Here, we report how the analysis of viral genetic variation using next-generation sequencing (NGS) can be used as a tool to improve mumps virus diagnostics. Analysis of NGS data from recently ...circulating mumps virus isolates allowed optimization of the current mumps virus real-time reverse transcription-PCR (RT-PCR) by primer and probe modifications due to nucleotide variations. The modified assay showed a higher efficiency and sensitivity than the previously used CDC protocol for the detection of currently circulating mumps virus strains and could therefore offer better support for outbreak control. The NGS sequence data were also used to make predictions of changes in the hemagglutinin-neuraminidase protein structure that could explain possible immune escape mechanisms.
The family Chlamydiaceae with the recombined single genus Chlamydia currently comprises nine species, all of which are obligate intracellular organisms distinguished by a unique biphasic ...developmental cycle. Anecdotal evidence from epidemiological surveys in flocks of poultry, pigeons and psittacine birds have indicated the presence of non-classified chlamydial strains, some of which may act as pathogens. In the present study, phylogenetic analysis of ribosomal RNA and ompA genes, as well as multi-locus sequence analysis of 11 field isolates were conducted. All independent analyses assigned the strains into two different clades of monophyletic origin corresponding to pigeon and psittacine strains or poultry isolates, respectively. Comparative genome analysis involving the type strains of currently accepted Chlamydiaceae species and the designated type strains representing the two new clades confirmed that the latter could be classified into two different species as their average nucleotide identity (ANI) values were always below 94%, both with the closest relative species and between themselves.
In view of the evidence obtained from the analyses, we propose the addition of two new species to the current classification: Chlamydia avium sp. nov. comprising strains from pigeons and psittacine birds (type strain 10DC88T; DSMZ: DSM27005T, CSUR: P3508T) and Chlamydia gallinacea sp. nov. comprising strains from poultry (type strain 08-1274/3T; DSMZ: DSM27451T, CSUR: P3509T).
Rickettsia (R.) helvetica is the most prevalent rickettsia found in Ixodes ricinus ticks in Germany. Several studies reported antibodies against R. helvetica up to 12.5% in humans investigated, ...however, fulminant clinical cases are rare indicating a rather low pathogenicity compared to other rickettsiae. We investigated growth characteristics of R. helvetica isolate AS819 in two different eukaryotic cell lines with focus on ultra-structural changes of host cells during infection determined by confocal laser scanning microscopy. Further investigations included partially sequencing of rickA, sca4 and sca2 genes, which have been reported to encode proteins involved in cell-to-cell spread and virulence in some rickettsiae. R. helvetica grew constantly but slowly in both cell lines used. Confocal laser scanning microscopy revealed that the dissemination of R. helvetica AS819 in both cell lines was rather mediated by cell break-down and bacterial release than cell-to-cell spread. The cytoskeleton of both investigated eukaryotic cell lines was not altered. R. helvetica possesses rickA, but its expression is not sufficient to promote actin-based motility as demonstrated by confocal laser scanning microscopy. Hypothetical Sca2 and Sca4 proteins were deduced from nucleotide gene sequences but the predicted amino acid sequences were disrupted or truncated compared to other rickettsiae most likely resulting in non-functional proteins. Taken together, these results might give a first hint to the underlying causes of the reduced virulence and pathogenicity of R. helvetica.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Here, we describe a small enterovirus outbreak including nine cases of aseptic meningitis in a New Zealand hospital in 2017. Most patients had a lymphocytic predominance in the CSF, their length of ...stay was short, and there were no paediatric cases or ICU admissions. VP1 genotyping revealed that the outbreak was caused by an echovirus E30 strain closely related to strains reported from the US, UK, Brazil, and Denmark. They all form a separate cluster within lineage "h", which leads to the proposal of establishing a new lineage tentatively named "j" for this group of echovirus E30 strains. However, whole genome sequencing and reference mapping to echovirus E30 sequences showed very poor mapping of reads to the 3' half of the genome. Further bioinformatic analysis indicated that the causative agent of this outbreak might be a mosaic triple-recombinant enterovirus composed of echovirus E6, echovirus E11, and echovirus E30 genome segments.
