Molecular characterization and phylogenetic analyses of full-length viral genomes from Iranian patients with chronic hepatitis B virus

In silico analysis of human herpes virus-8 genome: a comparison of the K1, VR1, and VR2 regions for genotyping and global geographical distribution

Investigations of the K1 gene revealed six main genotypes clustered according to geography. Here, the global distribution and HHV8 genotyping using the K1 gene and two hypervariable regions (VR1 and VR2) were evaluated. We searched GenBank for 6,889 HHV8-K1 genes via various keywords, selecting sequences longer than 730 bp. Afterwards, the VR1 and VR2 regions were derived from the K1 genes, and genotyping of the K1, VR1, and VR2 sequences was performed by applying phylogenetic tree and BioAfrica methods. The K1 genotyping result was most similar to that of VR1, followed by VR2. The most common genotypes and subtypes in the three regions studied were A (A2) and C (C3), which are found in Africa, America, and Asia. Although the A and C genotypes are more predominant, the other genotypes, B, D, E, and F, are more ancient and are commonly found in America, Asia, and Oceania. K1 is commonly used for HHV8 genotyping, but VR1 can be a reliable alternative when long-term PCR amplification is not possible. The genotyping and subtyping results of both methods were very similar (92%), and it can be inferred that both procedures can be applied for HHV-8 genotyping.

Frequency of Fusion Inhibitor Resistance Mutations Among Therapy-Naïve HIV Patients

Glycoprotein 41 (gp41) of the human immunodeficiency virus type 1 (HIV-1) protein plays a critical role in membrane fusion. Gp41 binds to proteins in the plasma membrane of CD4+ T cells, particularly the T-cell antigen receptor (TCR). These findings indicate that gp41 is involved in the assembly of HIV-1 at the plasma membrane of T cells and affects the stimulation of the TCR. To control HIV-1, new inhibitors were introduced to target the gp41 protein. However, mutations in this region might reduce their efficacy. The Gp41 region was amplified from the sera of 30 patients using nested polymerase chain reaction. The sequences were analyzed by bioinformatics tools to identify mutations and gp41 structural features. Subtyping and the interaction between fusion inhibitors and gp41 proteins were also examined. As the first report from Iran, docking analysis between fusion inhibitors and Iranian gp41 proteins showed that mutations in gp41 could not reduce the efficacy of the fusion inhibitors. Most of the patients were infected with CRF35-AD. Several post-modification positions, including glycosylation and phosphorylation sites, were identified in the gp41 protein. Our findings revealed no known multinational drug resistance to gp41 inhibitors; thus, fusion inhibitors can effectively inhibit HIV in Iranian patients. In addition, the present study introduced a new gp41 region (36-44 aa), which considerably influences the interactions between gp41 inhibitors and the gp41 protein. This region may play a pivotal role in suppressing gp41 inhibitors in CFR35-AD. Furthermore, gp41 can be considered a good target for subtyping analysis via the phylogenetic method.

Molecular evaluation of hepatitis B virus infection and predominant mutations of pre-core, basal core promoter and S regions in an Iranian population with type 2 diabetes mellitus: a case-control study

Background

This study was designed to evaluate the prevalence, genotypic patterns, and predominant mutations of hepatitis B virus (HBV) infection among diabetic patients.

Methods

Serum samples were obtained from 733 patients with type 2 diabetes mellitus and 782 non-diabetic controls. The presence of HBsAg and HBcAb was determined by ELISA. Nested PCR, targeting S and pre-core regions of the HBV genome, followed by sequencing was carried out to determine HBV genotypes and predominant mutations in the S, basal core promoter (BCP), and pre-core regions of the HBV genome.

Results

Of 733 diabetic patients, 94 cases (12.82%) were positive for HBcAb, 28 cases (3.82%) were positive for HBsAg, and 19 cases (2.59%) had HBV-DNA with genotype D, sub-genotype D1/D3 and subtype ayw2. An occult HBV infection was found in one of the HBV DNA-positive samples, which was positive for HBcAb but negative for HBsAg. P120T/G145R, G1896A/G1899A, and A1762T/G1764T were the most frequent point substitution mutations detected in the S, pre-core, and BCP regions of the HBV genome, respectively. P120T and G145R mutations were associated with low levels or undetectable levels of HBsAg in serum. Therefore, routine tests based on HBsAg detection cannot detect HBsAg-negative infected patients.

Conclusions

Relatively high prevalence of HBV infection was found in diabetic patients, while all of the HBV-infected patients were unaware of their infection. Therefore, screening for HBV infection should be included in the management program of diabetes for timely diagnosis and treatment of infected but asymptomatic patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07528-7.