Effects of Silver Nanoparticles Synthesized from Phenolic Extract of Agaricus bisporus Against Pathogenic Bacteria and Yeasts

Abstract

<i>Agaricus biosporus</i> is a mushroom known for its use for nutritional and medicinal purposes. This study tested whether silver nanoparticles (AgNPs) synthesized from phenolic compounds extracted from this mushroom have an efficient antimicrobial impact against pathogenic bacteria and yeast isolated from urine, sputum, and vaginal swabs. Different methods were employed in the characterization of AgNPs. The microorganisms of isolated bacteria and yeast were identified according to morphological features, results of biochemical tests, and the VITEK 2 compact system. The susceptibility to antibiotics was determined by the disk method. The bacteria and yeast resisted all antibiotics employed in this research. But the AgNPs had good antimicrobial activity against pathogenic bacteria and yeast. The highest inhibition zone of AgNPs against <i>Pseudomonas aeruginosa</i> in a 100 mg/mL concentration was 30 mm, while the minimal inhibition zone of AgNPs was 12 mm against <i>Escherichia coli</i> at the same concentration. The antibacterial effect of the synthesized AgNPs was concentration-dependent against Gram-positive and Gram-negative bacteria. With respect to the effect on yeast growth, there was a clear inhibitory effect of the synthesized AgNPs at 100 mg/mL, when the largest zone of inhibition was found against <i>Candida glabrata</i> (29 mm), and the minimal inhibition zone was found against <i>C. guillermondi</i> and <i>C. albican</i> (23 mm). Similarly, the AgNPs synergized with antibiotics were used against pathogenic bacterial and yeast isolates because when antibiotics and AgNPs were combined, the inhibition zones were larger compared to those of the antibiotics alone.