Antimicrobial effect of Malaysian vegetables against enteric bacteria
Authors: Hassanain Al-Talib, Norliana Dalila Mohamad Ali, Mohamed Harreez Suhaimi, Siti Shafika Nabila Rosli, Nurul Huda Othman, Nur Ain Sakinah Mansor, Amira Kartini Sulaiman Shah, Nurul Syuhada Ariffin, Alyaa Al-Khateeb
Number of views: 249
Objective: To investigate the antibacterial activities of green vegetables (pennywort,
mint, garlic, parsley and celery) against four common enteric bacteria [Salmonella
enterica (ATCC 25957) (S. enterica), Shigella flexneri (ATCC 12022) (S. flexneri),
Escherichia coli (ATCC 43889) (E. coli) and Enterobacter cloacae (ATCC 13047)
(E. cloacae)] as an alternative medicine for controlling food borne diarrhea disease and
the synergistic effect of green vegetables against those bacteria.
Methods: Five common vegetables (pennywort, mint, garlic, parsley and celery) were
purchased and extracted. The antimicrobial activities of these extracts were tested against
four common enteric bacteria (S. enterica, S. flexneri, E. coli and E. cloacae). Ten
different concentrations of the extracts (from 640 to 1.25 mg/mL) were prepared and used
for the study. The minimal inhibitory concentration (MIC) was determined by the broth
dilution method. The antimicrobial activities were assessed by using both well diffusion
and disc diffusion methods.
Results: Garlic extract showed excellent inhibitory effects on all enteric bacteria. Other
plants (parsley, celery, mint and pennywort) were not effective against enteric bacteria.
The MIC of garlic against S. flexneri and E. cloacae was 40 mg/mL. The MIC of
S. enterica and E. coli were 20 and 10 mg/mL, respectively. The performance of the well
diffusion method was better than that of the disc diffusion method with clear and sharp
inhibition zones of tested bacteria against plant extracts.
Conclusions: Garlic had excellent antimicrobial effects against enteric bacteria and was
recommended to be given to patients with gastroenteritis. The other vegetables (pennywort,
mint, parsley and celery) showed no inhibitory effects on enteric bacteria but still
can be used for its richness in vitamins and fibers. The performance of the well diffusion
method was better than that of the disc diffusion method in detecting the antibacterial
effects of green vegetables.