BD Phoenix^(TM)酵母菌鉴定板对临床分离酵母菌鉴定能力的评估

Evaluation of BD Phoenix^(TM) in identification of the yeast by using clinical yeasts

目的评估BD PhoenixTM酵母菌鉴定板对酵母菌的鉴定能力。方法选取白念珠菌18株,热带念珠菌22株,光滑念珠菌19株,克柔念珠菌8株,近平滑念珠菌20株,新生隐球菌14株,季也蒙念珠菌4株,平常念珠菌1株,葡萄牙念珠菌1株,头状地霉2株,挪威念珠菌1株,链状念珠菌1株,乳酒念珠菌1株,希木龙念珠菌1株,解脂念珠菌3株,皱褶念珠菌1株,菌膜念珠菌3株,共计120株。借助PhoenixTM100全自动微生物鉴定仪,使用BD PhoenixTM酵母菌鉴定板鉴定上述菌株。用真菌通用引物ITS1与ITS4对所有受试菌株的rDNA进行PCR扩增,对PCR产物进行序列测定、分析并作为金标准与BD PhoenixTM酵母菌鉴定板的结果比较,同时使用MALDI-TOF MS质谱分析对试验菌株进行菌种鉴定。结果 BD PhoenixTM酵母菌鉴定板除了对1株挪威念珠菌、1株平常念珠菌、1株解脂念珠菌、1株皱褶念珠菌未能鉴定以及1株链状念珠菌、1株克柔念珠菌、2株菌膜念珠菌、1株解脂念珠菌鉴定错误外其余试验菌株鉴定均正确,鉴定准确率为92.5%。所有鉴定结果均在17 h内获得,而白念珠菌、热带念珠菌、近平滑念珠菌的鉴定时间均小于6 h,并且不受推荐培养基的限制。所有菌株MALDI-TOF MS的鉴定结果与其rDNA ITS序列分析的结果完全一致。结论 BD PhoenixTM酵母菌鉴定板对多数酵母菌能够快速准确地鉴定到种,但对某些少见酵母菌的鉴定能力有待进一步考证。

Objective To evaluate the ability of BD PhoenixTM in identification of the yeast isolated from clinical speciemen.Methods 18 strains of Candida albicans,22 strains of C.tropicalis,19 strains of C.glabrata,8 strains of C.krusei,20 strains of C.parapsilosis,4 strains of C.guilliermondii,1 strain of C.inconspicua,C.lusitaniae,C.norvegensis,C.catenulata,C.kefyr,C.haemulonii,C.rugosa respectively,3 strains of C.lipolytica,3 strains of C.pelliculosa,2 strains of Geotrichum capitatum,14 strains of Cryptococcus neoformans were tested.The total of 120 stains were all isolated from clinical specimen.They were identified by using automated PhoenixTM 100 to test the BD PhoenixTM.The fungus-specific universal primers ITS1 and ITS4 were used to amplify the rDNA of isolates mentioned above.The products of PCR were sequenced and analyzed,which were compared with BD PhoenixTM as golden standard.MALDI-TOF MS were also used to identify all the tested strains.Results By using BD PhoenixTM,1 strain of C.norvegensis,C.inconspicua,C.lipolytica,C.kefyr,C.rugosa cant be identified and 1 strain of C.catenulate,1 strain of C.krusei,2 strains of C.pelliculosa and 1 strain of C.lipolytica had the wrong results.The other results were correct.The precision of identification for BD PhoenixTM was 92.5％.All the results were obtained in 17 hours.It took us less than 6 hours to identify C.albicans,C.tropicalis and C.parapsilosis without influence of proposed media.There was no difference between identification results of rDNA ITS sequencing and MALDI-TOF MS.Conclusions Most yeasts can be identified to the species level quickly and correctly by BD PhoenixTM But its ability of identifying some uncommon yeasts need to be tested.