Bioluminescent bacteria assay of veterinary drugs in excreta of food-producing animals.

The residues of pharmacological treatments on food-producing animals, present in the manure dispersed on agricultural land, can impact environmental and human health through toxic, genotoxic, and drug-resistance development effects. Biotoxicity assays can easily reveal the presence of noxious substances and those based on bioluminescent bacteria (BLB) are particularly simple and rapid. A BLB assay was developed as microplate format by using various strains of Vibrio sp. and was employed to evaluate their response to pure antibiotic solutions and to residues extracted from excreta of antibiotic treated pigs and turkeys. The residues were quantified by HPLC analysis. The BLB assay can be proposed as an easy-to-perform screening tool to assess the presence of residues due to undeclared current, or recently ended, pharmacological treatments, as well as to evaluate their permanence in manure.