甘肃夏河、碌曲县鼠疫主要宿主动物耶尔森菌感染状况调查

Investigation of infection status of Yersinia in main host animals of plague in Xiahe and Luqu counties of Gansu Province

目的:了解甘肃喜马拉雅旱獭鼠疫疫源地夏河、碌曲县鼠疫主要宿主动物耶尔森菌感染状况,为探索该疫源地鼠疫流行状态提供依据。方法:2014-2018年,现场采集20世纪50-60年代鼠疫活跃疫源地甘肃夏河、碌曲县鼠疫主要宿主动物肠回盲部及内容物、咽拭子(或舌根部)、血液样本,分别进行耶尔森菌分离、毒力测定及鼠疫耶尔森菌F1抗体检测。结果:958份回盲部及内容物样本检出24株耶尔森菌,检菌率为2.51%,分别为13株小肠结肠炎耶尔森菌(Yersinia enterocolitia,Y.e)、1株克氏耶尔森菌(Yersinia kristensenii,Y.k)、2株弗氏/中间耶尔森菌(Yersinia frederiksenii/intermedia,Y.f/i)、6株中间耶尔森菌(Yersinia intermedia,Y.i)、1株奥氏耶尔森菌(Yersinia aldouae,Y.a)、1株Yersinia massiliensis(Y.m)。958份咽拭子(或舌根部)样本检出19株耶尔森菌,检菌率为1.98%,分别为8株Y.e、1株假结核耶尔森菌(Yersinia pseudotuberculosis,Y.p)、4株Y.k、1株Y.f/i、4株Y.i、1株Yersinia ruckeri(Y.r)。检出的21株Y.e均没有致病性,毒力型别有ail-ystA-ystB+yadA-virF-rfbc-、ail-ystA-ystB-yadA-virF-rfbc-两种,分别占9.52%(2/21)、90.48%(19/21)。1079份血清样本F1抗体检测结果均为阴性。结论:夏河、碌曲县鼠疫主要宿主动物咽部及肠道内广泛存在耶尔森菌群,检出的Y.e均为非致病性菌株。本次调查结果为进一步研究该疫源地鼠疫耶尔森菌在宿主动物和其生存环境中如何保存提供了线索。

Objective To investigate the infection status of Yersinia in the main host animals of plague in Xiahe and Luqu counties,the Himalayan marmot plague foci of Gansu Province,and to provide a basis for exploring the epidemic status of plague in these foci.Methods Samples of the ileocecal region and contents,pharyngeal swabs(or tongue roots),and blood of the main host animals of plague in Xiahe County and Luqu County where the plague were active in the 1950s and 1960s were collected from 2014 to 2018.The Yersinia isolation,virulence determination and F1 antibody detection were performed,respectively.Results Totally 24 strains of Yersinia were detected in 958 samples of ileocecal region and contents with a bacterial detection rate of 2.51%,which were 13 strains of Yersinia enterocolitia(Y.e),1 strain of Yersinia kristensenii(Y.k),2 strains of Yersinia frederiksenii/intermedia(Y.f/i),6 strains of Yersinia intermedia(Y.i),1 strain of Yersinia aldouae(Y.a)and 1 strain of Yersinia massiliensis(Y.m).Totally 19 strains of Yersinia were detected in 958 samples of pharyngeal swabs(or tongue roots),and the detection rate was 1.98%,which were 8 strains of Y.e,1 strain of Yersinia pseudotuberculosis(Y.p),4 strains of Y.k,1 strain of Y.f/i,4 strains of Y.i,and 1 strain of Yersinia ruckeri(Y.r).The virulence types of 21 strains of Y.e were ail-ystA-ystB+yadA-virF-rfbc-,ail-ystA-ystB-yadA-virF-rfbc-,respectively,accounting for 9.52%(2/21)and 90.48%(19/21),none were pathogenic.The results of F1 antibody in 1079 serum samples were all negative.Conclusions Yersinia are widely found in the pharynx and intestines of the main host animals of plague in Xiahe and Luqu counties,and the Y.e detected are all non-pathogenic strains.The results of this investigation can provide clues for further study on the preservation of Yersinia pestis in host animals and their living environment.