Virulence Genes and Antimicrobial Resistance Profiles in Aeromonas hydrophila and Aeromonas dhakensis Isolated from the Brazilian Food Chain

<i>Aeromonas hydrophila</i> and <i>A. dhakensis</i> are ubiquitous microorganisms, widespread in aquatic environments, and can cause severe infections in humans and animals. This study aimed to determine the diversity of virulence genes <i>aer</i>A, <i>hly</i>A, <i>act</i>, and <i>alt</i> through polymerase chain reaction and the antimicrobial resistance through disk diffusion test of 101 <i>A. hydrophila</i> and 34 <i>A. dhakensis</i> strains from environmental, animal, and human sources gathered between 2016 and 2019 at the National Reference Laboratory for Enteric Diseases. Overall, the virulence gene distribution was <i>act</i> in 35.5% of the samples, <i>alt</i> in 40.7%, <i>aer</i>A in 42.2%, and <i>hly</i>A in 44.5%. Our results revealed that 76.3% of the 135 isolated <i>Aeromonas</i> exhibited at least one of the genes above. 76.3% of <i>A. hydrophila</i> and 76.5% of <i>A. dhakensis</i> exhibited virulence genes distributed among 15 and 12 virulence profiles, respectively. Antimicrobial resistance was observed in 86% of the strains (87.1% in <i>A. hydrophila</i> and 82.4% in <i>A. dhakensis</i>), with higher rates of resistance to Nalidixic acid (69.3%), Imipenem (31.1%), and Sulfamethoxazole-trimethoprim (15.5%). The occurrence of virulence genes and antimicrobial resistance in <i>A. hydrophila</i> and <i>A. dhakensis</i> from different sources indicates their diversity and pathogenicity, reinforcing that they can be a potential health risk source.