Centro de Pesquisa em Alimentos, Universidade Federal de Goiás , Goiânia, GO , Brasil.
Braz J Microbiol. 2012 Apr;43(2):692-7. doi: 10.1590/S1517-83822012000200034. Epub 2012 Jun 1.
The identification of dairy cows with greater or lower potential to develop mastits has been pursued for many years among different segments of the milk industry, including governmental organizations. Genomic studies have suggested that Single Nucleotide Polymorphisms (SNPs) within the pattern recognition receptors (PRR) could lead to different responses to pathogens, and consequently result in mastitis resistance or susceptibility. To investigate whether toll like receptor 4 (TLR4) gene is associated with subclinical mastitis in Holstein cows from a property in the state of Goiás, Brazil, TaqMan allelic discrimination and somatic cell count were performed. One hundred and fifty milk samples were analyzed for SCC and centesimal composition. Twenty percent of those samples with SCC above 200,000 (n=13) were screened for real-time PCR identification of microorganisms and blood samples were genotyped for TLR4 SNPs. There was a higher prevalence of Gram-positive bacteria in the analyzed samples (88.9%) and animals that had the combined genotypes AACCCC, GGTCGG and GACCGC presented the lowest somatic cell scores, and consequently those genotypes have the potential to be applied as molecular markers for assisted animal selection to improve milk quality.
多年来，包括政府组织在内的许多牛奶行业的不同领域都在努力寻找具有更高或更低患乳腺炎潜力的奶牛。基因组研究表明，模式识别受体 (PRR) 中的单核苷酸多态性 (SNP) 可能导致对病原体的不同反应，从而导致乳腺炎的抗性或易感性。为了研究巴西戈亚斯州一个牧场的荷斯坦奶牛的 toll 样受体 4 (TLR4) 基因是否与亚临床乳腺炎有关，进行了 TaqMan 等位基因鉴别和体细胞计数。对 150 份 SCC 和百分组成的牛奶样本进行了分析。在 SCC 高于 200,000 的那些样本中，有 20%（n=13）进行了实时 PCR 微生物鉴定筛选，同时对血液样本进行 TLR4 SNP 基因分型。分析样本中革兰氏阳性菌的患病率更高（88.9%），并且具有 AACCCC、GGTCGG 和 GACCGC 组合基因型的动物的体细胞评分最低，因此这些基因型有可能作为辅助动物选择的分子标记，以提高牛奶质量。
