Enterotypes are used for classifying individuals based on the gut microbiome. A number of studies are available to find the Enterotypes in healthy individuals; however, most of them lack comparisons at the world level. We analyzed the healthy human gut microbiomes of 495 datasets available in the European Nucleotide Archive (ENA) database derived from fifteen countries from four continents. Firmicutes and Bacteroidetes were the two most abundant phyla in the healthy human gut, worldwide. A high ratio of Proteobacteriato Actinobacteria and a low abundance of Prevotella were identified as the indicators of IBD. Prevotella, Bacteroides, and Bifidobacterium were identified as the Enterotypes in the inter-continental comparisons. At the intra-continental level, two (Bacteroides and Ruminococcaceae), four (Faecalibacterium, Bacteroides, Prevotella, and Clostridiales), and two (Prevotella, Bacteroides/Bifidobacterium) Enterotypes were identified in the American, European, and Asian continents, respectively. In addition, a high abundance of the unknown genus of Ruminococcaeae was observed in the Colombian human gut microbiome. A substantial impact of the geographical distance was observed on human gut microbiome variations, demonstrating a cumulative effect of factors, including dietary habits, genetics, lifestyle, environment, and climate, etc.

Heterogeneity amidst healthy individuals at genomic level is being widely acknowledged. This, in turn, is modulated by differential response to environmental cues and treatment regimens, necessitating the need for stratified/personalized therapy. We intend to understand the molecular determinants of Ayurvedic way (ancient Indian system of medicine) of endo-phenotyping individuals into distinct constitution types termed “Prakriti,” which forms the basis of personalized treatment. In this study, we explored and analyzed the healthy human gut microbiome structure within three predominant Prakriti groups from a genetically homogenous cohort to discover differentially abundant taxa, using 16S rRNA gene based microbial community profiling. We found Bacteroidetes and Firmicutes as major gut microbial components in varying composition, albeit with similar trend across Prakriti. Multiple species of the core microbiome showed differential abundance within Prakriti types, with gender specific signature taxons. Our study reveals that despite overall uniform composition of gut microbial community, healthy individuals belonging to different Prakriti groups have enrichment of specific bacteria. It highlights the importance of Prakriti based endo-phenotypes to explain the variability amongst healthy individuals in gut microbial flora that have important consequences for an individual's health, disease and treatment.

Herpesviridae family is one of the significant viral families which comprises major pathogens of a wide range of hosts. This family includes at least eight species of viruses which are known to infect humans. This family has evolved 180–220 million years ago and the present study highlights that it is still evolving and more genes can be added to the repertoire of this family. In addition, its core-genome includes important viral proteins including glycoprotein B and helicase. Most of the infections caused by human herpesviruses have no definitive cure; thus, search for new therapeutic strategies is necessary. The present study finds core-genome of human herpesviruses that differs from that of Herpesviridae family and nonhuman herpes strains of this family and might be a putative target for vaccine development. The phylogenetic reconstruction based upon the protein sequences of core gene set of Herpesviridae family reveals the sharp splits of its different subfamilies and supports the hypothesis of coevolution of viruses with their hosts. In addition, data mining for cis-elements in the genomes of human herpesviruses results in the prediction of numerous regulatory elements which can be used for regulating the expression of viral based vectors implicated in gene therapies.

The pathway of rubber (poly [cis-1,4-isoprene]) catabolism is well documented for Gram-positive rubber degraders but only little information exists for Gram-negative species. The first documented potent rubber degrading Gram-negative strain is Xanthomonas sp. strain 35Y that uses extracellular rubber oxygenases for the initial cleavage of the polyisoprene molecule. However, neither the exact phylogenetic position of Xanthomonas sp. strain 35Y nor the catabolic pathway of the primary polyisoprene cleavage products have been investigated. In this contribution, we started to address both these issues by a comprehensive taxonomic characterization and by the analysis of the draft genome sequence of strain 35Y. Evaluation of the 16S rRNA gene sequence pointed to a borderline taxonomic position of strain 35Y as a novel species of the genus Steroidobacter. Further, substantial differences in the genotypic properties of strain 35Y and the members of the genus Steroidobacter, including average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH), resolved the taxonomic position of strain 35Y and suggested its positioning as a novel species of the genus Steroidobacter. This was further confirmed by comparative analysis of physiological and biochemical features of strain 35Y with other members of the genus Steroidobacter. Thus, we conclude that strain 35Y represents a novel species of the genus Steroidobacter, for which we propose the designation Steroidobacter cummioxidans sp. nov., strain 35Y^T. A comprehensive analysis of the draft genome of S. cummioxidans strain 35Y revealed similarities but also substantial differences to rubber degrading Gram-positive counterparts. In particular, the putative transporters for the uptake of polyisoprene cleavage products differ from Gram-positive rubber degrading species. The draft genome sequence of S. cummioxidans strain 35Y will be useful for researchers to experimentally verify the predicted similarities and differences in the pathways of polyisoprene catabolism in Gram-positive and Gram-negative rubber degrading species.

The genus of Xanthomonas contains many well-known plant pathogens with the ability to infect some of the most important crop plants, thereby causing significant economic damage. Unfortunately, classical pest-control strategies are neither particularly efficient nor sustainable and we are, therefore, in demand of alternatives. Here, we present the isolation and characterization of seven novel phages infecting the plant-pathogenic species Xanthomonas translucens and Xanthomonas campestris. Transmission electron microscopy revealed that all phages show a siphovirion morphology. The analysis of genome sequences and plaque morphologies are in agreement with a lytic lifestyle of the phages making them suitable candidates for biocontrol. Moreover, three of the isolated phages form the new genus “Shirevirus”. All seven phages belong to four distinct clusters underpinning their phylogenetic diversity. Altogether, this study presents the first characterized isolates for the plant pathogen X. translucens and expands the number of available phages for plant biocontrol.

Streptomyces are well-known antibiotic producers, also characterized by a complex morphological differentiation. Streptomyces, like all bacteria, are confronted with the constant threat of phage predation, which in turn shapes bacterial evolution. However, despite significant sequencing efforts recently, relatively few phages infecting Streptomyces have been characterized compared to other genera. Here, we present the isolation and characterization of five novel Streptomyces phages. All five phages belong to the Siphoviridae family, based on their morphology as determined by transmission electron microscopy. Genome sequencing and life style predictions suggested that four of them were temperate phages, while one had a lytic lifestyle. Moreover, one of the newly sequenced phages shows very little homology to already described phages, highlighting the still largely untapped viral diversity. Altogether, this study expands the number of characterized phages of Streptomyces and sheds light on phage evolution and phage-host dynamics in Streptomyces.