侵袭性超级真菌:耳假丝酵母菌感染现状与研究进展

Current status and research progress of invasive super fungus Candida auris infection

耳假丝酵母菌(又名耳念珠菌)是2009年首次在日本发现的一种真菌病原新物种,因其感染具有多重耐药,深部组织侵袭性感染及病死率高的特征,故被称为"超级真菌"。耳假丝酵母菌可能存在基因组多样性,不同国家的分离株都有不同的克隆,因而需要进一步的研究来确定其转化为特定的侵袭性、毒性和耐药性的模式。中国大陆曾报道18例,发现首株(BJCA001)的亲缘关系与印度、巴基斯坦和法国等国家的分离株比较接近,与其他多个国家报道的多重耐药菌株不同。目前使用的传统微生物学鉴定方法难度高,常被误认为是其他酵母菌,特别是希木龙假丝酵母菌。基质辅助激光解吸电离飞行时间质谱仪及核糖体基因r DNA-ITS序列鉴定技术,可快速准确鉴定。耳假丝酵母菌感染主要有两种临床形式:定植与侵袭性深部感染。侵袭性深部感染则表现为多种形式,以血流感染(菌血症)最严重,病死率高(30%~72%)。本文就耳假丝酵母菌的特性、鉴定与分类、耐药性、流行与暴发等最新进展作一综述。

Candida auris is a new species of fungal pathogen discovered in Japan for the first time in 2009.Because of its multi-drug resistance,deep tissue invasive infection and high mortality,it is called as the"super fungus".Candida auris may have genomic diversity,and isolates in different countries have different clones,so further research is needed to determine its transformation into specific patterns of invasiveness,toxicity and resistance.Eighteen cases have been reported in China mainland,and the genetic relationship of the first strain(BJCA001)was relatively close to isolates from countries such as India,Pakistan,and France,and different from the multi-drug resistant strains reported in many other countries.The identification is difficult with the traditional microbiological methods currently in use and often mistaken for other yeasts,especially Candida haemulonii.Matrix-assisted laser desorption ionization time-of-flight mass spectrometer(MALDI-TOFMS)and rDNA-ITS sequence analysis provide rapid and accurate identification.There are two main clinical forms of Candida auris infection:colonization and invasive deep infection.Invasive deep infections are manifested in many forms,with bloodstream infection(bacteremia)being the most serious,with a high mortality rate(30%-72%).This article reviews the latest developments in the characteristics,identification and classification,drug resistance,prevalence and outbreaks of Candida auris.