75株蛋鸡源沙门菌的MLST分型与耐药性分析

MLST Typing and Drug Resistance Analysis of 75 Salmonella Strains Isolated from Laying Hens

旨在掌握2017年7月至2019年5月期间云南地区蛋鸡源沙门菌血清型、药物敏感性及毒力基因携带等基本情况。无菌采集发病鸡肝组织,共分离到沙门菌75株,对分离株进行MLST分型、药物敏感性及相关耐药基因和毒力基因检测。结果显示,MLST鉴定到ST78序列型鸡伤寒沙门菌54株(72.00%)、ST92序列型鸡白痢沙门菌21株(28.00%);分离株对青霉素的耐药率为100%,对其它抗生素的耐药率分别为:四环素26.67%、强力霉素26.67%、复方新诺明22.67%、阿莫西林18.67%、氨苄西林16.00%、恩诺沙星14.67%、链霉素8.00%、环丙沙星2.67%、庆大霉素1.33%,共存在7种耐药谱型,28.00%的菌株表现为多重耐药,且集中于鸡伤寒沙门菌;耐药基因tetA、sul2和bla_(TEM)的检出率分别为26.67%、10.67%和8.00%;毒力基因mogA、mgtC、bcfA、araB、stn和spvC的检出率均高达100%,而spvB的检出率为89.33%。结果表明,鸡伤寒沙门菌和鸡白痢沙门菌为云南地区蛋鸡源沙门菌主要流行血清型,多重耐药情况严重,耐药基因与毒力基因检出率较高。

The aim of this study was to investigate the serotypes,drug sensitivity and virulence genes of Salmonella isolated from laying hens in Yunnan between July 2017 and May 2019.A total of 75 Salmonella strains were isolated from the liver tissues of sick chickens.MLST serotyping,drug sensitivity,related resistance genes and virulence genes were detected.A total of 54 strains(72.00%)and 21 strains(28.00%)were determined to be ST78 and ST92,respectively,by MLST.The resistance rate to penicillin was 100%,and the resistance rates were 26.67%to tetracycline,26.67%to doxycycline,22.67%to sulfamethoxazole,18.67%to amoxicillin,16.00%to ampicillin,14.67%to enrofloxacin,8.00%to streptomycin,2.67%to ciprofloxacin,and 1.33%to gentamicin.There were seven profiles of drug resistance spectrum,with 28.00%of the strains(mainly S.Gallinarum)showing multiple resistance.The detection rates of resistance genes tetA,sul2 and bla_(TEM) were 26.67%,10.67%and 8.00%,respectively.The virulence genes mogA,mgtC,bcfA,araB,stn and spvC were detected in all 75 strains,while the detection rate of spvB was 89.33%.The present study showed that S.Gallinarum and S.Pullorum were the main epidemic serotypes of Salmonella in laying hens in Yunnan,and that the multiple drug resistance was predominant due to the high prevalence of drug resistance genes and virulence genes harbored in the Salmonella strains.