Canadian journal of microbiology最新文献_第6页

Biofilm disruption and gene expression alteration by phages against multidrug-resistant Pseudomonas aeruginosa. 噬菌体对多重耐药铜绿假单胞菌的生物膜破坏和基因表达改变。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2026-0082

Amna Aftab Mian, Abid Hussain, Saba Saba, Aatif Amin, Mohsin Tassawar Cheema, Muhammad Sohail, Hafiz Ghulam Murtaza Saleem, Mohsin Khurshid

{"title":"Biofilm disruption and gene expression alteration by phages against multidrug-resistant Pseudomonas aeruginosa.","authors":"Amna Aftab Mian, Abid Hussain, Saba Saba, Aatif Amin, Mohsin Tassawar Cheema, Muhammad Sohail, Hafiz Ghulam Murtaza Saleem, Mohsin Khurshid","doi":"10.1139/cjm-2026-0082","DOIUrl":"10.1139/cjm-2026-0082","url":null,"abstract":"Pseudomonas aeruginosa is a major opportunistic pathogen responsible for severe human infections and is increasingly associated with multidrug resistance and limited treatment options. In this study, we isolated and characterized bacteriophages targeting drug-resistant P. aeruginosa strains and evaluated their capacity to disrupt biofilms and modulate biofilm-associated gene expression. Phages recovered from sewage showed broad lytic activity against P. aeruginosa and were classified morphologically into the families Podoviridae and Myoviridae. Two phages, A2 and A4, exhibited the highest lytic activity against the resistant strains examined. Both phages significantly degraded preformed biofilms, with phage A4 showing comparatively stronger antibiofilm activity. In addition, phage exposure altered the expression of several biofilm-associated genes, including pelA, htpB, bifA, psl, fimW, and wspA. A notable finding was the reversal of bifA expression from downregulation at 12 h to upregulation at 24 h following treatment with phage A4. Collectively, these results demonstrate that phages A2 and A4 possess strong lytic and antibiofilm activities and are capable of modulating biofilm-associated transcriptional responses in drug-resistant P. aeruginosa. The findings support the potential application of bacteriophages as alternative therapeutic agents against drug-resistant biofilm-associated infections.","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","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":"148155320","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}

引用次数: 0

Core-genome multilocus sequence types of the IncI1 plasmids identified in Salmonella enterica subsp. Enterica serovars Heidelberg and Kentucky from Canadian poultry production are associated with factors related to production, year, and geographical region. 肠炎沙门氏菌IncI1质粒核心基因组多位点序列类型分析。来自加拿大家禽生产的海德堡和肯塔基的肠道血清型与生产、年份和地理区域相关的因素有关。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2026-0003

Benjamin M Hetman, David L Pearl, Richard Reid-Smith, E Jane Parmley, Eduardo N Taboada

{"title":"Core-genome multilocus sequence types of the IncI1 plasmids identified in Salmonella enterica subsp. Enterica serovars Heidelberg and Kentucky from Canadian poultry production are associated with factors related to production, year, and geographical region.","authors":"Benjamin M Hetman, David L Pearl, Richard Reid-Smith, E Jane Parmley, Eduardo N Taboada","doi":"10.1139/cjm-2026-0003","DOIUrl":"10.1139/cjm-2026-0003","url":null,"abstract":"The IncI1 plasmid is an important driver of antimicrobial resistance (AMR) in Salmonella enterica collected from human and poultry sources in Canada. In the present study, isolates of S. enterica subsp. enterica serovars Heidelberg (n = 1791) and Kentucky (n = 266), collected over 15 years of surveillance of Canadian poultry production, were subjected to whole-genome sequencing, from which IncI1 plasmid sequences were identified and extracted for genomic and epidemiological analyses. Extracted IncI1 sequences (n = 1123) were used to construct a novel plasmid core-genome multilocus sequence typing (pcgMLST) scheme, which was applied to a subset of plasmids specifically from chicken production (n = 940). From the pcgMLST analysis, four IncI1 genomic groups were identified, corroborated by differences in AMR potential and allelic diversity within and between groups. These groups were used to inform a multilevel multinomial model, which revealed associations with sampling year, location, and production stage. Taken together, this work demonstrates that IncI1 plasmid population dynamics in S. Heidelberg and S. Kentucky circulating in Canadian poultry production are complex and influenced by multiple factors driving dissemination across Canada.","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":"147833951","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}

引用次数: 0

Showcasing the Canadian GRDI-AMR One Health Project: advancing genomics research for combatting antimicrobial resistance. 展示加拿大GRDI-AMR One Health项目：推进基因组学研究以对抗抗菌素耐药性。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2025-0077

