Genetic Impact on the Risk of Intramammary Infection Following Staphylococcus aureus Challenge

摘要: Abstract This study evaluated relationships among intramammary challenge with Staphylococcus aureus , SCC, and susceptibility to infection determined the genetic contribution of special emphasis on bovine lymphocyte antigens. Intramammary S. Newbould 305 was used as a model for natural infection. A total 124 cows were challenged in all quarters 600 cfu 2ml PBS solution. Quarter milk samples bacteriology SCC taken at three times both before after challenge. Lymphocytes separated from whole blood tested standard microlymphocytotoxicity test determine presence antigens class I alleles. One hundred thirteen negative challenge, 11 exhibited positive counts one or more Fifty-three percent became infected Nineteen had no infected; 19 cows, one; 26 two; 25 three; 24 four Average 181,000 758,600. The prior that resisted higher than (282,000 91,000, respectively). reverse true Presence allele CA42, instead EU28 (based gene substitution), increased Heritability estimates experimental low unstable.