条件致病性真菌感染的基因分型与耐药性分析

Genotyping and resistance analysis for pathogenic fungi infection

目的研究临床条件致病性真菌感染的分布特点、实验室诊断、基因分型及耐药性,为临床诊断真菌感染及合理使用药物提供依据。方法对2013年1月-2014年1月,各病区送检标本中鉴定出的条件致病性真菌的分类和(1,3)-β-D葡聚糖检测(G试验)进行回顾性分析,应用PCR技术对白色假丝酵母菌25SrDNA中的transposable intron基因进行基因型分析,并应用黑马鉴定药敏仪,对各种基因型进行药物敏感试验。结果分离出的条件致病性真菌主要来自患者的痰液、血液、体液及脓液标本,其中白色假丝酵母菌562株占74.14%,近平滑假丝酵母菌88株占11.61%,光滑假丝酵母菌49株占6.46%;对164例高度疑似系统性真菌感染或真菌菌血症患者,同时进行真菌培养和G试验,检测阳性率分别为60.37%和76.83%;190株白色假丝酵母菌大多数为A型,B型次之,其中有两株未分型,A型对氟胞嘧啶、伊曲康唑和伏立康唑的耐药率高于B型和C型;A、B、C 3型对氟康唑均耐药,而对两性霉素B均敏感。结论假丝酵母菌属感染主要以呼吸道、消化道和泌尿道感染为主,不同地区、不同基因型的假丝酵母菌属对药物的敏感性有所不同,因此,快速而准确地鉴定与药敏试验及基因型分析对临床及时诊断和治疗假丝酵母菌属感染有重要意义。

OBJECTIVE To investigate the distribution characteristics, laboratory diagnosis, genotyping and drug resistance status of pathogenic fungi, so as to provide a guide for clinical diagnosis and rational drug use. METHODS Classification, drug susceptibility test and G test were analyzed in pathogenic fungi strains from speci- mens from Jan. 2013 to Jan. 2014, retrospectively. Polymerase chain reaction （PCR）technology was used to ana- lyze transposable intron gene in 25SrDNA, and automatic detection machine was used to perform identification and drug susceptibility tests for isolated pathogenic fungi. RESULTS Isolated pathogenic fungi were mainly found in patients＂ sputum specimens, blood specimens, body fluids and pus, including 562 strains of Candida alblcans （74.14%）, 88 strains of Candida parapsilosis （11.61%）, 49 strains of Candida glabrata. Fungi cultivation and G test were used in 164 patients with systemic fungal infection or fungal infection, the results of trial showed that the positive rate was 60.37% and 76.83% respectively. A type of Candida albicans was the most common in 190 patients with fungal infection, followed by B type, however, two strains were non-typeable, a higher resistance rate were also observed in A type of fungi compared with B type and C type of fungi to fluorine cytosine, itracon- azole and voriconazole, as well as A, B, C types of fungi were resistant to fluconazole, except for amphotericin B. CONCLUSION Candida are found in patients with respiratory tract, gastrointestinal tract and urinary tract infec- tion, The resistance rate is different for Candida in diverse regions and genotypes, so that the results of rapid and accurate identification,drug susceptibility test, as well as genotyping have remarkable significance to diagnose pa- tients with fungal infection in clinical.