Isolation of H9N2 avian influenza virus from bobwhite quail (Colinus virginianus) in Egypt.

This study describes the first isolation of H9N2 avian influenza virus (AIV) from commercial bobwhite quail (Colinus virginianus) in Egypt. Infected birds showed neither clinical signs nor mortality. Virus isolation and real-time reverse transcription polymerase chain reaction confirmed the presence of the H9N2 virus in cloacal swab samples collected at 35 days of age and the absence of other AIV subtypes, including H5 and H7. The hemagglutinin and neuraminidase genes of the isolated virus showed 99.1% and 98.2% nucleotide identity and 97.3% and 100% amino acid identity, respectively, to those of H9N2 viruses currently circulating in poultry in the Middle East. Phylogenetically, the Egyptian H9N2 virus was closely related to viruses of the G1-like lineage isolated from neighbouring countries, indicating possible epidemiological links.