Antimicrobial potential of silver nanoparticles from the leaves of Ageratum conyzoides against multidrug-resistant bacteria

It is becoming difficult to treat some bacterial infections even after the administration of multiple antibiotics and this has resulted in increased morbidity and mortality. The efficacy of nanoparticles (NPs) synthesized from the Ageratum conyzoides plant against multidrug-resistant (MDR) bacteria was investigated. A high peak at 440 nm suggested the presence of the AgNPs. The AgNPs were spheroid-shaped (11 - 50 nm). The silver nanoparticles (AgNPs; 100 µg/disc) inhibited the MDR bacteria, showing a high zone of inhibition(26.33 mm) against Klebsiella pneumoniae, while the lowest zone was found against Acinetobacter baumanii (14.50 mm). The AgNPs displayed increased inhibition zones when combined with antibiotics, of which K. pneumoniae was the most susceptible (32.67 mm), and the least was Pseudomonas aeruginosa (24.33 mm). The minimum inhibitory concentration against the tested pathogens ranged from 25 - 50 µg/mL. This study shows that the AgNPs from A. conyzoides are effective against the MDR bacteria.