Analysis of the entire nucleotide sequence of hepatitis B virus genotype B in the Philippines reveals a new subgenotype of genotype B

Abstract

The entire nucleotide sequences were determined for hepatitis B virus (HBV) genotype B (HBV/B) genomes extracted from five patients in the Philippines and designated GenBank AB219426, AB219427, AB219428, AB219429 and AB219430. The serotype of the first four isolates was ayw and that of GenBank AB219430 was adw. Divergences of entire sequences were 1?0-2?0 % between the first four isolates and 3?8-4?2 % between these four and GenBank AB219430. Phylogenetic-tree analysis revealed that, worldwide, HBV/B comprises five subgenotypes: B1, B2, B3, B4 and the new Philippines group, designated B5. Divergences of the entire genome sequences between four isolates in subgenotype B5 and isolates from other countries (subgenotypes) were 4?4-4?8 % with Vietnam (B4), 2?9-3?5 % with Indonesia (B3), 4?7-5?1 % with China (B2) and 5?4-6?0 % with Japan (B1). Similarly, GenBank AB219430 showed the lowest divergences: 3?4 % with the isolate from Indonesia (B3), 5?0 % with Vietnam (B4), 5?4 % with China (B2) and 6?1 % with Japan (B1). This is the first report of entire nucleotide sequences of HBV/B from the Philippines and the results show that these sequences belong to a new subgenotype, B5. The present study identified that HBV/B isolates throughout the world are divided genetically into five subgenotypes, the relationships between geographical distances and the genetic distances of HBV/B being well-correlated.

Novel Subgenotypes of Hepatitis B Virus Genotypes C and D in Papua, Indonesia

“…Subgenotypes (subgroups) have been identified for certain HBV genotypes (7,9,15,20,22,26). HBV/C has been classified into five subgenotypes, HBV/C1 to HBV/C5 (7,9,26,30), as has HBV/D, into HBV/D1 to HBV/D5 (3,5,22,28).…”

“…Subgroup Bj is found mostly in East Asia, including Japan, while subgroup Ba is found throughout Asia and has recombination with HBV/C in the C gene (31). More recently, subgroup Ba has been further divided into four subgenotypes, HBV/B2 to HBV/B5, with subgroup Bj being renamed subgenotype HBV/B1 (20,26,30).…”

The High Incidence of the Emergence of Entecavir-Resistant Mutants among Patients Infected with Lamivudine-Resistant Hepatitis B Virus

“…The inclusion criteria of these patients strictly followed those of the phase III clinical trial by Bristol-Myers Japan Inc. (Tokyo); briefly, both i) the presence of active HBV viremia (> 10 5 copy/mL), and ii) the presence of pathologily than genotype C (HBV/C), and those infected with HBV/B appear to have a better prognosis (Kikuchi 2000;Orito et al 2001). At present, HBV genotype B (HBV/B) has been clustered into five subgenotypes (Nagasaki et al 2006a). Lamivudine, the first approved orally administered nucleotide analogue, is well known for its safety and effectiveness in the treatment of HBV infections, including HBV cirrhosis, regardless of the HBV genotype (Yao and Bass 2000;Yao et al 2001;Yuen et al 2003).…”

Genetic Diversity of HBV Genotypes/ Subgenotypes and Their Correlation with Disease Progression

“…38,83,103,143,152,167 HBV/C has been classified into five subgenotypes, HBV/C1 to HBV/ C5, 38,83,167,190 HBV/D into HBV/D1 to HBV/D5. 21,31,152,172 Similarly, HBV/B was initially classified into two subgroups, Bj and Ba.…”

“…197 More recently, subgroup Ba has been further divided into four subgenotypes, HBV/B2 to HBV/B5, with subgroup Bj being renamed subgenotype HBV/B1. 143,167,190 …”