Antibactrial Activity of Asteriscus graveolens Methanolic Extract: Synergistic Effect with Fungal Mediated Nanoparticles against Some Enteric Bacterial Human Pathogens

Antibactrial activity of Asteriscus graveolens methanolic extract and its synergy effect with fungal mediated silver nanoparticles (AgNPs) against some enteric bacterial human pathogen was conducted. Silver nanoparticles were synthesized by the fungal strain namely Tritirachium oryzae W5H as reported early. In this study, MICs of AgNPs against E. aerogenes, Salmonella sp., E. coli and C. albicans in order were 2.13, 19.15, 0.08 and 6.38 µg/mL, respectively, while the MICs of A. graveolens ethanolic extract against the same bacteria were 4, 366, <3300 and 40 µg/mL, respectively. The MIC values at concentration less than 19.15 and 40 µg/ml indicating the potent bacteriostatic effect of AgNPs and A. graveolens ethanolic extract. Increasing in IFA was reported when Nitrofurantion and Trimethoprim were combined with Etoh extract with maximum increase in IFA by 6 and 12 folds for, respectively. Also, 10 folds increasing in IFA was reported when trimethoprim was combined with AgNPs: Etoh extract. But, there were no synergistic effect between the antifungal agents (Caspofungin and Micafungin) combined with AgNPs and or A. graveolens ethanolic extract against C. albicans. The potent synergistic effect of A. graveolens ethanolic extract and/or NPs with the conventional antibiotics is novel in inhibiting antibiotics resistant bacteria. In this study, remarkable increasing in the antibacterial activity, when the most resistant antibiotics combined with A. graveolens ethanolic extract and/or NPs was reported.