四川部分地区禽源空肠弯曲菌MLST分型及遗传进化分析

目的 为了解四川部分地区分离到的48株禽源空肠弯曲菌间的分子特征,以对来源不同的空肠弯曲菌进行分子分型及遗传进化分析。方法 本研究参照MLST数据库,选取了空肠弯曲菌MLST分型7个管家基因aspA, glnA, glyA, gltA, tkt, pgm和uncA作为目的基因分别扩增及测序,并将所得序列经比对后进行遗传进化分析。结果 48株分离株中共含24种不同的序列型分属于9种不同的克隆系及11种独特型,其中22株分离株含有新序列型,占分离株的45.83%(22/48);9种不同的克隆系中以CC-21、CC-353、CC-464克隆系所含菌株相对较多,而克隆系CC-45、CC-48最少,均为1株分离株;11种独特型共存于21株分离株中,其中以ST-8675序列型最多,为8株。遗传进化树显示,属同一克隆系的不同型别间的分离株亲缘关系较近,如同属于CC-21克隆系的ST-298与ST-760型别分离株处于同一小分支、亲缘关系较近,但不同克隆系的分离株间遗传进化关系较远,鹌鹑源分离株(V13-20)单独处于一大分支与其余禽源分离株间的亲缘关系最远。总体而言,不同地区、宿主来源的分离株呈现遗传多样性。结论 本研究中分离株间具有基因多样性,MLST分型为了解该地区空肠弯曲菌的遗传特性和分布特点提供了参考依据。

MLST typing and genetic evolution of Campylobacter jejuni isolated from poultry in some areas of Sichuan,China

To determine the molecular characteristics of 48 strains of Campylobacter jejuni isolated from some parts of Sichuan, the molecular typing and genetic evolution of Campylobacter jejuni were analyzed. According to MLST database the selection of Campylobacter jejuni MLST genotyping of 7 housekeeping genes aspA, glnA, glyA, gltA, tkt, pgm and uncA, the sequencing as target genes were amplified, and the sequences were compared with phylogenetic analysis. The result showed that there were 24 different sequences in 48 isolates, belonging to 9 different clones and 11 unique types, among which 22 of the isolates contained a new sequence, accounting for 45.83% (22/48). Among the 9 different clones, CC-21, CC-353, and CC-464 clones contained more strains relatively, while the clones CC-45 and CC-48 contained one isolated. The 11 unique types coexist in 21 isolates, of which 8 strains were the ST-8675 sequence types. Phylogenetic tree showed that the isolates belonging to different clones of the same clonal line have close genetic relationships, like the ST-298 and ST-760 isolates belonging to the CC-21 clonal line were on the same small branch and closely related. However, the genetic relationship between the isolates of different clonal lines was far away. The quail source isolates (V13-20) were in a large branch and has the most distant relationship with other poultry isolates. Overall, isolates from different regions and host sources showed genetic diversity. Gene polymorphism exists in the isolates in this study, and MLST typing provides a reference for understanding the genetic characteristics and distribution characteristics of Campylobacter jejuni in the area.