[Epidemiology and drug susceptibility of Pseudomonas aeruginosa strains isolated in the Chugoku region of Japan. Infection Forum in the Chugoku Region].

Recently, there have been reports concerning an increased frequency of isolation of multi-drug resistant Pseudomonas aeruginosa (MDRP) strains in hospitals and other clinical settings as well as the associated risk of their hospital-acquired infections; in such a situation, it has been a major challenge to establish methods of managing and treating the infections. In order to investigate the trend of P. aeruginosa, the Infection Forum in the Chugoku Region has conducted to a multi-center collaborative study to isolate P. aeruginosa strains from sputum and urine samples collected between October 2006 and September 2008, analyzed the drug susceptibility and the pulsed-field gel electrophoresis (PFGE) patterns of each strain, and assessed epidemiologic characteristics. Of the 738 P. aeruginosa strains collected in this study, 152 (20.6%), 179 (24.3%), 47 (6.4%), and 39 (5.3%) were found to be ciprofloxacin-resistant, imipenem-resistant, amikacin-resistant, and MDRP, respectively. Among the various antimicrobial agents tested, arbekacin (ABK) revealed the strongest inhibitory effects on each drug-resistant and MDRP strain; therefore, ABK was considered as a potential candidate for future treatment of diseases caused by P. aeruginosa. The study also showed that the detection rates of MDRP varied a lot from hospital to hospital. In addition, PFGE-based cluster analyses revealed several strains isolated in the same hospital exhibited a similar PFGE pattern and the same drug susceptibility, suggesting the presence of "unique" hospital-specific strains.