Investigation of Toxin Gene Diversity, Molecular Epidemiology, and Antimicrobial Resistance of Clostridium difficile Isolated from 12 Hospitals in South Korea
Investigation of Toxin Gene Diversity, Molecular Epidemiology, and Antimicrobial Resistance of Clostridium difficile Isolated from 12 Hospitals in South Korea
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DOI：
10.3343/kjlm.2010.30.5.491
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发表时间：
2010-10-01
影响因子：
--
通讯作者：
Lee, Kyungwon
中科院分区：
文献类型：
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作者：
Kim, Heejung;Jeong, Seok Hoon;Lee, Kyungwon
背景：艰难梭菌是抗生素相关性腹泻的主要原因。本研究的目的是了解韩国不同地区分离到的艰难梭菌的毒力状态、分子类型和药敏情况。方法：对2006-2008年间韩国12所教学医院408例腹泻患者分离到的408株艰难梭菌进行分析。用聚合酶链式反应检测艰难梭菌毒素基因TcdA、TcdB、cdtA、cdtB。采用聚合酶链式反应核糖体分型技术进行分子分型。结果：337株产毒菌株中，A毒素阴性菌株105株，B毒素阳性菌株(A-)B(+)菌株29株。聚合酶链式反应核糖体分型显示50种不同的核糖体类型。最常见的5种核糖体类型占所有已鉴定核糖体类型的62.0%。分离株对头孢西丁均不敏感，除1株外均对哌拉西林和哌拉西林-他唑巴坦敏感。对亚胺培南、头孢替坦、莫西沙星、氨苄西林和克林霉素的耐药率分别为25%、34%、42%、51%和60%。结论：本研究首次在全国范围内对艰难梭菌的毒力状况进行了研究，包括聚合酶链式反应核糖体分型和耐药性研究。A(-)B(+)菌株的患病率为25.7%，远高于其他国家的报告。二元产毒素菌株占所有菌株的7.1%，这在韩国并不罕见。最常见的核糖型是017，所有AB(+)菌株都表现出这种模式。我们没有分离出对甲硝唑或万古霉素敏感性降低的菌株。(Korea J Lab Med 2010；30：491-7)
Background: Clostridium difficile is a major cause of antibiotic-associated diarrhea. The objective of this study was to characterize clinical isolates of C. difficile obtained from various regions in Korea with regard to their toxin status, molecular type, and antimicrobial susceptibility.Methods: We analyzed a total of 408 C. difficile isolates obtained between 2006 and 2008 from 408 patients with diarrhea in 12 South Korean teaching hospitals. C. difficile toxin genes tcdA, tcdB, cdtA, and cdtB were detected by PCR. Molecular genotyping was performed by PCR ribotyping. Antimicrobial susceptibilities of the 120 C. difficile isolates were assessed by agar dilution methods.Results: Among 337 toxigenic isolates, 105 were toxin A-negative and toxin B-positive (A(-)B(+)) and 29 were binary toxin-producing strains. PCR ribotyping showed 50 different ribotype patterns. The 5 most frequently occurring ribotypes comprised 62.0% of all identified ribotypes. No isolate was susceptible to cefoxitin, and all except 1 were susceptible to piperacillin and piperacillin-tazobactam. The resistance rates of isolates to imipenem, cefotetan, moxifloxacin, ampicillin, and clindamycin were 25%, 34%, 42%, 51%, and 60%, respectively. The isolates showed no resistance to metronidazole or vancomycin.Conclusions: This is the first nationwide study on the toxin status, including PCR ribotyping and antimicrobial resistance, of C. difficile isolates in Korea. The prevalence of A(-)B(+) strains was 25.7%, much higher than that reported from other countries. Binary toxin-producing strains accounted for 7.1% of all strains, which was not rare in Korea. The most prevalent ribotype was ribotype 017, and all AB(+) strains showed this pattern. We did not isolate strains with decreased susceptibility to metronidazole or vancomycin. (Korean J Lab Med 2010;30:491-7)