Molecular Biology of Fulminant Hepatitis B Viruses

Fulminant hepatitis B (FHBV) is a rare but severe outcome of acute hepatitis B virus infection. The severe liver injury is attributed to an exaggerated immune response directed at clearing virus by causing lysis of infected hepatocytes. Multiple factors could contribute to severity of the disease. Our study has shown that although there are no specific variant(s) linked to severity, there are clusters of variants in the cis-acting regulatory elements which can upregulate replication of FHBV strains. The most novel concept to come out of this study is that, most of these variants are not unique to FHBV sequences but they are significant when they occur in the form of 'motifs' or combinations; we showed that these multiple motifs are associated with a common functional effect

Effect of D-chiro-inositol on hormonal parameters and insulin resistance in women with polycystic ovary syndrome

Background: Polycystic ovary syndrome (PCOS) is an endocrine disorder among women of reproductive age, characterized by hormonal imbalance and insulin resistance. D-chiro-inositol, a naturally occurring inositol isomer, has been suggested as a potential treatment option for PCOS. This study aimed to investigate the effects of D-chiro-inositol supplementation on hormonal parameters, and insulin resistance in women with PCOS. Methods: This randomized controlled study was conducted among 60 women of PCOS with insulin resistance, who were assigned to either Group A (D-chiro-inositol) or Group B (placebo) for 12 weeks. S. FSH, LH, S. total testosterone, fasting blood glucose, fasting insulin, and insulin resistance (HOMA-IR) were measured at baseline and after 12 weeks of treatment. Statistical analyses were performed using SPSS version 23.0 for Windows. Results: After 12 weeks of treatment, significant reductions in serum luteinizing hormone, serum total testosterone, fasting insulin, and HOMA-IR were observed in the D-chiro-inositol group compared to the placebo group. However, no significant changes were observed in fasting blood glucose levels. D-chiro-inositol was well-tolerated, with no significant differences in side effects between the two groups. Conclusions: D-chiro-inositol supplementation for 12 weeks significantly improved hormonal parameters, and insulin resistance in women with PCOS. The treatment was well-tolerated, suggesting that D-chiro-inositol can be an effective therapeutic option for patients with PCOS

Toxoplasma gondii Infection Is Associated with Low Birth Weight: Findings from an Observational Study among Rural Bangladeshi Women

Gestational Toxoplasma gondii (T. gondii) infection may cause substantial adverse effects on developing fetuses, newborns and also mothers. This study aims to estimate the seroprevalence of T. gondii among rural Bangladeshi pregnant women and determine the risk of a low birth weight (LBW). We followed a longitudinal design where 208 pregnant women were followed until the birth of their infants. Levels of IgG and IgM of T. gondii were assessed using chemiluminescent immunoassay. Modified Poisson regression was used to estimate crude and adjusted associations and multiple regression analysis was performed to understand the confounding and modifying effects of the variables. Thirty-nine (19%) children were born with LBW, among whom 15 (39%) mothers were positive for T. gondii IgG during pregnancy. After adjusting for several confounders and modifiers, pregnant women with T. gondii IgG or IgM seropositivity were significantly associated with LBW of infants (aRR: 2.00, 95% CI: 1.17-3.42). The strength of this association increased after adjusting for maternal education (aRR: 4.88, 95% CI: 1.74-13.69). The final model had an AROC of 0.84 with a sensitivity of 36% and specificity of 97%. Although causality is yet to be established, the study observed an association between T. gondii infection during pregnancy among rural Bangladeshi women and LBW of newborns

Epidemiology of Hepatitis B Virus Infection in Bangladesh: Prevalence among General Population, Risk Groups and Genotype Distribution

Despite a considerable body of published research on hepatitis B in Bangladesh, researchers continue to lament the lack of reliable information about hepatitis B virus (HBV) infection epidemiology. The present review aims to provide a comprehensive survey of the literature with particular focus on a number of epidemiological questions, as well as a commentary on the trends of hepatitis B research as it has taken place in Bangladesh. The key themes to emerge from this review are: first, beyond noting a declining trend, it is difficult to provide conclusive estimates about HBV prevalence in the general population of Bangladesh. The majority of the studies, even the ones conducted on apparently healthy populations, fail to be adequately representative for the reasons explored in the article. Secondly, HBV infection in Bangladesh is sharply stratified across sociodemographic lines, which speaks to the role of awareness and risk exposure in HBV prevalence. Third, more research on occult infection rates is required to estimate the extent of risk posed by the current blood donation screening program, which relies exclusively on hepatitis B surface antigen as a biomarker. The same considerations apply for the comparative importance of vertical versus horizontal transmission and prevalence among particular risk groups like healthcare workers with high occupational exposure. Finally, while recent studies do allow us, albeit with some ambiguity, to draw conclusions about distribution of HBV genotypes in Bangladesh, there needs to be an added emphasis on molecular epidemiology. It is hoped that the present review, the first of its kind in Bangladesh, will serve as an up-to-date summary of the course HBV epidemiology research in Bangladesh has taken thus far, as well as crucial gaps to address going forward

