成人及儿童皮肤癣菌病患者红色毛癣菌的基因分型与药物敏感性分析

目的 探讨成人和儿童皮肤癣菌病临床分离菌株中红色毛癣菌基因型的差异，基因型与发病部位、基因型与药物敏感性的关系。方法 利用随机引物OPAA11 5′-ACCCGACCTC-3′，OPD18 5′-GAGAGCCAAC-3′分别对来自成人及儿童皮肤癣菌病的红色毛癣菌菌株进行任意引物PCR，根据产物电泳带型进行基因分型，采用微量液体稀释法对氟康唑、伊曲康唑、特比萘芬、酮康唑、利拉萘酯、布替萘芬、益康唑、联苯苄唑进行体外敏感性分析。结果 两组的主要致病菌都为红色毛癣菌，两种随机引物扩增出的红色毛癣菌不同株带型均稳定清楚，按随机引物 OPAA11的扩增结果，其基因型分为4型。成人中Ⅰa、Ⅲa型分别占41.94%，儿童中Ⅰa型为65.96%，基因型构成在两组人群中的差异有统计学意义（P < 0.05）；体癣、足癣中基因型的分布在两组间差异均有统计学意义（P < 0.01；P < 0.05）。甲癣和股癣中基因型的分布差异无统计学意义（P > 0.05）；各基因型对8种抗真菌药物的MIC值均较低，特比萘芬的MIC最低，氟康唑的MIC值相对较高，酮康唑和氟康唑对Ⅰa、联苯苄唑对Ⅱa的活性高于其他基因型，伊曲康唑对Ⅲa型的活性略低于其他基因型，差异有统计学意义（P < 0.01或P < 0.05）。结论 红色毛癣菌为南京及周边地区儿童及成人皮肤癣菌病的主要致病菌，成人感染以Ⅰa、Ⅲa型为主，儿童感染以Ⅰa型为主。8种抗真菌药物对各基因型均有较好的抗菌活性，但酮康唑、氟康唑、联苯苄唑、伊曲康唑、特比萘芬对各基因型的敏感性有差异。

Genotyping and drug susceptability testing of Trichophyton rubrum isolated from children and adults with dermatophytosis

Objective To investigate the genotype of Trichophyton rubrum isolated from children and adults with dermatophytosis,and to explore the relationship between the genotype and location of lesions as well as drug susceptability of T.rubrum.Methods Dermatophytes were isolated from 67 children and 88 adults who had been diagnosed with dermatophytosis by microscopy and fongal culture.DNA was extracted from the clinical isolates of T. mbrum and random amplification of polymorphic DNA(RAPD)assay was performed with two random primers.i.e.,OPA11 5'ACCCGACCTC3'and OPD18 5'GAGAGCC AAC3',respectively.PCR products were subjected to electrophoresis to identify the genotypes of clinical isolates.Broth microdilution method was applied to assess the in vitro susceptibility of T. rubrum isolates to eight antifungal agents:fluconazole,itraconazole,terbinafine,ketoconazole,liranaflate,butenafine,econazole and bifonazole.Results T. rubrum was isolated from 47 children and 62 adults with dermatophytosis.RAPD assay yielded clear and stable DNA band profile.With primer OPA 11,these T.rubrum isolates were classified into 4 genotypes,i.e.,Ⅰ a,Ⅱ a,Ⅲa and Ⅳa.Both type Ⅰ a and Ⅲa represented 41.94%of the T. rubrmn isolates from adults,while type Ⅰa 65.96%of those from children;there was a significant difference in the genotype distribution between the two groups(P＜0.05).Also,the genotype distilbution was statistically different for tinea corporis and tinea pedis(P＜0.01,＜0.05 respectively)between adults and children,however,no significant difierence was observed for onychomycosis and tinea cruris(both P＞0.05).In vitro susceptibility test showed that all antifungal agents were effective against these T. rubrum isolates.Among these antifungals,terbinafine had the highest efficacy,and fluconazole exhibited the lowest effect against these isolates.Moreover,a higher efficacy was observed for ketoconazole and fluconazole against T. rubrum of type Ⅰ a than against other types of T. rubrum,and for bifonazole against T. rubrum isolates of type Ⅱ a than against other types.while the efficacy of itraconazole was lower against T. rubmm isolates of type Ⅲ a than against other types.Conclusions T. rubrum is the main pathogenic microorganism in adults and children with dermatophytosis.In adults,Ⅰ a and Ⅲ a are the predominate types of T. rubrum associated with dermatophytosis,while Ⅰ a is the common type in children.All the 8 antifungals tested have a good efficacy for various genotypes of T. rubrum,whereas the efficacy of fluconazole,itraconazole,kctoconazole,terbinafine and bifonazole varies with the genotypes of T. rubrum.