Research Article Antimicrobial Property of Extracts of Indian Lichen against

Copyright © 2013 Priya Srivastava et al.This is an open access article distributed under the Creative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Context. Usnea ghattensisG. Awasthi (Usneaceae) endemic fruticose lichen found growing luxuriantly in NorthernWestern Ghats of India, it also contains Usnic acid as a major chemical and tested against some human pathogenic bacteria. Objective. To explore antimicrobial properties of Usnea ghattensis against some human pathogenic bacteria. Materials and Methods. The lichen was extracted in acetone, methanol, and ethanol. In vitro antimicrobial activity was tested initially by Kirby-Bauer technique of disc diffusion method and was confirmed by minimum inhibitory concentration using Broth microdilution method according to the NCCLS guidelines. Results. Ethanol extract was most effective against Bacillus cereus and Pseudomonas aeruginosa with a zone of inhibition 29.8 ± 0.6mmand 12.3 ± 0.5mmdiameters at a concentration of 0.2mg/mL.Acetone andmethanol extract demonstrated almost similar activity against Staphylococcus aureus and the zone of inhibition was 24.6 ± 0.5 and 24.7 ± 0.4mm. Only methanol extract was showing activity against Streptococcus faecalis with a 13.5 ± 0.8mm zone. MIC value noted against Staphylococcu