Edward Topp, Catherine Carrillo, Tim McAllister, David Wilkinson

引用次数: 0

A qualitative scan on the challenges of AMR in Canada and experts' proposed solutions. 对加拿大抗菌素耐药性的挑战和专家提出的解决方案进行定性分析。

IF 1.6 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2025-0143

Armelle Lorcy, Antoine Garnier, Peter Daley, Ève Dubé

{"title":"A qualitative scan on the challenges of AMR in Canada and experts' proposed solutions.","authors":"Armelle Lorcy, Antoine Garnier, Peter Daley, Ève Dubé","doi":"10.1139/cjm-2025-0143","DOIUrl":"10.1139/cjm-2025-0143","url":null,"abstract":"Antimicrobial resistance (AMR) is a growing public health threat in Canada. In 2022, rising resistance was reported among key pathogens, yet national coordination remains inconsistent, with strategies varying widely by province and territory. This study explored AMR-related challenges in healthcare and the impact of the COVID-19 pandemic on AMR efforts in Canada. Using a qualitative design, researchers conducted semi-structured interviews with 59 experts from fields such as microbiology, public health, and industry. Participants were identified through environmental scanning and snowball sampling. Thematic analysis of transcripts revealed major barriers to a unified AMR response, including inconsistent surveillance, fragmented stewardship efforts, and decentralized health systems. According to participating AMR experts, COVID-19 disrupted AMR control by diverting resources and potentially increasing resistance but also led to improvements in infection prevention, public awareness, and health infrastructure. Participants emphasized the need for stronger political commitment, improved surveillance, a One Health approach, and better funded, coordinated stewardship programs. With the publication of the Pan-Canadian Action Plan in 2023, the Canadian federal government has announced changes. However, effectively addressing AMR will require a unified, multisectoral strategy that bridges political, health, and societal efforts across jurisdictions.","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-10"},"PeriodicalIF":1.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145556250","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}

引用次数: 0

Evaluation of transmission metrics in a slow-spreading highly pathogenic avian influenza (HPAI) outbreak in a commercial upland game bird system. 高原商业猎禽系统中一次慢传播高致病性禽流感（HPAI）暴发的传播指标评估。

IF 1.6 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2025-0203

Kaitlyn M St Charles, Amos Ssematimba, Peter J Bonney, Carol J Cardona

{"title":"Evaluation of transmission metrics in a slow-spreading highly pathogenic avian influenza (HPAI) outbreak in a commercial upland game bird system.","authors":"Kaitlyn M St Charles, Amos Ssematimba, Peter J Bonney, Carol J Cardona","doi":"10.1139/cjm-2025-0203","DOIUrl":"10.1139/cjm-2025-0203","url":null,"abstract":"In 2022, highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b was detected in United States (US) poultry, quickly escalating into an outbreak that surpassed the 2014/15 HPAI US event in scale and impact. Unlike in 2014/15, the 2022/3/4/5 outbreak has included numerous HPAI detections in previously infrequently affected commodities such as broilers and commercially-raised upland game birds. Here, we describe H5 HPAI detections that occurred between December 2023 and January 2024 in a multipremises, commerical upland game bird system located in the Midwestern US. We used an approximate Bayesian computation algorithm and stochastic within-flock HPAI transmission model to estimate the following: (1) time of HPAI introduction onto each affected premises, (2) number of days between estimated times of introduction and times of detection, and (3) the adequate contact rates and basic reproduction numbers within individual barns. Clinical signs and mortality observed in the infected pheasant flocks were largely consistent with other pheasant H5 clade 2.3.4.4b outbreaks. Across the system, the estimated transmission metrics were noticeably lower than those calculated from outbreaks in other poultry species. However, times to detection were similar to HPAI outbreaks that have occurred in other commodities.","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-8"},"PeriodicalIF":1.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145809499","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}

引用次数: 0

Highly pathogenic avian influenza (HPAI H5N1, clade 2.3.4.4b, genotype C2.1) in commercial ring-necked pheasants during the 2022 outbreak in the United States. 2022年美国商业环颈雉爆发高致病性禽流感（HPAI H5N1，分支2.3.4.4b，基因型C2.1）

IF 1.6 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2025-0198

Kayla R Niel, Kaitlyn M St Charles, Jonathan Y Elissa, Megan E Lighty, Amos Ssematimba, Marie Culhane, Alvin Crespo-Bellido, Nídia S Trovão, Martha I Nelson, Carol Cardona

