Abstract

Five frequently used disinfectants in our hospital (Specialist Hospital, Yola, Nigeria) were analyzed for bacterial contamination and sensitivity to antibiotics. For each disinfectant, 20 different samples of stock and left-over diluted solutions were used for the analysis. All the stock undiluted samples were free from any bacterial growth. However, all the left-over disinfectant samples were found to have significant bacterial contamination, predominantly gram negative bacteria and the contamination level varied from 2.6 x 105 to 3.5 x 108 cfu/ml. Amongst the 5 different disinfectants analyzed, Purit was found to be highly contaminated (30%), followed by Dettol (25%), Parazone (20%), Z-germicide (15%), Septol (10%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the isolates were significantly higher  than that of the control sensitive strains, but were lower than the values quoted by the manufacturers of these disinfectants. All the isolates showed variable sensitivity to antibiotics with each disinfectant showing sensitivity to at least four antibiotics tested in this study.

 Key words:  Disinfectant, bacterial contamination, left-over diluted samples, antibiotic susceptibility