Abstract
ABSTRACT :
Mastitis is the most costly disease for dairy farmers and industry, which are mainly ensued by the entry of bacteria of the teat canal . Shortly after the entry of the invading bacteria, the innate immunity recognize the invading pathogen through pattern recognition receptors and initiates the inflammatory response necessary to eliminate the invading bacteria . This initial inflammatory response release cytokines and chemo attractants for the rapid and massive influx of neutrophils from the blood to the site of infection which form the first line of cellular defense against bacteria .
In order to characterize the expression of gene associated with immune response mechanism to mastitis we quantified the relative expression of the IL-6, IL-8, IL-10 and IL-4 genes in milk somatic cells of cows with clinical mastitis . The mRNA abundance of a target gene was calibrated with that of a reference gene (B-Actin) and expressed as fold of induction, the average fold induction of all target cytokine genes was increased in response to bacterial infection, up regulated expression of cytokine-genes with S. aureus mastitis .
These finding suggest that animals with mastitis develop a preferentially cell mediated immune response,further study including number of samples are necessary to better characterize the gene expression profile in caws with S. aureus mastitis .

Key words: cytokines, gene expression, bovine mastitis milk