Puumala Orthohantavirus Reassortant Genome Variants Likely Emerging in the Watershed Forests.

Hemorrhagic fever with renal syndrome (HFRS) remains a prevalent zoonosis in the Republic of Tatarstan (RT), Russian Federation. Puumala orthohantavirus (PUUV), carried by bank voles (Myodes glareolus), is the principal zoonotic pathogen of HFRS in the RT. In this study, we sought to demonstrate the similarity of the PUUV genetic sequences detected in HFRS case patients and bank vole samples previously collected in some areas of the RT. Furthermore, we intended to identify the reassortant PUUV genomes and locate a potential site for their emergence. During 2019 outbreaks, the PUUV genome sequences of the S and M segments from 42 HFRS cases were analysed and compared with the corresponding sequences from bank voles previously trapped in the RT. Most of the PUUV strains from HFRS patients turned out to be closely related to those isolated from bank voles captured near the site of the human infection. We also found possible reassortant PUUV genomes in five patients while they were absent in bank voles. The location of the corresponding HFRS infection sites suggests that reassortant PUUV genomes could emerge in the bank voles that inhabit the forests on the watershed between the Kazanka River and Myosha River. These findings could facilitate the search for the naturally occurring reassortants of PUUV in bank vole populations.

Analysis of Puumala orthohantavirus Genome Variants Identified in the Territories of Volga Federal District.

Hemorrhagic fever with renal syndrome (HFRS) is a zoonotic disease commonly diagnosed in the Volga Federal District (VFD). HFRS is caused by Puumala orthohantavirus (PUUV), and this virus is usually detected in bank voles as its natural host (Myodes glareolus). The PUUV genome is composed of the single-stranded, negative-sense RNA containing three segments. The goal of the current study is to identify genome variants of PUUV strains circulating in bank voles captured in the Udmurt Republic (UR) and Ulyanovsk region (ULR). The comparative and phylogenetic analysis of PUUV strains revealed that strains from Varaksino site UR are closely related to strains previously identified in the Pre-Kama area of the Republic of Tatarstan (RT), whilst strains from Kurlan and Mullovka sites ULR are similar to strains from the Trans-Kama area of the RT. It was also found that Barysh ULR strains form a separate distinct group phylogenetically equidistant from Varaksino and Kurlan−Mullovka groups. The identified groups of strains can be considered as separate sub-lineages in the PUUV Russian genetic lineage. In addition, the genomes of the strains from the UR, most likely, were formed as a result of reassortment.

The Distribution of Puumala orthohantavirus Genome Variants Correlates with the Regional Landscapes in the Trans-Kama Area of the Republic of Tatarstan.

In the European part of Russia, the highest number of hemorrhagic fever with renal syndrome (HFRS) cases are registered in the Volga Federal District (VFD), which includes the Republic of Tatarstan (RT). Puumala orthohantavirus (PUUV) is the main causative agent of HFRS identified in the RT. The goal of the current study is to analyze the genetic variations of the PUUV strains and possible presence of chimeric and reassortant variants among the PUUV strains circulating in bank vole populations in the Trans-Kama area of the RT. Complete S segment CDS as well as partial M and L segment coding nucleotide sequences were obtained from 40 PUUV-positive bank voles and used for the analysis. We found that all PUUV strains belonged to RUS genetic lineage and clustered in two subclades corresponding to the Western and Eastern Trans-Kama geographic areas. PUUV strains from Western Trans-Kama were related to the previously identified strain from Teteevo in the Pre-Kama area. It can be suggested that the PUUV strains were introduced to the Teteevo area as a result of the bank voles' migration from Western Trans-Kama. It also appears that physical obstacles, including rivers, could be overcome by migrating rodents under favorable circumstances. Based on results of the comparative and phylogenetic analyses, we propose that bank vole distribution in the Trans-Kama area occurred upstream along the river valleys, and that watersheds could act as barriers for migrations. As a result, the diverged PUUV strains could be formed in closely located populations. In times of extensive bank vole population growth, happening every 3-4 years, some regions of watersheds may become open for contact between individual rodents from neighboring populations, leading to an exchange of the genetic material between divergent PUUV strains.

Characterization of the Puumala orthohantavirus Strains in the Northwestern Region of the Republic of Tatarstan in Relation to the Clinical Manifestations in Hemorrhagic Fever With Renal Syndrome Patients.

Over 1,000 cases of hemorrhagic fever with renal syndrome (HFRS) were recorded in the Republic of Tatarstan (RT) in 2015. HFRS is a zoonotic disease caused by several different Old World hantaviruses. In RT, Puumala orthohantavirus (PUUV) is a prevalent etiological agent of HFRS. We looked for the genetic link between the PUUV strains isolated from the bank voles and from the infected humans. In addition, possible correlation between the genetic makeup of the PUUV strain involved and different clinical picture of HFRS was investigated. Partial PUUV small (S) genome segment sequences were retrieved from 37 small animals captured in the northwestern region of RT in 2015. Phylogenetic analysis revealed that 34 PUUV sequences clustered with strains of the previously identified "Russia" (RUS) genetic lineage, while 3 remaining PUUV sequences clustered with the known lineage from Finland (FIN). Sequence comparisons showed that the majority of the S-segment sequences isolated in the current study displayed 98.2-100.0% sequence identity when compared with the strains isolated earlier from the HFRS patients hospitalized in Kazan city. HFRS patients infected with PUUV strains of either RUS or FIN genetic lineages were observed to have consistent differences in clinical presentation of the disease and laboratory findings. These findings indicated a strong genetic link between the infected bank voles and human HFRS cases from the same localities. Thus, S-segment sequences of the PUUV strains isolated from HFRS patients could serve as a molecular marker for determining the likely geographic area where infection occurred.

