Investigating the synergic effects of the extracts of Camellia sinensis, Rosmarinus officinalis and Thymus with ampicillin against resistant Pseudomonas aeruginosa species

The most common bacterium linked to the hospital and pneumonia-related infections is Pseudomonas aeroginosa, a known opportunistic pathogen. High mortality rates are brought on by this bacterium in hospitalized patients, immunocompromised individuals, and cystic fibrosis patients. The formation of biofilm structures has also made it more challenging to treat patients. Due to the severe side effects of the antibiotics, the lack of efficacy due to resistance, and the well-documented antibacterial effects of traditional plants, this study investigated the antibacterial properties of the combination of thyme, rosemary, and green tea. Therefore, the main purpose of the current study was to examine the antibacterial and anti-biofilm effects of the extracts of these three plants.

Pseudomonas arginosa strains were obtained from patients at Ghaem Hospital, Mashhad, Iran. The efficacy of various antibiotics on different strains was studied, and bacterial strains were classified into sensitive, semi-sensitive, and resistant. The minimum inhibitory concentration (MIC) of the combination of the three extracts, as well as the antibiotic of choice, was determined. The effect of the extract on the biofilm formation was also investigated.

The results indicated that the ternary composition has significant antibacterial and anti-biofilm effects; also, the combination of these three extracts has shown significant synergistic properties with each other. Further, the extracts inhibited the formation and growth of the biofilm.

Results of this study indicated that the optimum combination of the three extracts possessed a remarkable antibacterial and anti-biofilm activity. Further, we have shown the synergistic antibacterial activity of the three extracts improved in the presence of the antibiotic of choice, resulting in a decrease in the MIC value of the antibiotic.