Use of TUNEL staining to detect apoptotic cells in the lungs of cattle experimentally infected with Pasteurella haemolytica

Lung sections taken from calves with experimental Pasteurella haemolytica r espiratory infection exhibited increased numbers of TUNEL positive cells wi th time after challenge. This finding suggests that P. haemolytica, or toxi ns and other components released by the organism, induces apoptosis in bovi ne leukocytes in vivo. By so doing this might impair host defense and contr ibute in part to the severe pneumonia that characterizes bovine pasteurello sis. (C) 1999 Academic Press.