Aarestrup F M, Scott N L, Sordillo L M
National Veterinary Laboratory, Copenhagen, Denmark.
Infect Immun. 1994 Dec;62(12):5679-82. doi: 10.1128/iai.62.12.5679-5682.1994.
This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare genotype. The interaction between bacteria and neutrophils was measured by phagocytosis and bactericidal effect. The average percent killing of bacteria was lowest (40.0%) with strains belonging to the most common genotype, medium (50%) with strains belonging to the intermediate type, and highest (64.2%) with strains belonging to the rare type (P < or = 0.001). Statistically significant differences (P < or = 0.001) in the numbers of phagocytized bacteria were also found between the most prevalent type (6.27 bacteria per cell) and the other two types (intermediate type, 9.26/cell; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils.
本研究调查了中性粒细胞对从患乳腺炎奶牛分离出的不同基因型金黄色葡萄球菌的功能作用。研究选用了6株金黄色葡萄球菌，其中2株具有常见基因型，2株具有中间基因型，2株具有罕见基因型。通过吞噬作用和杀菌作用来测定细菌与中性粒细胞之间的相互作用。属于最常见基因型的菌株对细菌的平均杀灭率最低（40.0%），属于中间类型的菌株为中等（50%），属于罕见类型的菌株最高（64.2%）（P≤0.001）。在吞噬细菌数量方面，最常见类型（每个细胞吞噬6.27个细菌）与其他两种类型（中间类型，每个细胞吞噬9.26个；罕见类型，每个细胞吞噬10.5个）之间也存在统计学上的显著差异（P≤0.001）。这些发现表明，乳腺中金黄色葡萄球菌不同基因型流行率存在差异的原因之一是某些类型具有更强的抵抗牛中性粒细胞吞噬和/或杀灭的能力。
