Comparative Study of Disinfectant Efficacy of Bleach (JIK) and Ethanol against Staphylococcus Aureus and Pseudomonas Aeruginosa

Abstract

A disinfectant is one of the diverse groups of chemicals which reduce the number of microorganisms present on an inanimate object. To determine the comparative study of disinfectant efficacy of Bleach (Jik) and Ethanol against Staphylococcus aureus and Pseudomonas aeruginosa, pure bacteria isolates of S. aureus and P. aeruginosa were obtained from Microbiology Laboratory, Federal University of Agriculture Makurdi. These isolates were further confirmed by subjecting them to series of biochemical tests. Results from these confirmatory tests were compared with standard identification keys. Comparative experiment of these two disinfectants (ethanol and bleach) efficacy was conducted against Staphylococcus aureus and Pseudomonas aeruginosa using agar well diffusion method. Different concentrations 100% (v/v), 75% (v/v), 50% (v/v) and 25% (v/v) of bleach and ethanol were tested on both test organisms. The results showed that all the disinfectants inhibited the growth of the test organisms in their concentrated forms. The diameters of zone of inhibitions showed that 100% (v/v) concentration bleach (jik) had the highest zone of inhibition on Staphylococcus aureus and Pseudomonas aeruginosa which was measured to be 26.33±1.53 and 20.67±0.58 respectively with 25% (v/v) of bleach showing the least zone of inhibition on the test organisms. For ethanol the highest zone of inhibition was shown at 100% (v/v) concentration with 12.00±2.65 and 10.00±1.00 on Pseudomonas aeruginosa and Staphylococcus aureus respectively while at 25% (v/v) both test organisms were resistant to ethanol. The minimum inhibitory concentration of the bleach disinfectant on Staphylococcus aureus and Pseudomonas aeruginosa is determined at 50%, while the test organisms were resistant to the ethanol at all concentrations. Bleach had a better effect on Staphylococcus aureus than Pseudomonas aeruginosa whereas; ethanol had a better effect on Pseudomonas aeruginosa than Staphylococcus aureus. Generally Ethanol showed least sensitivity on both test organisms as compared to Bleach.