Diversity on the occurrence of Aeromonas spp. in Tilapia grown in three different fishfarms on the state of Rio de Janeiro

Abstract

Fish is a perishable food and, to assure its quality, many cares towards its handlings are necessary. Among the pathogenic agents that cause production loss are bacteria of the genus Aeromonas. These micro-organisms, present in water, compose the microbe community of aquatic organisms; cause diseases in animals and man. The study aimed to check the occurrence of Aeromonas spp. in Tilapia (Oreochromis niloticus), originated from three fish farms in the state of Rio de Janeiro: A, B and C. There were taken: 32, 20 and 18 samples, respectively. After sowing, colonies with characteristics of Aeromonas were observed: A – 180 plates, B – 73 plates and C – 33 plates. Besides Aeromonas, it was also identified in the lots: Pseudomona, Vibrio and Enterobacteriacea. After analysis significant difference was observed to the level of 5% (p<0,001) on the percentage of isolation. With Aeromonas, the following distribution of isolation was verified according to the origin: 62,9% from fish farming A, 25,5% from B and 11,5% from C. The diversity of genus on the tilapia samples varied according to the fish farming, indicating possible differentiated management between the producers and/or differentiated care relative to the origin and quality of cultivation water. On the lots A and B, there was predominance of Aeromonas, while lot C showed predominance of VibrioThe occurrence of Aeromonas in 68,1% of the samples of tilapia in all three fish farming is an indicative of warning to producers and government institutions to this risk that advises monitoring actions of the bacteria.