Differential proteomics analysis of plasma protein from Staphylococcus aureus mastitic and healthy dairy cows | 金黄色葡萄球菌乳房炎奶牛血浆的比较蛋白质组研究

Chinese. 为了分析金黄色葡萄球菌(Staphylococcus aureus)自然感染引起的隐性乳房炎奶牛血浆蛋白的表达变化，经细菌培养分离鉴定了乳中金黄色葡萄球菌，选择其感染的奶牛。采用二维凝胶电泳技术分离了临床健康奶牛和乳房炎奶牛的血浆蛋白，考马斯亮蓝G-250染色后PDQuest 8.0软件检测差异表达蛋白点，高效液相色谱串联离子阱质谱鉴定。结果发现，金黄色葡萄球菌乳房炎奶牛血浆中有10个蛋白点的表达量发生改变，其中6个蛋白点经质谱鉴定为结合珠蛋白、转甲状腺素蛋白和α1酸性糖蛋白等4种蛋白。金黄色葡萄球菌感染可造成奶牛血浆结合珠蛋白、α1酸性糖蛋白和血清淀粉样蛋白A的表达量增加。ELISA法测定血浆结合珠蛋白的结果也发现，金黄色葡萄球菌感染奶牛血浆结合珠蛋白水平显著高于健康牛(P0.01)。结果提示乳房炎奶牛血浆蛋白的变化可为揭示金黄色葡萄球菌感染乳腺炎症的应答提供依据。

English. The purpose of our study was to investigate the changes of plasma protein from the cows infected with Staphylococcus aureus. Dairy cows shown to be S. aureus-positive on bacteriological culture of milk from all 4 quarters, were classified as S. aureus subclinical mastitis. Two-dimensional gel electrophoresis was used to separate plasma protein from S. aureus subclinical mastitis and healthy dairy cows, and stained with Coomassie Blue G-250 solution. Differential expression proteins were detected by PDQuest 8.0 software and identified by ion trap mass spectrometer. The results showed that the ten protein spots were changed in cows subclinically infected with S. aureus mastitis, and six spots were identified as four proteins including haptoglobin, alpha 1 acid glycoprotein, transthyretin and serum amyloid protein A. Haptoglobin, alpha 1 acid glycoprotein, and serum amyloid protein A were up-regulated in plasma from S. aureus infected cows. ELISA detection of plasma haptoglobin showed that expression of haptoglobin was significantly higher in S. aureus infected cows than that in healthy controls (P0.01). Dairy cows infected with S. aureus mastitis altered the protein level in plasma suggested that these differential proteins may be useful to clarify the host defense mechanisms and the response to invasion of mammary tissues by S. aureus mastitis.