Investigation of the Efficacy of Some Disinfectants Against Nosocomial Gram Negative Bacteria

Nosocomial infections are an important cause of morbidity and mortality all over the world. Most bacteria that cause nosocomial infections can retain their viability ev en after exposure to disinfectants in routine practices. Therefore evaluation of the efficacy of disinfectants at each hospital is important. The objective of the present study wa s to determine the susceptibilities of nosocomial Escherichia coli , Klebsiella pneumoniae and Pseudomonas aeruginosa isolates to various disinfectants. Nosocomial isolates were obtained fr om Central Microbiology Laboratory, Ibn-i Sina Hospital, School of Medicine, Ankara University. Susceptibility testing was performed by the quantitative suspension test at contact times of 3, 5 and 10 minutes. According to the results, all of the isolates were found susceptible to 2% glutarald ehyde (2% GA), 4% chlorhexidine gluconate (4% CHG), 7.5% povidone iodine (7.5% PI), 10% povidone iodine (10% PI) and 70% 2-propanol (70% 2-P) at 3 minutes contact time. However, 4 x E. coli , 19 x K. pneumoniae and 30 x P. aeruginosa isolates were found susceptible to 3% hydrogen peroxide (3% HP) at 3 minutes contact time, 7 x E. coli and 10 x K. pneumoniae isolates were found susceptible at 5 minutes contact time and 11 x E.coli isolates were found susceptible at 10 minutes contact time. 4 x E.coli isolates were found resistant to 3% HP. In conclus ion, 2% GA, 4% CHG, 7.5% PI, 10% PI and 70% 2-P can be safely used against E. coli, K. pneumoniae and P. aeruginosa owing to their high effectiveness, however, 3% HP s hould not be preferred against E. coli due to the presence of resistant isolates in Ibn-i Sina Hospital, Ankara University.