Molecular characterization and antibacterial effect of endophytic actinomycetes Nocardiopsis sp. GRG1 (KT235640) from brown algae against MDR strains of uropathogens

Abstract

Our study is to evaluate the potential bioactive compound of Nocardiopsis sp. GRG1 (KT235640) and its antibacterial activity against multi drug resistant strains (MDRS) on urinary tract infections (UTIs). Two brown algae samples were collected and were subjected to isolation of endophytic actinomycetes. 100 strains of actinomycetes were isolated from algal samples based on observation of morphology and physiological characters. 40 strains were active in antagonistic activity against various clinical pathogens. Among the strains, 10 showed better antimicrobial activity against MDRS on UTIs. The secondary metabolite of Nocardiopsis sp. GRG1 (KT235640) has showed tremendous antibacterial activity against UTI pathogens compared to other strains. Influence of various growth parameters were used for synthesis of secondary metabolites, such as optimum pH 7, incubation time 5–7 days, temperature (30 °C), salinity (5%), fructose and mannitol as the suitable carbon and nitrogen sources. At 100 μg/ml concentration MIC of Nocardiopsis sp. GRG1 (KT235640) showed highest percentage of inhibition against Proteus mirabilis (85%), and E.coli, Staphylococcus auerues, Psuedomonas aeroginasa, Enterobactor sp and Coagulinase negative staphylococci 78–85% respectively.

Keywords

• Endophytes
• Multi-drug resistant strains
• Urinary tract infections
• Minimal inhibitory concentration