Veterinary Research Forum

Molecular identification of Avibacterium paragallinarum isolates from backyard and commercial layer chickens in Iran

Document Type : Original Article

Authors

Chnoor Poorshamohammad 1
Mohammad Hassanzadeh 1
Abbas Nouri 2
Mohammad Hassan Bozorgmehrifard 1
Mohammad Abdoshah 2
Fereshteh Sabouri 2
Mohsen Bashashati 2

1 Department of Avian Health and Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

2 Department of Avian Disease Research and Diagnostics, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran

10.30466/vrf.2025.2064747.4815
Abstract
Infectious coryza, caused by Avibacterium paragallinarum, poses a significant economic threat to the global poultry industry. Although infectious coryza is present in Iran, there is limited molecular data characterizing the circulating strains, particularly regarding key hemagglutinin genes such as hagA. This study aimed to investigate the genetic diversity and phylogenetic relationships of the Av. paragallinarum isolates recovered from commercial and backyard poultry in Iran by sequencing the hagA gene and comparing the findings with those of global strains. Twenty-three Av. paragallinarum isolates collected from Iranian poultry farms underwent PCR amplification and sequencing of the hagA gene. Nucleotide and deduced amino acid sequences were analyzed for homology, subjected to BLAST searches, and used for phylogenetic reconstruction. The isolates showed high sequence identity, ranging from 94.10 - 99.90% at the nucleotide level and 92.10 - 100% at the protein level. Phylogenetic analysis classified the isolates into five distinct clusters (Iran-1 to Iran-5). The largest cluster (Iran-1) showed a strong affiliation with strains from China and India, whereas the other isolates clustered with strains from South Korea, Germany, and Japan. Notably, the Iran-5 group exhibited high similarity to a non-typable strain from USA. Additionally, eight isolates encoded truncated HagA proteins, each consisting of 344 rather than 345 amino acids. This study demonstrates the circulation of genetically diverse Av. paragallinarum strains in Iran. These findings highlight the need for further molecular investigations to improve control measures and assess the efficacy of the vaccines currently used in the country.

