A total of 376 quarter milk samples collected from dairy cows affected with clinical mastitis and contact apparently normals were tested by California mastitis test (CMT) and cultured bacteriologically. Out of 165 mastitic quarter samples, 162 (98.1%) were bacteriologically positive. Staphylococcus aureus was isolated from 31.5% of the samples, Streptococcus agalactiae (16.4%). Streptococcus dysgalactiae (15.2%); E.coli (12.7%). Coagulase-negative Staphylococcus (10.3%). Klebsiella pneumoniae (7.3%), Pseudo- monas aeruginosa (3.0%), Actinomyces pyogenes (1.8%) and 3 cases were bacteriologically negative(1.8%) .In subclinical mastitis cases, 103 out of 119 samples were bacteriologically positive (86.6%), whereas 16 samples (13.4%) were negative. Adhesion-associated virulence characteristics of isolates (adhesins and hydrophobic activity) revealed that, S. agalactiae expressed the Highest adherence pattern to bovine udder epithelium cells (72.2±36.5 bacteria/cell), followed by S. aureus (67.4±16.3) and S. dysgalactiae (68.9±28.8), while A. pyogenes showed the lowest attachement tendency (42.9±12.6). For hydro- phobic surface-protein activity, the highest hydro- phobic activity was expressed by S. aureus (74.4 (12.4%) followed by S. agalactiae (68.5±24.7%) whereas K. pneumoniae expressed the lowest hydrophobic activity (5.3±2.6%). The resistence of isolates to phagocytosis by milk leucocytes, revealed that S. aureus showed the highest resistance to phagocytosis (8.4±2.4 bacteria/cell) while coagulase-negative staphylococci showed the lowest resistance (64.7±19.8 bacteria/cell).
The biochemical analysis of the whey protein of mastitic milk revealed a significant increase in the total whey protein by 10-13%. Lactoferrin in- creased by two to three folds. Serum albumin elevated by four-folds. Immunoglobulins increases