Antimicrobial activity of different plants extracts against Staphylococcus aureus and Escherichia coli.

Background: Microbial pathogens, mainly bacteria, are a major cause of food spoilage resulting in several foodborne diseases. Food spoilage can be prevented by the application of chemical preservatives in the food industry but such process has harmful effects on human health and causes the introduction of chemicals in several food chains, leading to toxicity and long-term complications. Due to such adverse effects, the need to find natural preservatives that are safer to use, effective and less complicated is increasing.

Objectives: This study is based on plant extracts that play a major role in microbicidal action (the use of natural preservatives is preferred over chemical ones). Antimicrobial action of different plant extracts was assessed using Staphylococcus aureus and Escherichia coli as experimental bacterial strains.

Material and methods: Ethanolic extracts of different plants like Punica granatum, Acacia catechu and Phyllanthus emblica were highly effective against the both analyzed bacterial strains at a dosage of 10 mg/mL, while the extracts of Ocimum bacilicum and Quercus infectoria were effective only against S. aureus and E. coli, respectively.

Results: Punica granatum and Phyllanthus emblica extracts were found to be the most effective and exhibited bacteriostatic and bactericidal activities against the highly infectious strains of pathogenic bacteria causing food spoilage, with minimum inhibitory concentration (MIC) of 2.5 mg/mL and minimum bactericidal concentration (MBC) of 5 mg/mL.

Conclusions: The plant extracts used in the study were highly effective in reducing bacterial contamination and can be used as an alternative to chemical preservatives to avoid and control foodborne diseases and for preservation of food with no health-related hazards caused by chemicals.