Discrepancy between Uptake and Intracellular Activity of Moxifloxacin in a Staphylococcus aureus -Human THP-1 Monocytic Cell Model
| Autor: | Jean Grellet, Claudine Quentin, Véronique Dubois, Marie-Claude Saux, Delphine Paillard |
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| Rok vydání: | 2002 |
| Předmět: |
Staphylococcus aureus
Time Factors Moxifloxacin Microbial Sensitivity Tests Bacterial growth Biology medicine.disease_cause Models Biological Monocytes Microbiology Anti-Infective Agents Extracellular medicine Humans Pharmacology (medical) THP1 cell line Cells Cultured Pharmacology Aza Compounds Minimum bactericidal concentration biology.organism_classification Infectious Diseases Quinolines Intracellular Bacteria Fluoroquinolones medicine.drug |
| Zdroj: | Antimicrobial Agents and Chemotherapy. 46:288-293 |
| ISSN: | 1098-6596 0066-4804 |
| DOI: | 10.1128/aac.46.2.288-293.2002 |
| Popis: | The correlation between uptake of moxifloxacin by THP-1, a continuous line of monocytic cells devoid of intrinsic bactericidal properties, and its activity against Staphylococcus aureus ATCC 25923, a susceptible reference strain (MIC and minimal bactericidal concentration of moxifloxacin, 0.1 mg/liter), was studied in a 5-h assay. The uptake of the drug, added to the culture medium at 0.2 to 32 mg/liter, was evaluated by high-performance liquid chromatography. The ratio of the cellular to extracellular concentration of moxifloxacin reached, at equilibrium, 4.36 ± 0.39 in uninfected cells and 6.25 ± 0.41 in infected cells. The intracellular activity of moxifloxacin, introduced into the extracellular fluid at 0.06 to 8 mg/liter, was determined by the enumeration of viable bacteria. At concentrations ≤0.2 mg/liter, the drug inhibited only the intracellular bacterial growth, while at concentrations ≥0.5 mg/liter, it decreased the bacterial inoculum by less than 1 log 10 unit, with a maximum effect at 3 to 4 h, followed by regrowth of surviving bacteria to 80 to 120% of the original level at 5 h. In contrast, when killing curves were determined by using Mueller-Hinton broth with a similar inoculum (10 7 CFU/ml), moxifloxacin at concentrations ≥0.2 mg/liter reduced the inoculum by at least 3 log 10 units at 3 to 4 h, leaving ≤0.1% survival at 24 h. Persisters exhibited a fluoroquinolone susceptibility identical to that of S. aureus ATCC 25923. Our data indicate that moxifloxacin at therapeutic extracellular concentrations accumulates approximately sixfold in infected THP-1 cells and remains active intracellularly, but significantly less active than under in vitro conditions. |
| Databáze: | OpenAIRE |
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