Antibacterial Effect of Some Nigerian Medicinal Plants on Drug-Resistant Salmonella Species Isolated from Enviromental Sources

ABSTRACT

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 20v/v. The concentration of all the extracts of the experimental plants that inhibited the growth of Salmonella species ranged from 10 to 20v/v with minimum inhibitory concentration of 5.0v/v. All the extracts at concentration of 20v/v exhibited 100growth inhibition on Salmonella isolates. All the isolates exhibited resistance patterns ranging from 50 to 100against 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