Changes in the mucopolysaccharide composition of mucus in ileal mucosal goblet cells from cattle infected with Mycobacterium avium subspecies paratuberculosis.

摘要

Samples of ileum from 34 Holstein and Jersey cows from 5 herds naturally infected with paratuberculosis were examined using bacterial cultures and histochemical methods. The mucopolysaccharide composition of mucus formed in goblet cells of ileal mucosa was determined by staining samples of the mucosa with alcian blue at pH 2.5 and PAS reaction. The staining allowed neutral mucins and glycoproteins to be distinguished from sialomucins and mixed mucins. In the ileal goblet cells from 13 cows in whichno M. avium subsp. paratuberculosis was detected, neutral mucins and glycoproteins formed the major component of mucus. Mixed mucins were present less frequently and sialomucins least frequently. In 13 cows with subclinical paratuberculosis the number of goblet cells with neutral mucins and glycoproteins increased and the number of goblet cells with sialomucins and mixed mucins decreased. Sialomucins were never present in 8 cows with clinical paratuberculosis; the level of mixed mucins decreased and neutral mucins and glycoproteins prevailed. Flattening and diminution of the goblet cells of ileal mucosa were observed in cows with clinical paratuberculosis.