奶牛粪便分离的伊氏李斯特菌伊氏亚种基因组序列测定及其分子特征分析

目的 了解某奶牛场奶牛粪便中李斯特菌的携带情况及其分离株的遗传特征。方法 用ISO 11290方法分离196份奶牛粪便样本中的李斯特菌,对分离的伊氏李斯特菌进行全基因测序,用MEGA6.0构建系统发育树,网站在线比对分析伊氏李斯特菌株的毒力基因、耐药基因及前噬菌体等。结果 196份奶牛场养殖的奶牛粪便样本中有9份样本为李斯特菌阳性,其中3株为伊氏李斯特菌伊氏亚种,6株为英诺克李斯特菌,分离率分别为1.53%和3.06%。3株伊氏李斯特菌伊氏亚种分离株具有包括LIPI-1和LIPI-2在内的绝大部分致病性李斯特菌毒力相关基因,携带一个不完整的前噬菌体及22个耐药相关基因。结论 养殖场奶牛粪便中携带伊氏李斯特菌伊氏亚种。对伊氏李斯特菌伊氏亚种分离株的全基因组、毒力基因、耐药基因、前噬菌体基因等遗传特征分析,为进一步分析其致病性提供了参考。

Genome sequencing and molecular characteristics of Listeria ivanovii subsp. ivanovii isolated from the cow feces

Listeria ivanovii, an opportunistic human pathogen, is an animal pathogen and primarily infects ruminants. Three Listeria ivanovii subsp.ivanovii strains and six Listeria innocua strains were isolated from the 196 cow feces samples with the prevalence of 1.53% and 3.06%, respectively. The main virulence genes including LIPI-1 and LIPI-2 of pathogenic Listeria were positive in three Listeria ivanovii subsp. ivanovii isolates. One incomplete prophage genes cluster and 22 drug resistance-related genes also existed in the genome of Listeria ivanovii subsp. ivanovii isolates. The results indicated that Listeria ivanovii subsp. ivanovii was carried in the cow feces. Genetic characteristics analysis of the virulence genes, resistance genes and prophage of Listeria ivanovii subsp. ivanovii isolates provide a reference for the subsp. ’s pathogenicity study.