The residues of tetracycline antibiotics in food

Određivanje koncentracije antibiotika u uzorcima životinjskog porijekla postalo je nužnim u svrhu zaštite krajnjih potrošača. Polovica upotrijebljenih antibiotika na svjetskoj razini primjeni se pri uzgoju domaćih životinja namijenjenih ljudskoj prehrani te se posljedično rezistentne bakterijske vrste uobičajeno prisutne u peradi, svinja, stoke i zečeva mogu naći u namirnicama namijenjenim ljudima, a kozumacijom istih one koloniziraju gastrointestinalni trakt ljudi i na taj način prenose vlastite rezistentne gene što doprinosi širenju antibiotičke rezistencije. U ovom radu analizirani su rezidui doksiciklina, klortetraciklina, oksitetraciklina i tetraciklina u mišiću goveda, kokoši, kunića, ovaca, patki, purana i svinja primjenom ELISA metode. ELISA metoda ima široku primjenu u određivanju rezidua antibiotika zbog mogućnosti precizne i ponovljive analize uzoraka na prisutnost antibiotika u različitim matriksima u zadovoljavajućem vremenskom periodu. Metoda ELISA je zbog svoje jednostavnosti, prihvatljive cijene analize i lake dostupnosti već dugo uobičajena laboratorijska metoda, a dobiveni rezultati su pokazali iznimnu preciznost i iskorištenje analiziranih uzoraka mišića u koje je bio dodan standard tetraciklinskog antibiotika. U slučaju da se ispitivani uzorak pokaže pozitivnim na tetraciklinski antibiotik u koncentraciji iznad dozvoljene primjenjuje se LC-MS/MS kao potvrdna metoda za dokazivanje prisutnosti antibiotika, zbog potvrđene preciznosti, osjetljivosti te ponovljivosti i linearnosti te metode. Primjenom ELISA metode u ispitivanim uzorcima nije dokazana koncentracija tetraciklinskih antibiotika veća od zakonski propisane te se stoga meso čiji su uzorci ispitani, može upotrijebiti za prehranu ljudi.Determing of antibiotic concentration in animal tissue samples has recently become obligatory with a purpose to protect the final consumers. Half of the antibiotic consumption in the world refers to the use in farming intended for human diet, resulting with contamination of food with resistant bacterial species normally present in poultry, pigs, cattle and rabbits. These bacteria colonize the human gastrointestinal tract carrying over their own resistant genes which contributes to their propagation The residues of doxytetracycline, chlorotetracycline, oxytetracycline and tetracycline in muscle tissue of cattle, chicken, rabbits, sheep, ducks, turkeys and pigs were analyzed in this thesis applying the ELISA method. The ELISA method is widely used in detection of antibiotic residues, due to the ability of precise and repeatable sample analysis regarding the presence of antibiotics in various matrices, in a satisfactory time frame. The ELISA method has been a custom laboratory method for a long period of time, due to its simplicity, acceptable analysis cost and availability. Further more, the results have shown an extreme precision and yield for the analyzed muscle samples in which the tetracycline antibiotic standard was added. In case an analyzed sample shows to be positive to tetracycline antibiotic in a concentration above the allowed limit, LC-MS/MS method is used as an affirmative method for proving of the antibiotic presence, due to its endorsed precision, sensitivity, repeatability and linearity. Applying ELISA method in the test pieces, it has been determined that the tetracycline concentration had been lower than the regulatory limit so the meat used for the testing is safe for consumption