Antibacterial activity of Thonningia sanguinea against some multi-drug resistant strains of Salmonella enterica

Background: The emergence of strains of S.enterica with multiple drug resistance (MDR) is of great concern worldwide.The extracts of flowers of Thonningia sanguinea are used in traditional medicine in Ivory Coast to treat diarrhoeal diseases including salmonellosis. Previous studies had shown inhibition of the MDR strain Salmonella Enteritidis lysotype 6. Objectives: The present study focused to investigate the effect of the extract of the flowers of Thonningia sanguinea on some clinical MDR strains of Salmonella namely S. Tyhpi, S. Typhimurium, S. Hadar and a sensitive strain (S. Enteritidis). Methods: The antimicrobial parameters were determined by double dilution with agar slant method. This method led us to determine MIC, IC(50) and MBC. Results: The MDR strain of S.Typhimurium presented the highest MIC (2.5 mg/ml) whereas the other two MDR strains (S. Hadar, S. Typhi) and the sensitive one (S. Enteritidis) had the same MIC (1.25 mg/ml). The four strains presented the same MBC (2.5 mg/ml). The MDR strain of S. Typhi is the most susceptible strain to the aqueous extract of the flowers of Thonningia sanguinea according to The IC(50) values. Conclusions: The aqueous extract of Thonningia sanguinea can provide an alternative therapy for the treatment of salmonellosis, mainly for typhoid fever caused by MDR strains of S Typhi. The extract also inhibits S.Hadar a MDR emerging strain in Ivory Coast.