Hepatitis B virus X protein: The X factor in chronic hepatitis B virus disease progression

Introduction: Hepatitis B virus (HBV) is the most common aetiological factor causing hepatocellular carcinoma (HCC). HBx gene plays an enigmatic role in HBV-related HCC. In this study we have analysed amino acid substitutions in HBx from HBV-infected individuals of different clinical stages. Materials and Methods: HBV-infected individuals (n = 93) were recruited in the study. DNA was extracted from plasma, amplified, and DNA sequencing was performed using specific primers targeting HBx gene (540 bp). Results: Among the study participants, 57% had chronic HBV infection, 30% had chronic liver disease (CLD) and 13% had HBV related HCC. Genotypes such as D1, D2, D3, A1, C2 and B2 were identified of which genotype D2 was predominant (78%). HBxC-terminal deletion was observed in four hepatitis B e antigen (HBeAg) negative participants with CLD. The frequency of aminoacid substitution in proapoptotic domain was higher in HBeAg negative participants including I127V (34%), K130M (34%), V131I (40%). The frequency of double mutation (K130M+V131I) and triple mutation (I127V+K130M+V131I) were found to be higher (32% and 36%) in HBeAg negative participants. Also, we identified L5M substitution (4.3%) in HBeAg positive participants with advanced liver disease. Conclusion: In HBx gene, aminoacid substitutions at positions 127, 130, 131 are associated with poor expression of HBeAg. We suggest screening for HBx aminoacid substitutions especially in patients with HBeAg negative chronic HBV infection to predict the clinical outcome and enable early treatment to prevent disease progression.

Detection of cytomegalovirus disease by real-time quantitative PCR targeting immediate early gene (ppUL83) in different samples among post-renal-transplant recipients

Renal transplantation is a treatment option for end-stage renal disease (ESRD). Cytomegalovirus (CMV) infection was analysed among symptomatic and asymptomatic post-renal-transplant recipients (PRTRs). A total of 30 PRTRs were enrolled. DNA was extracted and quantitative real-time PCR for CMV (CMV R-Gene, France) targeting ppUL83 gene was performed on whole blood, urine and saliva. The detection rate of CMV was found to be 27% (n = 8) in different samples, including whole blood, urine and saliva. Among 30 PRTRs, 53% (n = 16) of the PRTRs did not shed virus in saliva. About 7% of CMV was detected only in saliva among PRTRs who were symptomatic.

Sequencing of Porphyromonas gingivalis from saliva in patients with periodontitis and type 2 diabetes mellitus

Background: Porphyromonas gingivalis is a major periodontal pathogen. Saliva is the most easy, non-invasive microbiological sample for detection of periodontal pathogens. Aim and Objectives: A prospective study on 37 diabetic patients was grouped into well-controlled diabetes with/without periodontitis and uncontrolled diabetic with periodontitis. PCR and sequencing of P. gingivalis was performed in saliva samples. Materials and Methods: DNA was extracted from saliva using Triton X-100 and 16s rRNA gene (404 bp) was amplified by polymerase chain reaction. DNA sequencing was performed for two samples. Results:P. gingivalis was detected in 27.03% (n = 10), of which 30% (n = 9) were diabetic with periodontal disease and 14.3% (n = 1) were diabetic without periodontal disease. The percentage of poor oral hygiene was 50% and 20% in uncontrolled and controlled glycaemic patients, respectively. DNA sequencing of two samples showed 100% identity with the sequences in the GenBank database (Gen Bank accession no: KX640913-KX640914). Conclusion: Type 2 diabetes mellitus and periodontitis are interlinked. Early detection of P. gingivalis and appropriate treatment with doxycycline will also assist in controlling the glycaemic status.

Molecular characterization of Chikungunya virus during an outbreak in South India.

Introduction: Re-emergence of Chikungunya is a major public health problem in the southern states of India. Objectives: This study was undertaken to investigate an outbreak of Chikungunya, in June-August 2008 using PCR and determine the prevalent genotypes of Chikungunya virus (CHIKV) associated with the outbreak. Materials and Methods: Samples of blood were collected (in heparinized vacutainer tubes) from suspected patients of CHIKV infection from both Government Taluk Hospital in Kerala and a tertiary care hospital in Chennai, Tamil Nadu. A one-step RT-PCR was carried out on a block thermo-cycler targeting the E2 gene that codes for the viral envelope protein. The amplicons were verified for 305 bp size by standard agarose gel electrophoresis. The PCR products were purified, sequenced, and compared with other CHIKV strains reported from different geographical regions. A phylogenetic tree was constructed using MEGA 4. Results: Altogether 118 samples were collected from patients who presented with sudden onset of fever and/or joint pain, myalgia, and headache. CHIKV infection was confirmed by RT-PCR in 14 patients and all these cases were from Kerala. The positivity correlated with the early stage of the disease as all these patients had fever of less than seven days duration. The study isolates have been allotted the GenBank accession nos. GQ272368-GQ272381. Phylogenetic analysis of recent CHIKV isolates by partial sequencing of E2 region shows that isolates are closely related to strains from neighboring states and the African type. Conclusion: RT-PCR is a useful technique for the early detection of CHIKV infection during outbreaks. Molecular characterization of the strains indicates that majority of the strains have originated from the Central/East African strains of CHIKV.