Clemons K V, McCusker J H, Davis R W, Stevens D A
Department of Medicine, Santa Clara Valley Medical Center, San Jose, California.
J Infect Dis. 1994 Apr;169(4):859-67. doi: 10.1093/infdis/169.4.859.
Although considered nonpathogenic, Saccharomyces cerevisiae is being encountered more frequently in the clinical setting. To assess pathogenic potential, 13 clinical isolates, 10 nonclinical isolates, and 5 constructed strains of S. cerevisiae were analyzed. All were S. cerevisiae by biochemical profiles, sporulation, or genetic evidence. Intravenous inoculation of yeasts into CD-1 mice showed that some clinical isolates proliferated in the brain (5-fold) but nonclinical isolates were cleared (1000-fold) by day 7 after infection. Comparison of burdens with those of YJM128 (clinical) and Y55 (laboratory strain) revealed three virulence groupings: virulent, those greater than or equal to YJM128 (5 clinical and 2 genetic constructs); intermediate virulent, those less than YJM128 and greater than Y55 (5 clinical, 3 genetic constructs, and 4 nonclinical); and avirulent, those less than or equal to Y55 (1 clinical and 6 nonclinical). Genetic crosses indicated that virulence was a dominant trait. Growth of various isolates at 37 degrees C and 39 degrees C indicated that temperature is associated with but not solely responsible for differences in virulence. These data demonstrate that some clinical isolates of S. cerevisiae can proliferate and resist clearance in vivo and support the potential of S. cerevisiae as a cause of clinical disease.
尽管酿酒酵母被认为是非致病性的，但在临床环境中其出现频率却越来越高。为了评估其致病潜力，对13株临床分离株、10株非临床分离株和5株构建的酿酒酵母菌株进行了分析。通过生化特征、孢子形成或基因证据鉴定，所有菌株均为酿酒酵母。将酵母静脉接种到CD - 1小鼠体内，结果显示一些临床分离株在脑中增殖（增长5倍），但非临床分离株在感染后第7天被清除（清除1000倍）。将这些菌株的载量与YJM128（临床株）和Y55（实验室菌株）的载量进行比较，发现有三个毒力分组：强毒株，载量大于或等于YJM128的菌株（5株临床株和2株基因构建株）；中等毒力株，载量小于YJM128且大于Y55的菌株（5株临床株、3株基因构建株和4株非临床株）；无毒株，载量小于或等于Y55的菌株（1株临床株和6株非临床株）。遗传杂交表明毒力是显性性状。各种分离株在37℃和39℃下的生长情况表明，温度与毒力差异有关，但并非是造成毒力差异的唯一因素。这些数据表明，一些酿酒酵母临床分离株能够在体内增殖并抵抗清除，支持了酿酒酵母作为临床疾病病因的可能性。
