In vitro activity of rifampicin, rifapentine and rifabutin in combination with their 25-deacetyl-metabolites against various Mycobacterium tuberculosis lineages.
Charlotte Genestet, Chloé Bourg, Elisabeth Hodille, Olivier Bahuaud, Florence Ader, Sylvain Goutelle, Oana Dumitrescu
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引用次数: 0
Abstract
Objectives: Rifamycin agents (rifampicin (RIF), rifapentine (RFP), rifabutin (RFB)) are the cornerstone of tuberculosis (TB) therapy. Rifamycins are metabolized into 25-deacetyl-metabolites, which have been described has active and may contribute to in vivo drug effect. However, little is known about the combined effect of rifamycins and their metabolites across different Mycobacterium tuberculosis complex (MTBC) lineages.
Methods: This study included 14 MTBC strains representing the main lineages. Minimum inhibitory concentrations (MICs) were determined using microdilution assays for the three rifamycins and their metabolites. A checkerboard assay was used to assess drug interactions, with the fractional inhibitory concentration (FIC) index calculated for synergy or antagonism.
Results: MICs varied across rifamycins, RIF and its metabolite showed the highest MICs, followed by RFP and RFB and their respective metabolites. FIC indices for rifamycin-metabolite combinations indicated additive effects (FIC between 0.5 and 1.25), with no antagonism observed, even at clinically relevant metabolite-to-parent drug ratios, and without impact of MTBC lineage.
Conclusions: Rifamycin metabolites exhibit additive effects with parent drugs, potentially enhancing bactericidal activity. This highlights that rifamycin susceptibility testing should account for both parent drugs and their metabolites, as these metabolites also exhibit antimicrobial activity. Additionally, these findings support further pharmacokinetic/pharmacodynamic studies to optimize TB treatment regimens, particularly in relation to metabolite-to-parent drug ratios in patients.
期刊介绍：
Annals of Clinical Microbiology and Antimicrobials considers good quality, novel and international research of more than regional relevance. Research must include epidemiological and/or clinical information about isolates, and the journal covers the clinical microbiology of bacteria, viruses and fungi, as well as antimicrobial treatment of infectious diseases.
Annals of Clinical Microbiology and Antimicrobials is an open access, peer-reviewed journal focusing on information concerning clinical microbiology, infectious diseases and antimicrobials. The management of infectious disease is dependent on correct diagnosis and appropriate antimicrobial treatment, and with this in mind, the journal aims to improve the communication between laboratory and clinical science in the field of clinical microbiology and antimicrobial treatment. Furthermore, the journal has no restrictions on space or access; this ensures that the journal can reach the widest possible audience.
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