Studies on the Coliform Mastitis I. Histopathological Observation on Experimentally Induced Escherichia coli Mastitis in Rabbits

Han, Du Seik; Lee, Cha Soo

Korean Journal of Veterinary Research 1981;21(1):33-40.

Du Seik Han¹, Cha Soo Lee²

¹Department of Sanitation, Won Kwang Public Health Junior College
²Department of Veterinary Medicine, College of Agriculture, Gyeongbug National University

Coliform 유방염(乳房炎)에 관한 연구(硏究) 1. Escherichia coli에 의(依)한 유방염(乳房炎)의 실험병리학적(實驗病理學的) 관찰(觀察)

한두석¹, 이차수²

¹원광보건전문대학 위생학과
²경북대학교 농과대학 수의학과

Abstract

In order to clarify the morphological changes in the mammary glands of cows affected with coliform (Escherichia coli) mastitis, histopathological observations were undertaken on the mastitis of the lactating rabbits which was experimentally induced with E. coli or its endotoxin isolated from cases of acute and chronic matitis in dairy cattle. In the bacterial suspension-infused groups the affected quarters of udder showed cloudy swelling, hyperemia and hemorrhage to local necrosis and firmness. The microscopic findings of early stage of the mastitis were appearance of large numbers of heterophils in the glandular lumina and ducts accompanied by degeneration, necrosis and desquamation of epithelial cells, and also infiltration of heterophils, hemorrhage and edema in the interstitial tissue, and destruction of alveoli. Later, proliferation of firoblasts, plasma cells, lymphocytes, eosinophils and histiocytes appeared in the glandular tissue and necrotic foci of glandular tissue were surrounded by highly proliferated connective tissue. Granuloma-like inflammatory changes could be observed in the glandular tissue on the 7th days after infusion. The inflammatory response in the group infused with E. coli strain isolated from the natural case of acute mastitis was rapid and severe as compared with that of chronic mastitis. In the endotoxin-infused group the morphological changes were similiar to those of the bacterial suspension-infused groups.