Cui Xianyan, Wang Jian, Yang Chaojie, Liang Beibei, Ma Qiuxia, Yi Shengjie, Li Hao, Liu Hongbo, Li Peng, Wu Zhihao, Xie Jing, Jia Leili, Hao Rongzhang, Wang Ligui, Hua Yuejin, Qiu Shaofu, Song Hongbin
Nuclear-Agricultural Sciences, Zhejiang University Hangzhou, China ; Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
Front Microbiol. 2015 May 7;6:435. doi: 10.3389/fmicb.2015.00435. eCollection 2015.
Shigella flexneri serotype 2 variant (II:3,4,7,8) was isolated in 2008 and first reported in China in 2013. In the present study, epidemiological surveillance from 2003 to 2013 in China suggested that this serotype first appeared in Guangxi in 2003; it then emerged in Shanghai and Xinjiang in 2004 and in Henan in 2008. Of the 1813 S. flexneri isolates, 58 S. flexneri serotype 2 variant strains were identified. Serotype 2 variant has emerged as a prominent serotype in recent years, with 2a (32.6%), X variant (25.2%), 1a (9.4%), X (6.3%), 2b (5.4%), and 1b (3.6%). According to phenotypic and genotypic analysis, the serotype 2 variant originated from 2a to 2b. A higher antibiotic resistance rate was observed between 2009 and 2013 than that between 2003 and 2008. Among 22 cephalosporin-resistant isolates, bla TEM-1, bla OXA-1, bla CTX-3, bla CTX-14, and bla CTX-79 were detected. Among 22 fluoroquinolone-resistant isolates, a Ser80Ile mutation in parC was present in all of the isolates. Moreover, 21 isolates had three gyrA point mutations (Ser83Leu, His211Tyr, Asp87Asn, or Gly) and one isolate had two gyrA point mutations (Ser83Leu and His211Tyr). The prevalence of His211Tyr in the fluoroquinolone-resistant isolates is concerning, and the mutation was first reported in China. Besides, 22 isolates harbored the aac(6')-Ib-cr gene, and two isolates harbored qnrS1. In view of the increased epidemic frequency and multidrug-resistant strain emergence, continuous surveillance will be needed to understand the actual disease burden and provide guidance for shigellosis.
福氏志贺菌2型变种（II:3,4,7,8）于2008年分离得到，并于2013年在中国首次报道。在本研究中，2003年至2013年中国的流行病学监测表明，该血清型于2003年首次出现在广西；随后于2004年出现在上海和新疆，2008年出现在河南。在1813株福氏志贺菌分离株中，鉴定出58株福氏志贺菌2型变种菌株。2型变种近年来已成为一种突出的血清型，其中2a（32.6%）、X变种（25.2%）、1a（9.4%）、X（6.3%）、2b（5.4%）和1b（3.6%）。根据表型和基因型分析，2型变种起源于2a到2b。2009年至2013年期间观察到的抗生素耐药率高于2003年至2008年期间。在22株对头孢菌素耐药的分离株中，检测到bla TEM-1、bla OXA-1、bla CTX-3、bla CTX-14和bla CTX-79。在22株对氟喹诺酮耐药的分离株中，所有分离株的parC均存在Ser80Ile突变。此外，21株分离株有三个gyrA点突变（Ser83Leu、His211Tyr、Asp87Asn或Gly），一株分离株有两个gyrA点突变（Ser83Leu和His211Tyr）。His211Tyr在耐氟喹诺酮分离株中的流行情况令人担忧，该突变首次在中国报道。此外，22株分离株携带aac(6')-Ib-cr基因，两株分离株携带qnrS1。鉴于流行频率增加和多重耐药菌株出现，需要持续监测以了解实际疾病负担并为志贺菌病提供指导。
