小鼠腹腔感染中白色念珠菌芽管及蛋白酶活性与其毒力的相关性研究

Studies on correlative relationship between germ tube,proteinase and virulence of Candida albicans in murine model of intraperitoneal infection

目的 :探讨白色念珠菌与腹膜炎发生相关的毒力因子。方法 :40株临床分离菌分别以腹腔接种方式感染小鼠进行毒力试验 ,以血清中丙氨酸氨基转移酶 (ALT)和α -淀粉酶 (AM)活力为表示菌株毒力的指标。结果 :白念菌体外测得的芽管长度分别与受染动物血清中ALT、AM含量呈正相关 (rALT=0 . 893,rAM=0 . 80 1,P <0 . 0 1) ,菌株分泌型天冬氨酸蛋白酶 (SAP)活力与血中ALT、AM水平也存在显著的正相关关系 (P <0 .0 1) ,且经SAP特异抑制剂处理过的受染小鼠其ALT活性显著降低 (P <0 . 0 1)。结论

Objective:to investigate potential virulence factors which contribute to the occurance of peritonitis by C. albicans.Methods:Mice were infected by intraperitoneal (i.p.) innoculation with 40 clinical isolates ,respectively. Alanine aminotransferase(ALT) and amylase(AM) activities in the plasma were used as parameters for estimation of virulence.Results:Germ tube length measured in vitro correlated positively with ALT and AM activities (r\-\{ALT\}=0.893,r\-\{AM\}=0.801,P<0.01). ALT and AM levels in the blood were also correlated with secreted aspartic proteinase(SAP) activities of 40 strains(P<0.01).There was a significant reduction of ALT and AM levels when mice were treated with proteinase inhibitors before infection.Conclusion:Germ tubes and SAP contribute to virulence in the murine peritonitis model.