烟曲霉再鉴定、标准化CSP分型及体外药物敏感性

目的 了解烟曲霉复合体临床株菌种分布,经典烟曲霉临床株CSP基因型及对常见抗真菌药物敏感性状况.方法 菌株来源:北京大学真菌和真菌病研究中心保存分离自125名患者的162株烟曲霉复合体菌株.通过形态学,最高生长温度及分子生物学测序分步鉴定；对CSP基因进行扩增、测序,采用国际化命名体系进行CSP分型；采用微量液基稀释法测定经典烟曲霉对伊曲康唑(ITC)、两性霉素B(AMB)、伏立康唑(VRC)及卡泊芬净(CAS)的敏感性.结果 所有烟曲霉复合体菌株均为经典烟曲霉；共分为16个CSP基因型,最常见为t04A、t03和t01；分离自4名患者的13株菌对ITC的MICs≥4 μg/mL,其中2株菌AMB和VRC的MICa分别为4μg/mL和16 μg/mL.CAS的MECs最高为4μg/mL,仅1株.结论 未检出烟曲霉相关新种；经典烟曲霉临床株共16个CSP基因型,分布与国际研究结果基本一致,其中5个为新型.我国经典烟曲霉临床株ITC耐药率为3.2％,个别菌株AMB,VRC和CAS耐药.

Re-identification,standard CSP typing and in vitro susceptibility of Aspergillus fumigatus complex

Objective To investigate the strain distribution of Aspergillus fumigatus complex,the CSP genotypes and in vitro susceptibility of classic A.fumigatus strains.Methods One hundred and sixty-two strains of A.fumigatus complex isolated from 125 patients were re-identified as Aspergillus section Fumigati via macro-and micro-morphological characteristics,and classical A.fumigatus via maximum grow temperature.Atypical strains were identified based on internal transcribed spacer of the rDNA gene（rDNA ITS） sequencing.Classic A.fumigatus was typed by CSP gene sequencing and subsequently analyzed with the international nomenclature.In vitro antifungal susceptibility to itraconazole（ITC）,amphotericin B（AMB）,voriconazole（VRC） and caspofungin（CAS） were determined by broth microdilution susceptibility test.Results All strains were identified as classic A.fumigatus complex with 16 genotypes.Type t04A,t03 and t01 were most common in our study.MICs of ITC were ≥4 μg/mL in 13 strains isolated from 4 patients（3.2%）,two strains of which have MICs against AMB and VRC at 4 μg/mL and 16 μg/mL,respectively.The highest MEC against CAS was 4 μg/mL in 1 strain.Conclusions No newly proposed A.fumigatus associated specie was found.All clinical isolates of classic A.fumigatus in clinical were divided into 16 CSP genotypes,five of which had not been reported previously.Genotype distribution was similar with literature.ITC resistance rate was 3.2% in classical A.fumigatus in China.Resistances to AMB,VRC and CAS exist in some isolates.