Virulence genes of avian pathogenic Escherichia coli isolated from commercial chicken in Nepal

Rebanta Kumar Bhattarai; Hom Bahadur Basnet; Ishwari Prasad Dhakal; Evangelyn C Alocilja

doi:10.1016/j.cimid.2023.101961

Virulence genes of avian pathogenic Escherichia coli isolated from commercial chicken in Nepal

Comp Immunol Microbiol Infect Dis. 2023 Apr:95:101961. doi: 10.1016/j.cimid.2023.101961. Epub 2023 Feb 23.

Authors

Rebanta Kumar Bhattarai¹, Hom Bahadur Basnet², Ishwari Prasad Dhakal³, Evangelyn C Alocilja⁴

Affiliations

¹ Department of Veterinary Microbiology and Parasitology, Faculty of Animal Science, Veterinary Science and Fisheries, Agriculture and Forestry University, Nepal. Electronic address: rkbhattarai@afu.edu.np.
² Department of Veterinary Microbiology and Parasitology, Faculty of Animal Science, Veterinary Science and Fisheries, Agriculture and Forestry University, Nepal. Electronic address: hbbasnet@afu.edu.np.
³ Department of Medicine and Public Health, Faculty of Animal Science, Veterinary Science and Fisheries, Agriculture and Forestry University, Nepal. Electronic address: ipdhakal5@gmail.com.
⁴ Biosystems and Agricultural Engineering, Michigan State University, USA. Electronic address: alocilja@msu.edu.

PMID: 36870115
DOI: 10.1016/j.cimid.2023.101961

Abstract

Colibacillosis is the most common bacteriological disease in poultry. The purpose of this study was to determine the recovery rate of avian pathogenic Escherichia coli (APEC) strains, the distribution, prevalence of Escherichia coli Reference (ECOR) collection and virulence associated gene (VAG) in four types of chickens infected by colibacillosis. Commercial broilers and layers had the highest percentage of positive APEC isolates (91%). We confirmed the ECOR phylogroup including B1 and E for the first time in Nepal. The prevalences of these phylogroups among chicken types were significantly different (p < 0.001). Among 57 VAGs, the number of genes found per isolate ranged from 8 to 26, with the top 5 VAGs being fimH (100%), iss^a (92.2%), traT^a (90.6%), sit chro. (86%), and ironEC (84.8%). We found significant differences in gene prevalence among the chicken types. The predominance of B1 and E, and the VAG patterns suggest considering ECOR phylogroup and VAGs while formulating strategies for the prevention and control of APEC.

Keywords: Avian pathogenic E. coli (APEC); Broiler; Broiler breeder; Chicken; Colibacillosis; Escherichia coli Reference (ECOR) collection; Genotypic characterization; Layer; Layer breeder; Virulence-associated gene.

MeSH terms

Animals
Chickens
Escherichia coli
Escherichia coli Infections* / epidemiology
Escherichia coli Infections* / veterinary
Nepal / epidemiology
Phylogeny
Poultry Diseases* / epidemiology
Virulence / genetics