antibiofilm activity of nigella sativa (black seed) essential oil against selected pathogenic bacteria

The increase in antimicrobial resistance and tolerance over the years has become a serious public health problem, leading to the inevitable development of alternative antimicrobial agents as substitutes for industrial pharmaceutical antibiotics targeting humans and animals under the concept of one health. essential oils (eos) extracted from aromatic and pharmaceutical plants incorporate several bioactive compounds (phytochemicals) that positively affect human and animal health. herein, this work aimed to examine a standardized chemical composition and screen the antimicrobial and anti-biofilm activity of essential oil—black seed (c) was tested at three concentrations (50-100- 200 µg/ml) on three bacterial strains, such as bacillus cereus and klebsiella pneumoniae. biofilm was quantified by crystal violet staining in a microtiter plate assay, with optical density (od) read at 570 nm. black seed essential oil exhibits potent antibiofilm activity against gram-negative bacteria at moderate doses, but its variable activity against gram-positives and diminished efficacy at higher concentrations warrant further investigation. data suggest that biofilm activity depends on the bacterial species and the applied concentration. essential oils are prominent antimicrobial and anti-biofilm agents due to the presence of various active components in their composition.