摘要：Background and Objective: Biofilm is a complex microbial community highly resistant to antimicrobials agents. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality and considered as a major factor of bacterial pathogenicity. In the present study the antimicrobial and antibiofilm activities of 5 plant extracts ( Glycyrrhiza glabra roots, Laurus nobili , Malus domestica peels, Melissa officinalis and Lagenaria siceraria peels) were evaluated against clinical isolated microorganisms ( E. coli , S. aureus , P. aeruginosa and K. pneumonia ). Materials and Methods: The extracts of medicinal plant s were prepared using microwave assisted method by ethanol and water. Results: The results of this study revealed that, the aquatic extract of M. domestica peels showed powerful antimicrobial activity against E. coli with MIC value 1.56 mg mL1, the ethanolic extract of G. glabra roots showed good antimicrobial activity against P. aeruginosa with minimum inhibitory concentration (MIC) of 12.5 mg mL1. Most plant extracts in this study gave the minimum bactericidal concentration (MBC) ≥200 mg mL1 against tested bacteria. However, the aquatic extract of L. nobili at concentration of 12.5 mg mL1 showed the highest antibiofilm activity (86.7%) against S. aureus biofilm formation. The ethanolic extract of M. domestica peels at concentration of 25 mg mL1 showed the highest inhibition rate (90%) against P. aeruginosa biofilm formation. Conclusion: These results revealed the importance of the tested extracts in the control of common human pathogenic micro-organisms. Plant extract s used in this study may contain potential antimicrobial and antibiofilm components that may be of great use for the development of new therapies against the most common infectious bacterial isolates.
