湖北省高热病猪链球菌的分离鉴定和对小鼠的致病性研究

Streptococcus Isolated from Pig with High Fever Syndrome and Its Pathogenesis in Mice

【目的】从湖北省不同地区的高热症病例猪的心血、肝、淋巴结、肾和肺等分离出11株链球菌,进行血清型、毒力基因分布和病理学的初步研究。【方法】通过ATB自动生化鉴定系统RapidID32STREP链球菌鉴定、PCR分型、毒力基因的PCR检测及动物试验对分离菌株进行试验。【结果】11株均为猪链球菌,其中1株为7型,2株为9型,另8株为其它型,没有1型和2型。对11株猪链球菌的mrp、epf、sly、orf2、fbps、gdh6种毒力基因的分布情况进行PCR检测及动物试验表明:致病性和致死性较强的菌株毒力基因表型多为epf+orf2+fpbs+gdh+,显示除mrp、sly外,其它毒力因子也与菌株毒力相关。病理学变化表明急性死亡多表现为急性败血症症状,全身各组织器官广泛出血,以及肺炎、肾炎,脾脏淤血水肿和淋巴结脓肿。【结论】湖北省存在7型和9型的猪链球菌感染,猪链球菌在高热症中具有一定致病作用。

[Objective] The objective of this experiment is to study on serotype, distribution of virulence gene and pathology of 11 strains of Streptococcus, isolated from heart blood, liver, lymph node, kidney, lung and other tissues of swine from different areas in Hubei province, China. [Method] ATB aotu-biochemical reaction test system, PCR typing, PCR test of virulence factor genes and animal test assays were used. [ Result ] PCR typing assay indicated that 11 strains were Streptococcus suis including l serotype 7 strains, 2 serotype 9 strains, 8 other serotype strains, no serotype 1 strain or serotype 2 strain. Result of the genotypes of their mrp, epf, sly, orf2,fbps, gdh and mouse virulence test showed that the genotypes of high virulence streptococcus were epfor72＋ gdh＋ fpbs＋ strains without mrp＋ sly＋. Pathobiology showed that acute septicaemia, extensive blooding, lung fever, nephritis, congestion-dropsy in spleen and lymphatic abscess in all over the body, espciouly in the acute death. [Conclusion] Serotype 7 and serotype 9 existed in Hubei Province, streptococcus suis has some pathogenicity to ardent fever of swine.