Clemons K V, Park P, McCusker J H, McCullough M J, Davis R W, Stevens D A
Department of Medicine, Stanford University School of Medicine, California 94305, USA.
J Clin Microbiol. 1997 Jul;35(7):1822-8. doi: 10.1128/jcm.35.7.1822-1828.1997.
We have previously described differences in phenotype and virulence among clinical and nonclinical isolates of Saccharomyces. To further characterize these isolates, a comparison of restriction fragment length polymorphism (RFLP) patterns and genetic analysis were done. The cellular DNA of each of 49 clinical and 11 nonclinical isolates of Saccharomyces was digested with the endonuclease EcoRI, and the resultant fragments were separated by electrophoresis. Sixty isolates were grouped on the basis of the presence (group B) or absence (group A) of a 3-kb band. Group A contained 43 isolates (35 clinical and 8 nonclinical isolates) in 31 discernible subgroups, and group B had 17 isolates (14 clinical and 3 nonclinical isolates) in 10 subgroups. Interestingly, six of eight known vaginal isolates were group B, with four of those six being identical. Virulence of isolates was associated with membership in group A (P = 0.03). Comparison of known members of sibling species within the genus Saccharomyces, which cannot be distinguished by standard biochemical tests, showed that S. paradoxus, S. bayanus, and S. cerevisiae could be differentiated by RFLP analysis. Genetic analysis of the isolates forming viable spores showed that most group A isolates were diploid and members of the species S. cerevisiae. Those group A and B isolates unable to form viable spores may be diploid hybrids between Saccharomyces species. The group B isolates that formed viable spores were tetraploid and may also be interspecific hybrids. Overall, clinical isolates of Saccharomyces were very heterogeneous and exhibited little clonality. RFLP pattern analysis could be a useful method of demonstrating transmission in patients with infection or between environmental sources and patients.
我们之前已经描述过酿酒酵母临床分离株和非临床分离株在表型和毒力上的差异。为了进一步表征这些分离株，我们进行了限制性片段长度多态性（RFLP）模式比较和遗传分析。用核酸内切酶EcoRI消化49株酿酒酵母临床分离株和11株非临床分离株的细胞DNA，然后通过电泳分离所得片段。根据是否存在一条3 kb的条带，将60株分离株分为两组（B组）或无此条带的组（A组）。A组包含43株分离株（35株临床分离株和8株非临床分离株），分为31个可识别的亚组，B组有17株分离株（14株临床分离株和3株非临床分离株），分为10个亚组。有趣的是，8株已知的阴道分离株中有6株属于B组，其中6株中有4株相同。分离株的毒力与A组成员相关（P = 0.03）。对酿酒酵母属内无法通过标准生化试验区分的同宗物种的已知成员进行比较，结果表明，奇异酿酒酵母、贝酵母和酿酒酵母可通过RFLP分析进行区分。对形成有活力孢子的分离株进行遗传分析表明，大多数A组分离株是二倍体，属于酿酒酵母物种。那些无法形成有活力孢子的A组和B组分离株可能是酿酒酵母物种之间的二倍体杂种。形成有活力孢子的B组分离株是四倍体，也可能是种间杂种。总体而言，酿酒酵母临床分离株非常异质，几乎没有克隆性。RFLP模式分析可能是一种有用的方法，可用于证明感染患者之间或环境来源与患者之间的传播。
