Identification of epidemic strains of Acinetobacter baumannii by integrasegene PCR

Forty-eight clinical Acinetobacter isolates with different epidemic behavio r were investigated for the presence of integrons and plasmids and for anti biotic susceptibility. Integrons were demonstrated in 50% of the strains by an integrase gene PCR. Epidemic strains of Acinetobacter baumannii were fo und to contain significantly more integrons than nonepidemic strains. Also, the presence of integrons was significantly correlated with simultaneous r esistance to several antibiotics. Plasmids were detected in 42% of the stra ins. However, there was no significant correlation between the numbers of p lasmids and integrons in Acinetobacter species strains, no significant diff erence in the number of plasmids between epidemic and nonepidemic A. bauman nii strains, and no significant correlation between the presence of plasmid s and antibiotic resistance. Hence, it is likely that integrons play an imp ortant role in antibiotic resistance and thereby in the epidemic behavior o f A. baumannii. Because the integrase gene PCR identified almost three-quar ters of the epidemic A. baumannii isolates (17 of 23), this seems to be a r apid and simple technique for the routine screening and identification of c linical A. Baumannii isolates with epidemic potential.