Antimicrobial activity of phytofabricated silver nanoparticles using Carica papaya L. against Gram-negative bacteria

Mbarga Manga Joseph Arsene; Podoprigora Irina Viktorovna; Marukhlenko Alla; Morozova Mariya; Anyutoulou Kitio Linda Davares; Bassa Zacharie Carime; Gizinger Oksana Anatolievna; Yashina Natalya Vyacheslavovna; Zhigunova Anna Vladimirovna; Smolyakova Larissa Andreevna; Vasilieva Elena Aleksandrovna; Butusov Leonid Alekseevich; Borekhova Marina Nikolaïevna; Kezimana Parfait; Vodyashkin Andrey

doi:10.14202/vetworld.2023.1301-1311

Antimicrobial activity of phytofabricated silver nanoparticles using Carica papaya L. against Gram-negative bacteria

Vet World. 2023 Jun;16(6):1301-1311. doi: 10.14202/vetworld.2023.1301-1311. Epub 2023 Jun 13.

Authors

Mbarga Manga Joseph Arsene^{1

2}, Podoprigora Irina Viktorovna^{1

2}, Marukhlenko Alla³, Morozova Mariya³, Anyutoulou Kitio Linda Davares¹, Bassa Zacharie Carime⁴, Gizinger Oksana Anatolievna¹, Yashina Natalya Vyacheslavovna¹, Zhigunova Anna Vladimirovna¹, Smolyakova Larissa Andreevna¹, Vasilieva Elena Aleksandrovna¹, Butusov Leonid Alekseevich⁵, Borekhova Marina Nikolaïevna¹, Kezimana Parfait⁶, Vodyashkin Andrey⁷

Affiliations

¹ Department of Microbiology V.S. Kiktenko, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia.
² Research Institute of Molecular and Cellular Medicine, Medical Institute RUDN University named after Patrice Lumumba, Moscow, Russia.
³ Department of Pharmaceutical and Toxicological Chemistry, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia.
⁴ Department of Food Sciences and Nutrition, National School of Agro-industrial Sciences, University of Ngaoundere, Cameroon.
⁵ Institute of Innovative Engineering Technologies, RUDN University named after Patrice Lumumba, Moscow, Russia.
⁶ Department of Agrobiotechnology, Agrarian Institute, RUDN University named after Patrice Lumumba, Moscow, Russia.
⁷ Institute of Biochemical Technology and Nanotechnology. RUDN University named after Patrice Lumumba, Moscow, Russia.

Abstract

Background and aim: Antibiotic resistance, especially in Gram-negative bacteria, is a major public health risk affecting all industries requiring the use of antibiotics, including agriculture and animal breeding. This study aimed to use papaya extracts to synthesize silver nanoparticles (AgNPs) and evaluate their antimicrobial activity against various Gram-negative bacteria.

Materials and methods: Silver nanoparticles were synthesized from the aqueous extracts of papaya seed, root, and bark, with AgNO₃ used as a reducing agent. The phytofabricated AgNPs were analyzed by ultraviolet-visible absorbance, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, and photon cross-correlation spectroscopy (PCCS). The disc-diffusion method was used to perform antibacterial analysis, and the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations were determined. We also investigated the antibiofilm activity of AgNPs and attempted to elucidate the potential mechanism of action on Escherichia coli ATCC 25922.

Results: Phytofabrication of AgNPs was successful with papaya root (PR-AgNPs) and papaya seed (PS-AgNPs), but not with papaya bark. Silver nanoparticles using papaya root and PS-AgNPs were both cubic and showed maximum absorbances of 2.6 and 0.3 AUs at 411.6 and 416.8 nm wavelengths and average hydrodynamic diameters X50 of 59.46 ± 7.03 and 66.57 ± 8.89 nm, respectively. The Ag in both AgNPs was confirmed by X-ray fluorescence by a distinctive peak in the spectrum at the silver Kα line of 22.105 keV. Both AgNPs exhibited broad-spectrum antimicrobial and antibiofilm activity against all Gram-negative bacteria, and PR-AgNPs were slightly better than AgNPs-PS. The MIC ranged from 16 μg/mL-128 μg/mL and 16 μg/mL-64 μg/mL, respectively, for PS-AgNPs and PR-AgNPs. The elucidation of the mechanism of action revealed interference with E. coli ATCC 25922 growth kinetics and inhibition of H⁺-ATPase proton pumps.

Conclusion: Papaya seed and root extracts were efficient reducing agents for the biogenic synthesis of AgNPs, with noteworthy antibacterial and antibiofilm activities. Future studies should be conducted to identify the phytochemicals and the mechanism involved in AgNPs synthesis.

Keywords: Carica papaya; Gram-negative; antibiotic resistance; biogenic synthesis; silver nanoparticles.