Volume: 57 Issue: 2
Year: 2026, Page: 251-255, Doi: https://doi.org/10.51966/jvas.2026.57.2.251-255
Received: Dec. 14, 2025 Accepted: March 19, 2026 Published: June 30, 2026
Escherichia coli has more than 150 strains that inhabit a wide range of environments. Among them, avian pathogenic E. coli (APEC) strains are responsible for causing infections in birds of different ages, affecting multiple organs. These infections, collectively referred to as colibacillosis, result in high mortality rates in chicken and consequently impose severe economic losses on the global poultry industry. The pathogenicity of APEC strains is closely associated with specific virulence genes encoded within their genome. The objective of the study is to evaluate genes linked to APEC isolates from colibacillosis cases that have been reported from University Poultry and Duck farm, KVASU, Mannuthy. Here, 19 E. coli strains isolated from birds with colibacillosis were analysed for occurrence of six virulence associated genes. The virulence profiles showed that 100 % of the isolates were possessing the gene fimC, 57.89 per cent of isolates possessed iucD gene, and none of them were possessing papC, stx1, stx2 and st1genes.The study revealed that APEC isolates carry plasmid-associated virulence genes, highlighting the importance of continuous surveillance to control the transmission of APEC within poultry farms.
Keywords: APEC, virulence genes, characterisation, colibacillosis
Barnes, H. J., Vaillancourt, J. P., & Gross, W. G. (2003). Colibacillosis. In Y. M. Saif, H. J. Barnes, J. R. Glisson, A. M. Fadly, L. R. McDougald and D. E. Swayne (Eds.), Diseases of poultry (11th ed., p. 1231). Ames: Iowa State University Press.
Brüssow, H., Canchaya, C., & Hardt, W. D. (2004). Phages and the evolution of bacterial pathogens: From genomic rearrangements to lysogenic conversion. Microbiology and Molecular Biology Reviews, 68(3), 560–602. https://doi.org/10.1128/mmbr.68.3.560-602.2004
Camarda, A., Circella, E., Giovanardi, D., Pennelli, D., Battista, P., Campagnari, E., Bruni, G., & Tagliabue, S. (2007). Avian pathogenic Escherichia coli in Audouin gulls (Larus audouinii): Could they affect the survival of bird colonies? Italian Journal of Animal Science, 6(3), 317–320. https://doi.org/10.4081/ijas.2007.317
Chui, L., Couturier, M. R., Chiu, T., Wang, G., Olson, A. B., McDonald, R. R., Antonishyn, N. A., Horsman, G., & Gilmour, M. W. (2010). Comparison of Shiga toxin-producing Escherichia coli detection methods using clinical stool samples. Journal of Molecular Diagnostics, 12(4), 469–475. https://dx.doi.org/10.2353/jmoldx.2010.090221
Eid, H. I., Algammal, A. M., Nasef, S. A., Elfeil, W. K. & Mansour, G. H. (2016). Genetic variation among avian pathogenic E. coli strains isolated from broiler chickens. Asian Journal of Animal and Veterinary Advances, 11(6), 350–356. 10.3923/ajava.2016.350.356
Gao, Q., Wang, X., Xu, H., Xu, Y., Ling, J., Zhang, D., Gao, S., & Liu, X. (2012). Roles of iron acquisition systems in virulence of extraintestinal pathogenic Escherichia coli: Salmochelin and aerobactin contribute more to virulence than heme in a chicken infection model. BMC Microbiology, 12, 143. https://doi.org/10.1186/1471-2180-12-143
Hamed, B. M., Elenbaawy, M. I., Mahmoud, H., & Ragab, E. (2023). Investigation of antibiotic resistance pattern and virulence determinants in avian pathogenic Escherichia coli isolated from broiler chickens in Egypt. World Veterinary Journal, 13(1), 85–94.
