摘要
Based on recent molecular data, it has been suggested that Sporothrix globosa is the main causal agent of sporotrichosis in China. The objective of this study was to compare the morphology, growth characteristics, patterns of carbon source usage, and susceptibility to antifungal agents among Sporothrix strains. A total of 15 clinical strains confirmed to be S. globosa, from three different regions of China, and 11 ex-type strains from the CBS-KNAW biodiversity center were obtained. The elongated conidia of S. pal/ida, S. variecibatus, S. schenckii, and S. schenckii luriei were clearly different from the subglobose and globose conidia of S. globosa strains. S. schenckii is able to assimilate sucrose, raffinose, and ribitol. Susceptibility profiles of these Sporothrix species were evaluated by measuring minimum inhibitory concentrations （MICs）. Fluconazole, itraconazole, terbinafine, and amphotericin B showed good activity against most S. globosa clinical isolates from China. Potassium iodide also showed a low MIC against S. pal/ida, while fluconazole showed a high MIC for S. mexicana, S. humicola, S. g/obosa, S. schenckii, and S. inflata; these strains might be considered tolerant. The species showed differences in susceptibility to antifungal drugs and should therefore be properly identified during diagnosis prior to designing therapeutic strategies.
目的:研究申克孢子丝菌复合体在形态学、糖同化和抗真菌药物敏感性的差异,探讨不同种类孢子丝菌的形态、生理生化及抗真菌药物敏感的特性。创新点:首次对我国球形孢子丝菌与其它孢子丝菌模式菌株在形态学、生理生化和抗真菌药敏方面进行比较,从而找出我国孢子丝菌与模式菌株的差异和相同点。方法:实验选用15株从我国三个不同地区分离的球形孢子丝菌和11株购买的孢子丝菌模式菌株(表1),将这26株孢子丝菌菌株分别接种到2%的马铃薯葡萄糖琼脂平板培养基上,通过在不同时间段观察菌落生长特征,测量菌落直径,镜下观察菌丝、孢子形态,测定最小抑制浓度(MIC)并进行评价。结论:实验显示:根据顶端分生孢子的形态(图2)、不同时期菌种的菌落直径(图1)、糖同化实验(表2和表3)可进行简单鉴定我国球形孢子丝菌与孢子丝菌复合体;特比萘芬有较好的体外抑菌活性,而碘化钾、氟康唑、伊曲康唑、两性霉素B对不同的菌株的抗菌敏感性不同(表4)。综上所述,我国孢子丝菌临床菌株与孢子丝菌复合体在表型、生理生化及体外抗真菌药物敏感性上均有不同程度的差异。
基金
supported by the National Natural Science Foundation of China(No.31270062)
