Chen S C, Muller M, Zhou J Z, Wright L C, Sorrell T C
Centre for Infectious Diseases and Microbiology, University of Sydney, Westmead Hospital, Australia.
J Infect Dis. 1997 Feb;175(2):414-20. doi: 10.1093/infdis/175.2.414.
Fifty isolates of Cryptococcus neoformans were examined for extracellular phospholipase production after inoculation onto egg yolk agar; 49 produced a pericolonial precipitate indicative of phospholipase activity. Phospholipase B (PLB), lysophospholipase, and lysophospholipase-transacylase activities were identified by radiometric analysis in supernatants from 4 clinical isolates. The ratio of colony diameter to colony plus precipitate on agar (Pz) correlated with PLB activity. Phospholipase production was similar in 12 environmental and 13 clinical isolates of C. neoformans var. gattii. Environmental strains of C. neoformans var. neoformans (n = 8) produced more phospholipase at 72 h than did 17 clinical isolates (mean Pz, 0.57 vs. 0.72; P < .01); however, Pz values were similar at 96 h. Quantitation of cryptococci in the lungs and brains of BALB/c mice inoculated intravenously with 4 strains expressing high, intermediate, or low phospholipase activity revealed a correlation between phospholipase activity and virulence. Phospholipases secreted by C. neoformans may be implicated in virulence.
将50株新型隐球菌接种于蛋黄琼脂上，检测其胞外磷脂酶的产生情况；49株产生了菌落周围沉淀，表明有磷脂酶活性。通过放射性分析，在4株临床分离株的上清液中鉴定出磷脂酶B（PLB）、溶血磷脂酶和溶血磷脂酶转酰基酶活性。琼脂上菌落直径与菌落加沉淀的比值（Pz）与PLB活性相关。12株环境分离株和13株新型隐球菌变种格特隐球菌临床分离株的磷脂酶产生情况相似。新型隐球菌变种新生隐球菌的环境菌株（n = 8）在72小时时产生的磷脂酶比17株临床分离株更多（平均Pz，0.57对0.72；P <.01）；然而，在96小时时Pz值相似。对静脉接种4株表达高、中或低磷脂酶活性菌株的BALB/c小鼠的肺和脑中的隐球菌进行定量分析，结果显示磷脂酶活性与毒力之间存在相关性。新型隐球菌分泌的磷脂酶可能与毒力有关。
