<abstract xmlns="http://www.w3.org/1999/xhtml">

The antibacterial activity of zinc oxide nanoparticles (ZnO NPs) has received significant attention worldwide due to the emergence of multidrug-resistant microorganisms. Shiga toxin-producing <italic>Escherichia coli</italic> is a major foodborne pathogen that causes gastroenteritis that may be complicated by hemorrhagic colitis or hemolytic uremic syndrome. Therefore, this study aimed to evaluate the antimicrobial effect of ZnO NPs against <italic>E. coli</italic> O26 and its Shiga toxin type 2 (<italic>Stx2</italic>). Multidrug resistance phenotype was observed in <italic>E. coli</italic> O26, with co-resistance to several unrelated families of antimicrobial agents. Different concentrations of ZnO NPs nanoparticles (20 nm) were tested against different cell densities of <italic>E. coli</italic> O26 (108, 106 and 105 CFU/ml). The minimum inhibitory concentration (MIC) value was 1 mg/ml. Minimum bactericidal concentration (MBC) was 1.5 mg/ml, 2.5 mg/ml and 3 mg/ml, respectively, depending on ZnO NPs concentrations and bacterial cell density. Results showed a significant (P≤0.05) decrease in <italic>Stx2</italic> level in a response to ZnO NPs treatment. As detected by quantitative real-time PCR, ZnO NPs down-regulated the expression of the <italic>Stx2</italic> gene (P≤0.05). Moreover, various concentrations of ZnO NPs considerably reduced the total protein content in <italic>E. coli</italic> O26. There was a significant reduction in protein expression with increased ZnO NPs concentration compared to the non-treated control. Scanning electron micrographs (SEM) of the treated bacteria showed severe disruptive effects on <italic>E. coli</italic> O26 with increasing ZnO NPs concentration. The results revealed a strong correlation between the antibacterial effect and ZnO NPs concentrations. ZnO NPs exert their antibacterial activities through various mechanisms and could be used as a potent antibacterial agent against <italic>E. coli</italic> O26.
</abstract>

The antibacterial activity of zinc oxide nanoparticles (ZnO NPs) has received significant attention worldwide due to the emergence of multidrug-resistant microorganisms. Shiga toxin-producing Escherichia coli is a major foodborne pathogen that causes gastroenteritis that may be complicated by hemorrhagic colitis or hemolytic uremic syndrome. Therefore, this study aimed to evaluate the antimicrobial effect of ZnO NPs against E. coli O26 and its Shiga toxin type 2 (Stx2). Multidrug resistance phenotype was observed in E. coli O26, with co-resistance to several unrelated families of antimicrobial agents. Different concentrations of ZnO NPs nanoparticles (20 nm) were tested against different cell densities of E. coli O26 (108, 106 and 105 CFU/ml). The minimum inhibitory concentration (MIC) value was 1 mg/ml. Minimum bactericidal concentration (MBC) was 1.5 mg/ml, 2.5 mg/ml and 3 mg/ml, respectively, depending on ZnO NPs concentrations and bacterial cell density. Results showed a significant (P≤0.05) decrease in Stx2 level in a response to ZnO NPs treatment. As detected by quantitative real-time PCR, ZnO NPs down-regulated the expression of the Stx2 gene (P≤0.05). Moreover, various concentrations of ZnO NPs considerably reduced the total protein content in E. coli O26. There was a significant reduction in protein expression with increased ZnO NPs concentration compared to the non-treated control. Scanning electron micrographs (SEM) of the treated bacteria showed severe disruptive effects on E. coli O26 with increasing ZnO NPs concentration. The results revealed a strong correlation between the antibacterial effect and ZnO NPs concentrations. ZnO NPs exert their antibacterial activities through various mechanisms and could be used as a potent antibacterial agent against E. coli O26.

Antimicrobial impacts of zinc oxide nanoparticles on Shiga toxin-producing <italic>Escherichia coli</italic> (serotype O26)

Laboratory of Directorate of Veterinary Medicine

Department of Microbiology, Faculty of Veterinary Medicine

Department of Biological Science, Faculty of Sciences

Poultry Department, Faculty of Agriculture

Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine

Annals of Animal Science

This work is licensed under the Creative Commons Attribution 4.0 International License.

Antimicrobial impacts of zinc oxide nanoparticles on Shiga toxin-producing  (serotype O26)

The antibacterial activity of zinc oxide nanoparticles (ZnO NPs) has received significant attention worldwide due to the emergence of multidrug-resistant...

Antimicrobial impacts of zinc oxide nanoparticles on Shiga toxin-producing Escherichia coli (serotype O26)

Publicado en línea: 03 may 2023

Páginas: 461 - 471

Recibido: 24 oct 2022

Aceptado: 15 nov 2022

DOI: https://doi.org/10.2478/aoas-2022-0088

Palabras clave
ZnO NPs, O26, protein expression, SEM

© 2023 Rasha M. Sherif et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Antimicrobial impacts of zinc oxide nanoparticles on Shiga toxin-producing Escherichia coli (serotype O26)

Publicado en línea: 03 may 2023

Páginas: 461 - 471

Recibido: 24 oct 2022

Aceptado: 15 nov 2022

DOI: https://doi.org/10.2478/aoas-2022-0088

Palabras claveZnO NPs, O26, protein expression, SEM

© 2023 Rasha M. Sherif et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Palabras clave
ZnO NPs, O26, protein expression, SEM