Antimicrobial Drug Resistance and Disinfectants Susceptibility of Pseudomonas aeruginosa Isolates from Clinical and Environmental Samples in Jimma University Specialized Hospital, Southwest Ethiopia

P. aeruginosa is one of the most important pathogen that causes nosocomial infections often acquired from hospital environment and contaminated medical devices. The infections caused by this bacterium are particularly problematic because it is inherently resistant to several unrelated antimicrobial agents and antiseptics. Hence, the aim of this study was to determine drug resistance and disinfectants susceptibility of P. aeruginosa isolated from clinical samples and hospital environments. A laboratory based cross sectional study was conducted from May to September, 2012 on a total of 81 P. aeruginosa isolates. A standard bacteriological technique (conventional biochemical tests and pigment production) was used to identify the bacterium. Drug resistance and disinfectant susceptibility tests were determined by Kirby-Bauer disc-diffusion and through the classic method of successive dilutions respectively. In this study a total of 305 (160 clinical and 145 environmental) samples were investigated for P. aeruginosa and 81 isolates were obtained. This gives an overall P. aeruginosa isolation rate of 26.5% (81/305). About 47.5% of the clinical and 34.2% environmental isolates were detected from wounds and ward sinks respectively. Of these P. aeruginosa isolates, 95.1% were resistance to Trimethoprim-sulphametoxazole, 62% to Gentamicin, and 58% to Ceftriaxone. But, only 4.9% of isolates were resistance to Amikacin. Moreover, disinfectant susceptibility test revealed that hydrogen peroxide and sodium hypochlorite had a higher (92.6% & 91.4%) bactericidal activity compared to ethanol and savlon at the recommended user dilution. In general, our results indicated that P. aeruginosa was significantly resistance to commonly prescribed antimicrobial drugs, a situation that demands a more rational and appropriate use of antibiotics. Hydrogen peroxide and sodium hypochlorite were relatively more effective when used in recommended dilution. However, all tested disinfectants or antiseptics showed reduced bactericidal activities in higher dilutions. Therefore, strict adherence to the recommended dilution is important for better activity. The correct use of them also has to be considered appropriately as part of infection control practices.