Changes of antimicrobial resistance and extended-spectrum beta-lactamase production in Klebsiella spp. strains.

Changes of antimicrobial resistance and extended-spectrum beta-lactamase (ESBL) production of Klebsiella spp. strains isolated at the Central Military Hospital, Ruzomberok, Slovakia, with a special focus on the Anesthesiology--Resuscitation and Intensive Medicine Department during the years 1998-2002, were analyzed. Of 3920 gram-negative strains isolated from clinical materials during this period, Klebsiella spp. represented 8%. The incidence of ESBL-producing Klebsiella spp. isolates increased from 29% in 1998 to 69% in 2002. Of 17 antibiotics tested, meropenem was found to be the most effective drug (100%). The overall efficacy of cefotaxime was 31%, that of gentamicin 23%, and that of ciprofloxacin 54%. Analyzed Klebsiella isolates were characterized also by a high degree of multiresistance (53%). The high incidence of reduced antibiotic susceptibility among Klebsiella spp. strains isolated at the intensive-care department suggests that more effective strategies are necessary to control the selection and spread of resistant organisms in this hospital.