[Experimental udder infections with Escherichia coli. 4. Discussion of the pathogenesis of acute mastitis].

The correlations among findings obtained from experimental Escherichia coli udder infection and reported in the three previous communications are discussed in this paper. The defence capabilities elucidated included specific and unspecific activities of non-epithelial cells, primarily neutrophilic granulocytes, macrophages, lymphocytes, plasma cells, and mast cells, as well as the capability of epithelial cells proper of absorbing pathogenic material from lumens of lactiferous ducts and milk cisterns and of storing such material within intracytoplasmic vacuoles. Hence, alterations in the course of pathogenesis of acute coli mastitis were found to be of complex nature and could be properly followed up by their morphological patterns.