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

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.

Multilocus microsatellite typing of clinical Cryptococcus neoformans var.grubii strains from China and Brazil / 第三军医大学学报

Objective To understand the genotype distribution of clinical Cryptococcus neoformans var.grubii strains from China and Brazil using multilocus microsatellite typing(MLMT) method and to study the difference in their MLMT genotyping.Methods DNA was extracted from the identified 69 clinical Cryptococcus neoformans var.grubii strains.DNA fragments covering microsatellite loci(CNG1,CNG2,and CNG3) were amplified by PCR and sequenced.The number of each motif repeats in 3 microsatellite regions("TA","GA",and "CAT" repeats for CNG1,CNG2,and CNG3,respectively) was calculated.The MLMT types of 69 clinical Cryptococcus neoformans var.grubii strains were determined according to the repeat number of different motifs.Data were analyzed using SPSS 11.5 software.Results Five genotypes were identified in 33 clinical strains from China.Of these strains,29 were MLMT-17,accounting for 87.88% of the total strains.Ten genotypes were identified in 36 clinical strains from Brazil.Of the 36 strains,19 were MLMT-13,accounting for 52.78% of the total strains.Conclusion The difference is great in major genotype distributions of the clinical Cryptococcus neoformans var.grubii strains from China and Brazil.The genotype of clinical strains from Brazil is diversely distributed.