Year-end Sale % OFF 
Abstract
The genetic variability of hepatitis B virus (HBV) represents a challenge for the sensitivity of immunologic and molecular based assays. Based on sequence divergences in the entire genome of >8 %, HBV genomes have been classified into ten genotypes designated as A to J. The aim of this study was to determine HBV genotypes and subtype in samples of HBV infected patients in Bangladesh. The sera samples were collected from chronically infected HBV patients. At first the DNA positive HBV samples were screened by EIA in our laboratory and the 1063 bp region of surface gene was amplified, sequenced and genotyped by sequence analysis. The same sequences were also used for subtypes and mutational analyses. After that, genotyping was also carried out by nested PCR using genotype specific primers in the same region of HBV surface gene. A total of 39 samples were sequencing to find out the genotypes and subtypes. It was found that the prevalent genotype was genotype C (subgenotype C1) which accounted for 48.7 %. The other genotypes found were genotype A (23.1 %) and genotype D (28.2 %). Predominant subtypes in Bangladesh were adr (41 %) followed by subtype adw2 (28.2 %), ayw3 (25.6 %), and others. Additionally, genotyping was also done by nested PCR using type-specific primers. In this method, out of 17 samples 6 were found to be genotype C, followed by genotype D (4 of 17) and genotype A (3 of 17). In PCR-based genotyping system we also observed the mix genotypes; 3 samples contained both genotype A and D, and 2 samples contained both C and D. The genetic diversity of HBV and distribution of its genotypes and subtypes amongst Bangladeshi population were done in this study, which will help us to provide information regarding circulating genotypes in this region and also help physicians to prescribe proper antiviral/interferon therapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-1840-2) contains supplementary material, which is available to authorized users.
Highlights
Hepatitis B virus (HBV) infection is one of the most widespread viral infections in humans with a spectrum of liver diseases ranging from asymptomatic state to serious public health problem (Lee 1997)
Prior to definition of genotypes, HBV were categorized as subtypes based on serological differences (Norder et al 1992), based on immune reaction by amino acid pattern at specific location of “a” determinant which leads to the nine different subtypes designating adw2, adw4, adrq+, adrq−, ayw1, ayw2, ayw3, ayw4 and ayr
The deoxy ribonucleic acid (DNA) levels were previously measured for all patients using real time polymerase chain reaction (PCR) (HBV TaqMan, Roche), had a value ranged from 3.1 × 104 to 1.2 × 1012 copies/ml
Summary
Hepatitis B virus (HBV) infection is one of the most widespread viral infections in humans with a spectrum of liver diseases ranging from asymptomatic state to serious public health problem (Lee 1997). About 2 billion people have been infected worldwide with an estimated 300–350 million carrier, 40 % of whom may develop complicated clinical sequelae, including liver cirrhosis (LC), liver cancer, and hepatocellular carcinoma (HCC) (Yang et al 2008). According to WHO, approximately 600,000 deaths occur worldwide annually due to chronic complication of HBV associated liver disease (WHO 2008). Prior to definition of genotypes, HBV were categorized as subtypes based on serological differences (Norder et al 1992), based on immune reaction by amino acid pattern at specific location of “a” determinant which leads to the nine different subtypes designating adw, adw, adrq+, adrq−, ayw, ayw, ayw, ayw and ayr. In 2002, a new subtype adw has been described (Norder et al 1992; Magnius and Norder 1995). Their distributions within the genomic groups have shown to be restricted. Subtype adw is found to genotype A, B and C whereas; adw is only circulated on genotypes E and F (Norder et al 1992)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
