Intracellular accumulation and activity of ampicillin used as free drug and as its phthalimidomethyl or pivaloyloxymethyl ester (pivampicillin) against Listeria monocytogenes in J774 macrophages.
Intracellular accumulation and activity of ampicillin used as free drug and as its phthalimidomethyl or pivaloyloxymethyl ester (pivampicillin) against Listeria monocytogenes in J774 macrophages.
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DOI：
10.1093/jac/dkg431
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发表时间：
2003-10
期刊：
影响因子：
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通讯作者：
H. Chanteux;M. Mingeot-Leclercq;E. Sonveaux;F. Van Bambeke;P. Tulkens
中科院分区：
文献类型：
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作者：
H. Chanteux;M. Mingeot-Leclercq;E. Sonveaux;F. Van Bambeke;P. Tulkens
目的测定氨苄青霉素及其酯类药物在巨噬细胞中的蓄积情况，并测定其对单核细胞增生李斯特菌的抑制作用。方法定量评价氨苄西林、邻苯二甲酰亚胺甲基氨苄西林（PIMA）和新戊酰氧甲基氨苄西林（PIVA）对细胞内L。单核细胞增多症，并直接测量J774巨噬细胞中的细胞氨苄青霉素浓度。结果氨苄西林、PIMA和PIVA在细胞外浓度为3.6 μ M [氨苄西林10 x MIC（1.25 mg/L）; PIMA 1.83 mg/L和PIVA 1.67 mg/L]时，在5 h内引起细胞相关cfu下降0.5 log。在细胞外环境中加入β-内酰胺酶可消除氨苄西林和PIMA的活性，但不消除PIVA的活性。在低细胞外浓度下[0.5 x MIC氨苄青霉素（62.5 μ g/L）; PIMA（91.5 μ g/L）和PIVA（83.5 μ g/L）的等摩尔浓度]，氨苄青霉素和PIMA失去了所有活性（与对照组相比），但PIVA保持与较高浓度下相同的活性。如果每5小时更换一次培养基（以补偿细胞外PIVA的降解），则将细胞与低浓度（83.5 μ g/L）PIVA孵育20小时导致cfu减少2 log。用PIVA孵育细胞允许氨苄青霉素的显著（4至25倍）细胞积累，而用氨苄青霉素或PIMA孵育的细胞没有观察到氨苄青霉素积累。结论：首次证明PIVA（氨苄青霉素前药）可促进氨苄青霉素细胞内蓄积，从而提高氨苄青霉素细胞内活性。PIVA可用于控制L.单核细胞增多症。
AIMS To determine the intracellular accumulation in a macrophage cell line of ampicillin and ampicillin esters, and to measure their activity against intracellular Listeria monocytogenes. METHODS Quantitative evaluation of the activity of ampicillin, phthalimidomethylampicillin (PIMA) or pivaloyloxymethylampicillin (PIVA) against intracellular L. monocytogenes, and direct measurement of cellular ampicillin concentration in J774 macrophages. RESULTS Ampicillin, PIMA and PIVA caused a 0.5 log decrease in cell-associated cfu within 5 h when used at an extracellular concentration of 3.6 microM [10 x MIC of ampicillin (1.25 mg/L); 1.83 mg/L for PIMA and 1.67 mg/L for PIVA]. Addition of beta-lactamase in the extracellular milieu abolished the activity of ampicillin and of PIMA but not that of PIVA. At low extracellular concentrations [0.5 x MIC ampicillin (62.5 microg/L); equimolar concentrations for PIMA (91.5 microg/L) and PIVA (83.5 microg/L)], ampicillin and PIMA lost all activity (compared with controls), but PIVA remained as active as at the higher concentration. Incubation of cells with PIVA at the low concentration (83.5 microg/L) for 20 h caused a 2 log reduction of cfu if the medium was changed every 5 h (to compensate for the degradation of extracellular PIVA). Incubation of cells with PIVA allowed for a marked (four- to 25-fold) cell accumulation of ampicillin, whereas no ampicillin accumulation was seen for cells incubated with ampicillin or with PIMA. CONCLUSIONS This is the first demonstration that PIVA (a prodrug of ampicillin) can be used to promote ampicillin cellular accumulation and, thereby to increase ampicillin intracellular activity. PIVA could be useful for control of the intracellular multiplication of L. monocytogenes.