The milk proteome and the acute phase response during bovine mastitis

• Main Author: Hogarth, Caroline J.
• Published: University of Glasgow 2004
• Subjects: 636.2089819; SF600 Veterinary Medicine
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410642

The principal aims of the work presented in this thesis were to further investigate the pathophysiology of the acute phase proteins in bovine mastitis and to document the changes in the protein composition of milk during mastitis using modem proteomic methods. Mastitis is one of the most important diseases affecting cattle worldwide. It has adverse effects on the economics of milk production through reducing the quality and quantity of milk. Acute phase proteins (APPs) are valuable markers of inflammatory lesions and are widely used in the veterinary field for disease diagnosis. This study further investigated the presence of APPs, haptoglobin (Hp) 1 I and mammary- associated serum amyloid A3 (M-SAA3) in the milk of cows with mastitis and evaluated the possibility of using these proteins to detect mastitis. An Enzyme linked immunosorbent assay (ELISA) was developed and validated for the measurement of milk Hp. A commercially available ELISA was used for the detection ofM-SAA3 in milk. Both Hp and M-SAA3 showed similar kinetics to somatic cell counts and can be considered as sensitive and reliable markers of mastitis. Advanced proteomic methods were developed and used to further characterise the changes taking place in the proteins expressed in normal and mastitic milk. The methodology for analysis of the bovine milk proteome was successfully established. This part of the work concluded that the patterns of protein expression of clinically mastitic milk showed clear differences from that of normal milk. Further analysis of milk samples from a mild subclinical model of Staphylococcus aureus mastitis showed that alterations to the milk p:oteome were only minimal. However this study was useful in identifying areas worthy of future research. Recent publications on APP research speculate upon the local production ofM-SAA3 in the bovine mammary gland. The final objective of this study was therefore to investigate the expression of MSAA3 in bovine mammary tissue. Our studies confirm the local production of M-SAA3 in the bovine mammary gland and its up-regulation during bovine mastitis. This finding may provide further information on a possible role for this protein. Overall the findings detailed in this thesis indicate that APPs in milk are valuable markers of mastitis and additionally that the ease of collection of milk by non-invasive methods suggest that milk has potential for the discovery of disease biomarkers.