Role of TGF-β in pathology of Staphylococcus aureus induced chronic mastitis in mice Hingade Sonal4, Nagdive A.1,4, Pantawane P.2,4, Kesavan M.3,4, Karikalan M.4, Rai R.B.4, Sharma A.K.4,* 4Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly-243122, Uttar Pradesh, India. 1Division of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly-243122, Uttar Pradesh, India. 2Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly-243122, Uttar Pradesh, India. 3Division of Pharmacology And Toxicology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly-243122, Uttar Pradesh, India. *Corresponding author: e-mail: aksharmaivri@rediffmail.com
Abstract The aim of the present investigation was to study sequential histopathological changes and the role of transforming growth factor-β (TGF-β) in Staphylococcus aureus induced chronic mastitis in mice. The lactating female Swiss albino mice were inoculated by intramammary routeof 100 pl of inoculum containing 107cfu of a field strain of Staphylococcus aureus isolated from bovine mastitis case. The mammary gland tissue samples were collected at 1,5,10,20, 30, 40 and 50 days post infection (DPI) and subjected to histopathological and immunohistochemical assessment of TGF-β. The histopathological study at 1 DPI showed congestion, edema and infiltration of inflammatory cells predominantly the neutrophils in interstitium as well as in alveoli. As infection became more chronicwith passing of time, the expression of TGF-β kept upregulated correspondingly from 1.00±0.29 fold at 1 DPI to 2.86±0.06 folds at 50 DPI. The alveoli exhibited necrosis, desquamation of glandular epithelial lining in acute phase to atrophy of alveoli, increased interalveolarfibroplasia with or without suppurative changes and infiltration of macrophages, lymphocytes, plasma cells in interstitium of alveoli in chronic phase. The immunohistochemical expression of TGF-β was moreintense in cytoplasm of lymphocyte, macrophages and fibrocytesin mammary gland tissue during chronic phase. Thus, the level of TGF-β was found positively correlated both qualitatively and quantitatively with degree of chronicity and fibrosis in glandular parenchyma making the gland sclerosed and non-functional due to Staphylococcus aureus infection. Top Keywords Fibrosis, Mastitis, Mice, Staphylococcus aureus, TGF-β. Top |