Aeromonas aquariorum clinical isolates: antimicrobial profiles, plasmids and genetic determinants

The objective of this study was to investigate the antimicrobial resistance patterns of 47 clinical isolates of Aeromonas aquariorum and to identify the presence of plasmids and the relevant antibiotic resistance genes (ARGs). Antibiotic susceptibilities were determined by the standard disc diffusion method. The presence of plasmids and ARGs was detected by gel electrophoresis and monoplex PCR. Resistance to amoxicillin/clavulanic acid (98%), amoxicillin (91%), gentamicin (13%), trimethoprim/sulfamethoxazole (11%) and kanamycin (6%) was observed, whilst no ciprofloxacin- or amikacin-resistant strains were detected. All isolates harboured plasmids with sizes ranging from ca. 2 kb to 10 kb. PCR revealed that A. aquariorum carried three β-lactam resistance genes (blaTEM, blaMOX and blaPSE) and two sulphonamide resistance genes (sul1 and sul2). This study provides further understanding of the phenotypic and genotypic characteristics of multiresistant A. aquariorum clinical isolates.