Dirk Höper

Dr. Dirk Höper

orcid

Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2012 in Emerging Infectious Diseases
Verified
Journal Article
Open access
BHBernd Hoffmann
Bernd Hoffmann
MSMatthias Scheuch
Matthias Scheuch
DHDirk Höper
Dirk Höper
RJRalf Jungblut
Ralf Jungblut
MHMark Holsteg
Mark Holsteg
MBMartin Beer
Martin Beer
In 2011, an unidentified disease in cattle was reported in Germany and the Netherlands. Clinical signs included fever, decreased milk production, and diarrhea. Metagenomic analysis identified a novel orthobunyavirus, which subsequently was isolated from blood of affected animals. Surveillance was initiated to test malformed newborn animals in the affected region.

9 July 2015 in New England Journal of Medicine
Verified
Journal Article
Closed access
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BHBernd Hoffmann
Bernd Hoffmann
DTDennis Tappe
Dennis Tappe
DHDirk Höper
Dirk Höper
CHChristiane Herden
Christiane Herden
ABAnnemarie Boldt
Annemarie Boldt
MBMartin Beer
Martin Beer
Between 2011 and 2013, three breeders of variegated squirrels (Sciurus variegatoides) had encephalitis with similar clinical signs and died 2 to 4 months after onset of the clinical symptoms. With the use of a metagenomic approach that incorporated next-generation sequencing and real-time reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR), the presence of a previously unknown bornavirus was detected in a contact squirrel and in brain samples from the three patients. Phylogenetic analyses showed that this virus, tentatively named variegated squirrel 1 bornavirus (VSBV-1), forms a lineage separate from that of the known bornavirus species. (Funded by the Federal Ministry of Food and Agriculture [Germany] and others.)

4 September 2020 in Archives of Virology
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Journal Article
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Jens H. KuhnJens H. Kuhn
Jens H. Kuhn
SAScott Adkins
Scott Adkins
DADaniela Alioto
Daniela Alioto
SASergey Alkhovsky
Sergey Alkhovsky
GAGaya Amarasinghe
Gaya Amarasinghe
XZXueping Zhou
Xueping Zhou

25 April 2018 in Scientific Reports
Verified
Journal Article
Open access
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LZLaura Zani
Laura Zani
JFJan Hendrik Forth
Jan Hendrik Forth
LFLeonie Forth
Leonie Forth
INImbi Nurmoja
Imbi Nurmoja
SLSimone Leidenberger
Simone Leidenberger
Sandra  BlomeSandra Blome
Sandra Blome
African swine fever (ASF) was introduced into the Eastern European Union in 2014 and led to considerable mortality among wild boar. In contrast, unexpected high antibody prevalence was reported in hunted wild boar in north-eastern Estonia. One of the causative virus strains was recently characterized. While it still showed rather high virulence in the majority of experimentally infected animals, one animal survived and recovered completely. Here, we report on the follow-up characterization of the isolate obtained from the survivor in the acute phase of infection. As a first step, three in vivo experiments were performed with different types of pigs: twelve minipigs (trial A), five domestic pigs (trial B), and five wild boar (trial C) were inoculated. 75% of the minipigs and all domestic pigs recovered after an acute course of disease. However, all wild boar succumbed to infection within 17 days. Representative samples were sequenced using NGS-technologies, and whole-genomes were compared to ASFV “Georgia 2007/1”. The alignments indicated a deletion of 14560 base pairs at the 5’ end, and genome reorganization by duplication. The characteristic deletion was confirmed in all trial samples and local field samples. In conclusion, an ASFV variant was found in Estonia that showed reduced virulence.

28 February 2012 in PLOS ONE
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Journal Article
Open access
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NBNorbert Becker
Norbert Becker
HJHanna Jöst
Hanna Jöst
UZUte Ziegler
Ute Ziegler
MEMartin Eiden
Martin Eiden
DHDirk Höper
Dirk Höper
Jonas Schmidt-ChanasitJonas Schmidt-Chanasit
Jonas Schmidt-Chanasit
This study aimed to identify the causative agent of mass mortality in wild and captive birds in southwest Germany and to gather insights into the phylogenetic relationship and spatial distribution of the pathogen. Since June 2011, 223 dead birds were collected and tested for the presence of viral pathogens. Usutu virus (USUV) RNA was detected by real-time RT-PCR in 86 birds representing 6 species. The virus was isolated in cell culture from the heart of 18 Blackbirds (Turdus merula). USUV-specific antigen was demonstrated by immunohistochemistry in brain, heart, liver, and lung of infected Blackbirds. The complete polyprotein coding sequence was obtained by deep sequencing of liver and spleen samples of a dead Blackbird from Mannheim (BH65/11-02-03). Phylogenetic analysis of the German USUV strain BH65/11-02-03 revealed a close relationship with strain Vienna that caused mass mortality among birds in Austria in 2001. Wild birds from lowland river valleys in southwest Germany were mainly affected by USUV, but also birds kept in aviaries. Our data suggest that after the initial detection of USUV in German mosquitoes in 2010, the virus spread in 2011 and caused epizootics among wild and captive birds in southwest Germany. The data also indicate an increased risk of USUV infections in humans in Germany.

15 November 2006 in Journal of Bacteriology
Verified
Journal Article
Closed access
KRKathrin Rogasch
Kathrin Rogasch
VRVanessa RühMling
Vanessa RühMling
JPJan Pané-Farré
Jan Pané-Farré
DHDirk Höper
Dirk Höper
CWChristin Weinberg
Christin Weinberg
SESusanne Engelmann
Susanne Engelmann
The two-component system SaeRS consisting of the histidin kinase SaeS and the response regulator SaeR is known to act on virulence gene expression in Staphylococcus aureus . In order to get a more comprehensive picture on SaeR-regulated genes, we studied the contribution of the two-component system on global gene expression by using both the proteomic and transcriptomic approach. Altogether, a loss of SaeRS resulted in a decreased amount of at least 17 extracellular proteins and two cell surface-associated proteins, among them several important virulence factors such as HlgA, HlgB, HlgC, LukF, and LukM. SaeRS activates the expression of these genes at the transcriptional level. The amount of the five proteins Aur, SspA, SsaA, Plc, and GlpQ was negatively influenced by SaeRS. However, the transcription of the corresponding genes was not affected by the two-component system. SaeRS had also no measurable influence on the transcription of the regulatory genes agr , sarA , arlRS , and sigB that contribute to the regulation of SaeRS-dependent virulence factors identified in this investigation. Our results clearly show that SaeRS is strongly involved in the tight temporal control of virulence factor expression in S. aureus . Its precise role within the regulatory network remains to be determined.