title: Genotypes and S-gene variability of Mexican hepatitis B virus strains.
abstract: The genotypes and subtypes of 15 Mexican hepatitis B virus strains were determined by sequencing and phylogenetic analysis of the small S-gene. The most predominant strains were found to be divergent genotype/subtype F/adw4 strains (66.6%), followed by A/adw2 (20.0%), D/ayw3 (6.7%), and G/adw2 (6.7%). The S-genes of the Mexican genotype F strains and two Nicaraguan strains described previously formed a subcluster with more than 4% divergence from the other strains within this genotype. The Mexican strains within genotypes A and D showed the highest homology with strains from Europe and the United States. Ten amino acid substitutions not described previously were found in the S-genes of strains from nine chronic carriers, whereas the S gene in strains from six acute hepatitis B patients were highly conserved as compared to their respective genotypes. One genotype F strain from an HBsAg positive chronic carrier had a T to A mutation at position 647, forming a translational stop at codon 216. Two genotype F strains from HBsAg negative chronic carriers had a Val180 instead of an Ala found in the other genotype F strains. This study shows that a divergent genotype F predominates in Mexican strains analyzed, which presented amino acid substitutions not reported previously outside the a determinant.
authors.affiliation: Institute of chronic degenerative diseases, Civil Hospital of Belen, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico.
authors.forename: L V
authors.initials: LV
authors.lastname: Sánchez
authors.forename: M
authors.initials: M
authors.lastname: Maldonado
authors.forename: B E
authors.initials: BE
authors.lastname: Bastidas-Ramírez
authors.forename: H
authors.initials: H
authors.lastname: Norder
authors.forename: A
authors.initials: A
authors.lastname: Panduro
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006509:Hepatitis B / Q000821:virology*; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics; D006801:Humans; D008297:Male; D008800:Mexico; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D017386:Sequence Homology, Amino Acid
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens