Genetic relatedness of hepatitis A virus strains recovered from different geographical regions

Abstract

A pairwise comparison of the nucleic acid sequence of 168 bases from 152 wild-type or unique cell cultureadapted strains of hepatitis A virus (HAV) revealed that HAV strains can be differentiated genetically into seven unique genotypes (I to VII). In general, the nucleotide sequence of viruses in different genotypes differs at 15 to 25 % of positions within this segment of the genome. Viruses from four of the genotypes (I, II, III and VII) were recovered from cases of hepatitis A in humans, whereas viruses from the other three genotypes (IV, V and VI) were isolated only from simian species developing a hepatitis A-like illness during captivity. Among non-epidemiologically related human HAV strains, 81 were characterized as genotype I, and 19 as genotype III. Within each of these major genotypes, there were two distinct groups (subgenotypes), which differed in sequence at approximately 7-5 % of base positions. Each genotype and subgenotype has a characteristic amino acid sequence in this region of the polyprotein, with the most divergent genotypes differing at 10 of 56 residues. Strains recovered from some geographical regions belonged to a common (endemic) genotype, whereas strains from other regions belonged to several, probably imported, genotypes. Thus, HAV strains recovered in North America were for the most part closely related at the nucleotide sequence level, whereas in other regions, such as Japan and Western Europe, HAV strains were derived from multiple genotypes or sub-genotypes. These data indicate that patterns of endemic transmission can be differentiated from situations in which infections are imported due to travel.

The entire nucleotide sequences of two GB virus C/hepatitis G virus isolates of distinct genotypes from Japan.

“…The divergence of 12 % in the entire genomic sequence as a criterion for genotypic differences is smaller than that for HCV at 20 % (Tokita et al, 1996), and compares with that for both poliovirus and hepatitis A virus at 15 % (Rico- Hesse et al, 1987 ;Robertson et al, 1992) and human immunodeficiency virus type 1 at 14 % (Lowagie et al, 1993). Recently, Kao et al (1996) proposed distinct genetic groups of GBV-C by the comparison of a helicase region of 117 bp.…”

Infección por el virus de la hepatitis A: epidemiología y diversidad genética

“…Pertenece a la familia Picornaviridae y es el único miembro del género Hepatovirus. Se diferencia de otros picornavirus porque no produce efecto citopático (17) y por su alta estabilidad tanto genética como antigénica, entre otras características (18).…”

“…Para estudiar la diversidad genética del VHA, se utilizó en un principio el método de clasificación gené-tica empleado por Rico-Hesse y colaboradores para explorar la distribución geográfica del poliovirus, en el que las cepas se agruparon comparando la región VP1-2A (18,23,49). En 1992 se analizaron 152 cepas de VHA recuperadas de muestras de suero, heces y tejido hepático provenientes de humanos y simios, recolectadas alrededor del mundo (18).…”

“…En 1992 se analizaron 152 cepas de VHA recuperadas de muestras de suero, heces y tejido hepático provenientes de humanos y simios, recolectadas alrededor del mundo (18). Los resultados demostraron la existencia de siete genotipos (I-VII) y cuatro subgenotipos (IA, IB, IIIA, IIIB).…”

Genetic variability of hepatitis A virus strain HAF-203 isolated in Brazil and expression of the VP1 gene in Escherichia coli

“…A previous report has suggested the existence of at least seven distinct genotypes for HAV (Robertson et al 1992. In an attempt to better characterize the HAF-203 genotype, its nucleotide sequence was compared to 25 complete nucleotide sequences available in databanks.…”