Aeromonas sp. in freshwater fish and antimicrobial resistance: emerging pathogen

Abstract

The bacteria Aeromonas sp. are naturally reported in aquatic ecosystems and possess pathogenic potential, being considered as emerging pathogens in humans and animals. They also cause considerable losses in fish farming and, through water, can contaminate numerous foods. This study quantified and analyzed the antimicrobial resistance profile of Aeromonas sp. in fish. A total of 72 samples of two fish varieties (leather fish, Pseudoplatystoma fasciatum x Leiarius marmoratus and round fish, Colossoma macropomum x Piaractus mesopotamicus and Colossoma macropomum x Piaractus brachypomus) were purchased from two types of sources (fresh and frozen) and three commercial establishments (supermarket, market, and fishmonger). The 55 isolated Aeromonas cultures were evaluated for their antimicrobial resistance profile by the disc diffusion method. Upon quantification, the count of Aeromonas sp. ranged from 4.22 to 6.00 Log CFU/g; ten different species, including A. eucrenophila, A. hydrophila, A. caviae, A. media, A. jandaei, A. veronii bv. sobria, A. trota, A. schubertii, A. veronii bv. veronii, and A. shigelloides, were identified. Among the 55 isolates, 64.45% showed resistance to Ampicillin-sulbactam, and 75% were sensitive to gentamicin and ciprofloxacin. It was concluded that 100% of the evaluated samples were contaminated by Aeromonas sp., which may present a risk to consumer health since bacteria can be etiological agents of Foodborne Diseases. The antimicrobial resistance profile showed resistance to ampicillin and multi-resistance to different classes of antimicrobials, demonstrating problems with choosing an antimicrobial for treatment of any disease.