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1.  Genome sequencing of multidrug resistant novel Clostridium sp. BL8 reveals its potential for pathogenicity 
Gut Pathogens  2014;6:30.
Background
The human gut microbiome is important for maintaining the health status of the host. Clostridia are key members of the human gut microbiome, carrying out several important functions in the gut environment. Hence understanding the role of different Clostridium species isolated from human gut is essential. The present study was aimed at investigating the role of novel Clostridium sp. isolate BL8 in human gut using genome sequencing as a tool.
Findings
The genome analysis of Clostridium sp. BL8 showed the presence of several adaptive features like bile resistance, presence of sensory and regulatory systems, presence of oxidative stress managing systems and presence of membrane transport systems. The genome of Clostridium sp. BL8 consists of a wide variety of virulence factors like phospholipase C (alpha toxin), hemolysin, aureolysin and exfoliative toxin A, as well as adhesion factors, proteases, Type IV secretion system and antibiotic resistance genes. In vitro antibiotic sensitivity testing showed that Clostridium sp. BL8 was resistant to 11 different tested antibiotics belonging to 6 different classes. The cell cytotoxicity assay confirmed the cytotoxic effect of Clostridium sp. BL8 cells, which killed 40% of the Vero cells after 4 hrs of incubation.
Conclusions
Clostridium sp. BL8 has adapted for survival in human gut environment, with presence of different adaptive features. The presence of several virulence factors and cell cytotoxic activity indicate that Clostridium sp. BL8 has a potential to cause infections in humans, however further in vivo studies are necessary to ascertain this fact.
doi:10.1186/1757-4749-6-30
PMCID: PMC4115488  PMID: 25076986
Clostridium; Virulence; Antibiotic resistance; Ion Torrent PGM™
2.  Comparative Genome Analysis of Megasphaera sp. Reveals Niche Specialization and Its Potential Role in the Human Gut 
PLoS ONE  2013;8(11):e79353.
With increasing number of novel bacteria being isolated from the human gut ecosystem, there is a greater need to study their role in the gut ecosystem and their effect on the host health. In the present study, we carried out in silico genome-wide analysis of two novel Megasphaera sp. isolates NM10 (DSM25563) and BL7 (DSM25562), isolated from feces of two healthy individuals and validated the key features by in vitro studies. The analysis revealed the general metabolic potential, adaptive features and the potential effects of these isolates on the host. The comparative genome analysis of the two human gut isolates NM10 and BL7 with ruminal isolate Megasphaera elsdenii (DSM20460) highlighted the differential adaptive features for their survival in human gut. The key findings include features like bile resistance, presence of various sensory and regulatory systems, stress response systems, membrane transporters and resistance to antibiotics. Comparison of the “glycobiome” based on the genomes of the ruminal isolate with the human gut isolates NM10 and BL revealed the presence of diverse and unique sets of Carbohydrate-Active enzymes (CAZymes) amongst these isolates, with a higher collection of CAZymes in the human gut isolates. This could be attributed to the difference in host diet and thereby the environment, consequently suggesting host specific adaptation in these isolates. In silico analysis of metabolic potential predicted the ability of these isolates to produce important metabolites like short chain fatty acids (butyrate, acetate, formate, and caproate), vitamins and essential amino acids, which was further validated by in vitro experiments. The ability of these isolates to produce important metabolites advocates for a potential healthy influence on the host. Further in vivo studies including transcriptomic and proteomic analysis will be required for better understanding the role and impact of these Megasphaera sp. isolates NM10 and BL7 on the human host.
doi:10.1371/journal.pone.0079353
PMCID: PMC3832451  PMID: 24260205
3.  Opportunities and challenges for gut microbiome studies in the Indian population 
Microbiome  2013;1:24.
The gut microbiome is a complex ecosystem that affects the development, immunological responses and nutritional status of the host. Efforts are being made to unravel the complex interaction between the gut microbiome and host to have a greater understanding about its role in human health. Colonization of the gut by microbes begins at birth, but the succession and composition of the microbial community depends on a number of factors including, but not limited to, the age, diet, genetic composition, gender, geographic location, and health status of an individual. Therefore, inclusion of diverse human subjects in the study of the gut microbiome is indispensable. However, conducting such studies in India presents unique opportunities and challenges. The vast diversity in human genetic composition, dietary habits, and geographic distribution that exists in the Indian population adds to the complexity in understanding the gut microbiome. Gut microbiome-related studies from other parts of the world have reported a possible association of diseases such as obesity and diabetes with the human gut microbiome. In contrast, an in-depth assessment of risk factors associated with altered gut microbiome in such diseases in the Indian population is lacking. Studies including the Indian population may give insights into the association of the gut microbiome with various factors and diseases that may not be possible from studies on western populations. This review briefly discusses the significance of the gut microbiome on human health and the present status of gut microbiome studies in the Indian population. In addition, this review will highlight the unique opportunities and challenges for gut microbiome studies in the Indian population.
doi:10.1186/2049-2618-1-24
PMCID: PMC3971629  PMID: 24451035
Gut microbiome; Indian population; Diversity; Genetics; Diet
4.  Draft Genome Sequence of Methylophaga lonarensis MPLT, a Haloalkaliphilic (Non-Methane-Utilizing) Methylotroph 
Genome Announcements  2013;1(3):e00202-13.
Methylophaga lonarensis strain MPLT is a haloalkaliphilic methylotroph isolated from Lonar Lake, a saline and alkaline lake in Maharashtra, India. Strain MPLT utilizes methanol as its sole carbon and energy source. Here, we present the draft genome sequence of M. lonarensis MPLT (VKM B-2684T = MCC 1002T).
doi:10.1128/genomeA.00202-13
PMCID: PMC3650440  PMID: 23661481
5.  Changes in human gut flora with age: an Indian familial study 
BMC Microbiology  2012;12:222.
Background
The gut micro flora plays vital role in health status of the host. The majority of microbes residing in the gut have a profound influence on human physiology and nutrition. Different human ethnic groups vary in genetic makeup as well as the environmental conditions they live in. The gut flora changes with genetic makeup and environmental factors and hence it is necessary to understand the composition of gut flora of different ethnic groups. Indian population is different in physiology from western population (YY paradox) and thus the gut flora in Indian population is likely to differ from the extensively studied gut flora in western population. In this study we have investigated the gut flora of two Indian families, each with three individuals belonging to successive generations and living under the same roof.
Results
Denaturation gradient gel electrophoresis analysis showed age-dependant variation in gut microflora amongst the individuals within a family. Different bacterial genera were dominant in the individual of varying age in clone library analysis. Obligate anaerobes isolated from individuals within a family showed age related differences in isolation pattern, with 27% (6 out of 22) of the isolates being potential novel species based on 16S rRNA gene sequence. In qPCR a consistent decrease in Firmicutes number and increase in Bacteroidetes number with increasing age was observed in our subjects, this pattern of change in Firmicutes / Bacteroidetes ratio with age is different than previously reported in European population.
Conclusion
There is change in gut flora with age amongst the individuals within a family. The isolation of high percent of novel bacterial species and the pattern of change in Firmicutes /Bacteroidetes ratio with age suggests that the composition of gut flora in Indian individuals may be different than the western population. Thus, further extensive study is needed to define the gut flora in Indian population.
doi:10.1186/1471-2180-12-222
PMCID: PMC3511239  PMID: 23013146
Indian population; Firmicutes/Bacteroidetes ratio; Human gut microflora; YY-paradox

Results 1-5 (5)