1株抗须癣毛癣菌枯草芽孢菌的鉴定

为了探讨抗须癣毛癣菌感染新的治疗途径,从患须癣毛癣菌病兔自然恢复皮肤分离了1株细菌,经16S rDNA基因比对,并结合菌落形态进行了鉴定,通过体内外试验测定其对须癣毛癣菌的拮抗作用。结果显示,分离株能在营养琼脂培养基生长,菌落为皱褶圆形,菌体呈杆状,革兰染色阳性,基因序列分析与GenBank中的枯草芽孢杆菌相似率为99.8%,该分离株被鉴定为枯草芽孢杆菌。抗菌谱分析显示,分离株对须癣毛癣菌能形成抑菌圈,对白色念珠菌、平滑念珠菌、热带念珠菌、烟曲霉菌、黄曲霉菌没有抑制作用。该分离株与须癣毛癣菌混合培养,能明显抑制须癣毛癣菌生长。在皮肤涂抹试验中,该分离株能逆转由须癣毛癣菌引起的皮肤病变。本试验证实了分离的枯草芽孢杆菌对须癣毛癣菌有明显的拮抗作用。

Identification of one Bacillus subtilis strain against Trichophyton mentagrophytes

In order to explore a new therapeutic approach for the infection of Trichophyton mentagrophytes,one bacterium was isolated from the skin of the rabbits with the natural recovery from trichophytonosis.Through bacterial 16 S r DNA gene alignment and colony morphology was identified,and its antagonistic effect to Trichophyton mentagrophytes in vivo and in vitro was examined.The result showed that the isolated strain grew well in nutrient agar medium.The colonies of isolated strain were wrinkled and round.The cells were rod shape and Gram positive.Its sequence of 16 S rDNA gene was 99.8%which is homologous to that of Bacillus subtilis deposited in Gen Bank,and the isolated strain was identified as Bacillus subtilis.Antibacterial spectrum analysis showed that the isolated strain could form a zone of inhibition against Trichophyton mentagrophytes,but no effects on Candida albicans,Candida parapsilosis,Candida tropicalis,Aspergillus fumigatus,and Aspergillus flavus.The isolated strain could significantly inhibit the growth of Trichophyton mentagrophytes when they were mixed in culture.The experiment showed that isolated strain could reverse skin lesions caused by Trichophyton mentagrophytes through smeared skin.These data suggests that the Bacillus subtilis isolated can exert significant antagonistic effect on Trichophyton mentagrophytes.