不同源沙门氏菌对小鼠致病力的比较与毒力基因检测

目的 探究不同来源沙门氏菌的致病力及毒力基因分布的差异性。方法 采用改良寇氏法对7株不同来源的沙门氏菌进行小鼠致病性试验、病理剖检和组织切片观察,应用PCR检测质粒毒力基因和部分毒力岛基因。结果 7株菌株的LD₅₀按表中编号⑥、④、⑤、②、①、③、⑦依次降低,菌株⑦、①、③引致的病理变化最为明显,4株猪源沙门氏菌的致病力均高于3株鸡源菌株。仅菌株⑦菌株检出spvR、spvA、spvB、spvC、spvD质粒毒力基因;毒力岛毒力基因sscA、sseD、sseE 7株菌株全部检出,而sseC基因仅有③、④、⑤和⑦检出。结论 不同来源的沙门氏菌对小鼠的致病力具有明显差异,不同沙门氏菌对小鼠的致病力表型与其毒力基因的分布存在相关性。

Comparative study on pathogenicity of Salmonella isolates from different sources of laboratory mice and the detection of their virulence genes

The aim of this study was to explore the pathogenicity of Salmonella isolates from different sources and the distribution of their virulence genes. We tested the pathogenicity of seven Salmonella isolates from different sources by the modified Karber method. The pathological changes were observed, and the plasmid virulence genes (spv) and some pathogenicity island (SPI) genes were detected by PCR. Results showed that according to the number of strain in the table the LD₅₀ in the seven isolates were decreased in the order of ⑥, ④, ⑤, ②, ①, ③, ⑦. The most obvious pathological changes were caused by ①, ③ and ⑦. The pathogenicity of Salmonella isolates from swine was stronger than others from chicken. The spv genes detected from ⑦ isolate only. The SPI virulence genes sscA, sseD, and sseE were detected in all Salmonella isolates with the present of sseC in ③, ④, ⑤ and ⑦. Results suggested that there is obvious difference of pathogenicity to mice among Salmonella isolates from different sources, which indicated a correlation between pathogenicity to mice and the carrier condition of virulence genes of Salmonella isolates from different sources.