Antimicrobial activity of some of the South-Indian spices against serotypes of Escherichia coli, Salmonella, Listeria monocytogenes and Aeromonas hydrophila

Antibacterial activity of extracts of Allium sativum (garlic), Myristica fragrans (nutmeg), Zingiber officinale (ginger), Allium cepa (onion) and Piper nigrum (pepper) has been evaluated against 20 different serogroups of Escherichia coli, 8 serotypes of Salmonella, Listeria monocytogenes and Aeromonas hydrophila. Garlic extract showed excellent antibacterial activity against all the test organisms, except L. monocytogenes. Nutmeg showed good anti-listerial activity, although activity against E. coli and Salmonella were serotype dependent. Both garlic and nutmeg extracts were effective against A. hydrophila. Extracts of ginger showed inhibitory activity against two serogroups of E. coli: as O8 (enterotoxigenic E. coli) and O88 only. Extracts of onion and pepper did not show any antibacterial activity against the test organisms.