Drug Resistance Pattern of Pseudomonas aeruginosa Isolates Carrying MexAB-OprM Efflux Pump’s Associated Genes in Companion Birds with Respiratory Infection

Abstract

BACKGROUND: Pseudomonas aeruginosa is considered one of the most common bacterial pathogens causing nosocomial infections in human cases. However, the pathogenesis of this bacterium in companion birds is poorly understood. OBJECTIVES: The aim of the present study was to isolate P. aeruginosa from pet birds with respiratory illness manifestations referred to the clinic of the University of Tehran. Moreover, the antimicrobial susceptibility of the recovered P. aeruginosa isolates carrying MexAB-OprM efflux pump was evaluated. METHODS: Selective media and biochemical tests were used to isolate and identify P. aeruginosa isolates from 126 companion birds. The species-specific polymerase chain reaction (PCR) based on the 16S rRNA gene was applied to confirm P. aeruginosa. In addition, the sensitivity of isolates to 20 antimicrobial agents was assessed by an antimicrobial susceptibility test. Multiplex PCR was used to detect genes associated with MexAB-OprM efflux pump by specific primers in recovered P. aeruginosa isolates. RESULTS: All seven isolates identified as P. aeruginosa in culture by biochemical tests were confirmed utilizing species-specific PCR. The results of the antimicrobial susceptibility test demonstrated multidrug resistance (MDR) among the isolates with the highest resistance to neomycin, kanamycin, rifampicin, and vancomycin (100% of iso-lates) followed by colistin (57% of isolates). The mexA and oprM genes were detected in all isolates by multiplex PCR, while the mexB gene was not amplified in any of the seven isolates. CONCLUSIONS: We found P. aeruginosa isolates in sick birds and observed MDR in these isolates. Therefore, companion birds could be considered a potential public health concern, especially for owners and veterinary staff.