian Nosocomial Infection Surveillance Program. Previous Canadian studies have reported toxigenic <i>C. difficile</i> isolated from Canadian retail meat, suggesting that it may be a source of exposure for CA-CDI in Canada. In this study, 3/219 (1.4%) of retail pork and 0/99 (0%) of retail beef samples tested positive for toxigenic <i>C. difficile</i>, which were molecularly characterized by PCR ribotyping and whole-genome sequencing. All three isolates were obtained from pork and belonged to sequence types (STs)/ribotypes (RTs) that have previously been isolated from human clinical CA-CDI cases in Canada: ST1/RT027, ST8/RT002, and ST10/RT015. Retail meat isolates were susceptible to the antimicrobials tested, save one isolate with intermediate resistance to clindamycin. Genomic comparison to Canadian human clinical CA-CDI isolates with the same corresponding ST/RT types showed two of the three pork isolates clustered with CA-CDI isolates via core-genome multilocus sequencing typing, with single nucleotide variant (SNV) analysis showing further genomic relatedness of 2-11 SNVs. Retail meat may therefore be a low source of CA-CDI exposure in Canada, with the potential for foodborne transmission of select clones.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-7"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143498621","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":"Longitudinal screening of retail milk from Canadian provinces reveals no detections of influenza A virus RNA (April-July 2024): leveraging a newly established pan-Canadian network for responding to emerging viruses.","authors":"Hannah L Wallace, Jordan Wight, Mariana Baz, Barbara Dowding, Louis Flamand, Tom Hobman, François Jean, Jeffrey B Joy, Andrew S Lang, Sonya MacParland, Craig McCormick, Ryan Noyce, Rodney S Russell, Selena M Sagan, Jumari Snyman, Gabriela J Rzeszutek, Mustafa S Jafri, Isaac Bogoch, Jason Kindrachuk, Angela L Rasmussen","doi":"10.1139/cjm-2024-0120","DOIUrl":"10.1139/cjm-2024-0120","url":null,"abstract":"<p><p>Highly pathogenic avian influenza (HPAI) H5N1 has caused the deaths of more than 100 million birds since 2021, and human cases since 1997 have been associated with significant morbidity and mortality. Given recent detections of HPAI H5N1 in dairy cattle and H5N1 RNA detections in pasteurized retail milk in the United States, we established the pan-Canadian Milk Network in April 2024. Through our network of collaborators from across Canada, retail milk was procured longitudinally, approximately every 2 weeks, and sent to a central laboratory to test for the presence of influenza A virus RNA. Between 29 April and 17 July 2024, we tested 109 retail milk samples from all 10 Canadian provinces (NL, NS, PEI, NB, QC, ON, MB, SK, AB, and BC). All samples tested negative for influenza A virus RNA. This nationwide initiative was established for rapid retail milk screening as per the earliest reports of similar undertakings in the United States. Our independent testing results have aligned with reporting from federal retail milk testing initiatives. Despite no known HPAI infections of dairy cattle in Canada to date, H5N1 poses a significant threat to the health of both humans and other animals. By performing routine surveillance of retail milk on a national scale, we have shown that academic networks and initiatives can rapidly establish nationwide emerging infectious disease surveillance that is cost-effective, standardized, scalable, and easily accessible. Our network can serve as an early detection system to help inform containment and mitigation activities if positive samples are identified and can be readily reactivated should HPAI H5N1 or other emerging zoonotic viruses be identified in agricultural or livestock settings, including Canadian dairy cattle.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-7"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142342147","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":"Microbiome profiling suggests novel endosymbiont associations of insect pests of stored grain.","authors":"Janice Fajardo, Brian Harrison, Vincent A D Hervet, Matthew G Bakker","doi":"10.1139/cjm-2024-0095","DOIUrl":"10.1139/cjm-2024-0095","url":null,"abstract":"<p><p>Many arthropods, including economically important pests of stored grains, host intracellular bacterial symbionts. These symbionts can have diverse impacts on host morphology, stress tolerance, and reproductive success. The ability to rapidly determine the infection status of host insects and the identity of intracellular symbionts, if present, is vital to understanding the biology and ecology of these organisms. We used a microbiome profiling method based on amplicon