Emergence of blaoxa-carrying carbapenem resistance in multidrug-resistant acinetobacter baumannii in the intensive care unit

Abstract EN

Background: Emergence of multidrug-resistant (MDR) Acinetobacter baumannii infections is becoming a worldwide threat to hospitalized patients, particularly in intensive care units.

Objectives: The aim of this study was to investigate the antimicrobial susceptibility patterns and prevalence of blaOXA-type carbapenemases of A.

baumannii isolates in a teaching hospital in Iran.

Patients and Methods: The study included a total of 40 isolates of carbapenem-resistant A.

baumannii, obtained from 103 tracheal tubes in hospitalized ICU patients.

Antimicrobial susceptibility testing was performed according to CLSI guidelines.

The blaOXA-51, blaOXA-23, blaOXA-24, blaOXA-58, and ISAba1 genes were detected by PCR.

Results: All of the A.

baumannii isolates were resistant to imipenem and meropenem, and 100% of the isolates were MDR.

The blaOXA-51 and ISAba1 genes were detected in 100% of the isolates.

blaOXA-23 and blaOXA-24 were detected in 90% and 40% of the isolates, respectively, but blaOXA-58 was absent in the A.

baumannii isolates.

In addition, 32.5% of carbapenem-resistant strains contained at least three genes encoding blaOXA-type carbapenemase.

Colistin and polymyxin B were the most effective antibiotics.

The sole risk factor for infection of hospitalized patients with carbapenem-resistant Acinetobacter strains was age over 40 years (P = 0.042).

The mortality rate was 27.5%.

Conclusions: These findings signify the alarming spread of OXA genes inA.

baumannii strains in our intensive care unit.

The spread of carbapenem-resistant Acinetobacter strains has serious health implications and requires the application of strict infection-control measures.