Keywords

Avibacterium paragallinarum
Genetic diversity
hagA
Infectious coryza
Iran
Subjects
1.     Blackall PJ. Infectious coryza: overview of the disease and new diagnostic options. Clin Microbiol Rev 1999; 12(4): 627-632.
2.     Guo M, Liu D, Chen X, et al. Pathogenicity and innate response to Avibacterium paragallinarum in chickens. Poult Sci 2022; 101(1): 101523. doi: 10.1016/j.psj. 2021.101523.
3.     Guo M, Jin Y, Wang H, et al. Establishment of a multilocus sequence typing scheme for the characterization of Avibacterium paragallinarum. Vet Sci 2024; 11(5): 208. doi: 10.3390/vetsci11050208.
4.     Peighambari SM, Nouri A, Barzegari R, et al. Isolation and molecular identification of Avibacterium paragallinarum isolated from commercial layer and backyard chickens in Iran. Iran J Vet Med 2022; 16(3); 239-248.
5.     Nouri A, Bashashati M, Mirzaie SG, et al. Isolation, identification and antimicrobial susceptibility of Avibacterium paragallinarum from backyard chicken in retail markets of Karaj and Tehran cities, Iran. Arch Razi Inst 2021; 76(4): 1047-1053.
6.     Blackall PJ, Eaves LE, Rogers DG. Proposal of a new serovar and altered nomenclature for Haemophilus paragallinarum in the Kume hemagglutinin scheme. J Clin Microbiol 1990; 28(6): 1185-1187.
7.     Shelkamy MMS, Hashish A, Chaves M, et al. Develop-ment and validation of PCR assays for improved diagnosis of infectious coryza by differentiating pathogenic and nonpathogenic Avibacterium paragallinarum. Avian Dis 2025; 68(S1): 380-390.
8.     Page LA. Haemophilus infections in chickens. I. Characteristics of 12 Haemophilus isolates recovered from diseased chickens. Am J Vet Res 1962; 23: 85-95.
9.     Feberwee A, Dijkman R, Buter R, et al. Identification and characterization of Dutch Avibacterium paragallinarum isolates and the implications for diagnostics. Avian Pathol 2019; 48(6): 549-556.
10. Hsu YM, Shieh HK, Chen WH, et al. Immunogenicity and haemagglutination of recombinant Avibacterium paragallinarum HagA. Vet Microbiol 2007; 122(3-4): 280-289.
11. Jeong OM, Kang MS, Blackall PJ, et al. Genotypic divergence of Avibacterium paragallinarum isolates with different growth requirements for nicotinamide adenine dinucleotide. Avian Pathol 2020; 49(2): 153-160.
12. Chen X, Miflin JK, Zhang P, et al. Development and application of DNA probes and PCR tests for Haemophilus paragallinarum. Avian Dis 1996; 40(2): 398-407.
13. Hall TA. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/ NT. Nucleic Acids Symp Ser 1999; 41: 95-98.
14. Tamura K, Stecher G, Kumar S. MEGA11: molecular evolutionary genetics analysis version 11. Mol Biol Evol 2021; 38(7): 3022-3027.
15. Hashish A, Chaves M, Macedo NR, et al. Complete genome sequences generated using hybrid Nanopore-Illumina assembly of two non-typical Avibacterium paragallinarum strains isolated from clinically normal chicken flocks. Microbiol Resour Announc 2023; 12(10): e00128-23. doi: 10.1128/MRA.00128-23.
16. El-Gazzar M, Gallardo R, Bragg R, et al. Avibacterium paragallinarum, the causative agent of infectious coryza: a comprehensive review. Avian Dis 2025; 68(S1): 362-379.
17. Mirbagheri SMJ, Ahangaran MG. Concurrent infection of Avibacterium paragalinarum and Escherichia coli in layers with swollen head syndrome (SHS) in Isfahan province [Persian]. J Anim Environ 2022; 13(4): 97-102.
18. Corney BG, Diallo IS, Wright L, et al. Rapid and sensitive detection of Avibacterium paragallinarum in the presence of other bacteria using a 5' Taq nuclease assay: a new tool for diagnosing infectious coryza. Avian Pathol 2008; 37(6): 599-604.
19. Putra FN, Wahyuni AETH, Sutrisno B. Molecular detection and pyrG sequence analysis of Avibacterium paragallinarum using clinical samples of infraorbital exudates from layer chickens with infectious coryza symptoms in Indonesia. Vet World 2023; 16(8): 1655-1660.
20. Badr H, Roshdy H, Kilany W, et al. Isolation and molecular identification of Avibacterium paragallinarum in suspected cases of poultry. J Adv Vet Res 2022; 12(3): 253-258.
21. Deresse G, Assefa E, Tesfaw L, et al. Isolation, molecular detection, and sequence analysis of Avibacterium paragallinarum from suspected cases of infectious coryza infected chickens from different areas of Ethiopia, 2022-2024. BMC Microbiol 2025; 25 (1): 141. doi: 10.1186/s12866-025-03862-3.
22. Xu Y, Cheng J, Huang X, et al. Characterization of emergent Avibacterium paragallinarum strains and the protection conferred by infectious coryza vaccines against them in China. Poult Sci 2019; 98(12): 6463-6471.
23. Saravanan S, Murthy TRGK, Gowthaman V, et al. Detection and molecular characterization of Avibacterium paragallinarum from poultry. Indian J Anim Res 2023; B-5070: 1-7. doi: 10.18805/IJAR.B-5070.
Veterinary Research Forum
Volume 17, Issue 7
July 2026
Pages 489-496

  • Receive Date 10 July 2025
  • Revise Date 05 October 2025
  • Accept Date 27 October 2025

Home

Guide for Authors

Submit Manuscript

Reviewers

Contact Us