A RELIABLE COMBINATION METHOD TO IDENTIFICATION AND TYPING OF EPIDEMIC AND ENDEMIC CLONES AMONG CLINICAL ISOLATES OF ACINETOBACTER BAUMANNII

Background and Aim:The Gram-negative coccobacillus Acinetobacter baumannii as an important nosocomial pathogen has emerged a global health concern in recent years. Resistance to a broad range of antimicrobial agents (MDR), the tendency for epidemic spread and long-term persistence in the hospital setting make A. baumannii as a common yet difficult-to-treat pathogen. Three epidemic lineages are responsible for the majority of A.baumannii infections in clinical settings worldwide. Few reports have been published the epidemiology of nosocomial A.baumannii infection in Iran. The aim of this project is to investigate the molecular epidemiology of the A. baumannii isolatesMethods:In this study, we applied three easier, faster, and cost-effective methods including PCR-based open reading frames (ORFs) typing, sequence typing of blaOXA-51-like and MLST method to rapid typing of A. baumannii strainsResults:Taken together in the present study the results of ORFs typing, PCRsequencing of blaOXA-51-like genes and MLST sequence typing revealed there was a high prevalence (62%, 35/57) of ST2 as international and successful clone which detected among clinical isolates of multi-drug resistant A.baumannii with ORF pattern B and blaOXA-66 gene. Only 7% (4/57) of MDR isolates belonged to ST1 with ORF pattern A and blaOXA-69 gene. Interestingly, we detected singleton ST513 (32%, 18/57) that encoded blaOXA-90 and showed the ORF pattern H as previously isolated in Middle East.Conclusion:The using both of the PCR-based typing of seven ORFs and determination of allele number of blaOXA-51-like, could be effectively applied to rapid typing of A.baumannii strains without performing of MLST or PFGE.