Dionysius D A, Grieve P A, Milne J M
International Food Institute of Queensland, Queensland Department of Primary Industries, Hamilton, Australia.
J Dairy Sci. 1993 Sep;76(9):2597-600. doi: 10.3168/jds.S0022-0302(93)77594-3.
The antibacterial effects of various forms of lactoferrin on enterotoxigenic strains of Escherichia coli were tested in vitro using a microassay for bacterial growth. Native and apo-lactoferrin exhibited variable activity against 19 strains, whereas holo-lactoferrin had no effect. At a concentration of .2 mg/ml of apo-lactoferrin, strains could be distinguished as either sensitive or resistant to inhibition. Zinc-saturated lactoferrin was as inhibitory as apo-lactoferrin when sensitive and resistant strains were tested over the concentration range .04 to 1.0 mg/ml of lactoferrin. A bactericidal effect was observed for native, apo-, and Zn-saturated lactoferrin against some sensitive strains. The antibacterial activity of apo-lactoferrin depended on bacterial inoculum size and was not enhanced by the addition of lysozyme. Addition of holo-lactoferrin or cytochrome c diminished the antibacterial effect of apo-lactoferrin, whereas addition of BSA had no effect. Resistance to inhibition by lactoferrin was not related to the production of bacterial siderophores.
使用细菌生长微量测定法在体外测试了各种形式的乳铁蛋白对产肠毒素大肠杆菌菌株的抗菌作用。天然乳铁蛋白和脱铁乳铁蛋白对19株菌株表现出不同的活性，而全铁乳铁蛋白则无作用。在脱铁乳铁蛋白浓度为0.2mg/ml时，菌株可分为对抑制敏感或耐药。当在0.04至1.0mg/ml乳铁蛋白的浓度范围内测试敏感和耐药菌株时，锌饱和乳铁蛋白与脱铁乳铁蛋白的抑制作用相同。观察到天然、脱铁和锌饱和乳铁蛋白对一些敏感菌株有杀菌作用。脱铁乳铁蛋白的抗菌活性取决于细菌接种量，并且添加溶菌酶不会增强其抗菌活性。添加全铁乳铁蛋白或细胞色素c会降低脱铁乳铁蛋白的抗菌作用，而添加牛血清白蛋白则无作用。对乳铁蛋白抑制作用的耐药性与细菌铁载体的产生无关。
