Detection of ISAba1 in Acinetobacter baumannii Strains Carrying OXA Genes Isolated From Iranian Burns Patients


Background: The presence of carbapenemase-producing Acinetobacter baumannii has become a growing concern in patients who are hospitalized in burns centers.

Objectives: The aims of this study were to determine the antimicrobial susceptibility patterns and prevalence of blaOXA carbapenemases, as well as to detect the presence of ISAba1, in A. baumannii strains carrying OXA genes obtained from burns patients at Shahid Motahari hospital, Tehran, Iran.

Methods: From August 2013 to March 2014, 100 clinical A. baumannii isolates were collected from patients who were admitted to the burns ward at Shahid Motahari hospital. Antimicrobial susceptibility was determined using a disc diffusion test. PCR, sequencing, and multiplex PCR were used for the detection of blaOXA-23-like, blaOXA-51-like, blaOXA-24-like, and blaOXA-58-like genes, which were then sequenced. The ISAba1 gene was detected, and PCR was performed to detect the presence of ISAba1/blaOXA-51-like and ISAba1/blaOXA-23-like genes.

Results: The results showed that 93% of the strains were multi-drug resistant, while 82% of them were extensively drug resistant. Additionally, all the strains carried blaOXA-23-like and blaOXA-51-like genes, while 74% and 0% of the strains harbored blaOXA-24-like and blaOXA-58 genes, respectively. ISAba1 was detected in all the strains except for one. The co-existence of ISAba1/blaOXA-51-like genes and ISAba1/blaOXA-23-like genes was detected in 65% and 80% of strains, respectively.

Conclusions: The results of this study indicate that the emergence of OXA-type carbapenemases in A. baumannii causing nosocomial infections in burns patients could be of importance for hospital infection control systems in Iran.