ABSTRACT

The antimicrobial effectiveness of three selected disinfectants (ethanol, bleach and dettol) was determined using agar diffusion (paper disc) method. The test organisms used include Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Aspergillus niger and Aspergillus flavus. The undiluted concentrations of the disinfectants showed varying zones of inhibition against the test organisms. On E.coli it ranged from 19mm (Bleach).21mm(Ethanol) to 25mm (Dettol), on Staph aureus, 16mm (Ethanol),21mm(Bleach), 21mm (Dettol) on Klebsiella pneumonia it ranged from 18mm (Ethanol) , 19mm (Bleach) to 27mm(Dettol),on Bacillus subtilis,it ranges from 17mm(Ethanol).23mm(Dettol) to 24mm(Bleach). For the fungi the zones of inhibitions of the undiluted disinfectants on Aspergillus niger ranges from 18mm (Ethanol) 20mm (Bleach), to 26mm (Dettol) whereas, Aspergillus flavus ranges from 16mm (Ethanol), 19mm(Bleach) to 28mm(Dettol). The result showed that Dettol was most effective against the test organisms than the other disinfectants. Ethanol recorded the least antimicrobial activity. Disinfectant for external uses is necessary to avoid related infections or diseases caused by these test microorganisms.