title: Outbreak of Acinetobacter baumannii producing the carbapenem-hydrolyzing oxacillinase OXA-58 in Rome, Italy.
abstract: In this study 45 epidemic and sporadic isolates of Acinetobacter baumannii were investigated by antimicrobial resistance, integron identifications and genotyping. Isolates were genotyped by random amplified polymorphism (RAPD) DNA and pulsed-field gel electrophoresis (PFGE). Four different RAPD patterns were observed among the isolates of our collection, further discerned in six PFGE types. Two prevalent genotypes were identified, one corresponding to a carbapenem resistant epidemic clone, causing an outbreak at the intensive care unit of a hospital of Rome. Two class 1 integrons, carrying different gene cassette arrays, were identified among the two prevalent genotypes. Nucleotide analysis of the integron-variable regions revealed the presence of the aacA4, orfO, bla(OXA-20), and aacC1, orfX, orfX', aadA1 gene cassette arrays, respectively. All the carbapenem resistant strains analyzed in this study carried the bla (OXA-58) gene located on plasmids.
authors.affiliation: Department of Science and Public Health, Microbiology Unit, University of Rome La Sapienza, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Giordano
authors.forename: Paola
authors.initials: P
authors.lastname: Varesi
authors.forename: Alessia
authors.initials: A
authors.lastname: Bertini
authors.forename: Laura
authors.initials: L
authors.lastname: Villa
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Dionisi
authors.forename: Mario
authors.initials: M
authors.lastname: Venditti
authors.forename: Paolo
authors.initials: P
authors.lastname: Carfagna
authors.forename: Ida
authors.initials: I
authors.lastname: Luzzi
authors.forename: Carlo
authors.initials: C
authors.lastname: Mancini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Carattoli
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques; D015780:Carbapenems / Q000494:pharmacology*; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D032023:Integrons; D007362:Intensive Care Units; D019105:Random Amplified Polymorphic DNA Technique; D012384:Rome / Q000453:epidemiology; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases; C108449:oxacillinase