Abstract

Background: Multidrug resistant strains of Acinetobacter baumannii (MDR-AB) have emerged as alarming nosocomial pathogens among patients with burning. Objectives: The current study aimed to determine the susceptibility of A. baumannii species, carbapenems resistance patterns, and their association with IS(Aba)1 and IS(Aba)4 elements upstream of the bla(OXA)-like genes, and the distribution of international clone (IC) of A. baumannii isolates among patients with burning in Tehran, Iran. Materials and Methods: In the current study, 62 A. baumannii species isolates from patients with burning in Tehran, Iran, in 2012 were evaluated for the antimicrobial susceptibility, genetic relationships, ICs, carbapenemase encoding genes, and insertion elements ISAba upstream of bla(OXA)-like genes. Results: The highest rates of susceptibility were observed with colistin (88.7) and tigecycline (82.2). The extensively drug-resistance and pan drug-resistance were observed in 37.1 and 8.1 of the isolates, respectively. About 98.3 of 17 genotypes categorized into three distinct clusters. Thirty-six of the 62 isolates (58) belonged to the IC II lineage. The most prevalent acquired OXA-type carbapenemase was bla(OXA-23)-like (62.9). IS(Aba)1 and IS(Aba)4 were detected upstream of bla(OXA-23)-like genes in 45.1 and 12.9 of isolates, respectively. In 32.2 of all isolates, IS(Aba)1 laid upstream of bla(OXA-51)-like genes. The PCR results were negative for carbapenemase genes of Ambler class A and B, except bla(VIM-2). (1.6). Conclusions: It was the first study that attempted to detect the insertion elements ISAba and IC lineages in MDR-AB species isolated from patients with burning in Iran.