中国小肠结肠炎耶尔森菌分布及分子流行病学特征

目的 通过中国1980-2019年不同地区小肠结肠炎耶尔森菌的病原学与PFGE分子型别特征分析,为小肠结肠炎耶尔森菌病的防控提供依据。方法 对中国不同区域,不同来源标本分离到的6 847株小肠结肠炎耶尔森菌,进行血清型别、生化表型、毒力基因分布研究,对致病性菌株进行脉冲场凝胶电泳(PFGE)分析。结果 小肠结肠炎耶尔森菌中致病性菌株2 047株、非致病菌4 800株。致病性菌株仅存在两种血清型,O∶3占比88.96%(1 821/2 047)、O∶9占比11.04%(226/2 047)。18个省市自治区的致病株以O∶3血清型为主,宁夏回族自治区以O∶9血清型为主。非致病菌血清型众多,普遍比致病株具有更多的阳性生化反应。1 821株O∶3致病株分为93个PFGE型别,分布于19个省市自治区,其中K6GN11C30021、K6GN11C30012为优势带型(分别占比46.35%、22.5%),75.38%的人源菌株与分离自当地的动物、食品菌株带型一致;226株O∶9致病株共分为14个PFGE型别,分布于8个省市自治区,77.78%人源菌株与分离自当地的动物、食品菌株带型一致。结论 我国小肠结肠炎耶尔森菌分布广泛、宿主众多,致病株仅有两个血清型,非致病株血清型众多、可能比致病株具有更强的生化代谢能力与环境适应力。致病性菌株PFGE优势带型相对集中,地域分布广泛,多数人源菌株与分离自当地的动物、食品菌株带型一致,应警惕通过家畜家禽、食品及外环境等多种来源感染人的风险。

Distribution and molecular epidemiological characteristics of Yersinia enterocolitica in China

Based on the analysis of the etiology and PFGE molecular types of Yersinia enterocolitica in different regions of China from 1980 to 2019, this study provides a basis for the prevention and control of Yersinia enterocolitica. Methods: A total of 6847 strains of Yersinia enterocolitica isolated from samples from different regions in China were analyzed by pulsed field gel electrophoresis (PFGE). The serotypes, biochemical phenotypes and virulence gene distribution were studied. The results revealed 2047 pathogenic strains and 4800 non-pathogenic strains of Yersinia enterocolitica. Only two serotypes of pathogenic strains, O∶3 accounting for 88.96% (1821/2047) and O∶9 accounting for 11.04% (226/2 047), were identified. The O∶3 serotype was the main pathogenic strain in 18 provinces and autonomous regions, and the O∶9 serotype was the main pathogenic strain in the Ningxia Hui autonomous region. Many serotypes of non-pathogenic bacteria were found to exist and to generally cause more positive biochemical reactions than pathogenic strains. A total of 1821 pathogenic O∶3 strains were divided into 93 PFGE types, distributed in 19 provinces and autonomous regions, among which K6GN11C30021 and K6GN11C30012 were the dominant bands (46.35% and 22.5%, respectively), and 75.38% of the human strains were consistent with those isolated from local animal and food strains. A total of 226 O∶9 pathogenic strains were divided into 14 PFGE types, distributed in 8 provinces and autonomous regions; 77.78% of the human strains were consistent with the local animal and food strains. Therefore, Yersinia enterocolitica is widely distributed and has numerous hosts in China. The pathogenic strains have only two serotypes, whereas the non-pathogenic strains have many serotypes, which may have stronger biochemical metabolic ability and environmental adaptability than the pathogenic strains. The dominant bands of the pathogenic strain PFGE were relatively concentrated and widely distributed in the region. Most of the human strains were consistent with those isolated from local animals and food strains. The risk of human infection through livestock, poultry, food and the external environment should be vigilantly assessed.