The antibacterial effect of Mexican marigold (Tagetes erecta) leaf extract at room temperature against 10 gram positive multidrug resistant bacterial isolates including Enterococcus faecalis, Enterococcus faecium. Staphylococcus epidermidis, Staphylococcus aureus, Bacillus cereus, Erysipelothrix rhusiopathiae, Propionibacterium acne, Streptococcus pneumoniae, Streptococcus agalactine, Staphylococcus saprophyticus and 6 gram negative multidrug resistant bacterial isolates including Escherichia coli, Klebsiella pneumoniae, Pseudomonas auregenosa, Salmonella enteriditis, Acinetobacter baumannii, Alcaligen faecalis were studied by well diffusion method. The maximum antibacterial effect of Mexican Marigold leaf extract among those micro organism was obtained for Acinetobacter baumannii (Acitvity Index = 0.913333333) and Propionibacterium acne (Acitvity Index = 0.906666667) and minimum was for Streptococcus pneumonia (Activity Index = 0.026666667). The results suggest that species of Mexican marigold i.e. Tagetes erecta has antibacterial effect against airborne disease causing gram positive and gram negative bacteria and mainly against skin infection causing bacteria, and hence can be useful in developing drugs for diseases like dermatitis, acne, skin races and also can be developed as antiseptic.
Key words: Tagetes erecta, Leaf extract, Gentamicin, Activity index.