ABSTRACT
This study was undertaken to develop new analytical methods for assessment of anticoccidials. High-performance liquid chromatography (HPLC) was found to be a fast, reliable, and practical method. The anticoccidials used in this experiment were toltrazuril and diclazuril, and the analysis factors were specificity, linearity, accuracy, repeatability, and intermediate precision. The linearity of each anticoccidial was better than 0.99, and the accuracies were 99.5% and 99.1% with relative SD of 0.5 and 0.4, respectively. To assess whether the developed HPLC method could be effectively applied, toltrazuril and diclazuril post-market veterinary products (five products) that are currently sold were tested. The results revealed no non-compliant items and the method was applied successfully. Therefore, the newly developed HPLC method for anticoccidial assessment described in this study may be useful as a reference method in the Korean Standards of Veterinary Pharmaceuticals for the analysis of toltrazuril and diclazuril.
Subject(s)
Chromatography, High Pressure Liquid , Chromatography, Liquid , Coccidiostats , Methods , Sensitivity and Specificity , Veterinary DrugsABSTRACT
The effects of diclazuril on the bursa of Fabricius (BF) structure and secretory IgA (SIgA) expression in chickens infected with Eimeria tenella were examined. The morphology of the BF was observed by hematoxylin and eosin staining, while ultrastructural changes were monitored by transmission electron microscopy. E. tenella infection caused the BF cell volumes to decrease, irregularly arranged, as well as, enlargement of the intercellular space. Diclazuril treatment alleviated the physical signs of damages associated with E. tenella infection. The SIgA expression in BF was analyzed by immunohistochemistry technique. The SIgA expression increased significantly by 350.4% (P<0.01) after E. tenella infection compared to the normal control group. With the treatment of diclazuril, the SIgA was relatively fewer in the cortex, and the expression level was significantly decreased by 46.7% (P<0.01) compared with the infected and untreated group. In conclusion, E. tenella infection in chickens induced obvious harmful changes in BF morphological structure and stimulated the expression of SIgA in the BF. Diclazuril treatment effectively alleviated the morphological changes. This result demonstrates a method to develop an immunological strategy in coccidiosis control.
Subject(s)
Animals , Female , Male , Bursa of Fabricius/anatomy & histology , Chickens , Coccidiosis/drug therapy , Coccidiostats/administration & dosage , Eimeria tenella/physiology , Immunoglobulin A, Secretory/genetics , Nitriles/administration & dosage , Poultry Diseases/drug therapy , Triazines/administration & dosageABSTRACT
The experiment was carried out with 150 Cobb broiler chickens divided into 3 groups with 50 birds each. The groups of infected chickens orally received 1ml of inoculum containing 3x103 Eimeria acervulina sporulated oocysts at 12 days of age. Group 1 was kept as a positive control with infected non-medicated birds, group 2 was medicated with diclazuril (1%) with a dose of 1mL/4 L of drinking water for 2 successive days, 5 days after infection, while group 3 was kept as negative control with non-infected and non-medicated birds. Oocysts count per gram of feces, score of macroscopic intestinal lesions and weight gain were evaluated. The group treated with diclazuril showed significant and satisfactory improvement in the assessment criteria when compared to the infected non-medicated group. The results revealed more reduction in the total oocyst count and intestinal lesion score in the medicated than in the infected non-treated group. The results confirmed that (1%) liquid diclazuril is effective to control Eimeria infection.
O experimento foi realizado com 150 frangos de corte da linhagem Cobb, divididos em 3 grupos de 50 aves cada. Os frangos de dois grupos (G1 e G2) receberam, por via oral, 1mL de inóculo contendo 3x103 oocistos de Eimeria acervulina aos 12 dias de idade. O grupo 1 foi mantido como grupo controle positivo (infectado não medicado), o grupo 2 foi medicado com diclazuril (1%) na dose de 1mL/4 litros de água potável por dois dias sucessivos, cinco dias após a infecção. Um terceiro grupo (G3) foi mantido como controle negativo não infectado e não medicado. O número de oocistos por grama de fezes (OOPG), o escore de lesões macroscópicas intestinais e o ganho de peso corporal foram avaliados. No G1, o OOPG foi de 3,67x106 e o peso final foi de 1,392kg, valores significativamente diferentes do OOPG de 1,93x106 oocistos e do peso final de 1,613kg do G2 (diclazuril). Os resultados provaram que o diclazuril (1%) em formulação líquida e na dosagem de 1mL/4 litros de água por dois dias sucessivos foi eficaz no controle de Eimeria acervulina.