Anatomical spatial distribution of Influenza virus receptors in some poultry species raised in Egypt

Abstract

Background: Avian influenza H5N1 has been distressing not only the poultry industry but also humans causing fatal infections in Egypt. Understanding the initial steps in the viral infection was proposed by many to be a key for solving the entire problem. Domestic healthy chicken, Pekin duck, Egyptian goose, Japanese quail, pigeon and turkey were purchased; three adult birds per each species. Lectin histochemistry was performed using fluorescein isothiocyanate labelled Sambucusnigra agglutinin specific for SA?2,6-gal receptors, and FITC labelled Maackiaamurensis agglutinins specific for SA?2,3-gal receptors. Methods: From each bird, three specimens per each trachea, lung, duodenum, colon, liver and brain were used. In chicken, duck, goose, Japanese quail, domestic pigeon and turkey, both SA?2,3-gal and SA?2,6-gal receptors were expressed in at least one segment of respiratory and intestinal tracts except in pigeons where SA?2,3-gal receptors were not expressed in the respiratory tract while in ducks were not expressed in lower respiratory tract and in turkey not expressed in small intestine. The human type receptors were not expressed in the lower trachea of goose, large intestine of chicken and intestinal tract and liver of turkey and pigeons. Results: The widespread detection of both SA?2,6-gal and SA?2,3-gal receptors in different tissues from each species suggests that these birds organs may be potential targets for both avian and human influenza viruses, and can act as adaptive host for avian influenza viruses to change receptor specificity. This may indicate that different native bird species in Egypt could have participated equally or variably in the generation of H5N1 viruses that were able to extensively infect humans. All experimental procedures were approved by Damanhour university ethics committee. The widespread detection of both SA?2,6-gal and SA?2,3-gal receptors in different tissues from each species suggests that these birds organs may be potential targets for both avian and human influenza viruses, and can act as adaptive host for avian influenza viruses to change receptor specificity. Conclusion: This may indicate that different native bird species in Egypt could have participated equally or variably in the generation of H5N1 viruses that were able to extensively infect humans.