The diversity of viruses probably exceeds biodiversity of eukaryotes, but little is known about the origin and emergence of novel virus species. Experimentation and disease outbreak investigations ...have allowed the characterization of rapid molecular virus adaptation. However, the processes leading to the establishment of functionally distinct virus taxa in nature remain obscure. Here, we demonstrate that incipient speciation in a natural host species has generated distinct ecological niches leading to adaptive isolation in an RNA virus. We found a very strong association between the distributions of two major phylogenetic clades in Tula orthohantavirus (TULV) and the rodent host lineages in a natural hybrid zone of the European common vole (Microtus arvalis). The spatial transition between the virus clades in replicated geographic clines is at least eight times narrower than between the hybridizing host lineages. This suggests a strong barrier for effective virus transmission despite frequent dispersal and gene flow among local host populations, and translates to a complete turnover of the adaptive background of TULV within a few hundred meters in the open, unobstructed landscape. Genetic differences between TULV clades are homogenously distributed in the genomes and mostly synonymous (93.1%), except for a cluster of nonsynonymous changes in the 5' region of the viral envelope glycoprotein gene, potentially involved in host-driven isolation. Evolutionary relationships between TULV clades indicate an emergence of these viruses through rapid differential adaptation to the previously diverged host lineages that resulted in levels of ecological isolation exceeding the progress of speciation in their vertebrate hosts.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Sequencing of complete coding regions of a rotavirus k strain.•Closest phylogenetic relationship of RVK with RVC.•RVK belongs to the phylogenetic RVA-like clade of rotaviruses.•Comparison of partial ...sequences indicate high genetic variability of RVK.•The data confirm classification of RVK as a novel rotavirus species.
Rotaviruses are causative agents of diarrhea in humans and animals. Currently, the species rotavirus A-J (RVA-RVJ) and the putative species RVK and RVL are defined, mainly based on their genome sequence identities. RVK strains were first identified in 2019 in common shrews (Sorex aranaeus) in Germany; however, only short sequence fragments were available so far. Here, we analyzed the complete coding regions of strain RVK/shrew-wt/GER/KS14–0241/2013, which showed highest sequence identities with RVC. The amino acid sequence identity of VP6, which is used for rotavirus species definition, reached only 51% with other rotavirus reference strains thus confirming classification of RVK as a separate species. Phylogenetic analyses for the deduced amino acid sequences of all 11 virus proteins showed, that for most of them RVK and RVC formed a common branch within the RVA-like phylogenetic clade. Only the tree for the highly variable NSP4 showed a different branching; however, with very low bootstrap support. Comparison of partial nucleotide sequences of other RVK strains from common shrews of different regions in Germany indicated a high degree of sequence variability (61–97% identity) within the putative species. These RVK strains clustered separately from RVC genotype reference strains in phylogenetic trees indicating diversification of RVK independent from RVC. The results indicate that RVK represents a novel rotavirus species, which is most closely related to RVC.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rotaviruses infect humans and animals and are a main cause of diarrhea. They are non-enveloped viruses with a genome of 11 double-stranded RNA segments. Based on genome analysis and amino acid ...sequence identities of the capsid protein VP6, the rotavirus species A to J (RVA-RVJ) have been defined so far. In addition, rotaviruses putatively assigned to the novel rotavirus species K (RVK) and L (RVL) have been recently identified in common shrews (
), based on partial genome sequences. Here, the complete genome sequence of strain KS14/0241, a prototype strain of RVL, is presented. The deduced amino acid sequence for VP6 of this strain shows only up to 47% identity to that of RVA to RVJ reference strains. Phylogenetic analyses indicate a clustering separated from the established rotavirus species for all 11 genome segments of RVL, with the closest relationship to RVH and RVJ within the phylogenetic RVB-like clade. The non-coding genome segment termini of RVL showed conserved sequences at the 5'-end (positive-sense RNA strand), which are common to all rotaviruses, and those conserved among the RVB-like clade at the 3'-end. The results are consistent with a classification of the virus into a novel rotavirus species L.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The hepatitis E virus (HEV) was first identified in 1990, although hepatitis E-like diseases in humans have been recorded for a long time dating back to the 18th century. The HEV genotypes 1-4 have ...been subsequently detected in human hepatitis E cases with different geographical distribution and different modes of transmission. Genotypes 3 and 4 have been identified in parallel in pigs, wild boars and other animal species and their zoonotic potential has been confirmed. Until 2010, these genotypes along with avian HEV strains infecting chicken were the only known representatives of the family Hepeviridae. Thereafter, additional HEV-related viruses have been detected in wild boars, distinct HEV-like viruses were identified in rats, rabbit, ferret, mink, fox, bats and moose, and a distantly related agent was described from closely related salmonid fish. This