Janben, T., Schwarz, C., Preikschat, P., Voss, M., Philipp, H. C., & Wieler, L. H. (2001). Virulence-associated genes in avian pathogenic Escherichia coli (APEC) isolated from internal organs of poultry having died from colibacillosis. International Journal of Medical Microbiology, 291(4), 371–378. https://doi.org/10.1078/1438-4221-00143
Johnson, T. J., Siek, K. E., Johnson, S. J., & Nolan, L.K. (2006). DNA sequence of a ColV plasmid and prevalence of selected plasmid-encoded virulence genes among avian Escherichia coli strains. Journal of Bacteriology, 188(2), 745–758. http://dx.doi.org/10.1128/JB.188.2.745-758.2006
Kawano, M., Yaguchi, K., & Osawa, R. (2006). Genotypic analyses of Escherichia coli isolated from chickens with colibacillosis and apparently healthy chickens in Japan. Microbiology and Immunology, 50(11), 961–966. 10.1111/j.1348-0421.2006.tb03872.x
Laopiem, S., Witoonsatian, K., Kulprasetsri, S., & others. (2025). Antimicrobial resistance, virulence gene profiles and phylogenetic groups of Escherichia coli isolated from healthy broilers and broilers with colibacillosis in Thailand. BMC Veterinary Research, 21, 160. https://doi.org/10.1186/s12917-025-04626-x
Mellata, M. (2013). Human and avian extraintestinal pathogenic Escherichia coli: Infections, zoonotic risks, and antibiotic resistance trends. Foodborne Pathogens and Disease, 10(11), 916–932. https://doi.org/10.1089/fpd.2013.1533
Mellata, M., Ameiss, K. M., Mo, H., & Curtiss, R. (2010). Characterisation of the contribution to virulence of three large plasmids of avian pathogenic Escherichia coli χ7122 (O78:K80:H9). Infection and Immunity, 78(4), 1528-1541. https://doi.org/10.1128/IAI.00981-09
Paixao, A. C., Ferreira, A. C., Fontes, M., Themudo, P., Albuquerque, T., Soares, M. C., Fevereiro, M., Martins, L., & de Sá, M. I. C. (2016). Detection of virulence-associated genes in pathogenic and commensal avian Escherichia coli isolates. Poultry Science, 95(7), 1646–1652. https://doi.org/10.3382/ps/pew087
Paton, J. C., & Paton, A. W. (1998). Pathogenesis and diagnosis of Shiga toxin-producing E. coli infections. Clinical Microbiology Reviews, 11(3), 450–479. https://doi.org/10.1128/cmr.11.3.450
Pusz, P., Bok, E., Mazurek, J., Stosik, M. and Baldy-Chudzik, K. (2014). Type 1 fimbriae in commensal Escherichia coli derived from healthy humans. Acta Biochimica Polonica, 61(2), 389–392. https://doi.org/10.18388/abp.2014_1912
Roussan, D. A., Zakaria, H., Khawaldeh, G., & Shaheen, I. (2014). Differentiation of avian pathogenic Escherichia coli strains from broiler chickens by multiplex polymerase chain reaction (PCR) and random amplified polymorphic (RAPD) DNA. Open Journal of Veterinary Medicine, 4(4), 211–219. http://dx.doi.org/10.4236/ojvm.2014.410025
Singh, A., Chhabra, D., Gangil, R., Sharda, R., Sikrodia, R., & Audarya, S. (2023). Studies of virulence factors of avian pathogenic Escherichia coli in avian colibacillosis by in vitro method and PCR. Indian Journal of Animal Research, 57(5), 499–504. 10.18805/IJAR.B-4329
Sobur, A., Haque, Z. F., Sabuj, A. A., Ievy, S., Rahman, A. T., El Zowalaty, M. E., & Rahman, T. (2019). Molecular detection of multidrug and colistin-resistant Escherichia coli isolated from house flies in various environmental settings. Future Microbiology, 14(10), 847–858. https://doi.org/10.2217/fmb-2019-0053
Subedi, M., Luitel, H., Devkota, B., Bhattarai, R. K., Phuyal, S., Panthi, P., Shrestha, A., & Chaudhary, D. K. (2018). Antibiotic resistance pattern and virulence gene content in avian pathogenic Escherichia coli (APEC) from broiler chickens in Chitwan, Nepal. BMC Veterinary Research, 14, 113. https://doi.org/10.1186/s12917-018-1442-z
Wani, S. A., Samanta, I., Bhat, M. A., & Nishikawa, Y. (2004). Investigation of Shiga toxin-producing Escherichia coli in avian species in India. Letters in Applied Microbiology, 39(5), 389–394. https://doi.org/10.1111/j.1472-765x.2004.01586.x
Zakariazadeh, N., Shayegh, J., & Ghorbani, A. (2019). Phylogenetic typing and virulence gene profile of pathogenic and commensal avian Escherichia coli in Iran: A notable finding. Comparative Clinical Pathology, 28(2), 525–530. https://doi.org/10.1007/s00580-019-02921-2
© 2026 Vineetha et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Vineetha, P.G., Sankaralingam, S., Chacko, B., Prasoon, S., Harikrishnan, S., Nitha, P.N. & Arundhathi, U. (2026). Screening of avian pathogenic Escherichia coli isolates from clinical cases of colibacillosis for virulence associated genes. Journal of Veterinary and Animal Sciences, 57(2),251-255 https://doi.org/10.51966/jvas.2026.57.2.251-255