Multilocus microsatellite typing for the domestic strains of Cryptococcus neoformans var. grubii / 基础医学与临床

ABSTRACT

Objective Cryptococcus neoformans var.grubii isolates from 6 different cities in our country using multilocus microsatellite typing(MLMT) method were genotyped to explore the genotypic distribution of the variety.Methods The DNA of forty-three isolates of Cryptococcus neoformans var.grubii was extracted.The DNA fragments covering microsatellite loci CNG1,CNG2 and CNG3 were amplified using PCR,and then sequenced.The numbers of each motif repeat in 3 microsatellite regions("TA" repeats for CNG1,"GA" repeats for CNG2,and "CAT" repeats for CNG3) were calculated.According to the repeat numbers of these motif,the MLMT types of 43 strains of Cryptococcus neoformans var.grubii were determined.Results Out of 43 isolates,the percentage of MLMT-17 was 83.72%.In the clinical and environmental isolates,the percentages of MLMT-17 were 86.67% and 70%,respectively.Two new genotypes MLMT-39 and-40 were found.Conclusion MLMT-17 of Cryptococcus neoformans var.grubii is prevalent in both clinical and community environment in China.Implying the most clinical strains which resulted in cryptococcosis originated from indigenous environmental strains.