白念珠菌临床分离调查及基因分型研究

Investigating and genotyping of Candida albicans clinical isolates

目的了解白念珠菌临床分离情况,并探讨其药敏结果与基因分型的相关性。方法回顾性分析本院2011年3～11月间临床分离白念珠菌分布及耐药性;随机选取232株,采用PCR方法扩增白念珠菌25S rDNA基因内含子区进行基因分型研究;采用ATB真菌药敏试剂条进行药敏分析;统计分析药敏结果与基因分型的相关性。结果期间共检出酵母样真菌973例,占病原菌阳性样本数比率为15.7%(973/6196);其中分离白念珠菌562株,占58%(562/973),主要分布科室为呼吸科(39.1%)、老年科(13.2%)、ICU(7.7%)、神经内科(7.5%)、免疫科(6.0%)以及其他科室(26.5%);标本类型以下呼吸道为主(81.7%),其次为尿路(9.4%)、血液(1.8%)等。对氟胞嘧啶、两性霉素B、氟康唑、伊曲康唑及伏立康唑的耐药率分别为0.9%、0%、1.4%、1.6%和1.1%。随机选取的232株白念珠菌经PCR方法可分为3型:A型125株,B型96株,C型11株。各型在5种药物的耐药性上并无差异。结论临床分离酵母样真菌以白念珠菌为主,感染部位以下呼吸道为主;临床分离株对5种抗真菌药物敏感度较高,主要基因型为A和B型,不同基因分型间药敏结果并无统计学差异。

Objective To investigate the incidence of nosocomial Candida albicans infection in the Drum Town Hospital of Nanjing,and the correlation between drug-resistance and genotyping.Methods We investigated the clinical isolates of Candida albicans from March to November in 2011 retrospectively.Two hundred and thirty-two isolates were selectived randomly for the genotyping,with polymerase chain reaction for the 25S rDNA of Candida albicans.The antifungal susceptibility was carried out with the ATB fungal test.Results The results show that 6196 positive culture strains were isolated in this period,with 973 isolates being fungal strains.The separation rate for Candida albicans was 58%（562/973） and mainly distributed in pneumology department（39.1%）,with the main infected sites of lower respiratory tract（81.7）,than in urinary tract infection（9.4%）.The susceptibility test for the Candida albicans isolates showed that the drug resistance to flucytosine,amphotericin B,fluconazole,itraconazole and voriconazole were 0.9%,0%,1.4%,1.6% and 1.1%,respectively.The 232 clinical isolates were classified into three genotypes： genotype A（125 isolates）,genotype B（96 isolates） and genotype C（11 isolates）.Antifungal susceptibility test indicated that there were no statistically difference between the genotyping and drug-resistance.Conclusions In conclusion,Candida albicans was the mainly fungal isolate in the Drum Town Hospital of Nanjing,and the majority isolates were from lower respiratory tract.The clinical isolates of Candida albicans showed high susceptibility to the five antifungal drugs above.Genotypes A and B were the mainly isolates of Candida albicans.No statistically difference was found among the five antifungal drugs with the genotypes.