Impact of intramammary treatment on gene expression profiles of bovine mammary gland tissue after challenge with E. coli

The benefit of treatment in mild to moderate cases of E. coli mastitis in dairy cows remains a topic of discussion. We investigated the effect of intramammary treatment with Cefapirin + Prednisolone compared to Cefapirin only on gene expression profiles in experimentally induced E. coli mastitis. Five midlactating Holstein Friesian cows were challenged with 100 CFU in 3 quarters and treated with Cefapirin only in one quarter and the combination of Cefaprirn and Prednisolne in another quarter at 4, 12, 24 and 36h post challenge. After 24h (n=2) or 48h (n=3) post challenge cows were sacrificed and mammary gland tissue was collected from each quarter. From each cow total RNA of one non challenged quarter, one challenged not treated quarter, on Cefapirin treated and one Cefapirin + Prednisolone treated quarter was subjected to microarray analysis. Data were analyzed separately for the two sample time points