ANTIBACTERIAL EFFECT OF SOME NIGERIAN MEDICINAL PLANTS ON DRUG- RESISTANT SALMONELLA SPECIES ISOLATED FROM ENVIROMENTAL SOURCES

Sensitivity of Salmonella species isolated from different environmental sources to the extracts of Azadirachita indica, Psdium guajava, Kigelia africana and Aloe microcarpa was investigated. Susceptiblity of the isolates to amoxicillin, ofloxacin, tetracycline, gentamicin, nalixidic acid, nitrofuratoin and cotrimoxazone was also examined. The sensitivity assay was done using agar dilution technique at concentrations ranging from 0.5 to 20% v/v. The concentration of all the extracts of the experimental plants that inhibited the growth of Salmonella species ranged from 10 to 20% v/v with minimum inhibitory concentration of 5.0% v/v.  All the extracts at concentration of 20%v/v exhibited 100% growth inhibition on Salmonella isolates. All the isolates exhibited resistance patterns ranging from 50 to 100% against the antibiotics examined. Anti-nutrients constituents detected in all the plants materials were alkaloids (1.29-3.57%), tannins (4.69-6.33%), saponins (2.45-7.57%), phenols (0.26-0.60%) and Flavonoids 0.41-1.00%. The need to source for anti-typhoidal drugs from medicinal plants is discussed.