{"title":"Highly pathogenic avian influenza (HPAI H5N1, clade 2.3.4.4b, genotype C2.1) in commercial ring-necked pheasants during the 2022 outbreak in the United States.","authors":"Kayla R Niel, Kaitlyn M St Charles, Jonathan Y Elissa, Megan E Lighty, Amos Ssematimba, Marie Culhane, Alvin Crespo-Bellido, Nídia S Trovão, Martha I Nelson, Carol Cardona","doi":"10.1139/cjm-2025-0198","DOIUrl":"10.1139/cjm-2025-0198","url":null,"abstract":"Highly pathogenic avian influenza (HPAI) virus H5N1 clade 2.3.4.4b was introduced into North America in 2021. In 2022, clade 2.3.4.4b spilled into domestic poultry in the United States (U.S.), resulting in the largest HPAI outbreak in U.S. history. In December 2023, H5N1 2.3.4.4b was detected on an upland game bird farm in Pennsylvania. History, clinical signs, and gross lesions were suggestive of marble spleen disease. However, HPAI was identified by real-time reverse-transcriptase polymerase chain reaction; gene sequencing confirmed genotype C2.1 with phylodynamic analyses providing evidence of a wild bird introduction. Predictive mathematical modeling estimated the time of virus introduction onto the farm (15 days (95% C.I., 11-23) before the date of confirmed detection) being similar or longer than previously described for domestic poultry. Although bioexclusion measures were unable to prevent the initial exposure due to industry rearing practices, biocontainment procedures appeared to prevent spread. The lessons learned from this case may be important for other animal agriculture commodities, especially those species that are infrequently handled or observed and may have inaccurately calculated mortality levels. This well-characterized outbreak and other experiences with natural infection should be taken as opportunities to better understand the field dynamics of this virus.","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145809519","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}

引用次数: 0

Methylobacterium spp. and biological control of phytopathogenic Fusarium spp. 甲基杆菌与植物致病性镰刀菌的生物防治。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2026-0034

Daniel Palberg, R J Neil Emery

{"title":"Methylobacterium spp. and biological control of phytopathogenic Fusarium spp.","authors":"Daniel Palberg, R J Neil Emery","doi":"10.1139/cjm-2026-0034","DOIUrl":"10.1139/cjm-2026-0034","url":null,"abstract":"The biocontrol potential of Methylobacterium spp. against key phytopathogenic fungi was evaluated using in vitro antagonism assays and confined germination bioassays. Across 40 Methylobacterium isolates, inhibitory activity was highly variable and strain-dependent. Fusarium graminearum (UAMH 3329) was the most consistently suppressed pathogen; however, only M. thiocyanatum (NBRC 103124) and M. aminovorans (LMG 21752) produced significant inhibition (>30%, p < 0.05) across all three Fusarium species tested. Growth suppression was enhanced on nutrient-minimum agar amended with cell-free bacterial broth, supporting the involvement of diffusible inhibitory factors in fungal growth suppression. However, marked isolate- and substrate-dependent effects suggest that antagonism is contingent on specific bacterium-pathogen combinations. In germination assays, M. organophilum (LMG 6083) conferred protection to soybean (Glycine max) seeds challenged with F. graminearum, improving germination and seedling development in both artificial and soil substrates. Co-inoculated seeds exhibited lower disease severity scores (DSS), fewer necrotic lesions, and reduced fungal colonization during germination and emergence. Collectively, these findings identify candidate Methylobacterium strains with antagonistic activity against Fusarium spp. and provide a foundation for future characterization of their effectors relevant to integrated crop protection.","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"1-18"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148013587","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}

引用次数: 0

North American perspective on the highly pathogenic avian influenza H5Nx clade 2.3.4.4b outbreak (November 2021-March 2025). 北美对高致病性H5Nx分支2.3.4.4b爆发的看法（2021年11月- 2025年3月）。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2025-0275

Jolene Giacinti, Anthony V Signore, Mia Torchetti, Hector Enrique Valdez-Gómez, Carlos Javier Alcazar-Ramiro, Yohannes Berhane, Sarah Bevins, Krista Dilione, Damien O Joly, Mario Solís-Hernández, Trevor Thompson, Mitzunari Zalapa-Hernández

