Phagocytosis of mastitis isolates of Staphylococcus aureus and expression of type 5 capsular polysaccharide are influenced by growth in the presence of milk

作者：Laurent Sutra, Pascal Rainard, B. Poutrel · 发表于：Journal of Clinical Microbiology · 年份：1990 · DOI：10.1128/jcm.28.10.2253-2258.1990 · 被引用次数：52 · 研究领域：Milk Quality and Mastitis in Dairy Cows、Antimicrobial Peptides and Activities、Probiotics and Fermented Foods

Phagocytosis by bovine polymorphonuclear granulocytes of seven capsular polysaccharide type 5 Staphylococcus aureus strains isolated from mastitis [corrected] was investigated by means of luminol-dependent chemiluminescence. Bacteria were grown on four different agar media (brain heart infusion, Columbia broth, modified staphylococcus medium 110, and skim milk) and were opsonized by normal bovine serum. When compared to growth on brain heart infusion agar, Columbia agar, and modified staphylococcus medium 110 agar, growth on skim milk agar rendered five of the strains more resistant to opsonization. The other two strains were resistant in all culture media used. Short periods of incubation in milk after growth on brain heart infusion agar did not augment resistance to phagocytosis, indicating that mere adsorption of milk components on bacteria was not responsible. The variability of the chemiluminescence response of polymorphonuclear leukocytes was pronounced among strains with each growth medium except milk. Growth on modified staphylococcus medium 110 and on milk agar favored the masking of teichoic acid, as shown by inagglutinability with rabbit antiserum. Interestingly, agglutination by a monoclonal antibody to capsular polysaccharide type 5 was optimal when bacteria were grown on skim milk agar. This suggests that capsular polysaccharide participated in the masking effect. These findings indicate that masking of the bacterial target of most of the naturally acquired opso...