In vitro Evaluation of Antimicrobial Potential of Three Crude Extracts of Tridax procumbens Leaves

Aims: The decreasing sensitivity of microbial isolates to most available standard antimicrobial agents currently in use necessitates the search for novel and clinically effective ones especially from plant sources. In this research, effort was made to assay in vitro antimicrobial potential of three crude extracts of Tridax procumbens leaves.

Methodology: Disc diffusion method was used for the assay against six bacteria isolates: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Proteus vulgaris and Klebsiella pneumoniae. The study was carried out in three replicates for a period of 72 hrs.

Results: The results showed that highest sensitivity was observed with chloroform extract against Streptococcus pyogenes (34.00±0.58 mm), Escherichia coli (28.00±1.15 mm) and Klebsiella pneumoniae (28.00±0.58 mm). Ethanol extract exhibited moderate activity, while little antibacterial activity was seen with the aqueous extract. There was no inhibition of bacterial growth at all in the negative control (Distilled water). The sensitivity of chloroform extract of Tridax procumbens at 80µg/ml was higher but not significantly different (P>0.05) from ciprofloxacin (50µg/ml) against Escherichia coli, Proteus vulgaris, Streptococcus pyogenes and Klebsiela pneumoniae.

Conclusion: Tridax procumbens appear to be a source of novel broad spectrum antimicrobial agent.