review summarizes the characteristics of the so far known HEV-like viruses, their phylogenetic relationship, host association and proposed involvement in diseases. Based on the reviewed knowledge, a suggestion for a new taxonomic grouping scheme of the viruses within the family Hepeviridae is presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Urban rats present a global public health concern as they are considered a reservoir and vector of zoonotic pathogens, including Escherichia coli. In view of the increasing emergence of antimicrobial ...resistant E. coli strains and the on-going discussion about environmental reservoirs, we intended to analyse whether urban rats might be a potential source of putatively zoonotic E. coli combining resistance and virulence. For that, we took fecal samples from 87 brown rats (Rattus norvegicus) and tested at least three E. coli colonies from each animal. Thirty two of these E. coli strains were pre-selected from a total of 211 non-duplicate isolates based on their phenotypic resistance to at least three antimicrobial classes, thus fulfilling the definition of multiresistance. As determined by multilocus sequence typing (MLST), these 32 strains belonged to 24 different sequence types (STs), indicating a high phylogenetic diversity. We identified STs, which frequently occur among extraintestinal pathogenic E. coli (ExPEC), such as STs 95, 131, 70, 428, and 127. Also, the detection of a number of typical virulence genes confirmed that the rats tested carried ExPEC-like strains. In particular, the finding of an Extended-spectrum beta-lactamase (ESBL)-producing strain which belongs to a highly virulent, so far mainly human- and avian-restricted ExPEC lineage (ST95), which expresses a serogroup linked with invasive strains (O18:NM:K1), and finally, which produces an ESBL-type frequently identified among human strains (CTX-M-9), pointed towards the important role, urban rats might play in the transmission of multiresistant and virulent E. coli strains. Indeed, using a chicken infection model, this strain showed a high in vivo pathogenicity. Imagining the high numbers of urban rats living worldwide, the way to the transmission of putatively zoonotic, multiresistant, and virulent strains might not be far ahead. The unforeseeable consequences of such an emerging public health threat need careful consideration in the future.
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We screened samples from common shrews (Sorex araneus) collected in Germany during 2004-2014 and identified 3 genetically divergent rotaviruses. Virus protein 6 sequence similarities to prototype ...rotaviruses were low (64.5% rotavirus A, 50.1% rotavirus C tentative species K, 48.2% rotavirus H tentative species L). Shrew-associated rotaviruses might have zoonotic potential.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVES
Conventional aortic valve replacement (AVR) in young, active patients represents a suboptimal solution in terms of long-term survival, durability and quality of life. The aim of the ...present work is to present an update on the multicentre experience with the pulmonary autograft procedure in young, adult patients.
METHODS
Between 1990–2013, 1779 adult patients (1339 males; 44.7 ± 11.6 years) underwent the pulmonary autograft procedure in 8 centres. All patients underwent prospective clinical and echocardiographic examinations annually. The mean follow-up was 8.3 ± 5.1 years (range 0–24.3 years) with a total cumulative follow-up of 14 288 years and 662 patients having a follow-up of at least 10 years.
RESULTS
The early (30-day) mortality rate was 1.1% (n = 19). Late (>30 day) survival of the adult population was comparable with the age- and gender-matched general population (observed deaths: 101, expected deaths: 91; P = 0.29). Freedom from autograft reoperation at 5, 10 and 15 years was 96.8, 94.7 and 86.7%, respectively, whereas freedom from homograft reoperation was 97.6, 95.5 and 92.3%, respectively. The overall freedom from reoperation was 94.9, 91.1 and 82.7%, respectively. Longitudinal modelling of functional valve performance revealed a low (<5%) probability of a patient being in higher autograft regurgitation grades throughout the first decade. Similarly, excellent homograft function was observed throughout the first 15 years.
CONCLUSION
The autograft principle results in postoperative long-term survival comparable with that of the age- and gender-matched general population and reoperation rates within the 1%/patient-year boundaries and should be considered in young, active patients who want to avoid the shortcomings of conventional prostheses.
The nomenclature of hepatitis E virus (HEV) subtypes is inconsistent and makes comparison of different studies problematic. We have provided a table of proposed complete genome reference sequences ...for each subtype. The criteria for subtype assignment vary between different genotypes and methodologies, and so a conservative pragmatic approach has been favoured. Updates to this table will be posted on the International Committee on Taxonomy of Viruses website (http://talk.ictvonline.org/r.ashx?C). The use of common reference sequences will facilitate communication between researchers and help clarify the epidemiology of this important human pathogen. This subtyping procedure might be adopted for other taxa of the genus Orthohepevirus.
Lymphocytic choriomeningitis mammarenavirus (LCMV) is a globally distributed zoonotic pathogen transmitted by house mice (Mus musculus). We report the reemergence of LCMV (lineages I and II) in wild ...house mice (Mus musculus domesticus) and LCMV lineage I in a diseased golden lion tamarin (Leontopithecus rosalia) from a zoo in Germany.
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