Outbreak of Acinetobacter baumannii producing the carbapenem-hydrolyzing oxacillinase OXA-58 in Rome, Italy.
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.
Giordano
Alessandra
A
Department of Science and Public Health, Microbiology Unit, University of Rome La Sapienza, Rome, Italy.
Varesi
Paola
P
Bertini
Alessia
A
Villa
Laura
L
Dionisi
Anna Maria
AM
Venditti
Mario
M
Carfagna
Paolo
P
Luzzi
Ida
I
Mancini
Carlo
C
Carattoli
Alessandra
A
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*
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases; C108449:oxacillinase