Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO2 Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

György Schneider; Bettina Schweitzer; Anita Steinbach; Botond Zsombor Pertics; Alysia Cox; László Kőrösi

doi:10.3390/foods10081786

Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO₂ Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

Foods. 2021 Jul 31;10(8):1786. doi: 10.3390/foods10081786.

Authors

György Schneider¹, Bettina Schweitzer¹, Anita Steinbach¹, Botond Zsombor Pertics¹, Alysia Cox², László Kőrösi³

Affiliations

¹ Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Szigeti Street 12, H-7624 Pécs, Hungary.
² Department of Biotechnology, Nanophagetherapy Center, Enviroinvest Corporation, Kertváros Street 2, H-7632 Pécs, Hungary.
³ Research Institute for Viticulture and Oenology, University of Pécs, Pázmány Péter Street 4, H-7634 Pécs, Hungary.

Abstract

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO₂ nanoparticles (PF-TiO₂) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO₂ NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO₂ NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO₂/3 h and PF-TiO₂/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~10⁶ by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO₂/1 h and PF-TiO₂/12 h NPs was lower, typically causing a ~2-4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO₂/0 h was comparable to P25 TiO₂, a commercial TiO₂ with high photocatalytic activity. Our results show that PF-co-doping of TiO₂ NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.

Keywords: TiO2; antibacterial; co-doping; foodborne; nanoparticles; photocatalysis.