Selection of Natural Strains of Fungal Endophytes from Azadirachta indica A. Juss, with Anti-Microbial Activity Against Dermatophytes

V.   C.   Verma; S.   K.   Gond; Ashish      Mishra; A.      Kumar; R.   N.   Kharwar

Abstract

Increasing drug resistance among bacteria, fungi and other pathogenic microbes and the remarkable increase in the incidence of fungal infections like dermatomycoses in the world population underscore our inadequacy to deal with them. Thus there is an urgent need to search chemically novel, natural, renewable and safe anti-microbial substances that can offer opportunity for innovation of new drugs to combat the widespread dermatomycoses. Six fungal endophytic strains (Scytalidium sp. MCPL AzF 023, Pestalotiopsis sp. MCPL AzB 153, Colletotrichum sp. MCPL AzR 249, Alternaria sp. MCPL AzL 198, Nigrospora sp. MCPL AzS 076, and Chloridium sp. MCPL AzR 142) from Azadirachta indica A Juss were screened and evaluated their efficacy against dermatophytes Trichophyton and Microsporum. The susceptibility test was performed by whole plate diffusion method. The EtOAc extracted Scytalidium, Chloroform extracted Nigrospora, Colletotrichum, and Alternaria, ethyl ether extracted Nigrospora in particular significantly reduced the growth of dermatophytes. The MIC ranged from 125-400 μg ml-1 for Trichophyton and 200-350 μg ml-1 for Microsporum while the MFC ranged from 230 to 425 μg ml-1. The chloroform, EtOAc, and ethyl ether were the solvents that might dissolve major active fractions of Pestalotiopsis, Scytalidium and Chloridium. The growth patterns of dermatophytes were also significantly distorted at concentration of 100 μg ml-1 (below MIC), which is statistically significant with reference to untreated fungi. In this study, we recovered bioactive fractions that might be chemically novel and effective against dermatophytes particularly and on other human and plant pathogens in general. Thus we might anticipate some new bioactive compounds to design new effective drugs against dermatomycoses initially.