Links of gut microbiota composition with alcohol dependence syndrome and alcoholic liver disease.

BACKGROUND: Alcohol abuse has deleterious effects on human health by disrupting the functions of many organs and systems. Gut microbiota has been implicated in the pathogenesis of alcohol-related liver diseases, with its composition manifesting expressed dysbiosis in patients suffering from alcoholic dependence. Due to its inherent plasticity, gut microbiota is an important target for prevention and treatment of these diseases. Identification of the impact of alcohol abuse with associated psychiatric symptoms on the gut community structure is confounded by the liver dysfunction. In order to differentiate the effects of these two factors, we conducted a comparative "shotgun" metagenomic survey of 99 patients with the alcohol dependence syndrome represented by two cohorts-with and without liver cirrhosis. The taxonomic and functional composition of the gut microbiota was subjected to a multifactor analysis including comparison with the external control group. RESULTS: Alcoholic dependence and liver cirrhosis were associated with profound shifts in gut community structures and metabolic potential across the patients. The specific effects on species-level community composition were remarkably different between cohorts with and without liver cirrhosis. In both cases, the commensal microbiota was found to be depleted. Alcoholic dependence was inversely associated with the levels of butyrate-producing species from the Clostridiales order, while the cirrhosis-with multiple members of the Bacteroidales order. The opportunist pathogens linked to alcoholic dependence included pro-inflammatory Enterobacteriaceae, while the hallmarks of cirrhosis included an increase of oral microbes in the gut and more frequent occurrence of abnormal community structures. Interestingly, each of the two factors was associated with the expressed enrichment in many Bifidobacterium and Lactobacillus-but the exact set of the species was different between alcoholic dependence and liver cirrhosis. At the level of functional potential, the patients showed different patterns of increase in functions related to alcohol metabolism and virulence factors, as well as pathways related to inflammation. CONCLUSIONS: Multiple shifts in the community structure and metabolic potential suggest strong negative influence of alcohol dependence and associated liver dysfunction on gut microbiota. The identified differences in patterns of impact between these two factors are important for planning of personalized treatment and prevention of these pathologies via microbiota modulation. Particularly, the expansion of Bifidobacterium and Lactobacillus suggests that probiotic interventions for patients with alcohol-related disorders using representatives of the same taxa should be considered with caution. Taxonomic and functional analysis shows an increased propensity of the gut microbiota to synthesis of the toxic acetaldehyde, suggesting higher risk of colorectal cancer and other pathologies in alcoholics.

Genome analysis of E. coli isolated from Crohn's disease patients.

BACKGROUND: Escherichia coli (E. coli) has been increasingly implicated in the pathogenesis of Crohn's disease (CD). The phylogeny of E. coli isolated from Crohn's disease patients (CDEC) was controversial, and while genotyping results suggested heterogeneity, the sequenced strains of E. coli from CD patients were closely related. RESULTS: We performed the shotgun genome sequencing of 28 E. coli isolates from ten CD patients and compared genomes from these isolates with already published genomes of CD strains and other pathogenic and non-pathogenic strains. CDEC was shown to belong to A, B1, B2 and D phylogenetic groups. The plasmid and several operons from the reference CD-associated E. coli strain LF82 were demonstrated to be more often present in CDEC genomes belonging to different phylogenetic groups than in genomes of commensal strains. The operons include carbon-source induced invasion GimA island, prophage I, iron uptake operons I and II, capsular assembly pathogenetic island IV and propanediol and galactitol utilization operons. CONCLUSIONS: Our findings suggest that CDEC are phylogenetically diverse. However, some strains isolated from independent sources possess highly similar chromosome or plasmids. Though no CD-specific genes or functional domains were present in all CD-associated strains, some genes and operons are more often found in the genomes of CDEC than in commensal E. coli. They are principally linked to gut colonization and utilization of propanediol and other sugar alcohols.

Data on gut metagenomes of the patients with alcoholic dependence syndrome and alcoholic liver cirrhosis.

Alcoholism is associated with significant changes in gut microbiota composition. Metagenomic sequencing allows to assess the altered abundance levels of bacterial taxa and genes in a culture-independent way. We collected 99 stool samples from the patients with alcoholic dependence syndrome (n=72) and alcoholic liver cirrhosis (n=27). Each of the samples was surveyed using "shotgun" (whole-genome) sequencing on SOLiD platform. The reads are deposited in the ENA (project ID: PRJEB18041).