Wu Ying-Chen, Lee Jen-Jie, Tsai Bo-Yang, Liu Yi-Fen, Chen Chih-Ming, Tien Ni, Tsai Pei-Jane, Chen Ter-Hsin
Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, No.250, Guoguang Rd., South Dist., Taichung 402, Taiwan.
Department of Microbiology and Immunology, National Cheng Kung University, Medical College, No. 1, University Rd., Tainan 70101, Taiwan.
Int J Med Microbiol. 2016 Feb;306(2):115-22. doi: 10.1016/j.ijmm.2016.02.002. Epub 2016 Feb 12.
Clostridium difficile is a human and animal pathogen. Recently, the incidence of community-acquired C. difficile infection has increased, and many studies have indicated that C. difficile might be food-borne. The correlation between C. difficile infection in humans and in animals has been a topic of debate. The objective of this study was to determine the genetic relatedness of C. difficile from human and pigs in Taiwan. We investigated the molecular epidemiology of C. difficile in healthy humans and pigs from 2011 to 2015. The isolation rate of C. difficile from pigs in 13 commercial farms was 49% (100/204), and a high proportion of hypervirulent (C. difficile carrying tcdA, tcdB, and cdtA/B genes and a 39-bp deletion in the tcdC gene) ribotype 078 lineage isolates (90%, 90/100; including 078, 126, 127, and 066-like isolates) were identified. In addition, the C. difficile ribotype 127 isolates from pigs typically exhibited moxifloxacin resistance (37/43; 86%). In healthy humans, the isolation rate was 4.3% (3/69), and all healthy human isolates were non-toxigenic. In particular, we compared the porcine isolates with two patient strains (ribotype 127) obtained from two hospitals in central Taiwan. The multilocus variable number tandem repeat analysis revealed a high genetic relatedness between ribotype 127 from patients and pigs. This study indicated that isolates of the ribotype 078 lineage, and especially ribotype 127, were widely distributed in pig farms and showed a high frequency of moxifloxacin resistance. The closely related ribotype 127 from patients and pigs may have had a common origin or low diversity. In conclusion, C. difficile ribotype 127 is a noteworthy pathogen in pigs and poses a potential public health threat.
艰难梭菌是一种人和动物病原体。最近，社区获得性艰难梭菌感染的发病率有所上升，许多研究表明艰难梭菌可能通过食物传播。人类和动物中艰难梭菌感染之间的相关性一直是一个争论的话题。本研究的目的是确定台湾地区人类和猪源艰难梭菌的遗传相关性。我们调查了2011年至2015年健康人类和猪中艰难梭菌的分子流行病学。13个商业猪场中猪源艰难梭菌的分离率为49%（100/204），并鉴定出高比例的高毒力（携带tcdA、tcdB和cdtA/B基因且tcdC基因有39 bp缺失的艰难梭菌）核糖体分型078谱系分离株（90%，90/100；包括078、126、127和066样分离株）。此外，猪源艰难梭菌核糖体分型127分离株通常表现出对莫西沙星耐药（37/43；86%）。在健康人类中，分离率为4.3%（3/69），所有健康人类分离株均无毒力。特别是，我们将猪源分离株与从台湾中部两家医院获得的两株患者菌株（核糖体分型127）进行了比较。多位点可变数目串联重复分析显示患者和猪的核糖体分型127之间存在高度遗传相关性。本研究表明，核糖体分型078谱系分离株，尤其是核糖体分型127，在猪场中广泛分布，并表现出高频率的莫西沙星耐药性。患者和猪中密切相关的核糖体分型127可能有共同起源或低多样性。总之，艰难梭菌核糖体分型127是猪中一种值得关注的病原体，对公共卫生构成潜在威胁。
