Tylosin [KLH]

Introduction: The authorisation of tylosin as feed additive was withdrawn for reasons of human health concerning resistance of pathogenic bacteria. An analytical method for the identification and quantification of tylosin in animal feed was developed and validated. Material and Methods: The samples were extracted using an acidified methanol:water mixture and solid-phase extraction was employed for the isolation of the antibiotic from diluted feed samples. Tylosin was analysed by liquid chromatography with electrospray ionisation mass spectrometric detection. The method's performance was evaluated in adherence to the Commission Decision 2002/657/EC. Results: The recovery of the analyte from spiked samples was determined to be in the range from 78.9% to 108.3% depending on tylosin concentrations. The CC alpha and CC beta values for tylosin in feeds were determined at 0.085 mg kg(-1) and 0.091 mg kg(-1), respectively. The method detection limit was found to be 0.035 mg kg(-1) and the quantification limit 0.05 mg kg(-1). The applicability of the developed method was tested by analysing real feed samples. Conclusion: A reliable LC-MS method was developed to identify and quantify tylosin in animal feed with a good repeatability and a high specificity and sensitivity. Because of these characteristics, the proposed method is applicable and could be deemed necessary within the field of feed control and safety.

The World Health Organization has identified antimicrobial resistance as one of the most important threats to global health. Brazil is one of the world's leading meat producers and the Brazilian use of veterinary antimicrobials as therapeutic agents and prophylactic or growth promoters in animal production remains problematic. Many antimicrobials are not completely metabolized and their excretion represents a significant source of environmental exposure. The aim of this work was to estimate the exposure risk of soil and groundwater to pollution by growth promoters (GPs) and anticoccidial additives (AAs) in Brazil by using a method based on a geographical information system(GIS). The principle adopted is that the greater the amount of animals, the greater the quantity of antimicrobials present, and the greater the soil vulnerability to pollution. Our research showed that GPs and AAs are extensively used in the Brazilian animal production system. An analysis of market data showed that zinc bacitracin, monensin, salinomycin, colistin and tylosin are representative GPs and AAs. This study presents a qualitative approach for risk assessment based on worst-case scenarios. First, the probable environmental concentration was estimated using a correlation between the number of heads of the herds of poultry and cattle, and the amounts of drug released. The leaching risk potential was characterized for each compound, as proposed in ISO 15175. The potential of soil pollution was evaluated for each antimicrobial as a function of its binding and dissipation rates. These rates were calculated using georeferenced data of organic carbon, average temperature, water balance and hydro-geological parameters. The consequences were modeled based on Brazilian soil usage. Finally, the risk was calculated by combining the different maps generated using spatial multi-criteria decision analysis. Higher risk was found for the midwest, southeast and south regions of Brazil. Groundwater was found to be more vulnerable than soil. (C) 2018 Published by Elsevier B.V.