Investigating Irish bogland plants for antimicrobial activity and uncovering their mechanism of action

The emergence of antibiotic resistance is currently a worldwide threat as it renders our reservoir of antibiotics as ineffective when treating bacterial infections. In 2019, 4.95 million people died with an antibiotic-resistant associated infection. One of the biggest threats contributing to this crisis is the bacteria Acinetobacter baumannii. A. baumannii is a Gram-negative multi-drug resistant pathogen that commonly causes bloodstream, wound, and urinary tract infections. Multi-drug resistant (MDR) A. baumannii is currently at the top of the World Health Organisation’s list of priority pathogens and is in urgent need of novel therapeutic interventions. Fortunately, the natural environment serves as a vast and largely untapped resource for novel antibiotics, as plants have endured millennia of intensive selective pressure to prevent bacterial colonisation. Thus, the discovery of plant-derived antimicrobials are currently of great interest.

Using high throughput screening of Irish bogland plant extracts, we discovered an extract, derived from tormentil plants, that can inhibit the growth of A. baumannii in a dose-dependent manner. Through further analysis we were then able to identify the bioactive component of the MeOH extract, which was found to exhibit a more potent antibiotic effect against A. baumannii when used singularly. To determine the antimicrobial mechanism of action, we assessed the effect of this bioactive component on the bacteria’s gene expression using transcriptomics. We then demonstrated a successful reversal of the treatment, which validated the identified mechanism of action. Overall, our findings have the potential to open up novel avenues for treating MDR A. baumannii infections.

 

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Conflict of Interest

The author declares no conflict of interests.

Publication History

Article published online:
16 November 2023