RESUMO
Antibiotic residues in milk are a major health threat for the consumer and a hazard to the dairy industry, causing significant economic losses. This study aims to assess the presence of antibiotic residues in raw milk comparatively by a rapid screening test (BetaStar® Combo) and Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). A total of 445 samples were collected from 3 dairy companies of north-central Algeria (Algiers, Blida, Boumerdes), and they were rapidly screened for ß-lactams and tetracyclines; 52 samples, comprising 34 positive tanker-truck milk and 18 negative bulk-tank milk were tested by LC-MS/MS, which revealed 90.4% were contaminated (n = 47) and 55.3% exceeded the Maximum Residue Limit (MRL). The ß-lactams as parent compounds and their metabolites were the most frequently detected with maximum value for cloxacillin (1231 µg/kg) and penicillin G (2062 µg/kg). Under field condition, the false-positive results, particularly for tetracyclines, seems to be related to milk samples displaying extreme acidity values (≥19°D) or fat-level fluctuations (2.7 g/100 mL and 5.6-6.2 g/100 mL). Despite a relatively low prevalence (7.64%) of residues using the rapid test, the detection by LC-MS/MS of flumequine (52 µg/kg), cefaclor (maximum 220 µg/kg) and metabolites of ß-lactams at high levels should lead to reflections on the control of their human and environmental toxicological effects.
RESUMO
Resumen En esta publicación se describe el manejo y la evolución clínica de un carcinoma mamario felino (CMF) maligno en una gata mestiza de ocho años de edad con un trastorno congénito. La eficacia de la extirpación de la masa tumoral y el pronóstico del caso se establecieron mediante el examen histológico de rutina postoperatorio. Tras una mastectomía completa se extirpó un bulto de 6 cm de diámetro en la glándula mamaria torácica izquierda de aspecto multinodular y exudado purulento de coloración rojiza. El análisis histopatológico mostró la presencia de numerosos émbolos tumorales linfovasculares y células con alta frecuencia de figuras mitóticas con núcleos hipercromáticos. Estos hallazgos fueron consistentes con una neoplasia agresiva de mal pronóstico, lo que explicaba el fallecimiento de la paciente a las 7 semanas de la cirugía. Los hallazgos histológicos y citológicos son de importancia crítica para los clínicos en el manejo de las neoplasias mamarias más comunes en los gatos, con el fin de aliviar de la mejor manera posible a los animales con cánceres que amenazan su vida. También podría servir como modelo de cáncer para avanzar en el conocimiento de patologías similares en otras especies.
Abstract This report describes the handling and clinical evolution of a malignant feline mammary carcinoma (FMC) in an eight-year-old female crossbred cat with a congenital disorder. Hence, the efficacy of tumor mass removal and the case prognosis was established by postoperative routine histological examination. A 6 cm diameter lump in the left thoracic mammary gland of multinodular appearance and purulent exudate with a reddish hue was excised after the entire mastectomy. The histopathological analysis showed the presence of numerous lymphovascular tumor emboli and frequently mitotic cells with hyperchromatic nuclei. These were consistent with an aggressive malignancy with a poor prognosis explaining the patient's death within 7 weeks after surgery. Histology and cytology findings are of critical importance to clinicians in the management of the most common mammary malignancies in cats, to provide the best possible relief to animals with life-threatening cancer. It could also serve as a cancer model for advancing knowledge in congenitally affected humans.
