新疆不同来源单核细胞增生性李斯特氏菌分离株的部分生物学特性及相关性分析

Analysis of partial biological characterization and correlation of Xijiang Listeria moncytogenes isolates

为研究8株来自新疆发病绵羊和健康绵羊的单核细胞增生性李斯特氏菌(LM)分离株的部分生物学特性及相关性,本实验对8株LM分离株进行小鼠致病力检测、多重PCR谱系鉴定、血清型鉴定及InlA基因的PCR-RFLP分析。结果显示,健康绵羊与临床发病绵羊中分离的LM分离株对小鼠具有相同的致病性;除1株临床分离株为血清型4b和谱系Ⅰ外,其余7株均为血清型1/2a和谱系Ⅱ;5株健康绵羊分离株的毒力基因InlA的PCR-RFLP复合基因型均为E型,而3株临床发病绵羊中的分离株为C型或B型。两种不同来源LM在小鼠致病性血清型及谱系上具有一致性及相关性,但其毒力基因InlA存在多样性。初步揭示健康绵羊携带的LM可以经内源性感染而发生李氏杆菌病,表明内源性感染是造成绵羊李氏杆菌病流行的一种传染方式。

To analyze the isolates of Listeria moncytogenes from diseased and healthy sheep, the biological characterization and correlation of the 8 Xijiang isolates were studied by pathogenic tests in mice, multiplex PCRs for lineage, serovar identification and PCR-RFLP of lnlA gene. The results showed that all isolates from diseased and healthy sheep had the same pathogenicity in mice; exception of one isolate from diseased sheep which was serovar 4b and lineage Ⅰ , other isolates were serovar 1/2a and lingeage Ⅱ ; PCR-RFLP analysis indicated that the virulence gene InIA of 5 isolates from healthy sheep molecular subtypes were profile E, while 3 isolates from diseased sheep were profile C or B. There were consistency and correlativity among pathogenic, serovar and lingeage in mice, whereas the diversity of virulence gene InIA. These results indicated that endogenous infection of L. moncytogenes in healthy sheep which caused Listeriosis epidemic might be the way for L. moncytogenes transmission.