As part of the ongoing search for potent and resistance-free antimicrobial medicinal plants, the antimicrobial and synergistic effects of the plants, Allium sativum (E1) and Gongronema latifolium (E2) on Escherichia coli and Staphylococcus aureus were investigated. The sensitivities of E. coli and S. aureus to E1 and E2 and the minimum inhibitory concentrations of the plant extracts, individually and in combination with themselves, and with ciprofloxacin (CPX) and ampicillin (AMP), were tested using standard procedures. E1 and E2 individually showed appreciable antimicrobial effect (zones of inhibition > 16mm). The combination of E1 and E2 against the test organisms was not effective due to antagonism between E1 and E2. E1 or E2 when combined with CPX, completely suppressed the effect of CPX against E. coli, and rather produced additive effect on S. aureus similar to the combination of E2 and AMP against S. aureus, although CPX alone was more effective than either E1 or E2, unlike AMP. Synergism was observed in the combination of E1 and AMP against S. aureus. It is concluded that synergism associated with the combination of medicinal plants is doubtful. However, the synergistic or additive effect between garlic and conventional drugs to some strains of bacteria which are resistant to some conventional drugs, gives hope of fighting drug resistance.

Uptake of heavy metals, silver and cadmium by Pseudomonas aeruginosa (a Gram negative bacterium) and Micrococcus luteus (a Gram positive bacterium) was investigated in Cadmium and Silver stock solution using ion selective electrodes. Silver and cadmium uptake by the two organisms was described by Langmuir isotherms. Binding at one site type is indicated. It was observed that both organisms showed rapid uptake of metal mostly in the first minute. Uptake was complete by ten minutes. Micrococcus luteus concentrated more metal than Pseudomonas aeruginosa. M. luteus took up 200% more silver and 100% more cadmium than P. aeruginosa. We conclude that the two organisms, particularly M. Luteus have very high bioremediation potentials in heavy metals polluted environment.