贵州与中国大陆其它地区空肠弯曲菌MLST特征的比较分析

目的 了解贵州省鸡源空肠弯曲菌的分子流行特征，阐明各地菌株间的亲缘关系和进化特征。方法 在贵州省随机抽取7个大型养鸡场，共采集210份鸡的新鲜粪便样本，分离培养出38株空肠弯曲菌，采用多位点序列分型对分离株的序列型及克隆复合体进行构成和聚类分析，与PubMLST数据库中来自国内的分离株分子特征进行比较。结果 贵州省38株鸡源空肠弯曲菌分为23种ST型和8个克隆复合体，其中9种是目前中国大陆地区已有的ST型，2个等位基因和8种序列型为新发现的。ST型构成比前四位分别是ST - 45、ST - 161、ST - 354、ST - 4 324，与数据库中已有的6株贵州来源菌株相比，不存在共同的ST型。优势克隆复合体（CC - 45、CC - 354、CC - 52）与数据库中鸡源分离株的前三位克隆复合体没有重叠。菌株遗传进化树显示，本研究中属于优势克隆复合体的18株菌与国内部分人源、猪源、野生鸟源、鹅源分离株有较近的遗传距离。结论 贵州省鸡源空肠弯曲菌具有高度遗传多样性，在一定程度上表现出地域流行特征。序列型与国内华东地区的分离株有较高的交叉性，部分分离株与国内人、野生鸟、鹅等来源分离株遗传距离近，应加强对不同地区、不同宿主来源空肠弯曲菌的动态监测。

Comparative analysis of MLST characteristics of Campylobacter jejuni in Guizhou and other areas of mainland China

Objective To understand the molecular epidemic characteristics of Campylobacter jejuni from chickens in Guizhou Province, and to clarify the genetic relationship and evolutionary characteristics of strains in different regions. Methods Seven large chicken farms were randomly selected in Guizhou Province, 210 fresh chicken fecal samples were collected, and 38 strains of Campylobacter jejuni were isolated and cultured. The composition and clustering analysis of the sequence types and clonal complexes of the isolates were performed by multi-locus sequence typing, and the molecular characteristics of the isolates were compared with those in the PubMLST database in China. Results The 38 strains of Campylobacter jejuni from Guizhou Province were divided into 23 ST types and eight clonal complexes, nine of which were existent ST types in mainland China, and two alleles and eight sequence types were newly discovered. The top four of the ST-type composition ratios were ST-45, ST-161, ST-354, and ST-4 324. Compared with the six Guizhou-derived strains in the database, there was no overlapped ST-type. The dominant clone complex (CC-45, CC-354, and CC-52) did not overlap with the first three clone complexes of chicken-derived isolates in the database. The genetic evolutionary tree of strains showed that the 18 strains belonging to the dominant clone complex in this study had a relatively close genetic distance with some domestic isolates of human origin, pig origin, wild bird origin, and goose origin. Conclusion Campylobacter jejuni from Guizhou Province has a high degree of genetic diversity and shows the characteristics of regional epidemics to a certain extent. The sequence type has a high degree of crossover with isolates from East China, and some isolates are genetically close to isolates from domestic humans, wild birds, geese, and other sources. The dynamic monitoring of Campylobacter jejuni from different regions and different host sources should be strengthened.