Evaluation of the Antibacterial and Synergistic Activities of Aqueous and Alcoholic Extracts of Chamomile (Matricaria chamomilla L.) Against Selected Pathogenic Bacterial Strains

Abstract

The escalating global health crisis posed by antibiotic-resistant bacteria has prompted researchers to seek effective natural alternatives to combat these pathogens. Chamomile, a medicinal plant with recognized antibacterial properties, has emerged as a promising candidate. This study aimed to evaluate the impact of chamomile extracts (aqueous and alcoholic) on the growth of select pathogenic bacteria and investigate their synergistic effect with antibiotics on the susceptibility of these bacterial strains.  The antibacterial activity of aqueous and alcoholic chamomile extracts was assessed using the disc diffusion method against six pathogenic bacteria: Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Enterobacter cloacae. The synergistic effect of combining these extracts with antibiotics on the efficacy of the latter was also examined. Chemical analysis of the extracts was conducted to identify their active constituents. The aqueous extract exhibited no antibacterial activity, while the alcoholic extract demonstrated efficacy against Staphylococcus aureus. When combined with certain antibiotics, both aqueous and alcoholic extracts enhanced the susceptibility of most bacteria to the tested antibiotics, with the exception of Klebsiella pneumoniae, which exhibited increased resistance to the antibiotic tetracycline. Chemical analysis of the alcoholic extract revealed the presence of active compounds (alkaloids, saponins, glycosides, phenols) that could potentially account for its antibacterial effect. Chamomile exhibits an inhibitory effect on certain bacterial strains and demonstrates a synergistic effect with some antibiotics.