Jassem Agatha N, Prystajecky Natalie, Marra Fawziah, Kibsey Pamela, Tan Kennard, Umlandt Patricia, Janz Loretta, Champagne Sylvie, Gamage Bruce, Golding George R, Mulvey Michael R, Henry Bonnie, Hoang Linda M N
British Columbia Centre for Disease Control Public Health Laboratory, Vancouver, BC, Canada V5Z 4R4; Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5.
British Columbia Centre for Disease Control Public Health Laboratory, Vancouver, BC, Canada V5Z 4R4; Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
Can J Infect Dis Med Microbiol. 2016;2016:8207418. doi: 10.1155/2016/8207418. Epub 2016 Mar 29.
Background. Clostridium difficile is a major cause of gastrointestinal illness. Epidemic NAP1 strains contain toxins A and B, a deletion in repressor tcdC, and a binary toxin. Objectives. To determine the molecular epidemiology of C. difficile in British Columbia and compare between two time points in one region. Methods. C. difficile isolates from hospital and community laboratories (2008) and one Island Health hospital laboratory (2013) were characterized by pulsed-field gel electrophoresis, PCR-ribotyping, toxin possession, tcdC genotype, and antimicrobial susceptibility. Results. In 2008, 42.7% of isolates had NAP1 designation. Hospital-collected isolates were associated with older patients and more NAP1 types. Unlike other isolates, most NAP1 isolates possessed binary toxin and a 19 bp loss in tcdC. All isolates were susceptible to metronidazole and vancomycin. A 2013 follow-up revealed a 28.9% decrease in NAP1 isolates and 20.0% increase in isolates without NAP designation in one region. Then, community-associated cases were seen in younger patients, while NAP types were evenly distributed. Isolates without NAP designation did not cluster with a PFGE pattern or ribotype. Conclusions. Evaluation of C. difficile infections within British Columbia revealed demographic associations, epidemiological shifts, and characteristics of strain types. Continuous surveillance of C. difficile will enable detection of emerging strains.
背景。艰难梭菌是胃肠道疾病的主要病因。流行的NAP1菌株含有毒素A和B、阻遏蛋白tcdC缺失以及二元毒素。目的。确定不列颠哥伦比亚省艰难梭菌的分子流行病学，并比较一个地区两个时间点的情况。方法。通过脉冲场凝胶电泳、PCR核糖体分型、毒素携带情况、tcdC基因型和抗菌药物敏感性，对来自医院和社区实验室（2008年）以及一个岛屿卫生医院实验室（2013年）的艰难梭菌分离株进行特征分析。结果。2008年，42.7%的分离株被指定为NAP1。医院收集的分离株与老年患者以及更多的NAP1类型相关。与其他分离株不同，大多数NAP1分离株具有二元毒素且tcdC有19 bp的缺失。所有分离株对甲硝唑和万古霉素敏感。2013年的随访显示，一个地区的NAP1分离株减少了28.9%，无NAP指定的分离株增加了20.0%。随后，社区相关病例出现在年轻患者中，而NAP类型分布均匀。无NAP指定的分离株没有以脉冲场凝胶电泳模式或核糖体分型聚类。结论。对不列颠哥伦比亚省艰难梭菌感染的评估揭示了人口统计学关联、流行病学变化以及菌株类型的特征。持续监测艰难梭菌将有助于发现新出现的菌株。
