Evaluation of the effectiveness of some commonly used disinfectants against bacteria isolated from toilet floors of college of natural and pharmaceutical Sciences bayero university Kano

Abstract

Disinfectants are chemicals having the ability to destroy or inhibit the growth of microorganisms on inanimate surfaces. The disinfection of toilets floor is a cornerstone of infection control in schools and the general community. This study aimed to evaluate the effectiveness of three disinfectants against bacteria isolated from toilets floor of College of Natural and Pharmaceutical Sciences, Bayero University, Kano. Swabs were taken using sterile cotton swab before and after treatment with disinfectants. Five different bacteria were isolated from the toilets floor using standard microbiological methods. Biochemical methods were used to confirm their presence. These include Staphylococcus aureus, Escherichiacoli, Klebsiella spp, Bacillus spp and Pseudomonas spp. The effectiveness of three disinfectants (Chloroxylenol isopropyl alcohol(X), Sodium hypochlorite(Y) and 32% Phenol (Z)) was evaluated against the isolated bacteria. Three different concentrations (100%, 75% and 50%) of the disinfectant were tested on all the organisms using agar well diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration of each disinfectant were determined. The organisms were also tested against some standard antibiotics. The results obtained demonstrated that X is the most active among the disinfectants tested. Bacillus spp resist all the three disinfectant tested while S. aureus is the most susceptible organism. At 50% and 25% Y and Z failed to kill the organisms. Susceptibility pattern showed that S. aureus, E. coli, and Pseudomonas spp were more susceptible to X at rates of 73%, 64% and 57% respectively. At 100% concentration all the organisms exhibit highest zones of inhibition 25-27mm. MIC of all the disinfectant against all the isolates was 6.25µg except Klebsiella spp, Bacillus spp that exhibited 12.5 µg. The study revealed that all the disinfectants were active against all the organisms tested with the highest activity observed against X. There is need to disinfect surfaces regularly in order to reduce infectious diseases due to contact with pathogens in the environment.

Key Words: Disinfectant, susceptibility, toilets, microorganism, concentration