安徽省2018-2019年小肠结肠炎耶尔森菌分型分布及分子特征分析

Type distribution and molecular characteristics of Yersinia enterocolitica in Anhui province,China,2018-2019

目的了解2018-2019年安徽省小肠结肠炎耶尔森菌分型分布及分子特征。方法收集2018-2019年腹泻患者、动物粪便、食品等不同类型样本进行小肠结肠炎耶尔森菌的分离,对菌株进行系统生化鉴定、血清型分型、毒力基因PCR检测及脉冲场凝胶电泳(PFGE)分子分型。结果 2 186份样本中共分离到97株小肠结肠炎耶尔森菌,主要血清型为O∶3型和O∶5型,O∶3血清型21株,占21.65%(21/97),O∶5血清型17株,占17.53%(17/97),毒力基因分布为黏附侵袭位点基因(ail+)、耐热性肠毒素A基因(ystA+)、耐热性肠毒素B基因(ystB-)、黏附素(yadA+)和yop调节子转录活化因子(virF+)占19.59%(19/97),ail-、ystA-、ystB+、yadA-和virF-占63.92%(62/97)。PFGE分子分型显示腹泻患者和宿主猪的菌株相似性≥95.00%。结论在安徽省食品、环境和部分腹泻患者中小肠结肠炎耶尔森菌分离株大多为非致病性菌株,动物宿主猪和腹泻患者中存在致病性小肠结肠炎耶尔森菌,猪体内分离的菌株与人感染密切相关,猪是小肠结肠炎耶尔森菌致病性菌株的主要宿主。

Objective To investigate the type distribution and molecular characteristics of Yersinia enterocolitica in Anhui province, China, 2018-2019. Methods Different types of samples were collected from patients with diarrhea,animal feces, and food from 2018 to 2019, Y. enterocolitica strains were isolated to perform systematic biochemical identification, serotyping, polymerase chain reaction detection of virulence genes, and molecular typing by pulsed-field gel electrophoresis(PFGE). Results Among 2 186 samples, a total of 97 strains of Y. enterocolitica were isolated, with O∶3(21/97, 21.65%) and O∶5(17/97, 17.53%) being the main serotypes. Virulence gene analysis showed that 19.59%(19/97) of the strains were attachment invasion locus gene-positive(ail+), Yersinia stable toxin A gene-positive(ystA+),Yersinia stable toxin B gene-negative(ystB-), Yersinia adhesin A gene-positive(yadA+), and yop regulon transcriptional activator gene-positive(virF+);63.92%(62/97) were ail-, ystA-, ystB+, yadA-, and virF-. Molecular typing by PFGE showed ≥95.00% similarity between the strains from patients with diarrhea and the strains from the host pigs.Conclusion In Anhui province, most Y. enterocolitica strains isolated from food, environment, and some patients with diarrhea are non-pathogenic. There are pathogenic strains in the host pigs and some patients with diarrhea. Strains isolated from pigs are closely related to human infection. Pigs are the main host of pathogenic strains of Y. enterocolitica.