Kelsey J A, Bayles K W, Shafii B, McGuire M A
Department of Animal and Veterinary Science, College of Agriculture and Life Sciences, University of Idaho, Moscow, Idaho 83844, USA.
Lipids. 2006 Oct;41(10):951-61. doi: 10.1007/s11745-006-5048-z.
Staphylococcus aureus causes a variety of human infections including toxic shock syndrome, osteomyelitis, and mastitis. Mastitis is a common disease in the dairy cow, and S. aureus has been found to be a major infectious organism causing mastitis. The objectives of this research were to determine which FA and esterified forms of FA were inhibitory to growth of S. aureus bacteria. FA as well as their mono-, di-, and triacylglycerol forms were tested for their ability to inhibit a human toxic shock syndrome clinical isolate (MN8) and two S. aureus clinical bovine mastitis isolates (305 and Novel). The seven most potent inhibitors across all strains tested by minimum inhibitory concentration analysis included lauric acid, glycerol monolaurate, capric acid, myristic acid, linoleic acid, cis-9, trans-11 conjugated linoleic acid, and trans-10, cis-12 conjugated linoleic acid. Some of these lipids were chosen for 48-h growth curve analysis with a bovine mastitis S. aureus isolate (Novel) at doses of 0, 20, 50, and 100 microg/mL except myristic acid, which was tested at 0, 50, 100, and 200 microg/mL. The saturated FA (lauric, capric, myristic) and glycerol monolaurate behaved similarly and reduced overall growth. In contrast, the polyunsaturated FA (linoleic and cis-9, trans-11 conjugated linoleic acid) delayed the time to initiation of exponential growth in a dose-dependent fashion. The results suggest that lipids may be important in the control of S. aureus during an infection.
金黄色葡萄球菌可引发多种人类感染，包括中毒性休克综合征、骨髓炎和乳腺炎。乳腺炎是奶牛的常见疾病，已发现金黄色葡萄球菌是导致乳腺炎的主要感染源。本研究的目的是确定哪些脂肪酸（FA）及其酯化形式对金黄色葡萄球菌的生长具有抑制作用。测试了脂肪酸及其单酰基甘油、二酰基甘油和三酰基甘油形式抑制人类中毒性休克综合征临床分离株（MN8）以及两种金黄色葡萄球菌临床牛乳腺炎分离株（305和Novel）的能力。通过最低抑菌浓度分析，在所有测试菌株中最有效的七种抑制剂包括月桂酸、甘油单月桂酸酯、癸酸、肉豆蔻酸、亚油酸、顺-9，反-11共轭亚油酸和反-10，顺-12共轭亚油酸。除肉豆蔻酸在0、50、100和200μg/mL剂量下进行测试外，选择其中一些脂质以0、20、50和100μg/mL的剂量与牛乳腺炎金黄色葡萄球菌分离株（Novel）进行48小时生长曲线分析。饱和脂肪酸（月桂酸、癸酸、肉豆蔻酸）和甘油单月桂酸酯表现相似，均降低了总体生长。相比之下，多不饱和脂肪酸（亚油酸和顺-9，反-11共轭亚油酸）以剂量依赖的方式延迟了指数生长期开始的时间。结果表明，脂质在感染期间对金黄色葡萄球菌的控制中可能很重要。