BackgroundThe common cold is the most common infectious disease affecting humans and has a substantial economic impact on society. Human rhinoviruses, which cause almost two-thirds of colds, have ...demonstrated temperature-dependent replication which is optimal between 33°C and 35°C.MethodsThis randomised, single-blind, parallel-group trial completed at a single-centre in New Zealand, recruited 170 participants aged 18–75 years (mean age 27.5 years) who were within 48 hours of common cold symptom onset and had a symptom score (the Modified Jackson Score (MJS)) ≥7 and a negative point-of-care test for influenza. Participants were blinded to the intervention and randomised (1:1) to 5 days of either nasal high flow rhinothermy (rNHF) (100% humidified air delivered at 35 L/min and 41°C for 2 hours daily) (n=85) or ‘sham’ rhinothermy (100% humidified air delivered at 10 L/min and 31°C for 10 min daily) (n=85) and completed daily symptom diaries, which included the MJS, for 14 days, to investigate whether rNHF reduced common cold symptom severity and duration compared with ‘sham’ rhinothermy.ResultsAn intention-to-treat superiority analysis included all randomised participants and showed no difference between treatment groups for the primary outcome, the day 4 MJS analysed by analysis of covariance: mean (SD) 6.33 (3.97) for rNHF vs 5.8 (3.15) for ‘sham’; estimated difference (95% CI) 0.37 (−0.69 to 1.42), p=0.49. There was no difference in time until resolution of symptoms: mean (SD) 5.96 (4.47) days for rNHF vs 6.42 (4.09) days for ‘sham’; estimated difference (95% CI) 1.02 (0.75 to 1.38), p=0.91. There were no serious adverse events related to the study treatments.ConclusionsThis well-powered, single-blind randomised controlled trial does not provide evidence that 5 days of rNHF (100% humidified air heated to 41°C delivered at 35 L/min for 2 hours daily) reduces common cold symptom severity or duration. However, investigation of rNHF in the treatment of influenza is warranted.Trial registration numberACTRN12617001340325.
An extensive comparative analysis of orbivirus genomes revealed four cases of unclear numeration and protein designation, due to confused reference to protein size or segment size by which they are ...encoded. A concise nomenclature based on type species, sequence homology and functional characteristics independent of segment or protein size is suggested.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
IntroductionThe common cold is the most common infectious disease affecting humans. It is usually a self-limiting disease; however, the common cold can cause significant morbidity and has a ...substantial economic impact on society. Human rhinoviruses (HRVs), which cause up to two-thirds of colds, have temperature-dependent replication and most HRV strains replicate optimally at 33°C. Delivery of heated, humidified air to the upper airways has the potential to reduce viral replication, but evidence of the effectiveness of this treatment of the common cold is inconclusive. We plan to test the hypothesis that delivery of humidified air heated to 41°C at high flow, nasal high flow rhinothermy (rNHF), for 2 hours daily for five days is more effective in reducing common cold symptom severity and duration than five days of ‘sham’ rhinothermy.Methods and analysisThis is a randomised, single-blind, parallel-group trial comparing rNHF to ‘sham’ rhinothermy in the treatment of common cold. We plan to recruit 170 participants within 48 hours of the onset of symptoms of common cold and randomise them 1:1 to receive one of the two treatments for five days. The study duration is 14 days, which includes clinic visits on the first day of randomisation and four days post-randomisation, and a phone call on the 14th day. Participants will complete daily symptom diaries which include a symptom score, the Modified Jackson Score (MJS). The primary outcome is the MJS after four days.Ethics and disseminationNew Zealand Ethics Registration: 17/STH/174. Results will be published in a peer-reviewed medical journal, presented at academic meetings, and reported to participants.Trial registration numberU1111-1194-4345 and ACTRN12617001340325; Pre-results.
The genomes of Bhanja virus (BHAV) and Palma virus (PALV) two tick-borne viruses hitherto grouped into the Bhanja virus antigenic complex of the Bunyaviridae were determined by pyrosequencing. ...Phylogenetic analysis groups all three segments of BHAV and PALV into a distinct clade of tick-borne phleboviruses together with the newly described severe fever with thrombocytopenia syndrome virus and Uukuniemi virus. The terminal signature sequences which are signatures for taxonomic grouping and important for virus replication and RNA transcription show marked differences in the L- and S-segments.
Erve virus (ERVEV) is a European Nairovirus that is suspected to cause severe headache (thunderclap headache) and intracerebral hemorrhage. The mode of transmission to humans (ticks or mosquitoes) is ...still unknown. Currently, no standardized testing method for ERVEV exists and only a small partial sequence of the polymerase gene is available. Here, we present the first complete genome sequence of ERVEV S, M, and L segments. Phylogenetic comparison of the amino acid sequence of the L-protein (RNA-dependent RNA polymerase) revealed only 48 % homology to available L-protein sequences of other Nairoviruses like Crimean-Congo hemorrhagic fever virus, Nairobi sheep disease virus, Hazara virus, Kupe virus, and Dugbe virus. Among themselves, these Nairoviruses show 62–89 % homology in the L-protein sequences. Therefore, ERVEV seems to be only distantly related to other Nairoviruses. The new sequence data can be used for the development of diagnostic methods and the identification of the natural vector.
Stringent nonpharmaceutical interventions (NPIs) such as lockdowns and border closures are not currently recommended for pandemic influenza control. New Zealand used these NPIs to eliminate ...coronavirus disease 2019 during its first wave. Using multiple surveillance systems, we observed a parallel and unprecedented reduction of influenza and other respiratory viral infections in 2020. This finding supports the use of these NPIs for controlling pandemic influenza and other severe respiratory viral threats.
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