Molecular characterisation of Hepatitis B virus vaccine escape mutants in South Africa

[摘要] Since the introduction of vaccination against hepatitis B virus (HBV) infection in SouthAfrica, at least one case of infection despite vaccination has occurred. The purpose of thisstudy was to determine whether this infection was the result of mutations within the regionof the surface (S) gene encoding the a determinant epitopes of the hepatitis B surfaceantigen, which permitted viral vaccine-escape. HBV DNA was extracted from the serumand liver tissue of the patient and amplified within the complete 3 215 bp genome and Sgene, respectively. Following cloning, sequencing revealed a minor population displayingunique or uncommon S gene mutations that resulted in C138R, C139R, K141R, P142L,T143A, N146D, and T148A amino acid substitutions in the clones from the serum, andC139Y and D144N in the clones from the liver. Such isolates may represent South AfricanHBV vaccine-escape mutants that caused chronic infection in the host prior to theirreversion to wild-type.

[发布机构] University of the Witwatersrand