1Division of Veterinary Medicine, I.V.R.I, Izatnagar, Bareilly, (U.P)
Animal Health Division, C.I.R.G, Makhdoom, Mathura (U.P)
Online published on 19 December, 2013.
Immunogenic potential of autogenous bacterin was evaluated in mouse model mastitis. A total of twenty one lactating mice were divided into 3 groups comprising of 7 animals each. Group I (healthy control), group II (infected control) and group III (Bacterin treated) animals were used in the experimental trial. Group III animals were administered autogenous bacterin subcutaneously followed by two boosters at an interval of two weeks. Group II and Group III mice were challenged with pathogenic Staphylococcus aureus via intra-mammary route. Effect of autogenous bacterin was assessed at 0, 48 and 96 hours of post challenge (PC). The clinical score, differential leukocyte count (DLC and histological changes in mammary gland were evaluated. Total clinical score (TCS) based on general demeanour and mammary gland inflammation was higher in infected group, whereas significant (P< 0.05) reduction in TCS was observed in bacterin treated group. The relative percentage of lymphocytes decreased significantly in challenged groups II and III, conversely the relative percentage of neutrophils was higher in Group II mice at 96 h PC. Haematoxylin and eosin staining of mammary tissue sections revealed diffused necrosis, complete disintegration of cellular architecture and disruption of lactating alveoli at 96 h PC in infected group II mice, however, focal necrotic patches with less collagenous fibrocellular reaction could be observed in bacterin treated group III mice. Myeloperoxidase positive macrophages and bacterial count was higher (P<0.05) in infected group II mice as compared to bacterin treated Group III mice 96 h PC.
