EVALUATION OF ANTIBACTERIAL ACTIVITIES OF SELECTED DISINFECTANTS SOLD IN OGIGE MARKET IN NSUKKA, NIGERIA, ON SOME CLINICAL BACTERIAL ISOLATES

Abstract

Disinfectants are chemicals that can kill or inhibit the growth of microorganisms and are widely used in hospitals and in households. This study was aimed at evaluating the antibacterial activity of six household disinfectants (D1, D2, D3, D4, D5 and D6) used in Nsukka, Enugu Nigeria on four clinical bacterial isolates including Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. The test organisms used were obtained from Medical Diagnostic Laboratory of University of Nigeria, Medical Centre, Nsukka. Dilutions of each disinfectant were prepared. The antibacterial activities of various dilutions of the disinfectants against the test organisms were determined using well diffusion technique. Phenol coefficient of each disinfectant was determined using Rideal-Walker method. Dilutions of phenol (1:80, 1:90 and 1:100) and disinfectants (1:400, 1:450 and 1:500) were prepared. Test organisms (0.1 ml suspension) were inoculated into different dilutions of the disinfectants and phenol. At intervals of 5, 10 and 15 minutes, 0.1 ml was taken from each dilution and inoculated into nutrient broth (2 ml) and incubated for 48 h at 37 oC. All experiments were carried out in duplicates. D3 with active ingredients (chlorhexidine gluconate (0.3%) and cetrimide (3%)) showed the highest inhibition against all the test organisms. D4 with active ingredient (Dichloro-meta-xylenol) showed the least inhibition against all the test organisms followed by D6 with Lysol as active ingredient. The phenol coefficient of the disinfectants ranged from 0-5.5 for the test organisms. All the disinfectants exhibited antibacterial activity and the most active disinfectant contains chlorhexidine gluconate and cetrimide.