Temporal evolution of carbapenem-resistant Acinetobacter baumannii in Curitiba, southern Brazil
published online 02 February 2010.
Background
In the last few years, carbapenem-resistant Acinetobacter baumannii isolates (CR-AB) have been identified worldwide. The first description of OXA-23–producing A baumannii in Brazil was from the city of Curitiba in 2003. The aim of the present study was to evaluate the persistence and dissemination of the first OXA-23–producing A baumannii clone isolated from patients in Hospital de Clinicas, Curitiba, Brazil.
Methods
An antimicrobial susceptibility profile of the isolates was determined by the standard agar dilution method. Molecular detection of β-lactamase genes was done by polymerase chain reaction. The clonal relationship of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Epidemiologic and clinical features were evaluated as well.
Results
Genotypic analysis of 172 CR-AB isolates by PFGE identified 3 distinct major PFGE clusters (A, B, and C, accounting for 36, 69, and 65 isolates, respectively). All isolates carried the blaOXA-23–like gene and were multidrug-resistant, but were susceptible to tigecycline and polymixin B. The mortality rate related to CR-AB infection was 45.4%, and ventilator-associated pneumonia and bloodstream infections were the most frequent clinical manifestations.
Conclusions
The presence of 3 clones among the CR-AB isolates suggests that cross-transmission was the main mechanism responsible for dissemination of OXA-23 producers. PFGE pattern A was genotypically similar to that of the first OXA-23–producing A baumannii clone identified in Curitiba in 1999. This clone persisted in the same hospital until April 2004. The presence of the blaOXA-23–like gene was the main mechanism associated with carbapenem resistance among the isolates studied.
fPharmaceutical Sciences Post-Graduate Program, Federal University of Paraná, Curitiba, Brazil
gPequeno Príncipe College—Pelé Pequeno Príncipe Research Institute (FPP/IPPPP), Curitiba, Brazil
Address correspondence to Libera Dalla Costa, Universidade Federal do Paraná (UFPR), Hospital de Clínicas, Laboratório de Bacteriologia, UAD, Rua Padre Camargo, 280–1° andar, Curitiba, PR, 80060-240 Brazil.
Conflict of interest: A.C.G. is a research fellow for the Brazilian National Council for Scientific and Technological Development, Ministry of Science and Technology (under Grant 307714/2006-3), and has received research funding, speaking grants, conference support, and consulting fees from Janssen Cylag, Novartis, Sanofi-Aventis, and Wyeth.
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