Residuos de enrofloxacina y ciprofloxacina en músculo de pollos parrilleros

Resumen Las fluoroquinolonas son antimicrobianos de uso intensivo en medicina veterinaria. En Argentina la enrofloxacina es empleada en planteles avicolas y porcinos. La Ciprofloxacina, es un metabolito de la anterior que es empleada en medicina humana y es considerada una alternativa en medicina veterinaria. Niveles de residuos de enrofloxacina y ciprofloxacina se determinaron en forma simultanea en musculo de pollos naturalmente infectados con Mycoplasma spp. y tratados con estos antimicrobianos (5 mg/kg/12h oral) durante 5 dias. El objetivo de este trabajo fue establecer el momento adecuado de sacrificio de los animales, para su comercializacion en buenas condiciones clinicas y niveles aceptables de residuos. Se sacrificaron animales a cinco tiempos pos- tratamiento; 200 mg de musculo pectoral homogeneizados en buffer fosfato se desproteinizaron, evaporaron y eluyeron por cromatografia liquida de alta presion con deteccion por fluorescencia. La concentracion de residuos de enrofloxacina fue maxima a las 24 h de finalizado el tratamiento (0.073  + 0.006 mg/g), inferior al limite maximo de residuos establecido por entes reguladores internacionales (0.3 mg/g). Los niveles maximos (0.027  + 0.015 mg/g) se detectaron para ciprofloxacina a las 72 h. Es necesario desarrollar y examinar metodos simples y precisos para cuantificar residuos en diferentes productos y tejidos comestibles, promover la aplicacion de buenas practicas agricolas y elaborar regulaciones pertinentes. Palabras Clave: fluoroquinolonas, HPLC (cromatografIa liquida de alta presion), micoplasmosis, residuos. Summary Fluoroquinolones are antimicrobials of intensive usage in veterinary medicine. In our country enrofloxacin is employed in poultry and pig production. Ciprofloxacin, the mayor metabolite of enrofloxacin, is a useful resource in human medicine and one alternative for farm animals. Both antimicrobials were simultaneously detected in muscle of chickens naturally infected with Mycoplasma synoviae and administrated with enrofloxacin or ciprofloxacin (5mg/kg/12h oral) for 5 days. The purpose of this work was to determine the adequate slaughter moment of the animals, with good clinical conditions and acceptable residue levels. The animals were sacrificed at 5 times after treatment. The samples (200 mg) were homogenized in phosphate buffer, and extracted twice with dichloromethane. The fluoroquinolones were detected by high performance liquid chromatography with fluorescence detection at 295 nm excitation and 500 nm emission. The concentration of enrofloxacin residues was maximal at 24 h after treatment (0.073 + 0.006 Ig/g) and was lower than the maximal limit levels established by international regulations (0.3 Ig/g). In ciprofloxacin administrated animals the superior concentration of the antimicrobial in muscle was 72 h after treatment with 0.027 + 0.015 Ig/g. The consumers and the authorities must be concern about the control of veterinary residues in different products and edible tissues of farm animals. Key words: fluoroquinolones, HPLC (high pressure liquid chromatography), mycoplasmosis, waste.