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Andi Krumbholz

Publications and source records attributed to Andi Krumbholz.

10 recordsLinked to original sources

Amantadine resistance among porcine H1N1, H1N2, and H3N2 influenza A viruses isolated in Germany between 1981 and 2001.

This study was designed to gain insight into amantadine susceptibility of porcine influenza A viruses isolated in Germany between 1981 and 2001. The 12 studied H1N1, H1N2, and H3N2 porcine influenza virus strains were isolated in chicken eggs and passaged once in MDCK cells. Plaque reduction assays were applied to examine virus susceptibility to amantadine. Genotyping was used to confirm drug resistance. In the results of these antiviral studies, only 3 of the 12 isolates were shown to be amantadine-susceptible. All resistant strains contained the AA substitutions G16E, S31N, and R77Q in the membrane protein 2 (M2). Additionally, L27A was detected in two H1N1 strains. S31N and/or L27A are well-known amino acid substitutions in M2 that confer amantadine resistance. The role of the pig as an intermediate host of avian and human influenza A viruses, the possible involvement of genetic reassortment, and the high incidence of naturally amantadine-resistant porcine influenza A viruses suggest a real risk of emergence of amantadine resistant human viruses. Therefore, drug susceptibility monitoring appears to be warranted for effective application of those drugs.

Amantadine↗

Comparison of a LightCycler-based real-time PCR for quantitation of Epstein-Barr viral load in different clinical specimens with semiquantitative PCR.

Measurement of viral load is important in predicting and monitoring of Epstein-Barr virus (EBV)-associated diseases especially in immunocompromised patients. The objectives of this study were the development of a LightCycler-based real-time PCR assay using primers and probes which recognize the virus capsid antigen p23-encoding region and its comparison to the semiquantitative PCR. The LightCycler protocol shows a high degree of specificity and inter- and intra-assay reproducibility. Concerning sensitivity, a good correlation between both methods was demonstrated for standard plasmid DNA, reference DNA isolated from the EBV-genome containing Namalwa cell line, and DNA extracted from plasma/cerebrospinal fluid (CSF). The detection limit was determined with 1 copy/microl eluate for the standard plasmid DNA and with 500 copies/ml plasma or CSF. For DNA derived from peripheral blood mononuclear cells (PBMCs), a decrease of sensitivity by factor 10-100 was found when larger amounts of background DNA (500 and 100 ng) were used presuming an inhibitory effect of cellular DNA. This was supported by running dilutions of the plasmid standard carried out with EBV-negative Ramos cell DNA. Thus, the cut-off level was estimated with 100-500 copies/10(5) PBMCs, when 50 or 10 ng total DNA were tested. The results indicate that the real-time PCR described here is a first line tool for the determination of viral load in plasma and CSF. Semiquantitative nested PCR is used for screening of PBMCs viral load. Positive specimens containing more than 500 copies/10(5) cells are measured for exact values by real-time PCR. To circumvent inhibitory effects of cellular DNA, measurements should be carried out generally with 50-10 ng DNA.

Capsid Proteins↗

Prevalence of BK virus subtype I in Germany.

The primary infection with human polyomavirus BK (BKV) occurs in early childhood and leads to viral latency within the urogenital tract. Up to 90% of the adult population are seropositive. In immunosuppressed patients, the BKV may be reactivated resulting in typical disease patterns like hemorrhagic cystitis and tubulointerstitial nephritis. Based on serological and molecular methods, BKV isolates were classified into four subtypes previously. Sixty specimens obtained from German renal and bone marrow transplant recipients were analyzed to gain data on the prevalence of BKV subtypes in Germany. With 90.9%, BKV subtype I was found to be predominant in both patient groups. 6.1% of BKV strains were classified as subtype IV. This pattern of phylogenetic distribution is similar to that demonstrated previously in England, Tanzania, the United States and Japan. Remarkably, there was one German BKV virus with a sequence which clusters together with strain SB in subtype II. The BKV subtype I was found to consist of at least three subgroups designated as Ia, Ib, and Ic. While the majority of the German sequences represent subgroup Ic, most of the Japanese sequences are clearly distinct. These findings support the hypothesis of distinct geographical prevalence of BKV subgroups. For the genotyping region, a relationship of BKV subgroups to disease patterns like hemorrhagic cystitis or tubulointerstitial nephritis could not be demonstrated.

