Antimicrobial activity of camwood (Baphia nitida) dyes on common human pathogens

Antimicrobial activity of four aqueous extracts of camwood dyes obtained from different locations in Nigeria were investigated by agar diffusion, disc diffusion and agar dilution method against five clinical isolates obtained from inpatient attending the University of Port Harcourt Teaching Hospital. The isolates were Staphylococcus aureus, Escherichia coli, Bacillus cereus, Proteus vulgaris and Pseudomonas aeruginosa. Broad spectrum activity revealed B. cereus and S. aureus as more susceptible with zones of inhibition ranging from 5.4 to 19.2 mm, while, E. coli, P. vulgaris and P. aeruginosa were the least susceptible at an inhibition zone ranging from 0.8 to 15.6 mm. Results show that the extracts exhibited inhibitory activity against the test organisms at a minimum inhibitory concentration (MIC) of 37.5 mg/ml. Phytochemical screening revealed the presence of flavonoid and a trace of alkaloids. These results show that camwood dye possessed significant antimicrobial activity and hence can be used as a remedy for pathogenic infections.Key words: Antimicrobial activity, camwood extract, Nigeria, pathogenic microorganisms, zone of inhibition