Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 30, 2009
Publication Date: N/A
Mastitis remains one of the most prevalent and costly disease affecting the dairy industry worldwide. Escherichia coli intramammary infection elicits localized and systemic responses. Increase in milk somatic cell count, inflammatory cytokines, and acute phase proteins are well described but less is known regarding the profile of gene expression in the mammary gland during the infection. Our objective was to characterize gene expression patterns that become activated in different regions of the mammary gland during the acute phase of experimentally induce E. coli mastitis using microarray, quantitative Real Time PCR, and network analysis. Tissues evaluated were from Fürstenburg’s rosette, teat cistern, gland cistern, and lobulo-alveolar regions of control and infected mammary glands, 12 and 24 h after bacterial (or PBS) infusion. The main networks activated by E. coli infection pertained to immune and inflammatory response, with mark induction of genes encoding proteins that function in chemotaxis, leukocyte activation and signaling. Genomic response was greater in tissues of the teat cistern and gland cistern at 12 h post-infection, while tissues of the lobulo-alveolar region responded only, and most strongly of the regions, 24 h following the infection. Similar genetic networks were impacted in all regions during early phases of intramammary infection, although regional differences throughout the gland were noted. Data support an important sentinel function for the teat, as these tissues responded rapidly and intensely, with production of cytokines and anti microbial peptides.