中国临床球形孢子丝菌菌丝相药物敏感性分析

In vitro antifungal susceptibilities of mycelium phase of Sporothrix globosain China

目的检测我国临床球形孢子丝菌菌丝相对5种抗真菌药物的体外敏感性,同时对比我国不同地区菌株药物敏感性的差异。方法将重庆、吉林、北京地区既往基因鉴定为球形孢子丝菌的100株临床菌株接种于2%马铃薯葡萄糖琼脂培养基(PDA)上,25℃恒温培养7d获得菌丝相。依据美国临床与实验室标准化委员会(CLSI)制定的M38-A2方案,采用微量液基稀释法检测菌丝相对碘化钾、伊曲康唑、特比萘芬、氟康唑、两性霉素B的体外最低抑菌浓度(MIC)。质控菌株为近平滑念菌ATCC22019。结果碘化钾体外无抗真菌活性,特比萘芬MIC几何均值为0.14μg/mL,伊曲康唑和两性霉素B MIC几何均值分别为0.79μg/mL和0.63μg/mL,氟康唑MIC几何均值为45.89μg/mL。发现7株对伊曲康唑耐药菌株,吉林地区相对较多,但不同地区菌株的药物MIC值差异无统计学意义(P>0.05)。结论碘化钾无体外抗真菌活性,我国临床球形孢子丝菌对特比萘芬最敏感,其次为伊曲康唑和两性霉素B,对氟康唑敏感性最差,不同地区菌株对抗真菌药物的敏感性没有明显差异。

Objective To investigate the activities of five antifungal agents on mycelia form of Sporothrixglobosa and compare the differences in antifungal susceptibilities in different areas of China.Methods Total 100 isolates which were identified as Sporothrix globosa by molecular identification from Chongqing,Beijing and Jilin were subcultured on 2% potatodextrose agar plates at 25℃for 7d.Then according to modified CLSI microdilution method M38-A2,MICS were measured to evaluate the antifungal activities of potassium iodide（KI）,itraconazole（ITC）,terbinafin（TRB）,fluconazole（FLC）,amphotericin B（AmB）to these isolates in vitro.Candida parapsilosis ATCC22019 was used as quality control.Results Potassium iodide showed no antifungal activity against any Sporothrix globosaisolates.TRB gave the lowest geometric mean（GM=0.14μg/mL）MIC.ITC and AmB showed almost the same activity against all strains tested and the GM was 0.79μg/mL and 0.63μg/mL respectively.FLC gave the highest GM MIC（45.89μg/mL）.Seven isolates（four from Jilin,two from Chongqing,one from beijing）were found to be itraconazole-resistant,There was no difference in susceptibility according to the geographical source of the isolates（P0.05）.Conclusion Potassium iodide showed no antifungal activities in vitro.TRB was the most active drug,followed by the ITC and AmB.FLC was the least effective drug.There was no difference in antifungal susceptibilities in different areas of China.