title: Genetic analysis of HAV strains in Tunisia reveals two new antigenic variants.
abstract: To evaluate the genetic variability of hepatitis A virus (HAV) isolates in Tunisia, serum samples were collected from 99 patients in different Tunisian areas in 2003 containing 92 cases with acute hepatitis, five with severe acute hepatitis and two with fulminant hepatitis. The entire VP1 gene was amplified and sequenced. Sequences were then aligned and a phylogenetic analysis was performed. Additionally, the amino acid (aa) sequence of the VP1 was determined. The analysis of Tunisian HAV isolates revealed that all the isolates were sub-genotype IA with 96.4%-99.8% of identity and showed the emergence of two novel antigenic variants. The Tun31-03 antigenic variant, with a 38 aa deletion containing Met156, Val171, Leu174 and Ala176 and located between 150 and 187 aa of the VP1 protein where neutralization escape mutations, was found. The second antigenic variant, Tun36-03, was isolated from a patient with fulminant hepatitis and presented a substitution of Thr by Pro at position 10 of the VP1 protein. This amino acid is located in a peptide presenting an antigenically reactive epitope of the VP1 protein. This substitution has never been described previously.
authors: Laboratoire des Maladies Transmissibles et Substances Biologiquement Actives, Faculté de Pharmacie de Monastir, Rue Avicenne, 5000 Monastir, Tunisia. khelifi_hakima@yahoo.fr
authors: Hakima
authors: H
authors: Gharbi-Khelifi
authors: Khira
authors: K
authors: Sdiri
authors: Rafik
authors: R
authors: Harrath
authors: Lamia
authors: L
authors: Fki
authors: Hèla
authors: H
authors: Hakim
authors: Mathilde
authors: M
authors: Berthomé
authors: Sylviane
authors: S
authors: Billaudel
authors: Virginie
authors: V
authors: Ferre
authors: Mahjoub
authors: M
authors: Aouni
mesh_terms: D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D000940:Antigenic Variation / Q000235:genetics*; D000956:Antigens, Viral / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology / Q000821:virology*; D017957:Hepatitis A Virus, Human / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D014416:Tunisia / Q000453:epidemiology
chemical_list: D000956:Antigens, Viral