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Sandra Essbauer

Publications and source records attributed to Sandra Essbauer.

5 recordsLinked to original sources

Evaluation of sampling technique and transport media for the diagnostics of adenoviral eye infections. Adenovirus sampling and transport.

BACKGROUND: Human adenoviruses (HAdV) may cause pharyngoconjunctival fever, follicular conjunctivitis or epidemic keratoconjunctivitis (EKC). Especially, outbreaks of the latter may lead to severe economic losses when preventive measures are implemented too late. Thus, a safe sampling method, proper specimen transport conditions and a fast and sensitive diagnostic technique is mandatory. METHODS: Two commercially available virus transport systems (VTS) were compared with two NaCl-moisturised sampling devices, one of which comprises Dacron-tipped plastic-shafted swabs and the other a cotton-tipped wood-shafted swab, available in most ophthalmologists' offices. Downstream methods for specific detection of HAdV included direct immunofluorescence assay (IFA) of conjunctival swabs, virus isolation by cell culture and quantitative real-time polymerase chain reaction (qPCR). Furthermore, the influence of application of local anaesthetics prior to swabbing on subsequent detection of HAdV was investigated. RESULTS: Application of local anaesthetics had a positive influence on the amount of swabbed cells, thus increasing the chance of obtaining positive results by IFA. Neither isolation of HAdV by cell culture nor by qPCR was negatively influenced by this pretreatment. Surprisingly, both commercially available VTS performed significantly worse than the NaCl-moisturised swabs. This was shown with regard to virus recovery rates in cell culture as well as viral genome copy numbers in the qPCR. CONCLUSIONS: Based on our results, the following recommendations are provided to improve sampling, transport and diagnostic techniques regarding conjunctival swabs for diagnosis of human adenovirus infection: (1) application of local anaesthetics, (2) NaCl-moisturised VTS for shipment of specimens, and (3) detection of HAdV by qPCR. The latter method proved to be superior to virus isolation by cell culture, including subsequent identification by IFA, because it is faster, more sensitive and allows simultaneous handling of a number of samples. Hence, countermeasures to prevent further virus spread in an outbreak situation can be implemented earlier, thus reducing the number of subsequent adenoviral infections.

Adenovirus Infections, Human↗

Seroprevalence of tick-borne and mosquito-borne arboviruses in European brown hares in Northern and Western Germany.

Tríbec virus (Kemerovo serogroup, genus Orbivirus), Eyach virus (genus Coltivirus), and Tahyna virus (California encephalitis serogroup, genus Bunyavirus) are arthropod-borne viruses known to occur in Germany. These viruses are also suspected to cause human disease. So far, no information is available on their geographical distribution in Germany and their natural transmission cycles. A total of 166 sera from European brown hares (Lepus europaeus) collected in seven districts of the Federal State of Schleswig-Holstein and in four districts of the Federal State of North Rhine-Westphalia was tested by plaque reduction neutralization test (PRNT) for antibodies against Tríbec virus, Eyach virus, Tahyna virus, and Central European encephalitis virus. One out of 22 sera (4.5%) collected in the district Nord-Friesland in Schleswig-Holstein was found positive (PRNT(90) 1:10) against Tríbec virus. Neither did sera from other regions of Schleswig-Holstein nor from hares from North Rhine-Westphalia react against any of the arboviruses tested. For the first time, antibodies against Tríbec virus could be found in a European brown hare in Germany. The negative serological results for Central European encephalitis virus are in line with the current knowledge of its natural distribution within Germany. The negative serological results for Tahyna virus or Eyach virus argue against an autochthonous circulation of these viruses in the regions tested.

Animals↗

Investigations on the ORF 167L of lymphocystis disease virus (Iridoviridae).

The predicted open reading frame 167L (ORF 167L) of lymphocystis disease virus (LCDV, Iridoviridae ) isolated from plaice, dab and flounder was investigated. The ORF 167L corresponding genes of the three LCDV isolates were amplified, cloned and sequenced. A comparison of the LCDV strains showed that the nucleotide sequence of ORF 167L and its deduced amino acid sequence were highly conserved in the genus lymphocystivirus (a homology of 80% in dab and flounder/plaice, 97% in plaice and flounder). The N-terminus protein predicted from the ORF 167L suggests similarities to the tumor necrosis factor receptor (TNFR)-family, and to TNFR-like proteins, which play an important role in various poxvirus species. Further, homology to the CUB-domain was shown at the C-terminus of the LCDV protein. Phylogenetic analyses of partial LCDV protein sequences identified two clusters: one cluster containing the flounder and plaice LCDV isolate (LCDV-1), and another cluster, containing the dab LCDV isolate (LCDV-2). The ORF 167L of plaice LCDV was expressed in Escherichia coli, and in fish cells. The expressed ORF resulted in a 30-kDa cytoplasmic protein lacking a signal peptide. An established monoclonal antibody (mAb 18) was used to detect LCDV proteins in skin explants of flounders and cryosections of dab skin. Specific fluorescence was found in the cytoplasm of intact epitheloid cells of the lymphocystis capsule and in the epidermis skin covering the lymphocystic nodules. LCDV-specific labelling of mAb 18 was also shown in spleen and liver tissue of LCDV-positive flounders. The ORF 167L protein seemed not to have the extracellular receptor function predicted from the usual cellular TNFR. The myxomavirus M-T2 protein, a poxviral TNFR homologue, was also shown not to have TNFR-like functions but to be involved in the apoptosis signal cascade.

Amino Acid Sequence↗

A parvovirus isolated from royal python (Python regius) is a member of the genus Dependovirus.

Parvoviruses were isolated from Python regius and Boa constrictor snakes and propagated in viper heart (VH-2) and iguana heart (IgH-2) cells. The full-length genome of a snake parvovirus was cloned and both strands were sequenced. The organization of the 4432-nt-long genome was found to be typical of parvoviruses. This genome was flanked by inverted terminal repeats (ITRs) of 154 nt, containing 122 nt terminal hairpins and contained two large open reading frames, encoding the non-structural and structural proteins. Genes of this new parvovirus were most similar to those from waterfowl parvoviruses and from adeno-associated viruses (AAVs), albeit to a relatively low degree and with some organizational differences. The structure of its ITRs also closely resembled those of AAVs. Based on these data, we propose to classify this virus, the first serpentine parvovirus to be identified, as serpentine adeno-associated virus (SAAV) in the genus Dependovirus.

Amino Acid Sequence↗

Cowpox and a cat.

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Adolescent↗