A Comprehensive In-Silico Analysis of Deleterious Missense SNPs in Human Trehalase Gene: Gaining an Interactome Insights into Type 2 Diabetes Mellitus

Introduction: Trehalase (TREH), a glycoside hydrolase enzyme that catalyses the conversion of trehalose to glucose in sugar metabolism. In spite of severe health threats caused by diabetes worldwide, no systematic and programmed study on human TREH Single Nucleotide Polymorphism (SNPs) and its functional role in Type 2 Diabetes Mellitus (T2DM) has been performed. Aim: This study aimed to identify pathogenic missense SNPs in the human TREH gene. Materials and Methods: A series of different bioinformatic tools including Sorting Intolerant from Tolerant (SIFT), Polyphen, I-mutant, Variant Effect Predictor, Project Hope and GeneMANNIA were used for this study. At all stages, a p-value of 0.05 was considered as statistically significant. Results: This study demonstrated 10 potential mutations out of 241 missense human TREH SNPs from the SNP Database (dbSNP) database of National Center for Biotechnology Information (NCBI), three of which confirmed to have damaging effects on protein function. Out of these three, rs535722007 had the most deleterious effect that altered secondary properties and tertiary structure of the experimental TREH protein and decreased the stability. Further analysis showed a strong connection among TREH, Insulin (INS) and other genes of carbohydrate metabolism associated with T2DM. Gene expression studies found the down-regulation of TREH in all of the experimental studies linked toT2DM. Conclusion: As the probability of the disease predisposition increases with SNPs in primary or co-expressed gene(s), therefore, characterisation of TREH SNPs from human and its gene networking analysis can aid in better understanding of genetic variations and signalling pathways as well as to elucidate the effective diagnostic and treatment strategies.

Induction of systemic, mucosal and memory antibody responses targeting Vibrio cholerae O1 O-specific polysaccharide (OSP) in adults following oral vaccination with an oral killed whole cell cholera vaccine in Bangladesh

BACKGROUND

Oral cholera vaccine (OCV) containing killed Vibrio cholerae O1 and O139 organisms (Bivalent-OCV; Biv-OCV) are playing a central role in global cholera control strategies. OCV is currently administered in a 2-dose regimen (day 0 and 14). There is a growing body of evidence that immune responses targeting the O-specific polysaccharide (OSP) of V. cholerae mediate protection against cholera. There are limited data on anti-OSP responses in recipients of Biv-OCV. We assessed serum antibody responses against O1 OSP, as well as antibody secreting cell (ASC) responses (a surrogate marker for mucosal immunity) and memory B cell responses in blood of adult recipients of Biv-OCV in Dhaka, Bangladesh.

METHODOLOGY/PRINCIPAL FINDINGS

We enrolled 30 healthy adults in this study and administered two doses of OCV (Shanchol) at days 0 and 14. Blood samples were collected before vaccination (day 0) and 7 days after each vaccination (day 7 and day 21), as well as on day 44. Serum responses were largely IgA with minimal IgG and IgM responses in this population. There was no appreciable boosting following day 14 vaccination. There were significant anti-OSP IgA ASC responses on day 7 following the first vaccination, but none after the second immunization. Anti-OSP IgA memory B cell responses were detectable 30 days after completion of the vaccination series, with no evident induction of IgG memory responses. In this population, anti-Ogawa OSP responses were more prominent than anti-Inaba responses, perhaps reflecting impact of previous exposure. Serum anti-OSP responses returned to baseline within 30 days of completing the vaccine series.

CONCLUSION

Our results call into question the utility of the 2-dose regimen separated by 14 days in adults in cholera endemic areas, and also suggest that Biv-OCV-induced immune responses targeting OSP are largely IgA in this highly endemic cholera area. Studies in children in cholera-endemic areas need to be performed. Protective efficacy that extends for more than a month after vaccination presumably is mediated by direct mucosal immune response which is not assessed in this study. Our results suggest a single dose of OCV in adults in a cholera endemic zone may be sufficient to mediate at least short-term protection.

Isolation and characterization of Bacillus sp. strain BC01 from soil displaying potent antagonistic activity against plant and fish pathogenic fungi and bacteria

Fungal and bacterial pathogens infect a diverse range of hosts including various plant and animal species. Fungal and bacterial diseases, especially of plants and aquatic animals, such as fish, lead to significant damage to crops and aquaculture, respectively, worldwide. The present study was conducted to isolate and characterize potent Bacillus strains with significant antagonistic activity against the major plant and fish pathogenic fungi and bacteria. We randomly collected 22 isolates of Bacillus from the soil, rhizosphere, and sediment from different parts of Bangladesh. Initial characterization, based on in vitro antagonistic activity on the culture plate, resulted in the selection of four gram-positive Bacillus sp. isolates. Among these, the isolate BC01, obtained from soil demonstrated the highest broad-spectrum anti-bacterial and anti-fungal activities. We confirmed the genus of BC01 to be Bacillus by morphological and biochemical tests as well as using molecular data analysis tools, including the study of 16s rDNA, phylogenetic relationship, and evolutionary divergence scores. The isolate significantly inhibited the mycelial growth of the plant pathogen, Penicillium digitatum and fish pathogen, Aphanomyces invadans in vitro. The anti-bacterial effect of the isolate was also evaluated against Pseudomonas spp. and Xanthomonas spp., the two deadliest plant pathogens, and Aeromonas veronii, Pseudomonas fluorescens, and Streptococcus iniae, three major fish pathogens that are primarily responsible for global aquaculture loss. The results of the present study could pave the way for developing potent drugs to combat microbial infection of plants and fish.