Abstract

The aim of the research was to investigate the antibacterial activities and the phytochemical properties of aqueous and ethanolic extracts of Mango (Mangifera indica) and Neem (Azadirachta indica) leaves, on clinical isolates of Salmonella typhi, Salmonella paratyphi A, B and C, in Lafia, Nigeria. The agar well diffusion technique was used and the analyses were done in triplicates. At the highest aqueous and ethanolic extract concentration of 80 mg/ml, S. typhi, showed inhibition zones of 29.4±0.1mm and 30.0±0.01 mm respectively, while S. paratyphi A, B and C, exhibited inhibition zones of 14.4±0.2, 21.2±0.4, 13.4±0.1 mm and 18.0±0.03, 20.0±0.04, 21.0±0.04 mm, respectively. At aqueous and ethanolic lower extract concentration of 10 mg/ml, S. typhi, exhibited inhibition zones of 8.4±0.01 and 9.0±0.1 mm, respectively, while S. paratyphi A, B and C, showed inhibition zones of 9.5±0.01, 9.1±0.01, 6.2±0.01 mm and 9.0±0.01, 9.0±0.01, 9.0±0.01 mm, respectively of Neem leaf extract. The MIC and MBC, of aqueous and ethanolic extracts against organisms were 2.5 and 5.0 mg/ml, respectively. The qualitative phytochemical results showed the presence of alkaloids, anthraquinones, carbohydrates, cardiac glycosides, flavonoids, tannins, terpenoids and saponins. Conclusively, the aqueous and ethanolic extracts of the studied medicinal plant exhibited bactericidal activities against all tested organisms, and this supports the claim by traditional medical practitioners and vendors of the use of the plants for the cure of typhoid fever. Further studies are recommended on the toxicity and safe dosage regimen of the plants since the infusion of the plant is taken orally by people for cure of typhoid fever.

Key words: Salmonella organisms, typhoid fever, phytochemical constituents, bacteria, medicinal plants.