国内临床分离阿萨希毛孢子菌3个新基因型分析

Three new genotypes of Trichosporon asahii strains isolated from Chinese patients

目的通过对IGS1区基因序列分析,明确国内临床分离8株阿萨希毛孢子菌(T.asahii)的基因型,为T.asahii感染的流行病学研究提供依据。方法以国内不同地区、不同患者临床分离的8株T.asahii为研究对象,PCR扩增、克隆IGS1区,寻找基因突变位点,构建系统发生树,明确国内T.asahii的基因型。结果 IGS1区长度均为643bp,部分菌株碱基发生突变;8株T.asahii共发现5个基因型,其中3株为国际上首次发现的新基因型,分别命名为基因型10(BZ702)、11(BZ704)、12(BZ901),3株为基因型1(BZ701、BZ705、BZ706),2株为基因型4(BZ703、BZ902)。结论中国的T.asahii菌株具有不同于其他国家的多种基因型,种内多样性更丰富,这可能与中国地域广阔有关,为T.asahii感染的流行病学研究提供了依据。

OBJECTIVE To provide important reference for epidemiologic research on Trichosporon asahii（T.asahii） through analyzing the genotypes of the intergenic spacer（IGS） 1 region of the rRNA gene in 8 T.asahii isolates obtained from Chinese patients.METHODS Totally 8 T.asahii strains isolated from Chinese patients in different regions were collected as the research objects.IGS1 region was amplified by using specific primers of PCR in order to find out the mutation sites,establish molecular phylogenetic tree of T.asahii strains and make clear of the genotypes of T.asahii isolates.RESULTS IGS1 regions of all eight strains were successfully amplified with a length of 643bp.Sequence analysis revealed that nucleotide variation occurred in several of the strains.Five genotypes were identified from the eight isolates,including three novel genotypes,separately named genotype 10（BZ702）,11（BZ704）,and 12（BZ901）,three strains of genotype 1（BZ701,BZ705,BZ706）,and two strains of genotypes 4（BZ703,BZ902）.CONCLUSION The results suggest that genotypes of the T.asahii isolated from Chinese patients are different from those of other countries with more diversified species which may related to the vast land of China,which provide new insights for the epidemiology of T.asahii.