Calado, Cecília2022-03-072022-03-072021-01CALADO, Cecília R. C. – Variability of neutrophil-activating protein among Helicobacter pylori strains. Romanian Archives of Microbiology and Immunology. ISSN 1222-3891. Vol. 80, N.º 1 (2021), pp. 43-50.1222-3891http://hdl.handle.net/10400.21/14385The Helicobacter pylori neutrophil activating protein (NAP) presents relevant inflammatory and immunomodulatory activity and has consequently been explored as a diagnosis and therapeutic target. In the present work, nap gene sequences, retrieved from H. pylori isolated world-wide, were analyzed, a high genetic diversity (with 88% of alleles) being observed in accordance with other virulence factors. The phylogenetic analysis did not reveal the separation of strains per geographical region according to a bacterial panmictic population. When compared to other genes of virulence factors of H. pylori, such as the vacuolating cytotoxin A (vacA), nap presents slightly lower genetic variability, concerning the number of alleles and polymorphic sites, pointing to a possible lower pressure of the host immune system. The nap genetic diversity is associated to a high proportion of synonymous substitutions in relation to non-synonymous substitutions, pointing to equilibrium between the need for antigenic diversity as a mechanism to escape the host immune system and the maintenance of the proteins function. All this information could be put to good use when planning the NAP application as a therapeutic or diagnostic target.engHelicobacter pyloriGenetic variabilityNeutrophil-activating proteinjournal article10.54044/RAMI.2021.01.06