sequencing to rapidly screen 35 captive insect colonies. This method effectively revealed single and mixed infections by intracellular bacterial symbionts, as well as the presence or absence of a dominant symbiont, when that was the case. Because no a priori decisions are required about probable host-symbiont pairing, this method is able to quickly identify novel associations. This work highlights the frequency of endosymbionts, indicates some unexpected pairings that should be investigated further, such as dominant bacterial taxa that are not among the canonical genera of endosymbionts, and reveals different colonies of the same host insect species that differ in the presence and identity of endosymbiotic bacteria.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-6"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142674980","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>Lavandula angustifolia</i> oil induces oxidative stress, stiffening of membranes, and cell wall in <i>Cryptococcus</i> spp.","authors":"Yohana Porto Calegari-Alves, Rafael Lopes da Rosa, Renata Pereira Costa, Camila Innocente-Alves, Aline Martins Faustino, John R Yates, Walter Orlando Beys-da-Silva, Lucélia Santi","doi":"10.1139/cjm-2024-0084","DOIUrl":"10.1139/cjm-2024-0084","url":null,"abstract":"<p><p>The <i>Cryptococcus neoformans</i> and <i>Cryptococcus gattii</i> species complexes are the etiological agents of cryptococcosis, a disease responsible for 181 000 deaths annually worldwide due to late diagnosis and limited treatment options. Studies focusing on the identification of new substances with antifungal activity, such as essential oils (EOs), are urgently needed. While the antifungal effects of EO have already been suggested, their mechanism of action at the molecular level still requires evaluation. In this work, we assessed the molecular changes induced by the exposure of <i>Cryptococus neoformans</i> (H99) and <i>Cryptococcus deuterogatti</i> (R265) to lavender essential oil (LEO) using a morphological and proteomics approach. The identified proteins were categorized by Gene Ontology according to biological processes and molecular functions, and Kyoto Encyclopedia of Genes and Genomes pathway analysis was also conducted. Our findings indicate that LEO creates a stressful environment in both strains; however, the response to this stimulus differs between the two species. In <i>C. neoformans</i>, changes were observed in energy metabolism and pathways related to alternative sources of energy and oxidative stress response. In <i>C. deuterogatti</i>, changes were identified in pathways related to cellular architecture, implying that the cell underwent morphological changes such as membrane and cell wall stiffening.</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":"142766495","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":"Cecal microbiome in broiler chicken related to antimicrobial feeding and bird's sex.","authors":"Philip H W Mak, Xianhua Yin, Lindsey Clairmont, Lisa Bean-Hodgins, Elijah G Kiarie, Joshua Tang, Dion Lepp, Moussa S Diarra","doi":"10.1139/cjm-2024-0190","DOIUrl":"10.1139/cjm-2024-0190","url":null,"abstract":"<p><p>This study investigated the cecal microbiome of broilers raised under specific antimicrobial feeding programs (AFPs). A total of 2304 day-old Ross-708 male (M, <i>n</i> = 1152) and female (F, <i>n</i> = 1152) chicks were distributed into 48 floor pens which were allocated to one of three AFPs: Conventional, raised without medically important antibiotics (RWMIA), and raised without antibiotics (RWA). At 28 (D28) and 41 (D41) days of age, cecal contents were collected for culture dependent and independent analyses. At both 28 and 41 days, <i>Enterococcus</i> was more abundant in RWA-raised broilers than other groups with the most abundance of this bacterium being found in female birds (<i>P</i> < 0.05). At D41, the most abundant <i>Eimeria tenella</i> counts was observed in RWA-raised broiler ceca (<i>P</i> < 0.05). Sex effects were observed on the abundances of four of the 248 identified antimicrobial resistance genes while abundances of 10 were modulated by AFPs (<i>P</i> < 0.05). Ceca of females birds showed more <i>tssB</i> than males, and ceca of RWMIA-raised birds contained the highest abundance of <i>chuY</i> genes regardless of sex. This study showed that in a specific feeding program, cecal resistome can be affected by chicken's sex contributing to understand the AMR related to the AMU.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-19"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490856","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":"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}