Comparative Microbiological Study of some Chlorhexidine containing Disinfectants

Abstract

In the present study; twenty- four strains (MSSA, MRSA, Pseudomonas and E.coli) were isolated from patients suffering from nosocomial infection. Each strain was subjected to three disinfectants including Hibisol (Zeneca pharmaceuticals),Alkanol (Atkan Pharma S.A.E) and Cyteal (product of Pierre Fabre Laboratories),each containing the substance chlorhexidine as the active ingredient. The study was conducted over a period of seven months, from January 1999 till June 1999 at the Microbiology and Immunology Laboratory. Each strain was subjected to each disinfectant for different periods of time starting from 15 seconds, gradually increasing to 240 seconds. The action of disinfectant was then stopped by adding a neutralizer (Tween 80), then colony count was done to detect the number of the remaining living organism after each exposure time. The activity of the disinfectant was compared as regards percentage of decrease in colony count for each organism at each time interval and time needed to reach complete eradication of the tested organism in order to choose the best one for practical use. In the study, it was found that Gram-positive bacteria (MSSA and MRSA) are more resistant to chlorhexidine than Gram-negative bacteria (Pseudomonas and E. . . Hibisol proved to be the most efficient disinfectant used in the study as regards its effect on the twenty four strains tested, then Cyteal and Alkanol comes in the second position as they share nearly the same results.