RESUMEN
The potential use of clinically approved beta-lactams for Buruli ulcer (BU) treatment was investigated with representative classes analyzed in vitro for activity against Mycobacterium ulcerans. Beta-lactams tested were effective alone and displayed a strong synergistic profile in combination with antibiotics currently used to treat BU, i.e. rifampicin and clarithromycin; this activity was further potentiated in the presence of the beta-lactamase inhibitor clavulanate. In addition, quadruple combinations of rifampicin, clarithromycin, clavulanate and beta-lactams resulted in multiplicative reductions in their minimal inhibitory concentration (MIC) values. The MIC of amoxicillin against a panel of clinical isolates decreased more than 200-fold within this quadruple combination. Amoxicillin/clavulanate formulations are readily available with clinical pedigree, low toxicity, and orally and pediatric available; thus, supporting its potential inclusion as a new anti-BU drug in current combination therapies.
Asunto(s)
Úlcera de Buruli/tratamiento farmacológico , Mycobacterium ulcerans/efectos de los fármacos , Inhibidores de beta-Lactamasas/farmacología , beta-Lactamasas/metabolismo , Administración Oral , Amoxicilina/farmacología , Amoxicilina/uso terapéutico , Úlcera de Buruli/microbiología , Claritromicina/farmacología , Claritromicina/uso terapéutico , Ácido Clavulánico/farmacología , Ácido Clavulánico/uso terapéutico , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Quimioterapia Combinada , Humanos , Pruebas de Sensibilidad Microbiana , Mycobacterium ulcerans/enzimología , Rifampin/farmacología , Rifampin/uso terapéutico , Inhibidores de beta-Lactamasas/uso terapéuticoRESUMEN
The synthesis of dehydrophos derivatives featuring modified peptide chains, characterized by the presence of substituents in the vinyl moiety, or possessing a phosphonic acid monoalkyl ester other than the monomethyl ester one, has been accomplished by a versatile procedure based on Horner-Wadsworth-Emmons olefination with suitable aldehydes and on the selective hydrolysis of the dialkyl phosphonate group. Such derivatives have been tested against a series of bacterial strains, using the naturally occurring peptide, dehydrophos, for comparison. Thus, the effects of the aforementioned structural variations on antimicrobial activity have been studied.