Epidemiological typing of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates by pulsed-field gel electrophoresis and antibiotic susceptibility patterns

Over a 16-month period, Klebsiella pneumoniae isolates from 102 patients ad mitted to a university hospital in Liege (Belgium) produced extended-spectr um B-lactamases. Pulsed-field gel electrophoresis of genome macrorestrictio n patterns with XbaI and antibiotic susceptibility patterns subdivided 39 i solates into eight clonally related groups. Two of them were implicated in the course of this outbreak. They were responsible for successive waves of infection or colonization in different wards of the hospital while the othe rs were encountered sporadically. A B-lactamase with an isoelectric point o f 7.6 and consistent with type SHV-2 characterized all nine isolates chosen among both major groups. (C) Elsevier, Paris.