Investigating The Antimicrobial Efficacy Of Disinfectants Against Bacterial Biofilms

ABSTRACT

Microbial bioflims have become inexorably linked with man's failure to control them by antibiotic and biocide regimes that are effective against suspended bacteria and the spread of bioflim-related infections. The antimicrobial efficacy of three disinfectants (Dettol, Izal and Hypo) on two bioflim-producing bacteria was determined using the paper disc diffusion method. The test organisms were Staphylococcus aureus and Pseudoinonas aeruginosa isolated from skin and wounds. The morphological examination, gram reaction and biochemical tests were carried out to characterize the microorganisms. Bioflim detection test was also performed using Congo red agar method. The diluted concentrations of the disinfectants showed varying zones of inhibition with hypo showing the highest inhibitory effect against the microorganisms. On S. aureus, hypo showed zones of inhibition ranging from 12-20mm, dettol (10-18mm) and izal (8- 1 5mm) while for P. aeruginosa hypo measured (11-16mm), dettol (8-14mm) and izal (6- 10mm). In spite of the antibacterial property demonstrated by the diluted disinfectants, the undiluted disinfectants had higher antibacterial effect on the test organisms in all cases. On S. aureus it ranged from 26mm (hypo), 21mm (dettol) and 19mm (izal) and on P. aeruginosa it ranged from 22mm (hypo), 19mm (dettol) and 14mm (izal). The minimum inhibitory concentrations of the disinfectants showing appreciable activity against the test microorganisms were also determined. Therefore, findings in this study qualifies these disinfectants as potential sterilizing agents to be used externally so contraction of infections caused by not only the test organisms but other pathogens can be avoided.