2007-2011年江苏省南京市细菌性痢疾病原学监测结果分析

Etiological surveillance of bacillary dysentery in Nanjing,Jiangsu,2007-2011

目的对江苏省南京市2007-2011年细菌性痢疾的血清群(型)分布、耐药谱、毒力基因携带情况及脉冲场凝胶电泳(PFGE)分析,为江苏省南京市细菌性痢疾的防控提供依据。方法对从江苏省南京市2007-2011年各医院腹泻病患者中分离的75株志贺菌进行血清群(型)、耐药性和毒力基因检测,并进行PFGE分子分型。结果75株志贺菌包括宋内志贺菌54株(72.0%),福氏志贺菌21株(28.0%),除2010年福氏X型为优势血清型外,其余年份宋内志贺菌为优势血清群;75株菌普遍对氨苄西林、四环素和磺胺甲恶唑耐药,耐药率在61.1%～95.2%之间;三重及以上耐药菌株占所有测试菌株的88.0%;毒力基因ipaH、sen、set1、ial阳性率分别为100%、46.7%、24.0%、48.0%;福氏志贺菌优势毒力基因模式为Ⅰ型(66.7%),宋内志贺菌优势基因模式为Ⅶ型(61.1%)和Ⅳ型(25.9%);宋内志贺菌分为20个PFGE基因型,其中以S7、S8、S10三个带型为主,占宋内志贺菌的53.7%;相似度>95%,可能来自于同一克隆系;福氏志贺菌分为17种带型,各带型较散在分布。结论江苏省南京市志贺菌流行菌群不断变迁,宋内志贺菌有取代福氏志贺菌成为流行菌群的趋势;多重耐药现象严重;福氏志贺菌优势毒力基因模式为Ⅰ型、宋内志贺菌为Ⅶ型和Ⅳ型;PFGE型别呈现多元化流行特点。

Objective To understand the serotype,drug resistance,carriage of virulence genes and PFGE patterns of Shigella in Nanjing from 2007 to 2011and provide evidence for the prevention and control of bacillary dysentery.Methods Totally 75 Shigella strains were isolated from hospitals in Nanjing to conduct serotyping,drug resistance test,virulence gene detection and PFGE.Results Of the 75 Shigella strains,54(72.0%) were identified as S.sonnei and 21(28.0%) as S.flexneri.Shigella sonnei was predominant during this period except 2010,when S.flexneri serotype X was predominant,and All the strains isolated were resistant to ampicillin,achromycin and sulfamethylisoxazole and the resistance rate ranged from 61.1% to 95.2%.Up to 88.0% of the resistant strains were multiple drug resistant.The carriage rates of virulence genes ipaH,sen,set1 and ial were 100%,46.7%,24.0% and 48.0%,respectively.Virulence gene type Ⅰ was predominant in S.flexneri strains(66.7%),and type Ⅶ(61.1%) and Ⅳ(25.9%) in S.sonnei strains.All the S.sonnei strains had 20 PFGE patterns,the patterns S7,S8 and S10(53.7%) were predominant,which shared similarity of above 95%.All the S.flexneri strains had 17 PFGE patterns.Conclusion The serotype of Shigella changed constantly in Nanjing,there is a trend of S.flexneri to be predominant circulating strain instead of S.sonnei.The multidrug resistance of Shigella strains is very serious.Virulence gene type I was predominant in S.flexneri strains and type Ⅶ and Ⅳ in S.sonnei strains.