Abstract

The leaves of Spondias mombin L. consumed as infusion in Ivory Coast are used to treat gastrointestinal disorders such as diarrhea. In this study, the leaves’ extract, after purification by the ethyl acetate method, was evaluated for its effect on growth and cell viability of two Gram positive bacteria (Staphylococcus aureus ATCC25923 and Listeria monocytogenes ATCC25051) and four Gram negative bacteria (Pseudomonas aeruginosa ATCC27853, Escherichia coli ATCC25922, Salmonella enteritidis ATCC27042 and Klebssiela pneumonia ATCC27001) which are foodborne pathogens. This evaluation was performed by following their growth by a spectrophotometric method in Mueller-Hinton broth contained amount of antibacterial fraction ranging from 0.5 to 3%. The total inhibition of the Gram positive species’ growth was observed in the medium at 2.5% of antibacterial fraction, while that of the Gram negative species was observed in the medium at 3% of antibacterial fraction after 24 h of incubation. The test of the percentage in reduction of Alamar blue indicating cell viability showed that in the medium at 2.5% of antibacterial fraction, around 3% of cells were still alive for the two Gram positive bacteria after two days of incubation. At these same concentration and incubation time, around 7% of the cells were still alive for the four Gram negative bacteria. These results suggest that different classes of compounds in the extract are likely responsible for the bactericidal activities. Thus, it can be used as a natural preservative and an alternative to current chemical preservatives used in food which are harmful for human health.

Key words: Antibacterial fraction, bacteria, cell viability, foodborne pathogens, growth rate.