环境/定植耳念珠菌的分离鉴定及药敏分析

Isolation,identification and antimicrobial susceptibility of environmental/colonized Candida auris

目的分离、鉴定重症监护病房环境及患者体表定植的耳念珠菌,并分析其药物敏感性。方法对存在耳念珠菌感染患者的重症监护病房内96处环境和14例患者体表采样及培养,培养产物经质谱、Vitek 2 Compact全自动微生物鉴定系统鉴定,并经全基因组测序(WGS)技术确认菌种。检测菌株最低抑菌浓度(MIC)判断其药物敏感性。结果质谱鉴定出16株耳念珠菌,其中,环境检出8株,患者体表定植8株,Vitek 2 Compact系统仅鉴定出其中的5株。16株环境/定植分离株经测序证实为耳念珠菌,与耳念珠菌南亚分支(Ⅰ)的基因组具有高度相似性。16株耳念珠菌的药敏结果基本一致,均对两性霉素和氟康唑耐药,均对5-氟胞嘧啶和伏立康唑敏感,对伊曲康唑敏感或中介。结论耳念珠菌感染患者可引起环境污染和其他患者体表定植,建立针对环境/定植耳念珠菌的有效监测方法有助于开展感染控制工作。

Objective To isolate and identify Candida auris(C.auris)colonized in the environment of intensive care unit(ICU)and patients’body surface,and analyze the antimicrobial susceptibility.Methods Ninety-six environmental specimens from ICU and 14 specimens from body surfaces of ICU patients with C.auris infection were taken and cultured.Culture products were identified by mass spectrometry and Vitek 2 Compact automated microbial identification system.Species were confirmed by whole genome sequencing(WGS)technology.Antimicrobial susceptibility was determined through minimum inhibitory concentration(MIC).Results 16 strains of C.auris were identified by mass spectrometry,8 of which were environmental strains and 8 were colonized on the patients’body surface.Vitek 2 Compact system only identified 5 strains.Sixteen environmental/colonized isolates were confirmed to be C.auris through sequencing,exhibiting high genomic similarity with the South Asian branch(Ⅰ)of C.auris.Antimicrobial susceptibility testing results of the 16 C.auris strains were consistent,all of which were resistant to amphotericin and fluconazole,susceptible to 5-fluorocytosine and voriconazole,and susceptible to or intermediated to itraconazole.Conclusion Patients infected with C.auris can cause environmental contamination and colonization on body surface of other patients.Establishing effective monitoring methods for environmental/colonized C.auris can promote infection control.