Contamination of Animal Feed with Undeclared Tetracyclines—Confirmatory Analysis by Liquid Chromatography–Mass Spectrometry after Microbiological Plate Test
Monika Przeniosło-Siwczyńska,
Ewelina Patyra,
Aleksandra Grelik,
Maja Chyłek-Purchała,
Beata Kozak,
Krzysztof Kwiatek
Affiliations
Monika Przeniosło-Siwczyńska
Department of Hygiene of Animal Feedingstuffs, National Veterinary Research Institute, Partyzantow 57 Avenue, 24-100 Pulawy, Poland
Ewelina Patyra
Department of Hygiene of Animal Feedingstuffs, National Veterinary Research Institute, Partyzantow 57 Avenue, 24-100 Pulawy, Poland
Aleksandra Grelik
Department of Hygiene of Animal Feedingstuffs, National Veterinary Research Institute, Partyzantow 57 Avenue, 24-100 Pulawy, Poland
Maja Chyłek-Purchała
Department of Hygiene of Animal Feedingstuffs, National Veterinary Research Institute, Partyzantow 57 Avenue, 24-100 Pulawy, Poland
Beata Kozak
Department of Hygiene of Animal Feedingstuffs, National Veterinary Research Institute, Partyzantow 57 Avenue, 24-100 Pulawy, Poland
Krzysztof Kwiatek
Department of Hygiene of Animal Feedingstuffs, National Veterinary Research Institute, Partyzantow 57 Avenue, 24-100 Pulawy, Poland
The presence of tetracycline (TC) antibiotics was determined in animal feed that had been previously screened with a microbiological plate test. Feed samples were screened by a microbiological plate test on a pH 6.0 culture medium seeded with Bacillus cereus ATCC 11778 able to pre-reveal the presence of tetracyclines. Subsequently, confirmation and quantification were performed using a validated HPLC method with mass spectrometric detection. In 2013–2018, 353 feed samples were analysed to detect antibacterial substances, of which 186 (52.7%) were suspected to contain tetracyclines. Forty-two out of 186 (22.6%) samples analysed by the chromatographic method contained undeclared tetracyclines, which were determined at concentrations from 0.3 to 49 mg kg−1. The most frequently identified contaminating tetracyclines were doxycycline and chlortetracycline.
