江苏部分地区禽致病性大肠杆菌分离株的生物学特征及耐药性研究  

Biological characteristics and antibiotic resistance of avian pathogenic Escherichia coli in some areas of Jiangsu Province

作　　者：徐亚亚[1] 袁华根[1] 孙晨明[1] 郭子涵 黄晴 XU Yaya;YUAN Huagen;SUN Chenming;GUO Zihan;HUANG Qing(Jiangsu Agri-animal Husbandry Vocational College,Taizhou 225300,China)

机构地区：[1]江苏农牧科技职业学院,江苏泰州225300

出　　处：《畜牧与兽医》2021年第11期74-79,共6页Animal Husbandry & Veterinary Medicine

基　　金：中国特色高水平高职学校和专业建设项目(教职成函[2019]14号);江苏农牧科技职业学院校级科研项目(NSF201906);江苏省大学生创新创业训练计划项目(202112806071H)。

摘　　要：为了解江苏部分地区禽致病性大肠杆菌(APEC)的分子流行状况,从临床分离鉴定出120株APEC,并对分离株的血清型、种系发生型、毒力基因型和耐药性进行检测。血清型检测结果显示,在已定型的95株分离株中,最常见的血清型为O78,约占定型菌株比例为27.4%,其他主要血清型还有O18、O24和O88等。APEC分离株种系发生型以B2型和D型为主,分别占受试分离株的35.6%和28.5%,而A型和B1型分别占22.8%和13.1%。对已知的12种毒力基因的检测发现,铁摄取基因的检出率相对较高,如tonB(93.3%)、iutA(90.8%)、iroN(84.2%)和feoB(82.5%),其他受检基因fimH、iss、cvaC和traT的检出率也在70%以上,而hlyD、papC、irp-2和tsh基因在APEC菌株中的检出率低于30%。筛选40株分离株进行1日龄雏鸡致病力试验,确定出高致病株和低致病株分别占65%和35%。进一步分析发现高致病株比低致病株检出率高的毒力因子有iutA、tsh、iroN、irp-2、iss和cvaC(P<0.05),提示这6种毒力基因可作为鉴别APEC毒力的靶标基因。APEC分离株大多呈现多重耐药,对受试的13种抗生素的耐药率均超过了50%,特别是对强力霉素、四环素、先锋IV、氨苄青霉素、磺胺异噁唑的耐药率甚至达到了80%以上。本研究丰富了APEC流行病学数据,为指导临床APEC菌株的鉴定和防控提供科学依据。To understand the molecular prevalence of avian pathogenic Escherichia coli(APEC)in some areas of Jiangsu Province,120 APEC isolates were clinically isolated and identified.The serotypes,phylogenetic groups,virulence genotype and antibiotic resistance of the isolates were detected.Our results showed that the most common serotype was O78,accounting for 27.4%of the 95 isolates,and the other main serotypes were O18,O24 and O88.The phylogeny of the APEC isolates was mainly B2 and D,accounting for 35.6%and 28.5%of the tested isolates,respectively,while A and B1 accounted for 22.8%and 13.1%,respectively.We detected the prevalence rate of 12 known virulence genes in APEC isolates.The iron-uptake related genes,such as tonB(93.3%),iutA(90.8%),iroN(84.2%)and feoB(82.5%)were highly prevalent.The prevalence rate of the other genes fimH,iss,cvaC and traT was also over 70%,while the prevalence rate of hlyD,papC,irp-2 and tsh genes in the APEC strains was less than 30%.40 APEC isolates were screened for pathogenicity test in 1-day-old chicks,and 65%and 35%of the isolates were high and low pathogenic isolates,respectively.Further analysis showed that the occurrence frequency of 6 virulence genes,including iutA,tsh,iroN,irp-2,iss and cvaC were highly prevalent in the highly pathogenic strains than that of the lowly pathogenic strains(P<0.05),which indicated that these 6 virulence genes could be used as target genes for the identification of APEC virulence.Most of the APEC isolates showed multiple antibiotic resistance,and the resistance rate was over 50%,and especially,the antibiotic resistance rate to doxycycline,tetracycline,cefalexin,ampicillin,and sulfamisoxazole was over 80%.This study enriched the epidemiological data of APEC and provided a scientific basis for the identification,prevention and control of APEC strains in clinical practice.

关 键 词：禽致病性大肠杆菌 血清型 种系发生型 毒力基因 耐药性 

分 类 号：S855.1[农业科学—临床兽医学]