Antibacterial Activity of Four Plant Extracts Extracted from Traditional Chinese Medicinal Plants against Listeria monocytogenes, Escherichia coli, and Salmonella enterica subsp. enterica serovar Enteritidis.

The worldwide ethnobotanical use of four investigated plants indicates antibacterial properties. The aim of this study was to screen and determine significant antibacterial activity of four plant extracts in vitro and in a poultry digest model. Using broth microdilution, the concentrations at which four plant extracts inhibitedListeria monocytogenes, Salmonella enteritidis,andEscherichia coliover 24 h was determined.Agrimonia pilosaLedeb, Iris domestica(L.) Goldblatt and Mabb, Anemone chinensisBunge, andSmilax glabraRoxb all exhibited a minimum inhibitory concentration (MIC) of 62.5 mg/L and a minimum bactericidal concentration (MBC) of 500 mg/L against one pathogen.A. pilosaLedeb was the most effective againstL. monocytogenesandE. coliwith the exception ofS. enteritidis, for whichA. chinensisBunge was the most effective. Time-kills ofA. pilosaLedeb andA. chinensisBunge againstL. monocytogenes, E. coliandS. enteritidisincubated in poultry cecum were used to determine bactericidal activity of these plant extracts.A. chinensisBunge, significantly reducedS. enteritidisby >= 99.99% within 6 h.A. pilosa Ledebexhibited effective significant bactericidal activity within 4 h againstL. monocytogenesandE. coli. This paper highlights the potential of these plant extracts to control pathogens commonly found in the poultry gastrointestinal tract.