RESUMEN
A total of 121 plant extracts were screened for their antimicrobial activities and for the alkaloids, Ethanolic extracts were tested for the presence of alkaloids with both Mayer's and Dragendorff's reagents, The extracts were also tested for their, in vitro, antimicrobial activity by an agar dilution- streak method against eight microorganisms. The total extracts used in this study represent 36 families. Forty seven extracts [38.8 percent] were found to contain alkaloids, of which 13 genera have not been previously reported in the literature as alkaloid- bearing plants. Twenty nine extracts [24%] showed antimicrobial activity. Ten plant extracts were active at the level of 100 mcg/ml, against Staph aureus of which one plant extract [Cleome guinqueneriva DC.] showed activity at this level against two microorganisms [Staph aureus and Proteus vulgaris], while another nineteen extracts showed activity at the level of 1000 mcg/ml against one microorganism, of which five extracts were active against two microorganisms