Molecular-epidemiological evaluation of Serratia marcescens isolates from patient specimens in one Japanese hospital during the three years from April 1999 to March 2002

摘要

One hundred fifty-six isolates of Serratia marcescens from patient specimens in Showa University Fujigaoka Hospital between April 1999 and March 2002 were investigated in this study. Forty-two isolates with serotype O2, detected mainly from patient respiratory specimens, were susceptible to the antimicrobial agents tested, whereas 30 isolates with serotype O14, detected mainly from patient urine, were resistant. Moreover, 19 isolates with serotype O14 susceptible to imipenem were intermediate or resistant to meropenem, while they did not produce metallo beta-lactamase. Both serotypes were significantly distributed in the ICU and surgical wards, compared with other wards. Ten isolates with O2/B (bacteriocin type) 16 and 14 isolates with O14/B76J, showing identical or closely-related clones by pulsed-field gel electrophoresis (PFGE) analysis of Spe I-restricted chromosome, were detected from different inpatients' specimens during approximately 2 and a half years. The existence of such long-lasting microorganisms suggested the possibility of hospital-acquired infection caused by inadequate use of antimicrobial agents and disinfection procedures for medical tools such as bite blocks and catheters.