| Autor: |
Abou Elez RMM; Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt., Elsohaby I; Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt.; Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada.; Department of Infectious Diseases and Public Health, Jockey Club of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong., El-Gazzar N; Department of Botany and Microbiology, Faculty of Science, Zagazig University, Zagazig 44519, Egypt., Tolba HMN; Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt., Abdelfatah EN; Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt., Abdellatif SS; Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt., Mesalam AA; Department of Therapeutic Chemistry, National Research Centre (NRC), Dokki, Cairo 12622, Egypt., Tahoun ABMB; Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt. |
| Abstrakt: |
Salmonella enterica is one of the most common causes of foodborne illness worldwide. Contaminated poultry products, especially meat and eggs are the main sources of human salmonellosis. Thus, the aim of the present study was to determine prevalence, antimicrobial resistance profiles, virulence, and resistance genes of Salmonella Enteritidis ( S. enteritidis ) and Salmonella Typhimurium ( S. Typhimurium) isolated from laying hens, table eggs, and humans, in Sharkia Governorate, Egypt. The antimicrobial activity of Biosynthesized Silver Nanoparticles (AgNPs) was also evaluated. Salmonella spp. were found in 19.3% of tested samples with laying hens having the highest isolation rate (33.1%). S. Enteritidis) (5.8%), and S. Typhimurium (2.8%) were the dominant serotypes. All isolates were ampicillin resistant (100%); however, none of the isolates were meropenem resistant. Multidrug-resistant (MDR) was detected in 83.8% of the isolates with a multiple antibiotic resistance index of 0.21 to 0.57. Most isolates (81.1%) had at least three virulence genes ( sopB , stn, and hilA ) and none of the isolates harbored the pefA gene; four resistance genes ( blaTEM , tetA , nfsA, and nfsB ) were detected in 56.8% of the examined isolates. The AgNPs biosynthesized by Aspergillus niveus exhibit an absorption peak at 420 nm with an average size of 27 nm. AgNPs had a minimum inhibitory concentration of 5 µg/mL against S. enteritidis and S. typhimurium isolates and a minimum bactericidal concentration of 6 and 8 µg/mL against S. enteritidis and S. typhimurium isolates, respectively. The bacterial growth and gene expression of S. enteritidis and S. typhimurium isolates treated with AgNPs were gradually decreased as storage time was increased. In conclusion, this study indicates that S. enteritidis and S. typhimurium isolated from laying hens, table eggs, and humans exhibits resistance to multiple antimicrobial classes. The biosynthesized AgNPs showed potential antimicrobial activity against MDR S. enteritidis and S. typhimurium isolates. However, studies to assess the antimicrobial effectiveness of the biosynthesized AgNPs in laying hen farms are warranted. |
