Combating Multidrug-Resistant Avian pathogenic E. coli: Virulence Gene Profiling and the Potential of Chitosan Nanoparticles

Nofal, Abdelmohsen A.; Marouf, Sherif A; Ibrahim, Hazem M.; Shalaby, Azhar G.; Ragab, Eman

doi:10.21608/ejvs.2025.411634.3025

Combating Multidrug-Resistant Avian pathogenic E. coli: Virulence Gene Profiling and the Potential of Chitosan Nanoparticles

Articles in Press

Document Type : Original Article

Authors

¹ Damietta Regional Laboratory, Animal Health Research Institute, Agriculture Research Center (ARC)

² Professor of Microbiology, Faculty of Veterinary Medicine, Cairo University

³ Veterinary Serum and Vaccine Research Institute, Agricultural Research Center (ARC)

⁴ Central Laboratory for Quality Control of Poultry Production.

⁵ department of veterinary microbiology, faculty of veterinary medicine, Cairo university

10.21608/ejvs.2025.411634.3025

Abstract

Avian pathogenic Escherichia coli (APEC) is a leading cause of colibacillosis, contributing to significant economic losses in poultry production worldwide. This study aimed to investigate the prevalence of virulence and antimicrobial resistance genes in APEC isolates from different Egyptian governorates in addition evaluation the antimicrobial efficacy of chitosan nanoparticles (CNPs) as a pathogenic Escherichia coli (APEC) is a leading cause of colibacillosis, contributing to significant economic losses in poultry production worldwide. This study aimed to investigate the prevalence of virulence and antimicrobial resistance genes in APEC isolates from different Egyptian governorates in addition evaluation the antimicrobial efficacy of chitosan nanoparticles (CNPs) as a potential alternative treatment. A total of 180 visceral organ samples were collected from broiler, layer, and breeder chickens suspected of colibacillosis; 158 (88%) yielded bacterial isolates, of which 85 (54%) were confirmed as E. coli biochemically, and 69 (81%) were serotyped. Antimicrobial susceptibility testing revealed high levels of antimicrobial resistance, with complete resistance to streptomycin and nalidixic acid, and notable resistance to ampicillin, tetracycline, and doxycycline. PCR detected three virulence genes (papC, iss, iutA) and three resistance genes (blaCTX-M, qnrA, and sul1), with sul1 present in all isolates. CNPs synthesized via ionic gelation showed a mean particle size of 56.6 nm and demonstrated effective antibacterial activity at a minimum inhibitory concentration of 50 mg/ml. These findings highlight the alarming prevalence of MDR APEC in Egyptian poultry and suggest that CNPs hold promise as a sustainable antimicrobial alternative.

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