Aeromonas species in aquaria: a reservoir of gastrointestinal infections?

To assess the role of aquaria in the epidemiology of aeromonas associated gastroenteritis, the prevalence and antibiotic susceptibility of aeromonads in ornamental aquaria were determined and compared to that of isolates obtained from patients with gastroenteritis. Thirty-eight (76%) of 50 aquaria, including those located in our hospital, yielded 61 isolates: 24 (39.3%) Aeromonas sorbria, 18 (29.0%) A. hydrophila, 15 (24.6%) A. caviae, and four (6.5%) which could not be speciated. In comparison, 41 (65%) of 63 faecal isolates were A. caviae. The aquarium isolates, in contrast to enteric isolates, were generally resistant to chloramphenicol, tetracycline, and trimethoprim/sulphamethoxazole. These findings indicate aquaria are unlikely sources of aeromonas-associated gastroenteritis, but their role as possible reservoirs for non-enteric infections with aeromonads needs to be defined.