Beecher, C,Daly, M,Ross, RP,Flynn, J,McCarthy, TV,Giblin, L

2012

January

Journal of Dairy Science

Characterization of the bovine innate immune response in milk somatic cells following intramammary infection with Streptococcus dysgalactiae subspecies dysgalactiae

Validated

()

mastitis Streptococcus dysgalactiae ssp. dysgalactiae immune response CXCR1 MAMMARY EPITHELIAL-CELLS SINGLE NUCLEOTIDE POLYMORPHISMS STAPHYLOCOCCUS-AUREUS ESCHERICHIA-COLI DAIRY-CATTLE INFLAMMATORY CYTOKINES CLINICAL MASTITIS CXCR2 GENE COW MILK GLAND

95

5720

5729

The innate immune response of milk somatic cells in cows to Streptococcus dysyalactiae ssp. dysgalactiae was investigated by deliberate intramammary challenge. Cows were challenged with 2,500 colony-forming units of Strep. dysgalactiae DPC 5435, previously isolated from a clinical mastitis case. Eight of the 9 cows treated showed clinical signs of mastitis (swollen udders, increased somatic cell score, and clotted milk) within 1 wk of challenge. Messenger RNA levels of IL-beta and toll-like receptor 4 ( TLR4) in milk somatic cells increased approximately 40 fold within 48 h of infusion, whereas tumor necrosis factor a, increased 16 fold within the same time frame. Interestingly, cows homozygous for the G allele of the C-X-C chemokine receptor type 1 (CXCR1)-777 polymorphism had higher IL-8 and CXCRI transcript abundance at 24 h postinfusion compared with cows homozygous for the C allele. The difference in expression of these genes at this critical time point may influence the severity of disease within different genotypes.

DOI 10.3168/jds.2012-5338