Microbiological contamination in Amazonian fish: Pseudomonas spp. and Salmonella spp. in tambaqui ( Colossoma macropomum ) and pirarucu ( Arapaima gigas )

The growing consumption of fish poses complex challenges to food quality and safety. This study evaluated the load and spoilage potential of Pseudomonas spp. as well as the prevalence of Salmonella spp. in the processing of tambaqui and pirarucu. Samples were collected at a fish-packing plant in the Legal Amazon, Brazil, at the reception (P1) and filleting (P2) stages. Pseudomonas spp. counts indicated a high potential for spoilage under refrigeration, with predominance of lipolytic enzymatic profile. Tambaqui showed the highest bacterial counts, although a reduction in populations was observed between P1 and P2. This variation among species was associated with intrinsic and handling factors, as well as the impact of processing, such as post-evisceration washing with hyper chlorinated water (5 ppm) applied only to tambaqui. Regarding safety, Salmonella spp. exhibited high prevalence at P1 (68.2% in tambaqui and 50% in pirarucu). Despite the reduction in P2, the persistence of the pathogen (36.4% and 33.3%, respectively) highlights failures in sanitation and critical risks of cross-contamination. It is concluded that there is an urgent need to optimize pre-requisite programs and hygiene-sanitation procedures in the industry to mitigate microbiological risks and ensure the safety of native fish.