Clinical and bacteriologic epidemiology of extended-spectrum beta-lactamase-producing strains of Klebsiella pneumoniae in a medical intensive care unit.
The epidemiology of extended-spectrum beta-lactamase (ESBL)-producing strains of Klebsiella pneumoniae was studied over a 16-month period in a medical intensive care unit (ICU). A control program involving enhanced isolation procedures, surveillance cultures at admission and then at 1-week intervals, and selective digestive decontamination (SDD) was instituted. Phenotypic and genotypic markers (plasmid content and DNA macrorestriction polymorphism determined by pulsed-field gel electrophoresis) were used to compare 138 strains of ESBL-producing K. pneumoniae. The incidence of colonization and/or infection with ESBL producers was 11.9%. ESBL-producing K. pneumoniae strains were isolated from 64 of 65 patients. Fifty-five cases were considered acquired in the ICU, while nine cases were imported. Forty-five infections occurred in 32 patients; 20 infections involved the urinary tract. SDD failed to reduce the incidence of acquisition of ESBL-producing K. pneumoniae. Combined use of markers was necessary to achieve accurate differentiation of strains. A single epidemic clone (SHV-4 beta-lactamase-producing K. pneumoniae) was the cause of 85% of the ICU-acquired cases. Sporadic occurrence of SHV-5, TEM-3, SHV-2, and SHV-3 producers accounted only for a few cases.
Decré
D
D
Service de Microbiologie, Hôpital Bichat-Claude Bernard, Paris, France.
Gachot
B
B
Lucet
J C
JC
Arlet
G
G
Bergogne-Bérézin
E
E
Régnier
B
B
D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis; D004352:Drug Resistance, Microbial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D016680:Genome, Bacterial; D005838:Genotype; D006801:Humans; D007362:Intensive Care Units; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000145:classification / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D010297:Paris / Q000453:epidemiology; D010641:Phenotype; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction / Q000379:methods; D001618:beta-Lactamases
D004269:DNA, Bacterial; D001618:beta-Lactamases