Effects of environmental concentration of the antibiotics oxytetracycline and florfenicol in fishes.

Abstract

An assessment of the genotoxicity and induction of changes in the gills of tilapia (Oreochromis niloticus) and curimbatá (Prochilodus lineatus) or pacu (Piaractus mesopotamicus) after exposure to florfenicol and oxytetracycline will be investigated. Therefore, this study will be conducted in two stages. In the first stage, an exposure to the environmental concentration of florfenicol and oxytetracycline found in the water of Ilha Solteira Reservoir (Santa Fé do Sul, São Paulo), where is located one of the largest fish farm (tilapia) in Brazil, and to the half and double of the environmental concentration to verify the induction of micronuclei and other nuclear abnormalities, DNA breakage, and changes in the gills will be conducted. The negative and positive control will also be used. In the second stage, such genotoxic responses of the first stage, ie, induction of micronuclei and other nuclear abnormalities and breaks in the strand of DNA through the comet assay will be evaluated after exposure of mixtures to environmental concentration of oxytetracycline and florfenicol and to twice of the environmental concentration for both antibiotic concentrations besides the environmental concentration of both isolated. Also, in this case, negative and positive controls will be used. For both steps, the exposure time is 96 hours.