Evaluation of E. coli susceptibility to plant extracts from unconventional food plants

Unconventional food plants (PANC) are plants that are not normally consumed, but can
be part of human food because they provide innumerable nutritional benefits as well as
being used for technological purposes. The ethanolic plant extracts of plants have been
of industrial interest because it is a natural product that can be used to replace
synthetic antimicrobials, antioxidants and additives. The aim of this work is to evaluate
the susceptibility of three PANCs: taioba (Xanthosoma sagittifolium Schott), moringa
oleifera and ora-pro-nobis (Pereskia aculeata Mill) in E. coli ATCC 35218. A sterile
cotton swab was immersed in a tube containing the turbidity-adjusted bacterial
suspension of 0.5 McFarland scale. On the surface of a PCA agar plate (approximately
4 mm) where the discs impregnated with crude ethanolic extracts and hypochlorite 200
ppm were inoculated as positive control in triplicate. The plates were then incubated at
37 ° C under aerobic conditions. After 24 hours, the diameters of the inhibition halos
promoted by the extracts were measured using a digital caliper. The inhibition halo
diameters were observed only in the moringa extract with a mean of 11.66 mm (p
<0.05), the taioba extract and the ora-pro-nobis extract showed no formation of halo,
as well as hypochlorite at 200 ppm. It is concluded that only the moringa extract
presents action in E. coli ATCC 35218 pure in concentration of 1.5x108