不同氧浓度对新生隐球菌尿素酶和磷脂酶的影响  

Effects of oxygen concentration on urease and phospholipase secreted by Cryptococcus neoformans

作　　者：孔庆涛[1] 桑红[1] 王乐 曾梅华[1] 王高峰[1] 张敏[1] 吕桂霞 沈永年 刘维达[2] 

机构地区：[1]南京军区南京总医院皮肤科 [2]中国医学科学院协和医科大学皮肤病研究所真菌科

出　　处：《医学研究生学报》2012年第11期1128-1131,共4页Journal of Medical Postgraduates

基　　金：国家自然科学基金(81071331)

摘　　要：目的低氧对新生隐球菌毒力因子的影响尚不清楚。文中探讨不同氧浓度对新生隐球菌分泌尿素酶和磷脂酶的影响。方法以厌氧、微需氧和CO2产气袋建立不同氧浓度(氧浓度分别为0%、8%和15%)培养条件,以尿素酶培养基和卵黄培养基采用平板法培养不同血清型的6株新生隐球菌,观察尿素酶培养基颜色变化情况,计算沉淀圈比值(PZ值),比较不同氧浓度培养条件下新生隐球菌分泌尿素酶和磷脂酶的情况。结果第7天正常氧浓度培养条件下除菌株ATCC32609外,其余菌株均出现颜色变化,CO2培养条件下仅菌株BLS63和ATCC34874出现轻微颜色变化,微含氧及厌氧培养条件下所有受试菌株均未出现颜色变化。菌株BLS71、ATCC32609和ATCC34874微含氧培养条件下的PZ值大于其他培养条件,差异有统计学意义(P<0.05)。其余菌株在正常氧、CO2和微含氧培养条件下PZ值差异无统计学意义(P>0.05)。厌氧培养条件下所有受试菌株均未产生肉眼可见的沉淀圈。结论低氧可能对新生隐球菌尿素酶和磷脂酶活性有抑制作用。Objective There is a lack of information on the effect of hypoxia on the virulence of Cryptoeoecus neoformans. This study was to investigate the effects of different concentrations of oxygen on the activity of urease and phospholipase secreted by Cryptoeoe- eus neoformans. Methods Using urea agar and egg yolk agar, we cultured 6 Cryptoeoccus neoformans strains of different serum types under different conditions of oxygen concentration established by AnaeroPack-Campylo （APC）. We observed ehanges in the color of the medium, determined the urease activity of the strains, and compared the phospholipase activities of Cryptocoeeus neoformans by the ratio of the eolony diameter to the total diameter of the colony plus the precipitation zone （PZ）. Results All the strains except ATCC32609 displayed pink intensity after incubated in atmospheric condition for 7 days, but none showed urease activity in anaerobie condition after incubated for 14 days. The PZs of BLS71, ATCC32609 and ATCC34874 were bigger at APC-indueed oxygen concentrations than in other conditions （P 〈 0.05）. None of the strains exhibited phospholipase activity in anaerobic condition. Condusion Hypoxic eonditions may inhibit the activities of urease and phospholipase secreted by Cryptoeeccus neofonnans.

关 键 词：新生隐球菌 氧浓度 尿素酶 磷脂酶 

分 类 号：Q814.9[生物学—生物工程]