Ramadan M A, Tawfik A F, Shibl A M, Gemmell C G
Division of Microbiology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
J Med Microbiol. 1995 May;42(5):362-6. doi: 10.1099/00222615-42-5-362.
The effect of azithromycin and erythromycin on growth, cell surface hydrophobicity and the susceptibility to the bactericidal activity of human polymorphonuclear leucocytes (PMNL) was examined in four Streptococcus species. Exposure to either 10 x MIC azithromycin or erythromycin induced a post-antibiotic effect (PAE) of between 2.4 and 4.3 h. Erythromycin caused a longer PAE for S. sanguis than azithromycin under the same conditions. The cell surface charge (hydrophobic or hydrophilic) of the streptococci was altered significantly during PAE; loss of hydrophobicity was induced by both macrolides, and this effect was variable amongst the species. The decrease in hydrophobicity was not related to inhibition of growth. The effect of each drug during PAE on the interaction of opsonised suspensions of the streptococci with human PMNL revealed that erythromycin, and to a lesser extent azithromycin, increased susceptibility to the bactericidal activity of human PMNL; this effect was abolished following PAE. The present study clearly showed that PAE should not only be considered as delayed bacterial growth, but also as modulation of bacterial susceptibility to phagocytosis which may influence the outcome of the host-parasite relationship.
研究了阿奇霉素和红霉素对四种链球菌生长、细胞表面疏水性以及对人多形核白细胞（PMNL）杀菌活性敏感性的影响。暴露于10倍MIC的阿奇霉素或红霉素均可诱导2.4至4.3小时的抗生素后效应（PAE）。在相同条件下，红霉素对血链球菌产生的PAE比阿奇霉素更长。在PAE期间，链球菌的细胞表面电荷（疏水或亲水）发生了显著变化；两种大环内酯类药物均诱导了疏水性的丧失，且这种效应在不同菌种间存在差异。疏水性的降低与生长抑制无关。PAE期间每种药物对调理过的链球菌悬浮液与人PMNL相互作用的影响表明，红霉素以及程度较轻的阿奇霉素增加了对人PMNL杀菌活性的敏感性；PAE后这种效应消失。本研究清楚地表明，PAE不仅应被视为细菌生长的延迟，还应被视为细菌对吞噬作用敏感性的调节，这可能会影响宿主-寄生虫关系的结果。
