C2-3919. Genotypic Characteristics of Extended-Spectrum β-lactamase (ESBL)-Producing Klebsiella pneumoniae Isolates Causing Bacteremia and Urinary Tract Infections in Korea
Session: Poster Session: Surveys of Resistance Trends in Enterobacteriaceae
Tuesday, October 28, 2008: 12:00 AM
Room: Hall C
Background: The prevalence of ESBL in Klebsiella pneumoniae in Korea has been estimated as 17.7% to 30.0%. We investigated ESBL prevalence, ESBL genes, and prevalent clones of ESBL-producing K. pneumoniae isolates causing bacteremia and urinary tract infections (UTIs) in Korea.
Methods: A total of 410 K. pneumoniae isolates were collected from eight tertiary-care hospitals in Korea during two years (2006-2007); 189 K. pneumoniae from patients with UTIs and 221 isolates from patients with bacteremia. In vitro antimicrobial susceptibility testing was performed for all isolates and ESBL production was tested using double disk method. To characterize genotypes of ESBL-producing K. pneumoniae isolates, MLST analysis was performed. Results: 25.7% of 189 K. pneumoniae isolates from UTIs produced ESBLs, and 13.6% of isolates from bacteremia produced ESBLs (p, <0.001). Most ESBL-producing K. pneumoniae isolates (98.7%) contained blaSHV genes. blaCTX-M genes such as blaCTX-M-14 and blaCTX-M15 were detected in 36.4%. The distribution of ESBL genes was not different significantly between isolates from UTIs and bacteremia. MLST analysis showed that the most prevalent clone of ESBL-producing K. pneumoniae causing UTIs and bacteremia was ST11 (3-3-1-1-1-1-4), which occupied 57.5% and 70.0%, respectively. However, most ST11 isolates contained different ESBL gene profiles. Conclusion: A single genotype of ESBL-producing K. pneumoniae isolates is prevailing in Korea in terms of MLST, but most isolates might acquire ESBL genes independently or many clones might distribute in Korea.
Doo Chung1, Harim Lee, MS2, Jae Song3, Ji Lee, MD4, Jin Baek2, Kwan Ko5, Mi Lee6 and  K. S. Ko, None., (1)Samsung Medical Center, Sungkyunkwan University School of Medecine, (2)ARFID, (3)Myongji University, (4)Bundang CHA Hosp., Kyunggi-Do, Korea, Republic of, (5)Sungkyunkwan University School of Medecine, Suwon, Korea, Republic of, (6)Asian-Pacific Research Foundation for Infectious Diseases (ARFID)