Occurrence of the <i>aacA4</i> gene among multidrug resistant strains of <i>Pseudomonas aeruginosa</i> isolated from bronchial secretions obtained from the Intensive Therapy Unit at University Hospital in Bialystok, Poland

Abstract

The aim of this study was to investigate the prevalence of the <em>aacA4</em> gene in a population of multidrug resistant strains of <em>P. aeruginosa</em> isolated from bronchial secretions obtained from the Intensive Therapy Unit (ITU). Twelve MDR isolates were tested for antibiotic susceptibility and the presence of the <em>aacA4</em> gene. In this study, 58.3% of the strains contained (6’)-Ib’ aminoglycoside acetyltransferase gene. All of the studied strains (<em>aacA4</em>-positive and <em>aacA4</em>-negative) were susceptible only to colistine (100%). Among other antibiotics, the lowest resistance rates were those shown against ceftazidime (14.3% to 20%) and imipenem (28.6% to 40%). Our studies frequently revealed the presence of the <em>aacA4</em> gene as a factor responsible for resistance; it is probable that other mechanisms of resistance to aminoglycoside antibiotics also occurred.

Keywords

• Pseudomonas aeruginosa
• aacA4 gene
• antimicrobial susceptibility