Lorian V, Atkinson B
Antimicrob Agents Chemother. 1980 Nov;18(5):807-13. doi: 10.1128/AAC.18.5.807.
Twelve strains of Staphylococcus aureus isolated from patients and two collection strains were grown on membranes placed on agar containing subminimal inhibitory concentrations of oxacillin. Clusters of staphylococci held together by thick cross walls resulted. These organisms, as well as the same strains grown in the same way on drug-free medium (control), were eluted from the membranes and were incubated with human polymorphonuclear leukocytes (PMNs) from various donors. Phagocytosis was comparable for both staphylococci exposed to oxacillin and control staphylococci, but the killing effect was different. The staphylococci grown on membranes in the presence of oxacillin were less susceptible to killing than the control staphylococci, but the killing effect was different. The staphylococci grown on membranes in the presence of oxacillin were less susceptible to killing than the control staphylococci. After 0.5 and 1 h of incubation with PMNs, the killing rates for oxacillin-grown versus control staphylococci were 52 and 70% and 65 and 85%, respectively (P < 0.01). After 2 and 3 h of incubation, the killing was similar. Most clusters of staphylococci contain a few individual cells that are located in the center of the cluster and are surrounded by other staphylococci; therefore, they are protected from adverse agents in the environment. This could explain why the phagocytized clusters are less susceptible than control staphylococci to the killing effect of PMNs during the first hour of incubation. Oxacillin does not penetrate into PMNs and in the absence of the drug the cross walls lyse, liberating the constituent staphylococci. This coincides with the increase in the percentage of cluster killing by PMNs after 2 and 3 h of incubation.
从患者体内分离出的12株金黄色葡萄球菌菌株和2株标准菌株，在含有亚最小抑菌浓度苯唑西林的琼脂平板上的滤膜上培养。结果形成了由厚的交叉壁连接在一起的葡萄球菌簇。这些菌株以及在无药培养基（对照）上以相同方式培养的相同菌株，从滤膜上洗脱下来，并与来自不同供体的人多形核白细胞（PMN）一起孵育。暴露于苯唑西林的葡萄球菌和对照葡萄球菌的吞噬作用相当，但杀伤效果不同。在苯唑西林存在下于滤膜上生长的葡萄球菌比对照葡萄球菌更不易被杀伤。与PMN孵育0.5小时和1小时后，苯唑西林处理组与对照组葡萄球菌的杀伤率分别为52%和70%以及65%和85%（P<0.01）。孵育2小时和3小时后，杀伤情况相似。大多数葡萄球菌簇包含一些位于簇中心且被其他葡萄球菌包围的单个细胞；因此，它们受到环境中不利因素的保护。这可以解释为什么在孵育的第一个小时内，被吞噬的葡萄球菌簇比对照葡萄球菌更不易受到PMN的杀伤作用。苯唑西林不会渗透到PMN中，在没有药物的情况下，交叉壁会溶解，释放出组成葡萄球菌。这与孵育2小时和3小时后PMN对葡萄球菌簇杀伤百分比的增加相吻合。
