Poster Presentation BacPath 2024

Investigation Antibacterial Activity of Medicinal Plant Infusions Against Pathogenic Bacteria (#81)

Tesleem Ibrahim 1 , Chen Situ 1
  1. Queens University, Belfast, PLEASE SELECT, United Kingdom

The wide use and abuse of antibiotics in human and animal medicine have led to the severe spread of antimicrobial resistance. This problem reduces the effectiveness of antibiotics. There is an urgent need to develop novel therapeutics for treating infectious diseases caused by multidrug-resistant microorganisms. The past decades have witnessed global exploration of medicinal plants as an alternative to therapeutic antibiotics. This present study investigated the antibacterial activity of plant infusions against Salmonella enterica (NCTC 13349) and E. coli (NCTC 13352 and 11560). The broth microdilution and checkerboard methods in 96 well plates were used to determine the susceptibility of the pathogens to the infusions and their combination therapy with antibiotics, respectively. Fifteen plants producing nineteen infusions (different parts of some plants used) were used based on their traditional knowledge and antibacterial activity in the scientific literature. Preliminary antibacterial results showed that the infusions showed varying antibacterial activity with the minimum inhibitory concentration (MIC) ranging from 0.078 to 10mg/mL, but only eight infusions from Sanguisorba officinalis, Smilax china, Bridelia speciosa, Agrimonia pilosa, Hedyotis diffusa, Pulsatilla chinesis and Cyrtomium fortunei (42.1%) showed excellent and moderate activity against the pathogens. However, the promising finding was that a significant combination therapy was observed between seven infusions, erythromycin and penicillin, against the pathogens. In combination, plant infusions reduced the MIC of the antibiotics up to 512% folds, resulting in 99% potency and more than Log3 reduction. These results open up a hopeful path in the fight against antimicrobial resistance. Further studies are needed to determine these plant infusions' likely modes of action and safety profile.