Prevalence of genotypes and subtypes of hepatitis B viruses in Bangladeshi population

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

<i>Vibrio cholerae</i> Persisted in Microcosm for 700 Days Inhibits Motility but Promotes Biofilm Formation in Nutrient-Poor Lake Water Microcosms

<div><p>Toxigenic <i>Vibrio cholerae</i>, ubiquitous in aquatic environments, is responsible for cholera; humans can become infected after consuming food and/or water contaminated with the bacterium. The underlying basis of persistence of <i>V. cholerae</i> in the aquatic environment remains poorly understood despite decades of research. We recently described a “persister” phenotype of <i>V. cholerae</i> that survived in nutrient-poor “filter sterilized” lake water (FSLW) in excess of 700-days. Previous reports suggest that microorganisms can assume a growth advantage in stationary phase (GASP) phenotype in response to long-term survival during stationary phase of growth. Here we report a <i>V. cholerae</i> GASP phenotype (GASP-700D) that appeared to result from 700 day-old persister cells stored in glycerol broth at −80°C. The GASP-700D, compared to its wild-type N16961, was defective in motility, produced increased biofilm that was independent of <i>vps</i> (p<0.005) and resistant to oxidative stress when grown specifically in FSLW (p<0.005). We propose that <i>V. cholerae</i> GASP-700D represents cell populations that may better fit and adapt to stressful survival conditions while serving as a critical link in the cycle of cholera transmission.</p></div

Genotype Analysis of Bacillus anthracis Strains Circulating in Bangladesh.

In Bangladesh, anthrax, caused by the bacterium Bacillus anthracis, is considered an endemic disease affecting ruminants with sporadic zoonotic occurrences in humans. Due to the lack of knowledge about risks from an incorrect removal of infected carcasses, the disease is not properly monitored, and because of the socio-economic conditions, the situation is under-reported and under-diagnosed. For sensitive species, anthrax represents a fatal outcome with sudden death and sometimes bleeding from natural orifices. The most common source of infection for ruminants is ingestion of spores during grazing in contaminated pastures or through grass and water contaminated with anthrax spores. Domestic cattle, sheep and goats can also become infected through contaminated bone meal (used as feed) originating from anthrax-infected carcasses. The present investigation was conducted to isolate B. anthracis organisms from 169 samples (73 soil, 1 tissue, 4 bone and 91 bone meal samples) collected from 12 different districts of Bangladesh. The sampling was carried out from 2012 to 2015. Twelve samples resulted positive for B. anthracis. Biomolecular analyses were conducted starting from the Canonical Single Nucleotide Polymorphism (CanSNP) to analyze the phylogenetic origin of strains. The analysis of genotype, obtained through the Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) with the analysis of 15 Variable Number Tandem Repeats (VNTR), demonstrated four different genotypes: two of them were previously identified in the district of Sirajganj. The sub-genotyping, conducted with Single Nucleotide Repeats analysis, revealed the presence of eight subgenotypes. The data of the present study concluded that there was no observed correlation between imported cattle feed and anthrax occurrence in Bangladesh and that the remarkable genetic variations of B. anthracis were found in the soil of numerous outbreaks in this country

Resistance of GASP-700D to oxidative (H₂O₂) stress.

<p><i>V. cholerae</i> strains N16961S-24, N16961R-24 and GASP-700D were grown (ca. 10⁸ cfu/ml) in FSLW supplemented with 20 mM H₂O₂. The cultures were examined at 5 min interval for 15 min for the presence of culturable bacteria as determined by standard plate count. Error bars indicate means ± standard deviation (SD) from triplicate experiments. The stress resistance of each strain was compared with that of N1961S-24 using one-way ANOVA test. A p-value of <0.005 was considered statistically significant.</p