Grant R G, Finch J M
Institute for Animal Health, Compton Laboratory, Newbury.
Res Vet Sci. 1997 Jan-Feb;62(1):74-8. doi: 10.1016/s0034-5288(97)90184-3.
The ability of macrophages isolated from the bovine mammary gland to phagocytose and kill Streptococcus uberis was investigated. The strains of S uberis used were selected on the basis of their known resistance (C197C) or sensitivity (EF20) to phagocytosis by bovine peripheral blood neutrophils in the same assay system. Macrophages isolated from mammary secretions collected during the mid-dry period were capable of phagocytosing both strains of S uberis in the presence of serum and skimmed milk. The removal of complement from serum by heat-inactivation did not influence the opsonization of S uberis for phagocytosis by mammary macrophages and both IgG1 and IgG2 isotypes were found to opsonise both strains. The uptake of S uberis into the cells was confirmed by electron microscopy. Potential mechanisms by which S uberis could resist phagocytosis by neutrophils but not by macrophages are discussed.
研究了从牛乳腺分离的巨噬细胞吞噬和杀死乳房链球菌的能力。所使用的乳房链球菌菌株是根据它们在同一检测系统中对牛外周血中性粒细胞吞噬作用的已知抗性（C197C）或敏感性（EF20）来选择的。从干奶中期收集的乳腺分泌物中分离的巨噬细胞在血清和脱脂乳存在的情况下能够吞噬两种乳房链球菌菌株。通过热灭活从血清中去除补体并不影响乳房链球菌被乳腺巨噬细胞吞噬的调理作用，并且发现IgG1和IgG2两种同种型都能调理这两种菌株。通过电子显微镜证实了乳房链球菌被细胞摄取。讨论了乳房链球菌能够抵抗中性粒细胞吞噬但不能抵抗巨噬细胞吞噬的潜在机制。