{"title":"North American perspective on the highly pathogenic avian influenza H5Nx clade 2.3.4.4b outbreak (November 2021-March 2025).","authors":"Jolene Giacinti, Anthony V Signore, Mia Torchetti, Hector Enrique Valdez-Gómez, Carlos Javier Alcazar-Ramiro, Yohannes Berhane, Sarah Bevins, Krista Dilione, Damien O Joly, Mario Solís-Hernández, Trevor Thompson, Mitzunari Zalapa-Hernández","doi":"10.1139/cjm-2025-0275","DOIUrl":"10.1139/cjm-2025-0275","url":null,"abstract":"Influenza A (H5Nx) highly pathogenic avian influenza viruses of clade 2.3.4.4b were first detected in North America in late 2021, initiating a multi-year outbreak unprecedented in geographic extent, duration, and host range. Surveillance conducted across Canada, the United States, and Mexico has documented widespread detections in wild birds and poultry, and repeated spillover into wild and domestic mammals. Genomic analyses reveal successive lineage replacements and extensive reassortment between Eurasian and North American lineages, with over 100 distinct genotypes identified to date. Recent events, including detection of genotype B3.13 in United States dairy cattle and the emergence of genotype D1.1 across all four North American migratory bird flyways, highlight ongoing viral evolution and cross-species transmission risks. This synthesis provides a continental overview of the outbreak from 1 November 2021 to 31 March 2025, summarizing surveillance results and genomic trends to inform continued One Health preparedness and response efforts.","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":"147873544","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}

引用次数: 0

Antifungal activity of emodin against the Cryptococcus neoformans/Cryptococcus gattii complexes: an effect on the enzyme superoxide dismutase. 大黄素对新型隐球菌/加蒂隐球菌复合物的抗真菌活性：对酶超氧化物歧化酶的影响。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2025-0257

Paulo Ricardo Monteiro Araújo, Marrie da Silva Dutra, Maria Gleiciane Rocha, Vinícius Carvalho Pereira, Raissa Geovanna Pereira Lopes, Andreza Pereira Braga, Lorena Mayana Beserra de Oliveira, Pedro Filho Noronha Souza, Waldemiro Aquino Pereira-Neto, Géssica Dos Santos Araújo, Rossana de Aguiar Cordeiro, José Júlio Costa Sidrim, Glaucia Morgana de Melo Guedes, Raquel Carvalho Montenegro, Débora de Souza Collares Maia Castelo-Branco, Marcos Fábio Gadelha Rocha

{"title":"Antifungal activity of emodin against the Cryptococcus neoformans/Cryptococcus gattii complexes: an effect on the enzyme superoxide dismutase.","authors":"Paulo Ricardo Monteiro Araújo, Marrie da Silva Dutra, Maria Gleiciane Rocha, Vinícius Carvalho Pereira, Raissa Geovanna Pereira Lopes, Andreza Pereira Braga, Lorena Mayana Beserra de Oliveira, Pedro Filho Noronha Souza, Waldemiro Aquino Pereira-Neto, Géssica Dos Santos Araújo, Rossana de Aguiar Cordeiro, José Júlio Costa Sidrim, Glaucia Morgana de Melo Guedes, Raquel Carvalho Montenegro, Débora de Souza Collares Maia Castelo-Branco, Marcos Fábio Gadelha Rocha","doi":"10.1139/cjm-2025-0257","DOIUrl":"10.1139/cjm-2025-0257","url":null,"abstract":"The Cryptococcus neoformans/Cryptococcus gattii species complexes include encapsulated yeasts that cause cryptococcosis. Emodin has demonstrated antimicrobial activity. This study evaluated emodin's antifungal activity against both planktonic cells and mature biofilms of the Cryptococcus neoformans/Cryptococcus gattii complexes, and its interaction with superoxide dismutase (SOD). Planktonic susceptibility was assessed by broth microdilution (CLSI; M27-A4). Mature biofilms were treated with emodin (128-1024 µg mL-1) and evaluated by crystal violet staining for biomass and the [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium] (MTT) assay for metabolic activity. Confocal laser microscopy (CLSM) and LIVE/DEAD™ staining were used to analyze viability and structure. Molecular docking assays with AutoDock Vina showed emodin's potential to bind SOD, and this was validated through the nitro blue tetrazolium (NBT) reduction assay. Emodin had inhibitory effects on planktonic cells, with MIC values ranging from 256 to 512 µg mL-1. Against mature biofilms, emodin at 1024 µg mL-1 reduced biomass by 72% and metabolic activity by 99% compared to the drug-free control. Additionally, emodin reduced structural parameters of biofilms and SOD activity, supporting its role in oxidative stress induction. These findings highlight emodin's potential antifungal activity against Cryptococcus neoformans/Cryptococcus gattii complexes biofilms and inhibitory effect on SOD activity as a potential mechanism of action.","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"72 ","pages":"1-9"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147484611","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}

引用次数: 0

SynBio 8.0: A portrait of a growing Canadian ecosystem. SynBio 8.0：一个成长中的加拿大生态系统的肖像。

IF 2.4 4区生物学

Canadian journal of microbiology Pub Date : 2026-01-01 DOI: 10.1139/cjm-2026-0122

Jeremy Gagnon, Caitlin Oh, Aracely Maribel Diaz-Garza

引用次数: 0