Long-term dissemination of an OXA-40 carbapenemase-producing Acinetobacter baumannii clone in the Iberian Peninsula

• Published in: Journal of antimicrobial chemotherapy 2004-07, Vol.54 (1), p.255-258
• Main Authors: Da Silva, G. J., Quinteira, S., Bértolo, E., Sousa, J. C., Gallego, L., Duarte, A., Peixe, L.
• Format: Article
• Language: English
• Subjects: Acinetobacter baumannii; Acinetobacter baumannii - drug effects; Acinetobacter baumannii - enzymology; Acinetobacter baumannii - genetics; Acinetobacter Infections - epidemiology; Acinetobacter Infections - microbiology; Acinetobacter spp; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; beta-Lactamases - biosynthesis; beta-Lactamases - genetics; Biological and medical sciences; Chromosomes, Bacterial - genetics; Cross Infection - microbiology; DNA Fingerprinting; DNA, Bacterial - genetics; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; epidemic clones; Humans; Imipenem - pharmacology; Medical sciences; Microbial Sensitivity Tests; oxacillinases; Pharmacology. Drug treatments; Portugal - epidemiology; Reverse Transcriptase Polymerase Chain Reaction; Spain - epidemiology; β-lactamases
• ISSN: 0305-7453; 1460-2091; 1460-2091
• DOI: 10.1093/jac/dkh269

Objective: The main objectives of this study were to assess the clonal relatedness of Acinetobacter baumannii carbapenem-resistant isolates recovered from the Iberian Peninsula and to investigate the production of carbapenemases. Methods: One hundred and sixty-two imipenem-resistant A. baumannii isolates were collected from 1998 to 2003 in three Portuguese university hospitals. An imipenem-resistant isolate (988FFP strain) recovered in 1995 from a smaller hospital unit, was also included, as well as an OXA-40-producing A. baumannii Spanish strain (SM28). Susceptibility tests were carried out by disc diffusion and Etest methods. DNA fingerprints were obtained by PFGE of ApaI-digested chromosomal DNA. Carbapenemase activity was determined by a bioassay and spectrophotometry. The detection of the blaOXA-40 gene was conducted through PCR analysis, cloning and nucleotide sequencing. Results: All the isolates presented a similar multi-resistance pattern, including imipenem (MIC >32 mg/L). The Iberian isolates showed an identical PFGE pattern with minor band variations, including isolate 988FFP collected in 1995. PCR results revealed a blaOXA-type gene in 65 isolates and nucleotide sequence analysis revealed the presence of the blaOXA-40 gene in seven representative Portuguese isolates from the various geographically dispersed hospitals. Conclusions: Our results indicate that a multi-resistant epidemic clone of A. baumannii, carrying blaOXA-40, is disseminated in the Iberian Peninsula, persisting in Portugal since 1995.