Drug Resistance Modulation in Staphylococcus Aureus, a New Biological Activity for Mesoionic Hydrochloride Compounds

• Main Authors: Petrônio Filgueiras de Athayde-Filho, Cledualdo Soares de Oliveira, David Peter Harding, Bruno Freitas Lira, Jorge Gonçalo Fernandes Lorenzo, José Pinto Siqueira-Júnior, José Maria Barbosa-Filho, Vivyanne dos Santos Falcão-Silva
• Format: Article
• Language: English
• Published: MDPI AG 2011-02-01
• Series: Molecules
• Subjects: mesoionic compounds; modulation of drug resistance; efflux pump inhibitor
• Online Access: http://www.mdpi.com/1420-3049/16/3/2023/
• ISSN: 1420-3049

Two salts of the mesoionic compounds 1,4-diphenyl-5-(5-nitro-2-furanyl)-1,3,4-thiadiazolium-2-thiol chloride (MC-1) and 4-phenyl-5-(5-nitro-2-furanyl)-1,3,4-thiadiazolium-2-phenylamine chloride (MC-2) were synthesized utilizing 1,4-diphenyl-thiosemicarbazide and 5-nitro-2-furoyl chloride as starting materials. Their structures were characterized by IR, 1H-NMR, 13C-NMR and elemental analysis. These compounds were analyzed for their influence on the effectiveness of norfloxacin, tetracycline, and erythromycin (standard antibiotics) against resistant strains of Staphylococcus aureus. MC-1 and MC-2, at sub-inhibitory concentrations of 16 μg/mL, favourably modulated the antibiotic activity of tetracycline by 16- and 32-fold, respectively (MIC), and that of erythromycin by 4-fold.