Molecular pathogenic and host range determinants of reassortant Egyptian low pathogenic avian influenza H9N2 viruses from backyard chicken

Abstract

Since the introduction of H9N2 low pathogenic avian influenza virus in Egypt, it became an endemic disease causing considerable economic losses in different poultry sectors especially in the presence of other secondary bacterial and viral infections. The H9N2 viruses in Egypt are in continuous evolution that needs deep analysis for their evolution pattern based on the genetic constitutions of the pathogenic determinant genes (HA, PB2, PB1, PA, and NS). In this work, samples were collected from the backyard chickens from 3 Egyptian governorates. Five selected viruses were sequenced and analyzed for the hemagglutinin gene which showed genetic relatedness to the Asian G1 lineage group B, similar to the circulating H9N2 viruses in Egypt since 2013. The sequence for PB2, PB1, PA, HA and NS genes of the selected five viruses indicate a natural re-assortment event with recent Eurasian subtypes and similar to Egyptian H9N2 virus isolated from pigeon in Egypt during 2014. The Egyptian viruses of our study possess amino acids signatures including S42, V127, L550, L672 and V504 in the internal genes NS1, PA, and PB2, of respectively of an impact on virus transmission and replication. This work indicates that the H9N2 is in continuous evolution with alarming to the reassortment occurrence.

Epidemiological surveillance of H9N2 avian influenza virus infection among chickens in farms and backyards in Egypt 2015-2016

“…The endemicity and widespread of H9N2 AIV infection among the poultry population in Egypt have made it an additional risk factor in the poultry industry. H9N2 AIV also has the potential to be transmitted to humans, especially with the cocirculation of other influenza subtypes in Egypt [ 18 , 24 ]. Available epidemiological data revealed that H9N2 AIV was initially distributed through Lower Egypt and Giza Governorate.…”

Phylogeographic Dynamics of Influenza A(H9N2) Virus Crossing Egypt

“…In 2014, a reassortant LPAIV H9N2 was reported in pigeon containing five internal gene segments (PB2, PB1, PA, NP, and NS) form Eurasian AIV subtypes (Kandeil et al, 2017). The same genotype was found in backyard chickens in three Egyptian governorates in 2015 (Samir et al, 2019). Recently a new genotype was described similar to the reassortant H9N2 but inherited its NP gene segment from the Egyptian 2010 H9N2 viruses (Kandeil et al, 2019).…”

Nitrate Is Crucial for the Proliferation of Gut Escherichia coli Caused by H9N2 AIV Infection and Effective Regulation by Chinese Herbal Medicine Ageratum-Liquid

“…H9N2 AIV is prone to secondary infection of bacteria and other pathogens, the most common of which is Escherichia coli (E. coli) infection, which is associated with high mortality in poultry (Barbour et al, 2009;Samy and Naguib, 2018;Nguyen et al, 2019). The H9N2 AIV subtype poses a significant public health threat, as it can replicate in permissive mammalian tissues without prior adaptation (Samir et al, 2019). Furthermore, several influenza viruses that infect humans all originate from variants of H9N2 AIV (Lam et al, 2013;Chen et al, 2014); hence, the potential harmful effects of H9N2 AIV on aquaculture and human health and safety cannot be ignored.…”