Pidsadny Paula E, Du Tim, Hizon Romeo, Ahmed Sean, Tan Derek, Zhanel George G, Bay Denice C, Reid-Smith Richard J, Charlebois Audrey, Golding George R
University of Manitoba, Rady Faculty of Health Sciences, Department of Medical Microbiology and Infectious Diseases, Winnipeg, MB, Canada.
National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada.
Can J Microbiol. 2025 Jan 1;71:1-7. doi: 10.1139/cjm-2024-0193.
Community-associated 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 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 , 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.
社区获得性感染（CA-CDI）在加拿大仍是一个令人担忧的问题，占此前通过加拿大医院感染监测计划报告病例的四分之一。加拿大此前的研究报告称，从加拿大零售肉类中分离出了产毒菌株，这表明它可能是加拿大CA-CDI的一个暴露源。在本研究中，219份零售猪肉样本中有3份（1.4%）、99份零售牛肉样本中有0份（0%）产毒菌株检测呈阳性，通过PCR核糖体分型和全基因组测序对其进行了分子特征分析。所有三株分离株均来自猪肉，属于此前在加拿大人类临床CA-CDI病例中分离出的序列类型（STs）/核糖体分型（RTs）：ST1/RT027、ST8/RT002和ST10/RT015。零售肉类分离株对所测试的抗菌药物敏感，但有一株对克林霉素呈中度耐药。与具有相同相应ST/RT类型的加拿大人类临床CA-CDI分离株进行基因组比较，结果显示，三株猪肉分离株中有两株通过核心基因组多位点测序分型与CA-CDI分离株聚类，单核苷酸变异（SNV）分析显示，它们在基因组上有2-11个SNV的进一步相关性。因此，在加拿大，零售肉类可能是CA-CDI暴露的一个低来源，某些克隆有通过食物传播的可能性。
