Braga P C, Sala M T, Mancini L, Da Sasso M
Department of Pharmacology, School of Medicine, University of Milan, Italy.
Chemotherapy. 1998 Jan-Feb;44(1):42-9. doi: 10.1159/000007089.
The exposure of bacteria to antibiotics at even sub-minimum inhibitory concentrations (sub-MICs) induces physicochemical and biochemical modifications that facilitate phagocytosis and intracellular killing by polymorphonuclear leukocytes (PMNs). These PMN functions were investigated by exposing Staphylococcus aureus strains to different sub-MICs (1/2 to 1/32 MIC) of rokitamycin (RKM). Although phagocytosis and the index of phagocytosis of the antibiotic-exposed staphylococci were not significantly modified with respect to controls, the percentage of killing significantly increased after exposure to 1/2 and 1/4 MIC by 31 and 22%, respectively. Taking into consideration the other aspect of a possible direct interaction between RKM and PMNs, it was observed that up to 10 micrograms/ml of RKM did not interfere with phagocytosis but significantly enhanced killing activity by up to 33%. This effect can be correlated with the high uptake of RKM by PMNs (cellular/extracellular ratio congruent to 30.5). The relevance of these in vitro observations to clinical situations remains to be further investigated.
即使在亚最低抑菌浓度（亚 MIC）下，细菌暴露于抗生素也会诱导物理化学和生化修饰，从而促进多形核白细胞（PMN）的吞噬作用和细胞内杀伤。通过将金黄色葡萄球菌菌株暴露于不同亚 MIC（1/2 至 1/32 MIC）的罗他霉素（RKM）来研究这些 PMN 功能。尽管与对照相比，暴露于抗生素的葡萄球菌的吞噬作用和吞噬指数没有显著改变，但暴露于 1/2 和 1/4 MIC 后，杀伤百分比分别显著增加了 31%和 22%。考虑到 RKM 与 PMN 之间可能存在直接相互作用的另一个方面，观察到高达 10 微克/毫升的 RKM 不会干扰吞噬作用，但会显著增强杀伤活性，最高可达 33%。这种效应可能与 PMN 对 RKM 的高摄取有关（细胞/细胞外比率相当于 30.5）。这些体外观察结果与临床情况的相关性仍有待进一步研究。
