{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T05:14:10Z","timestamp":1787030050158,"version":"build-2736575974"},"reference-count":32,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,11,24]],"date-time":"2023-11-24T00:00:00Z","timestamp":1700784000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Recovery and Resilience Facility (RRF)","award":["RRF-2.3.1-21-2022-00001"],"award-info":[{"award-number":["RRF-2.3.1-21-2022-00001"]}]},{"name":"Recovery and Resilience Facility (RRF)","award":["RRF-2.3.1-21"],"award-info":[{"award-number":["RRF-2.3.1-21"]}]},{"name":"National Recovery Fund budget estimate","award":["RRF-2.3.1-21-2022-00001"],"award-info":[{"award-number":["RRF-2.3.1-21-2022-00001"]}]},{"name":"National Recovery Fund budget estimate","award":["RRF-2.3.1-21"],"award-info":[{"award-number":["RRF-2.3.1-21"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Veterinary Sciences"],"abstract":"<jats:p>Our study aimed to investigate the virulence of three recent H9N2 LPAIV strains belonging to the G1 lineage, isolated from field infections in North Africa and the Middle East. Three-week-old commercial broiler chickens (in total 62) were included and randomly allocated into three infected test groups and one control group. Each test group was inoculated intranasally\/intratracheally with one of the three H9N2 isolates at a dose of 108 EID50 virus. The control group received phosphate-buffered saline (PBS) via the same route of application. The pathogenicity was evaluated based on clinical signs and gross pathological and histopathological lesions, the viral antigen load was assessed through immunohistochemistry staining (IHC), and a semi-quantitative detection of the genetic material was conducted via a real-time PCR. Our findings confirmed the obvious respiratory tract tropism of the virus strains with variable renal tropism. In contrast to the highly pathogenic AIVs, the tested H9N2 strains did not show replication in the central nervous system. The virus presence and lesions, mainly in the respiratory tract, were predominant on dpi 5 and significantly reduced or disappeared by dpi 11. A clear difference was demonstrated among the three isolates: the A\/chicken\/Morocco\/2021\/2016 strain proved to be significantly more virulent than the Egyptian and Saudi Arabian ones, which showed no remarkable difference.<\/jats:p>","DOI":"10.3390\/vetsci10120671","type":"journal-article","created":{"date-parts":[[2023,11,24]],"date-time":"2023-11-24T06:51:28Z","timestamp":1700808688000},"page":"671","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Evaluation of the Virulence of Low Pathogenic H9N2 Avian Influenza Virus Strains in Broiler Chickens"],"prefix":"10.3390","volume":"10","author":[{"given":"M\u00e1rta","family":"B\u00f3na","sequence":"first","affiliation":[{"name":"Department of Animal Hygiene, Herd Health and Mobile Clinic, University of Veterinary Medicine, Istv\u00e1n utca 2, 1078 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00f3zsef","family":"F\u00f6ldi","sequence":"additional","affiliation":[{"name":"Euvet Bt., Asb\u00f3th utca 2, 2100 G\u00f6d\u00f6ll\u0151, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0069-4914","authenticated-orcid":false,"given":"Lilla","family":"D\u00e9nes","sequence":"additional","affiliation":[{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest, Istv\u00e1n utca 2, 1078 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Harnos","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, University of Veterinary Medicine, Istv\u00e1n utca 2, 1078 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bettina","family":"Paszerbovics","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, University of Veterinary Medicine, Istv\u00e1n utca 2, 1078 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M\u00edra","family":"M\u00e1ndoki","sequence":"additional","affiliation":[{"name":"Department of Pathology, University of Veterinary Medicine, Istv\u00e1n utca 2, 1078 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,24]]},"reference":[{"key":"ref_1","first-page":"19","article-title":"Increasing impact of H9N2 avian influenza virus in the world","volume":"145","author":"Farsang","year":"2023","journal-title":"Hung. 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