Inhibition of Biofilms by Extracts From Vernonia adoensis in Pseudomonas aeruginosa and Staphylococcus aureus

From Vernonia adoensis in Pseudomonas aeruginosa and Staphylococcus aureusBackground: Bacteria that form biofilms have become a leading cause of increased morbidity and mortality in healthcare settings, as they are responsible for over 65% of nosocomial infections.Biofilms are a major cause of drug resistance in bacteria.Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic pathogens that cause numerous infections and are known for their ability to produce biofilms.Vernonia adoensis is an African ethnomedicinal plant commonly used to treat various disease conditions and has been shown to have antibacterial activity.Objectives: This study aimed to investigate the effects V. adoensis extract on biofilms formed by P. aeruginosa and S. aureus and to determine the phytochemicals present in the extract. Methods:The effect of the extract on the biofilms of P. aeruginosa and S. aureus was determined on 96-microwell plates using crystal violet.The phytochemical constituents of the extract were determined using ultra-performance liquid chromatography-mass spectroscopy (UPLC-MS). Results:The extract disrupted the biofilms of the bacteria.At 100 g/mL, the extract inhibited the formation of P. aeruginosa and S. aureus biofilms by 93% and 17%, respectively.V. adoensis was more potent in decreasing the attachment efficiency of the biofilm of P. aeruginosa as it caused the detachment of 84% of the biofilm in the presence of safety data sheets (SDS), but only 17% of the biofilm of S. aureus.Five compounds (kaempferol, quinic acid, caffeic acid, rhamnetin I, and luteolin were identified using UPLC-MS.Some of these compounds have demonstrated antimicrobial activity. Conclusion:V. adoensis contains bioactive components that may be exploited as lead compounds for the development of new antimicrobial agents with antibiofilm activity.