Antibacterial and Anti-Biofilm Activities of<i> Neocarya Macrophylla</i> Against Clinical Bacterial Isolates

Abstract

Background: The increasing threat of bacteria resistant to current antibiotics underscores the need for an alternative source of antimicrobial agents. This study was designed to investigate the antibacterial and antibiofilm activity of Neocarya macrophylla against two important human pathogens commonly associated with biofilm-related infections.
Methods: The methanolic extract of N. macrophylla leaves and its n-butanol and ethylacetate fractions were screened in-vitro for their antimicrobial activity using agar well diffusion technique while the antibacterial and antibiofilm activity of the extract and its fractions were investigated against clinical isolates of S. aureus and P. aeruginosa using microbroth dilution technique and microtiter plate method respectively.
Results: The methanolic leaf extract and its fractions exhibited substantial antimicrobial activity. The n-butanol and ethylacetate fractions showed highest activity against P. aeruginosa and S. aureus respectively. The MIC and MBC of the extract and its fractions against both S. aureus and P. aeruginosa ranged from 3.125-37.5 mg/ml and 6.25-75 mg/ml respectively. In addition, a concentration-dependent antibiofilm activity against the test organisms was also observed with the ethylacetate fraction exhibiting the highest antibiofilm activity.
Conclusion: The extracts and fractions of N. macrophylla exhibited remarkable antibacterial and antibiofilm activities against S. aureus and P. aeruginosa. The plant thus can be considered as a potential source of bioactive principles in the continuous fight against bacterial virulence and resistance.

Keywords: Neocarya macrophylla, Antimicrobial activity, Antibiofilm activity, Antimicrobial resistance.