Microbiome Responses to an Uncontrolled Short-Term Diet Intervention in the Frame of the Citizen Science Project.

Personalized nutrition is of increasing interest to individuals actively monitoring their health. The relations between the duration of diet intervention and the effects on gut microbiota have yet to be elucidated. Here we examined the associations of short-term dietary changes, long-term dietary habits and lifestyle with gut microbiota. Stool samples from 248 citizen-science volunteers were collected before and after a self-reported 2-week personalized diet intervention, then analyzed using 16S rRNA sequencing. Considerable correlations between long-term dietary habits and gut community structure were detected. A higher intake of vegetables and fruits was associated with increased levels of butyrate-producing Clostridiales and higher community richness. A paired comparison of the metagenomes before and after the 2-week intervention showed that even a brief, uncontrolled intervention produced profound changes in community structure: resulting in decreased levels of Bacteroidaceae, Porphyromonadaceae and Rikenellaceae families and decreased alpha-diversity coupled with an increase of Methanobrevibacter, Bifidobacterium, Clostridium and butyrate-producing Lachnospiraceae- as well as the prevalence of a permatype (a bootstrapping-based variation of enterotype) associated with a higher diversity of diet. The response of microbiota to the intervention was dependent on the initial microbiota state. These findings pave the way for the development of an individualized diet.

Alteration of the exDNA profile in blood serum of LLC-bearing mice under the decrease of tumour invasion potential by bovine pancreatic DNase I treatment.

Taking into account recently obtained data indicating the participation of circulating extracellular DNA (exDNA) in tumorigenesis, enzymes with deoxyribonucleic activity have again been considered as potential antitumour and antimetastatic drugs. Previously, using murine Lewis lung carcinoma and hepatocellular carcinoma A1 tumour models, we have shown the antimetastatic activity of bovine DNase I, which correlates with an increase of DNase activity and a decrease of exDNA concentration in the blood serum of tumour-bearing mice. In this work, using next-generation sequencing on the ABS SOLiD™ 5.500 platform, we performed a search for molecular targets of DNase I by comparing the exDNA profiles of healthy animals, untreated animals with Lewis lung carcinoma (LLC) and those with LLC treated with DNase I. We found that upon DNase I treatment of LLC-bearing mice, together with inhibition of metastasis, a number of strong alterations in the patterns of exDNA were observed. The major differences in exDNA profiles between groups were: i) the level of GC-poor sequences increased during tumour development was reduced to that of healthy mice; ii) levels of sequences corresponding to tumour-associated genes Hmga2, Myc and Jun were reduced in the DNase I-treated group in comparison with non-treated mice; iii) 224 types of tandem repeat over-presented in untreated LLC-bearing mice were significantly reduced after DNase I treatment. The most important result obtained in the work is that DNase I decreased the level of B-subfamily repeats having homology to human ALU repeats, known as markers of carcinogenesis, to the level of healthy animals. Thus, the obtained data lead us to suppose that circulating exDNA plays a role in tumour dissemination, and alteration of multiple molecular targets in the bloodstream by DNase I reduces the invasive potential of tumours.

Genetic diversity of Ixodes pavlovskyi and I. persulcatus (Acari: Ixodidae) from the sympatric zone in the south of Western Siberia and Kazakhstan.

The most epidemiologically significant tick species in Siberia involved in transmission of a large number of pathogens causing human infectious diseases is Ixodes persulcatus. Ixodes pavlovskyi, being more active, also poses epidemiological threats. These tick species share morphology, activity seasons and geographic distribution range. In this paper, we characterize the geographic and genetic structures of I. persulcatus and I. pavlovskyi populations inhabiting the southern part of Western Siberia (Russia and Kazakhstan)--the western part of I. pavlovskyi distribution range. The data are based on six distinct Ixodes tick populations. Analysis of the concatenated mitochondrial marker sequences (16S rRNA and COI) and the nuclear sequence (ITS2) showed genetic polymorphisms in both I. persulcatus and I. pavlovskyi ticks inhabiting the sympatric zone. We could not determine the phylogeographic structure of I. pavlovskyi populations whereas for I. persulcatus significant within-region variance was shown. Notably, the abundance of I. persulcatus ticks negatively correlates with nucleotide and haplotype diversity in the concatenated sequence of mitochondrial gene (16S rRNA and COI) fragments. This is the first description of the genetic polymorphism of I. persulcatus and I. pavlovskyi ticks coexisting in a sympatric zone based on analysis of mitochondrial and nuclear markers.

Complete Genome Sequencing of Borrelia valaisiana and Borrelia afzelii Isolated from Ixodes persulcatus Ticks in Western Siberia.

Lyme disease, caused by bacteria of the Borrelia burgdorferi sensu lato complex, is the most frequent tick-borne infection in Eurasia. Here, we report the complete genome sequence of the Borrelia valaisiana Tom 4006 and Borrelia afzelii Tom 3107 strains isolated from Ixodes persulcatus ticks in western Siberia.

Draft Genome Sequence of Bacillus cereus Strain F, Isolated from Ancient Permafrost.

