Molecular epidemiology of clostridium difficile in a tertiary medical center in Israel: emergence of the polymerase chain reaction ribotype 027.

BACKGROUND The rate of infection with Clostridium difficile colitis and its associated mortality have been increasing in the last decade. The molecular epidemiology of C. difficile in Israel has not been studied. OBJECTIVES To screen for the existence of the 027 and 078 ribotypes and determine the longitudinal molecular epidemiology of the circulating clinical C. difficile isolates in a large hospital in central Israel. METHODS Polymerase chain reaction (PCR) ribotyping was performed on C. difficile isolates obtained from hospitalized patients from November 2003 to May 2004 (first study period) and September 2009 (second study period). Isolates with PCR ribotype patterns, unlike those of the available reference strains (078 and 027), were labeled with letters. Forty-six isolates from the first study period and 20 from the second were analyzed. RESULTS PCR strain typing of C. difficile isolates yielded approximately 26 unique ribotypes. During the first study period, ribotype A and B accounted for 30% and 28%, respectively, whereas ribotype E and K accounted for 6.5% for each. During the second study period, ribotypes A, E and K disappeared, and the incidence of ribotype B decreased from 28% to 15%. One isolate (1/20, 5%) emerged during the second period and was identified as ribotype 027. Moxifloxacin resistance was found in 93% of ribotype A isolates, 81% of the ribotype B group, and in 44% of other ribotypes. CONCLUSIONS The predominant ribotypes circulating in our institution were diverse and changing. This is the first report on the emergence of the 027 ribotype in Israel.