Original scientific paper

https://doi.org/10.24099/vet.arhiv.0724

Molecular characterization of the hemagglutinin gene of H9N2 avian influenza viruses isolated from broiler flocks in Morocco from 2016 to 2018

Abderrazak El Khantour ; Department of Genetics and Biometry, Faculty of Sciences of Kenitra University IbnTofail, Kenitra, Morocco; Department of Pharmacy and Veterinary Inputs, ONSSA, Rabat, Morocco
Abdelmajid Soulaymani ; Department of Genetics and Biometry, Faculty of Sciences of Kenitra University IbnTofail, Kenitra, Morocco
Mohamed Salek ; Private veterinarian, Mohammadia, Morocco
Abdelkarim Filali Maltouf ; Department of Microbiology and Molecular Biology, Faculty of Sciences of Rabat, University Mohamed V, Morocco
Fatiha El Mellouli ; Regional Laboratory of Analysis and Research of Casablanca (lRARC), Casablanca, Morocco
Mariette F. Ducatez ; Université de Toulouse, ENVT, INRA, UMR 1225, Toulouse, France
Siham Fellahi ; Department of Pathology and Veterinary Public Health, Avian Pathology Unit, Agronomy and Veterinary Institute Hassan II, Rabat, Morocco

Abstract

Avian influenza viruses of the H9N2 subtype continue to spread in wild birds and poultry worldwide. Infection with H9N2 avian influenza virus was detected for the first time in Morocco in January 2016. In this study, a total of 105 organ and tracheal swab samples from 21 broiler farms in Morocco were collected from July 2016 to October 2018 for H9N2 screening. The suspicion of disease was based on severe respiratory signs such as sneezing, coughing, rales and gasping, while H9N2 virus infection was confirmed by real-time RT-PCR. Hemagglutinin (HA) genes of four isolates were amplified by conventional RT-PCR, sequenced, and aligned for phylogenetic analyses. Among the 21 flocks, 48% (10/21) were qRT-PCR positive for H9, with the cycle threshold values ranging from18.6 to 34.8. The maximum similarity in nucleotide and protein sequences (96-98%) was observed between the Moroccan viruses and an H9 virus isolated from broiler chickens in 2017 in Burkina Faso (A/chicken/BurkinaFaso/17RS93-19/2017) and from a layer chicken in the United Arab Emirates in 2015 (A/chicken/Dubai/D2506/2015). The HA genes revealed the close relationship between the four Moroccan viruses, with 97.9%-99.9% nucleotide identity. Phylogenetic analysis showed that the Moroccan viruses belonged to the G1 lineage, and likely originated from the Middle East, as previously reported in 2016.

Keywords

avian influenza; H9N2; molecular evolution; phylogeny; Morocco

Hrčak ID:

245820

URI

https://hrcak.srce.hr/245820

Publication date:

10.11.2020.

Article data in other languages: croatian

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