Screening of native plants of Argentina for antivirulent activity against Pseudomonas aeruginosa: A Promising Alternative to Combat Multi-Drug Resistant Infections

COMBA RUETSCH, CAMILA; GARCIA CHIALVA, DIEGO; SMANIA ANDREA MARIA; CARPINELLA MARIA CECILIA; LUJAN ADELA MARÍA

Bernal

Congreso; 3º Congreso Latinoamericano de Ecología Microbiana.; 2023

ISME Latinoamerica

Bacteria's social behavior plays a crucial role in coordinating the expression of virulence factors during infections. Quorum sensing (QS), a cell-to-cell communication system, regulates populationdensity-dependent changes in bacterial behavior, and modulates virulence functions in many pathogens. Pseudomonas aeruginosa is a non-fermentative opportunistic gram-negative bacterium that is amajor cause of multi-drug resistant infections, and its virulence is regulated by QS. Given the limited therapeutic options for P. aeruginosa infections, there is an urgent need to identify alternativeprevention and treatment strategies. Antivirulence agents, which disarm bacteria of their virulence factors without affecting essential survival factors, have emerged as a promising alternative. In thisstudy, 42 extracts obtained from mostly native plants from Argentina were screened for their antivirulent activity against P. aeruginosa by measuring the production of different virulence factors andbiofilm formation. The results showed that 11 ethanol extracts demonstrated antivirulent activity, inhibiting more than 60% of pyocyanin production. These extracts were obtained from Ipomoeahieronymi, Lantana grisebachii, Mandevilla pentlandiana, Trichocline reptans, Wedelia buphthalmiflora, Acalypha communis, Flourensia oolepis, Acanthostyles buniifolius, Thalictrum decipiens, Lippiaturbinata and Chromolaena hookeriana. To confirm this activity, we determined the inhibition capacity of other QS-regualted phenotypes such as swarming, violacein production and biofilm formation.Additionally, minimum inhibitory concentrations (MICs) of these extracts were determined to assess their activity at lower concentrations. Based on our findings, the extracts from M. pentlandiana andA. communis demonstrated the most reproducible results and would be selected for further investigations. The results of this study are novel and promising. The use of natural products to targetbacterial virulence represents a potential sustainable and eco-friendly alternative to traditional antibiotics. Moreover, the identification of native plants with potent antivirulent activity against P.aeruginosa suggests that local ecosystems could offer a valuable source of biologically active compounds. Further studies on the active constituents of these extracts, their mechanisms of action, andtheir potential toxic effects will be perfomed. The present work provides a basis for the development of new antivirulence therapies against multidrug-resistant pathogens and highlights theimportance of exploring microbial ecology as a source of innovative solutions to combat infectious diseases