Bacillus cereus strain F was isolated and cultured from a sample of permafrost, aged presumably about 3 million years, on the Mammoth Mountain (62°56'N, 133°59'E). These genome data provide the basis to investigate Bacillus cereus F, identified as a long-term survivor of the extremely cold and close environment.

Evolutionary time-scale of primate bocaviruses.

Human bocavirus (HBoV) is associated with acute gastroenteritis in humans, occurring mostly in young children and elderly people. Four bocavirus genotypes (HBoV1-HBoV4) have been found so far. Since there were no data on the contribution of HBoV to gastroenteritis in Russia, 1781 fecal samples collected from infants hospitalized with acute gastroenteritis in Novosibirsk, Russia during one year were tested for the presence of nucleic acids from HBoV and three major gastrointestinal viruses (rotavirus A, norovirus II, and astrovirus). HBoV was detected only in 1.9% of the samples: HBoV1 was detected in 0.6% and HBoV2, in 1.3%. Complete genome sequencing of three Novosibirsk isolates was performed. An evolutionary analysis of these sequences and the available sequences of human and great apes bocaviruses demonstrated that the current HBoV genotypes diverged comparatively recently, about 60-300years ago. The independent evolution of bocaviruses from chimpanzees and gorillas commenced at the same time period. This suggests that these isolates of great apes bocaviruses belong to separate genotypes within the species of human bocavirus, which is actually the primate bocavirus. The rate of mutation accumulation in the genome of primate bocaviruses has been estimated as approximately 9×10(-4)substitutions/site/year. It has been demonstrated that HBoV1 diverged from the ancestor common with chimpanzee bocavirus approximately 60-80years ago, while HBoV4 separated from great apes bocaviruses about 200-300years ago. The hypothesis postulating independent evolution of HBoV1 and HBoV4 genotypes from primate bocaviruses has been proposed.

Whole-genome sequencing of Borrelia garinii BgVir, isolated from Taiga ticks (Ixodes persulcatus).

Most Lyme borreliosis cases in Russia result from Borrelia garinii NT29 group infection. Borrelias of this group circulate exclusively in Ixodes persulcatus ticks, which are seldom found beyond Russia and the far east. Here we report the whole-genome sequence of Borrelia garinii BgVir isolated from an I. persulcatus female.

A comparative study of cell-free apoptotic and genomic DNA using FISH and massive parallel sequencing.

OBJECTIVE: Study of circulating DNA (cirDNA) generation mechanisms with respect to their influence on the content of cirDNA is very important since it could indicate the best molecular targets for diagnostic applications. Since apoptosis was shown to be one of the main sources of cirDNA, we performed in vitro comparative study of cell-free apoptotic and genomic DNA (gDNA). METHODS: DNA isolated from culture medium of apoptotic human umbilical vein endothelial cells (cm-apoDNA) and the gDNA from the same living cells was analyzed using FISH and sequenced on SOLiD 3 platform. RESULTS/CONCLUSIONS: FISH demonstrates overrepresentation of C-positive chromosome regions in cm-apoDNA. SOLiD 3 data show enrichment of cm-apoDNA for Alu repeats: the content of AluJ, AluS and AluY repeats was, respectively, 2.47-fold (standard deviation (SD) 3.6%), 2.45-fold (SD 5.5%) and 2.79-fold (SD 6.1%) higher in cm-apoDNA. By contrast, some of L1 elements were underrepresented in cm-apoDNA: the content of L1MA and L1ME was, respectively, 1.4-fold (SD 22%) and 1.45-fold (SD 9%) lower in cm-apoDNA. In contrast to FISH, these data and the predominant location of Alu repeats in euchromatic regions evidence the non-uniform gDNA degradation during apoptosis leading to the enrichment of cm-apoDNA with coding sequences.

Unbiased approach to profile the variety of small non-coding RNA of human blood plasma with massively parallel sequencing technology.

OBJECTIVE: Understanding structures of circulating RNA expands fundamental knowledge of cell communications and signaling pathways as well as allows developing new molecular diagnostic approaches. The aim of this study was to deploy a new approach to sequencing cDNA library construction which expands the capabilities of high-throughput sequencing analysis of small non-coding RNAs. With the approach, we performed massively parallel sequencing of human blood plasma RNA to document profile of common and peculiar RNA species normally circulating in blood of healthy individuals. METHODS: Total RNA was extracted from blood plasma samples of eight apparently healthy individuals. To obtain comprehensive cDNA libraries RNA was dephosphorylated and then 5'-phosphorylated. 5'-Phosphorylated total plasma RNA was ligated with adapters, reverse transcribed and eight personalized cDNA libraries were constructed. Libraries were sequenced with SOLiD(™) technology. RESULTS/CONCLUSION: Fragments of rRNA, mitochondrial transcripts, microRNAs, fragments of scRNAs, snRNA and snoRNA, fragments of several mRNAs as well as the set of newly discovered transcripts were found to be permanent representatives of human blood plasma RNAs. Advanced mapping allowed to identify circulating herpes virus and enterobacterial transcripts. Documented profile of circulating RNA of healthy individuals provides basis for development of new approaches in research and diagnosis of human pathology.