Avian Pathology Unit, Department of Veterinary Pathology and Public Health, Agronomy and Veterinary Institute Hassan II, Rabat B.P. 6202, Morocco.
IHAP, Toulouse University, INRAE, ENVT, 31300 Toulouse, France.
Viruses. 2022 Mar 4;14(3):529. doi: 10.3390/v14030529.
Low pathogenic H9N2 avian influenza (LPAI H9N2) is considered one of the most important diseases found in poultry (broiler, laying hens, breeding chickens, and turkeys). This infection causes considerable economic losses. The objective of this work was to monitor and assess the presence of avian influenza virus (AIV) H9N2 in eight different regions of Morocco using real-time RT-PCR, and to assess the phylogenetic and molecular evolution of the H9N2 viruses between 2016 and 2019. Field samples were collected from 108 farms suspected of being infected with LPAI H9N2 virus. Samples were analyzed using H9N2-specific real-time RT-PCR. Highly positive samples were subjected to virus isolation and seven isolates were fully sequenced. Low pathogenic H9N2 avian influenza virus was introduced in Morocco in 2016. We show that in 2018-2019, the virus was still present irrespective of vaccination status. Phylogenetic and molecular analyses showed mutations related to virulence, although our viruses were related to 2016 Moroccan viruses and grouped in the G1 lineage. Specific amino acid substitutions were identified in Moroccan H9N2 viruses that are believed to lead to increased resistance to antiviral drugs.
低致病性 H9N2 禽流感（LPAI H9N2）被认为是家禽（肉鸡、蛋鸡、种鸡和火鸡）中最重要的疾病之一。这种感染会导致巨大的经济损失。本工作的目的是使用实时 RT-PCR 监测和评估摩洛哥八个不同地区的 H9N2 禽流感病毒（AIV）的存在情况，并评估 2016 年至 2019 年间 H9N2 病毒的系统发育和分子进化。从 108 个疑似感染低致病性 H9N2 病毒的农场采集了田间样本。使用 H9N2 特异性实时 RT-PCR 对样本进行分析。高度阳性的样本进行病毒分离，7 个分离株进行了全序列测序。低致病性 H9N2 禽流感病毒于 2016 年在摩洛哥被引入。我们表明，在 2018-2019 年，无论疫苗接种状况如何，该病毒仍然存在。系统发育和分子分析显示与毒力相关的突变，尽管我们的病毒与 2016 年摩洛哥病毒有关，并且属于 G1 谱系。在摩洛哥 H9N2 病毒中发现了一些特定的氨基酸取代，据信这些取代会导致对抗病毒药物的耐药性增加。
