title: Extended-spectrum beta-lactamase-producing Enterobacteriaceae in an Italian intensive care unit: clinical and therapeutical remarks.
abstract: In this study we evaluated the prevalence of Enterobacteriaceae and the epidemiology of ESBL+ microorganisms in an ICU of our Institution over a 5-year period and analyzed the clinical features and outcomes of the infections caused by these microorganisms. The most frequent ESBL+ isolate was Proteus mirabilis (69 isolates, 58%); a high rate of positive results in the double-disk synergy test (DDS) was also recognized for Klebsiella pneumoniae (52 isolates, 51%), whereas this phenomenon was observed less frequently in other species. In 312 cases the isolated microorganism was considered to be the cause of infection; we documented 103 wound infections, 89 UTIs, 62 LRTIs, 30 primary bacteremias, 27 infections of indwelling catheters and 1 CNS infection. The overall mortality rate due to ESBL+ strains was 1%, compared with 10.6% rate caused by ESBL-negative Enterobacteriaceae. This could be explained because ESBL+ strains caused mostly localized infections (wound infections and UTIs), whereas systemic or severe infections were sustained by ESBL-negative strains, and therapy with carbapenems was started promptly after ESBL+ isolation (always within 24h after strain isolation).
authors.affiliation: Laboratori Sperimentali di Ricerca, Area Infettivologica, IRCCS Policlinico San Matteo, Pavia, Italy. e.carretto@smatteo.pv.it
authors.forename: E
authors.initials: E
authors.lastname: Carretto
authors.forename: V
authors.initials: V
authors.lastname: Emmi
authors.forename: D
authors.initials: D
authors.lastname: Barbarini
authors.forename: F
authors.initials: F
authors.lastname: Capra Marzani
authors.forename: A
authors.initials: A
authors.lastname: Bolongaro
authors.forename: A
authors.initials: A
authors.lastname: Braschi
authors.forename: P
authors.initials: P
authors.lastname: Marone
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D003428:Cross Infection / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology / Q000401:mortality / Q000517:prevention & control; D004755:Enterobacteriaceae / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology / Q000401:mortality / Q000517:prevention & control; D006801:Humans; D017053:Infection Control; D007362:Intensive Care Units; D007558:Italy / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases