福氏志贺菌感染豚鼠和HeLa细胞的毒力

目的 研究福氏志贺菌感染豚鼠和HeLa细胞后细菌致病能力的差异，探讨痢疾的防治。方法 选用28株福氏志贺菌感染豚鼠眼角膜，观察角膜结膜病变反应，并进行细胞学、细菌学、病理组织切片检查。然后再选出12株福氏志贺菌强毒株和两株弱毒株，通过噬斑形成实验，观察对HeLa细胞的侵袭能力。结果 28株福氏志贺菌均在3d之内引起豚鼠发病，但症状表现有差异，除2株福氏志贺菌感染豚鼠后发病时间延长、症状轻微外。其余菌株则引起较为严重的角膜结膜炎，尤其在感染第3天，出现最为典型的临床表现。噬斑形成试验结果与豚鼠感染试验基本相符。结论 检测福氏志贺菌的毒力可用HeLa细胞噬斑形成试验替代Sereny试验。利用Sereny试验和HeLa细胞噬斑形成试验鉴定出26株福氏志贺菌的强毒株和2株弱毒株，用于毒力基因的进一步分析。

Virulence of Shigella Flexneri in Infected Guinea Pigs and HeLa Cells

Purpose To study the pathogenicity of Shigella through infecting guinea pigs'eyes and HeLa cells.It contributes to further discuss on the prevention and the treatment of dysentery. Methods Twenty-eight strains of Shigella flexneri isolated from clinical samples were chosen to infect guinea pigs'eyes,then we observed the response of keratoconjunctivis and conducted experiments in cytology,bacteriology,and pathology.From the 28 strains,we selected 12 strains with high virulence and 2 strains with low virulence,then we investigated their abilities of invading HeLa cells by the test of plaque formation. Results All the 28 strains of Shigella flexneri caused keratoconjunctivis in guinea pigs within three days.Twenty-six strains caused acute and severe keratoconjunctivis,while the guinea pigs infected by the other two strains produced symptoms relatively late and slight.The typical symptoms occurred especially in the third day after infection.The results of plaque-formation tests are consistent with that of the Sereny test. Conclusions Twenty-six high-virulence strains and 2 low-virulence strains were identified by the Sereny test and tests of plaque formation,which would be applied in further analysis of virulent genes.Plaque formation test can substitute for Sereny test in detecting the virulence of Shigella flexneri.