Antibiofilm Effect of Biogenic Silver Nanoparticles Combined with Oregano Derivatives against Carbapenem-Resistant Klebsiella pneumoniae

Sara Scandorieiro; Franciele Maira M B Teixeira; Mara C L Nogueira; Luciano A Panagio; Admilton G de Oliveira; Nelson Durán; Gerson Nakazato; Renata K T Kobayashi

doi:10.3390/antibiotics12040756

Antibiofilm Effect of Biogenic Silver Nanoparticles Combined with Oregano Derivatives against Carbapenem-Resistant Klebsiella pneumoniae

Antibiotics (Basel). 2023 Apr 14;12(4):756. doi: 10.3390/antibiotics12040756.

Authors

Sara Scandorieiro^{1

2}, Franciele Maira M B Teixeira³, Mara C L Nogueira³, Luciano A Panagio⁴, Admilton G de Oliveira^{5

6}, Nelson Durán⁷, Gerson Nakazato¹, Renata K T Kobayashi¹

Affiliations

¹ Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, Universidade Estadual de Londrina, Londrina 86057-970, Brazil.
² Laboratory of Innovation and Cosmeceutical Technology, Department of Pharmaceutical Sciences, Center of Health Sciences, Hospital Universitário de Londrina, Londrina 86038-350, Brazil.
³ Department of Dermatological, Infectious and Parasitic Diseases, Faculdade de Medicina de Sao Jose do Rio Preto, São José do Rio Preto 15090-000, Brazil.
⁴ Laboratory of Medical Mycology and Oral Microbiology, Department of Microbiology, Center of Biological Sciences, Universidade Estadual de Londrina, Londrina 86057-970, Brazil.
⁵ Laboratory of Microbial Biotechnology, Department of Microbiology, Center of Biological Sciences, Universidade Estadual de Londrina, Londrina 86057-970, Brazil.
⁶ Laboratory of Electron Microscopy and Microanalysis, Center of Biological Sciences, Universidade Estadual de Londrina, Londrina 86057-970, Brazil.
⁷ Institute of Biology, Universidade Estadual de Campinas, Campinas 13083-862, Brazil.

Abstract

Resistant bacteria may kill more people than COVID-19, so the development of new antibacterials is essential, especially against microbial biofilms that are reservoirs of resistant cells. Silver nanoparticles (bioAgNP), biogenically synthesized using Fusarium oxysporum, combined with oregano derivatives, present a strategic antibacterial mechanism and prevent the emergence of resistance against planktonic microorganisms. Antibiofilm activity of four binary combinations was tested against enteroaggregative Escherichia coli (EAEC) and Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC): oregano essential oil (OEO) plus bioAgNP, carvacrol (Car) plus bioAgNP, thymol (Thy) plus bioAgNP, and Car plus Thy. The antibiofilm effect was accessed using crystal violet, MTT, scanning electron microscopy, and Chromobacterium violaceum anti-quorum-sensing assays. All binary combinations acted against preformed biofilm and prevented its formation; they showed improved antibiofilm activity compared to antimicrobials individually by reducing sessile minimal inhibitory concentration up to 87.5% or further decreasing biofilm metabolic activity and total biomass. Thy plus bioAgNP extensively inhibited the growth of biofilm in polystyrene and glass surfaces, disrupted three-dimensional biofilm structure, and quorum-sensing inhibition may be involved in its antibiofilm activity. For the first time, it is shown that bioAgNP combined with oregano has antibiofilm effect against bacteria for which antimicrobials are urgently needed, such as KPC.

Keywords: MTT; anti-quorum sensing; carvacrol; crystal violet; green nanotechnology; oregano oil; scanning electron microscopy; thymol.

Grants and funding

This study was supported by the Postgraduate Program in Microbiology of Universidade Estadual de Londrina and in part by the National Council for Scientific and Technological Development—CNPq (305972/2022-7) and (305414/2021-6). Sara Scandorieiro was funded by a Ph.D. scholarship Coordination for the Improvement of Higher Education Personnel (CAPES)-Finance Code 001.