甄氏外瓶霉的核糖体基因分型研究

Population studies of Exophiala jeanselmeis by sequence analysis in the ribosomal DNA

目的:应用核糖体基因(rDNA)序列对甄氏外瓶霉进行分型研究。方法:试验菌株包括甄氏外瓶霉及其变种 20株(模式株、标准株、临床及自然分离株),丛梗孢外瓶霉 8株,威尼克外瓶霉 1株 (标准株及临床和环境分离株),疣状瓶霉 1株。煮沸冷冻法提取DNA,常规PCR扩增核糖体基因及其转录间隔区,应用DNA多序列分析等方法进行研究。结果:甄氏外瓶霉核糖体基因及其转录间隔区变异较大,DNA序列分析显示,不同来源、不同致病性的甄氏外瓶霉可分为 7型,个别菌种与其他甄氏外瓶霉的遗传距离较大。结论:甄氏外瓶霉核糖体基因及其转录间隔区序列变异较大,个别菌株的归属有待于进一步研究。

Objective: To study the populations of Exophiala jeanselmei strains from diverse sources using rDNA sequences. Methods: Tested strains included 20 isolates of Exophiala jeanselmei (type culture, reference culture, clinical and environmental isolates), 8 isolates of E. moniliae, 1 isolate of Exophiala werneckii, respectively. DNA was isolated with boiled-iced water method. Ribosomal DNA and its internal transcribed spacer regions were amplified and analyzed with sequencing. Results: The ribosomal genes of E. jeanselmei varied greatly. Twenty strains of this species were divided into 7 types. The genetic distances of some strains in this species were quite long. Conclusion: The ribosomal RNA genes and their internal transcript sequences vary more widely than those of the other species in this genus.