Klebsiella pneumoniae isolates causing liver abscess in Taiwan

Klebsiella pneumoniae has been the leading cause of pyogenic liver abscess in Taiwan during the period from 1985 to 1999, which is different from othe r countries. The present study investigated the in vitro antimicrobial susc eptibilities of 51 K. pneumoniae isolates collected from blood cultures of patients with liver abscess in Taiwan during the period from 1993-1997, and typed by pulsed-field gel electrophoresis (PFGE). All 51 isolates were res istant to ampicillin, but susceptible to other antimicrobial agents. The mi nimum inhibitory concentrations (MICs) were less than 1 mu g/ml for the thi rd- and fourth-generation cephalosporins, monobactam, carbapenems, and cipr ofloxacin. In comparison, 62 isolates of K. pneumoniae from community-acqui red bacteremic patients without liver abscess had similar antimicrobial sus ceptibilities, while 142 isolates from patients with hospital-acquired bact eremia without liver abscess were much less susceptible to all of the teste d antimicrobial agents. PFGE molecular epidemiologic analysis found 20 out of 51 isolates belonged to eight clusters of genetically related strains, w ith two or three isolates in each clusters. The other 31 isolates were gene tically distinct strains. This study demonstrated that K. pneumoniae isolat es which cause liver abscess in Taiwan remained susceptible to a wide range of antimicrobial agents and that they were not genetically related. (C) 20 00 Elsevier Science Inc. All rights reserved.