曲霉菌临床分离株的分子鉴定及体外抗真菌药物敏感性分析

Molecular identification and antifungal susceptibility in clinical isolates of Aspergillus species

摘要:

目的 研究曲霉菌临床分离株的分子鉴定及体外抗真菌药物的敏感性。方法 采用Internal Transcribed Spacer（ITS）及β-tubulin基因部分测序对临床分离的53株经形态学鉴定为曲霉的菌株进行分子鉴定，并按照美国临床实验室标准化协会（CLSI）推荐的M38-A2微量液基稀释法测定唑类（伊曲康唑、伏立康唑、泊沙康唑），两性霉素B和棘白菌素类（米卡芬净、阿尼芬净和卡泊芬净）共7种抗真菌药物对所有菌株的最低抑菌浓度（minimum inhibitory concentration, MIC）或最低有效浓度（minimum effective concentration, MEC）。结果 53株曲霉菌包含烟曲霉复合体22株（烟曲霉21株和仑图卢斯曲霉1株），黑曲霉复合体23株（塔宾曲霉16株、黑曲霉5株和百岁兰曲霉2株）及土曲霉和黄曲霉各4株；米卡芬净、阿尼芬净、卡泊芬净、泊沙康唑、伏立康唑、伊曲康唑、两性霉素B对曲霉菌株的MIC90为0.031、0.031、0.25、0.5、0.5、1、2μg/mL。除1株烟曲霉对伊曲康唑（MIC≥16μg/mL）和伏立康唑（MIC为2μg/mL）耐药及1株仑图卢斯曲霉对两性霉素B耐药（MIC为8μg/mL）外，其余菌株对7种药物均敏感。4种曲霉复合体对7种抗真菌药物的敏感性差异有统计学意义（P＜0.05）。结论 棘白菌素类药物体外抗曲霉菌活性最好，两性霉素B体外抗曲霉菌活性相对较差，唑类药物介于以上两者之间。不同种曲霉菌对不同抗真菌药物的敏感性存在差别。

Abstract:

Objective To investigate the molecular identification and susceptibility to antifungal agents of clinical isolates of Aspergillus species. Methods Fifty-three clinical isolates of Aspergillus were identified to species level based on Internal Transcribed Spacer(ITS) and β-tubulin gene sequencing. The in vitro susceptibility to anidulafungin, caspofungin, micafungin, posaconazole, voriconazole, itraconazole and amphotericin B was tested by CLSI M38-A2. Results Among 53 isolates, there were 21 strains of Aspergillus fumigatus, 16 of Aspergillus tubingensis, 5 of Aspergillus niger, 4 of Aspergillus flavus, 4 of Aspergillus terreus, 2 of A. welwitschiae and 1 of A. lentulus. The MIC90 of micafungin,anidulafungin, caspofungin, posaconazole, voriconazole, itraconazole, amphotericin B were 0.031, 0.031, 0.25, 0.5, 0.5,1 and 2μg/mL.One Aspergillus fumigatus strain showed resistance to itraconazole and voriconazole. Aspergillus lentulus strain was resistant to Amphotericin B. Other strains were sensitive to 7 antifungal angents.The susceptibility of 4 species complexes to different antifungal drugs was statistically significant differences（P＜0.05）. Conclusion Echinocandins drugs have best antifungal activity against 5 Aspergillus species, followed by asoles and amphotericin B. Different species of Aspergillus show different patterns of antifungal susceptibility.