Antimicrobial activity of some plant extracts against bacterial strains causing food poisoning diseases.

Prevention of food spoilage and food poisoning pathogens is usually achieved by use of chemical preservatives which have negative impacts including: human health hazards of the chemical applications, chemical residues in food & feed chains and acquisition of microbial resistance to the used chemicals. Because of such concerns, the necessity to find a potentially effective, healthy safer and natural alternative preservatives is increased. Within these texts, Plant extracts have been used to control food poisoning diseases and preserve foodstuff. Antimicrobial activity of five plant extracts were investigated against Bacillus cereus , Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa and Salmonella typhi using agar disc diffusion technique. Ethanolic extracts of Punica granatum, Syzygium aromaticum , Zingiber officinales and Thymus vulgaris were potentially effective with variable efficiency against the tested bacterial strains at concentration of 10 mg/ml while extract of Cuminum cyminum was only effective against S. aureus respectively. P. granatum and S. aromaticum ethanolic extracts were the most effective plant extracts and showed bacteriostatic and bactericidal activities against the highly susceptible strains of food borne pathogenic bacteria ( S. aureus and P. aeruginosa ) with MIC's ranged from 2.5 to 5.0 mg/ml and MBC of 5.0 and 10 mg/ml except P . aeruginosa which was less sensitive and its MBC reached to 12.5 mg/ml of S. aromaticum respectively. These plant extracts which proved to be potentially effective can be used as natural alternative preventives to control food poisoning diseases and preserve food stuff avoiding healthy hazards of chemically antimicrobial agent applications.