EVALUATION OF THE PERFORMANCE OF BACILLUS CEREUS FOR ASSAY OF TETRACYCLINES IN CHICKEN MEAT

Abstract

ABSTRACTIn the Kenyan poultry industry, there is lack of affordable and easy‐to‐perform antibiotic residue screening methods. The aim of this study was to determine the limits of detection (LODs) of oxytetracycline (OTC) and evaluate whether it is reliably detectable at maximum residue limits (MRLs) in poultry tissues. Microbiological detection was achieved by agar well diffusion using Bacillus cereus, three medium pH and two poultry organs. Inhibition zones increased significantly (P < 0.001) when OTC was detected at a decreasing pH in both the liver and the kidney. OTC was detected below the MRLs of 600 ng/g in the liver and 1,200 ng/g in the kidney. However, growth media pH and antibiotic concentration affected the LODs. B. cereus plate at pH 7 can be used effectively for routine screening for OTC residues. The LODs were 131.3 ng/mL and 33.4 ng/mL, in the liver and the kidney, respectively.PRACTICAL APPLICATIONSApproximately 14.6 tons of active antibiotics are annually used in food animal production in Kenya. Most of the methods for screening of veterinary drugs in animal products are expensive. This is one of the factors that has contributed to the failure of observance of regulations regarding antibiotic residues in most developing countries. The described method can screen for residues of drugs in chicken meat inexpensively, quickly and with ease. This forms a basis for wider adaptability in the developing world so that unsafe samples can be selected from a majority of samples that do not contain drug residues for further quantitative testing.