Medical Technology Institute of Xuzhou Medical University, Xuzhou 221004, China; Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
J Glob Antimicrob Resist. 2017 Sep;10:29-34. doi: 10.1016/j.jgar.2017.03.009. Epub 2017 Jun 9.
The rapid emergence of drug-resistant Shigella sonnei is a serious public health problem. This study aimed to characterise the antimicrobial resistance patterns, molecular subtypes, and integron types and resistance gene cassettes in S. sonnei from Jiangsu Province, China.
In total, 340 S. sonnei were collected in 2002-2011 throughout Jiangsu Province. Antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), PCR amplification of integrons, restriction fragment length polymorphism (RFLP) and DNA sequencing of cassette regions were performed.
Resistance rates to ampicillin (67.7%), nalidixic acid (75.2%), tetracycline (73.7%) and trimethoprim/sulfamethoxazole (68.7%) remained high. Strains from Centre and South Jiangsu showed higher resistance and multiresistance rates compared with the North. PFGE analysis indicated that large-scale clonal transmission among different cities occurred several times during 10 years. Among all strains, 55.9% (190/340) harboured class 1 integrons, 80.3% (273/340) harboured class 2 integrons and 49.4% (168/340) harboured an atypical class 1 integron. Resistance rates to nine antimicrobials in the class 1 integron-positive group were significantly higher than in the negative group (P<0.05). Seven different gene cassettes were detected in class 1 integrons. The most prevalent type was aacA4-cmlA1 (114/286). Class 2 integrons carried the gene cassette array dfrA1-sat1-aadA1, and the atypical class 1 integron carried bla-aadA1.
The increasing antimicrobial resistance and significant clonal transmission of S. sonnei circulating in Jiangsu were closely related to the high prevalence of integrons and gene cassettes. Long-term cross-regional monitoring of antimicrobial resistance is urgently required for S. sonnei.
志贺氏菌属宋内氏血清型（Shigella sonnei）耐药的快速出现是一个严重的公共卫生问题。本研究旨在分析江苏省分离的宋内氏志贺菌的抗菌药物耐药模式、分子亚型、整合子类型和耐药基因盒。
2002-2011 年期间，从江苏省采集了 340 株宋内氏志贺菌。进行抗菌药物敏感性试验、脉冲场凝胶电泳（PFGE）、整合子 PCR 扩增、内切酶片段长度多态性（RFLP）和盒区 DNA 测序。
氨苄西林（67.7%）、萘啶酸（75.2%）、四环素（73.7%）和甲氧苄啶-磺胺甲噁唑（68.7%）的耐药率仍然很高。与北部地区相比，中南部地区的菌株显示出更高的耐药性和多重耐药性。PFGE 分析表明，10 年内不同城市之间发生了多次大规模的克隆传播。在所有菌株中，55.9%（190/340）携带 1 类整合子，80.3%（273/340）携带 2 类整合子，49.4%（168/340）携带非典型 1 类整合子。1 类整合子阳性组对 9 种抗菌药物的耐药率明显高于阴性组（P<0.05）。在 1 类整合子中检测到 7 种不同的基因盒。最常见的类型是 aacA4-cmlA1（114/286）。2 类整合子携带 dfrA1-sat1-aadA1 基因盒，非典型 1 类整合子携带 bla-aadA1 基因。
江苏省流行的宋内氏志贺菌的抗菌药物耐药性不断增加和明显的克隆传播与整合子和基因盒的高流行密切相关。迫切需要对宋内氏志贺菌进行长期的跨区域抗菌药物耐药性监测。
