Repetitive-sequence-based genotyping and clonal relationship analysis of acinetobacter baumannii in nosocomial infections

Abstract

Background: Rapid, reliable determination of the genetic relatedness of clinical isolates in a microbiologic laboratory is essential when investigating cases of nosocomial outbreak. Methods: Twenty-four Acinetobacter baumannii strains were collected in intensive care units (ICUs) from June 2008 to May 2010. The minimum inhibitory concentrations (MICs) of 18 antimicrobial agents were determined for each strain. Genotyping and dendrographic analysis of A. baumannii strains were performed using the DiversiLab System. Results: Twenty-four A. baumannii strains were classified into 4 groups: Group 1, composed of 16 strains divided into 4 patterns; Group 2, composed of 6 strains divided into 3 patterns; and Groups 3 and 4, composed of one strain each. The groups showed different patterns of drug resistance, and variable patterns of drug resistance were observed within each group. Conclusions: The DiversiLab System provides a simple, rapid method for evaluating the epidemiological status of nosocomial A. baumannii infections. © 2012 by the American Society for Clinical Pathology.