Antimicrobial activity of two medicated soaps on pathogenic bacteria isolated from human skin

Medicated soaps labeled as being “antimicrobial” can be purchased from any supermarket, but the antimicrobial spectrum of activity is rarely mentioned. Thus the in vitro antimicrobial activity of two popular brands medicated soaps, Dettol and Lifebuoy was conducted by agar disc diffusion method. Reference bacterial strains were isolated from human skin. The isolated strains (Sample-1 and Sample-2) were characterized by morphologically and biochemically. Both the samples were gram negative, non-motile with positive methyl red, catalase, starch hydrolysis, citrate BSA and EMB test. Their maximum growth was achieved at pH6 and 40°C temperature. Sample-1reported its optimal growth when fructose and yeast extract were used as a carbon and nitrogen source respectively. Whereas glucose and peptone were better carbon and nitrogen sources respectively for Sample-2. These two strains were treated with three different concentrations (50mg/ml, 75mg/ml and 100mg/ml) of Dettol and Lifebuoy soap. Both the soaps showed satisfactory results with all the three concentrations. But their activities were different from each other. Degree of their activities was also increased with the increased concentration. Dettol soap was much stronger than Lifebuoy soap in their antibacterial activity against the two strains having the highest zone of inhibition 10 mm, 15 mm respectively with the concentration of 100 mg/ml. Thus Dettol soap can be recommended for daily use.