Amino Acid Sequence↗

Molecular-based reclassification of the bovine enteroviruses.

Bovine enteroviruses are currently classified into two serotypes within the species Bovine enterovirus (BEV). Comparison of the sequences of six American and eleven German BEV isolates with published BEV sequences revealed the necessity to revise the taxonomy of these viruses. Molecular data indicate that the bovine enteroviruses are composed of two clusters (designated BEV-A and -B) each with two and three geno-/serotypes, respectively. Whereas low amino acid identity of the capsid proteins 1C (VP3) and 1D (VP1) is the main criterion for the discrimination of geno-/serotypes, the BEV clusters, presumably representing species, differ in sequence identity of all viral proteins. In addition, characteristic lengths of (i) the capsid proteins 1B, 1C and 1D, (ii) the 2C protein, and (iii) the 3'-non-translated region are observed. The BEVs can be distinguished from the other enteroviruses by sequence identity and unique features of the 5'-non-translated region, i.e. a conserved second cloverleaf and characteristic RNA structures of the internal ribosome entry site. Phylogenetically, the closest relatives of the bovine enteroviruses are the porcine enteroviruses. Incongruent phylogenies of the 5'-non-translated region, the capsid proteins and the 3D polymerase indicate frequent intraserotypic and interserotypic recombination within the non-capsid and the capsid region of the BEV genome.

3' Untranslated Regions↗

[Umbilical endometriosis].

A 40-year-old woman with a history of a growing erythematous nodule in the umbilicus was diagnosed histopathologically with endometriosis. This umbilical endometriosis occurred spontaneously without any previous surgical procedures. The lesion was partially removed surgically; she then entered menopause with a spontaneous involution of the residuum during the following months so that further invention was not required. Umbilical endometriosis is very rare with an estimated incidence of 0.5 to 1% of all patients with endometrial ectopia. As the clinical appearance of umbilical endometriosis may share features with a variety of other disorders, we discuss the clinical picture and differential diagnostic considerations in detail.

Adult↗

[Relapsing polychondritis as a rare different diagnosis of erysipelas].

A 76-year old patient with painful erythematous swelling of the right ear was initially treated with antibiotics under the suspected diagnosis of erysipelas. Her failure to respond and a history of previous laryngeal and nasal swelling suggested the possibility of relapsing polychondritis. High dose prednisolone therapy produced marked improvement. Relapsing polychondritis should be considered as a rare, but important differential diagnostic consideration for erysipelas.

Aged↗

Detection of porcine teschoviruses and enteroviruses by LightCycler real-time PCR.

Porcine picornaviruses comprising at least 23 serotypes grouped into six species were described as causative agents of neurological disorders, reproductive failure, and aphthae-like dermal lesions of swine. Other viruses such as classical swine fever virus (CSFV), African swine fever virus, pseudorabies virus (PRV), vesicular stomatitis virus, vesicular exanthema virus, porcine respiratory and reproductive syndrome virus, and porcine parvovirus (PPV) may cause diseases with similar clinical symptoms. Therefore, rapid and reliable PCR detection of the most frequent porcine picornaviruses is of interest. A real-time RT-PCR protocol employing LightCycler technology to detect all known serotypes of the three porcine enterovirus (PEV) cytopathic effect (CPE) groups was established. It uses three sets of primer pairs and group-specific hybridisation probes. The primer pairs were designed to amplify highly conserved sequences of the 5'-non-translated region (5'-NTR) of the relevant virus species. The one-step real-time PCR based on the LightCycler technology is more rapid and less contamination-prone than the nested RT-PCR and allows the precise quantitation of the virus load in the tested specimens. All acknowledged serotypes of the three PEV CPE groups and all tested field strains isolated from clinical specimens were detectable. Viruses of the PEV CPE group III can be distinguished from the closely related swine vesicular disease virus (SVDV).

5' Untranslated Regions↗

Sequencing of porcine enterovirus groups II and III reveals unique features of both virus groups.

The molecular classification of the porcine enterovirus (PEV) groups II and III was investigated. The sequence of the almost complete PEV-8 (group II) genome reveals that this virus has unique L and 2A gene regions. A reclassification of this group into a new picornavirus genus is suggested. PEV group III viruses are typical enteroviruses. They differ from other enteroviruses by a prolonged stem-loop D of the 5'-cloverleaf structure.

3' Untranslated Regions↗