Biology subjects

Bleicker, T.

Publications and source records attributed to Bleicker, T..

3 recordsLinked to original sources

bioRxiv2024

Ongoing evolution of Middle East Respiratory Syndrome Coronavirus, Kingdom of Saudi Arabia, 2023-2024

Middle East respiratory syndrome coronavirus (MERS-CoV) circulates in dromedary camels in the Arabian Peninsula and occasionally causes spillover infections in humans. Due to lack of sampling during the SARS-CoV-2 pandemic, current MERS-CoV diversity is poorly understood. Of 558 dromedary camel nasal swabs from Saudi Arabia, sampled November 2023 to January 2024, 39% were positive for MERS-CoV RNA by RT-PCR. We generated 42 MERS-CoV and seven human 229E-related CoV by high-throughput sequencing. For both viruses, the sequences fell into monophyletic clades apical to the most recent available genomes. The MERS-CoV sequences were most similar to those from lineage B5. The new MERS-CoVs sequences harbor unique genetic features, including novel amino acid polymorphisms in the Spike protein. The new variants require further phenotypic characterization to understand their impact. Ongoing MERS-CoV spillovers into humans pose significant public health concerns, emphasizing the need for continued surveillance and phenotypic studies.

evolutionary biology↗

bioRxiv2023

Antigenic cartography using variant-specific hamster sera reveals substantial antigenic variation among Omicron subvariants

SARS-CoV-2 has developed substantial antigenic variability. As the majority of the population now has pre-existing immunity due to infection or vaccination, the use of experimentally generated animal immune sera can be valuable for measuring antigenic differences between virus variants. Here, we immunized Syrian hamsters by two successive infections with one of eight SARS-CoV-2 variants. Their sera were titrated against 14 SARS-CoV-2 variants and the resulting titers visualized using antigenic cartography. The antigenic map shows a condensed cluster containing all pre-Omicron variants (D614G, Alpha, Delta, Beta, Mu, and an engineered B.1+E484K variant), and a considerably more distributed positioning among a selected panel of Omicron subvariants (BA.1, BA.2, BA.4/5, the BA.5 descendants BF.7 and BQ.1.18; the BA.2.75 descendant BN.1.3.1; and the BA.2-derived recombinant XBB.2). Some Omicron subvariants were as antigenically distinct from each other as the wildtype is from the Omicron BA.1 variant. The results highlight the potential of using variant-specifically infected hamster sera for the continued antigenic characterisation of SARS-CoV-2.

immunology↗

bioRxiv2022

Genetic variability, including gene duplication and deletion, in early sequences from the 2022 European monkeypox outbreak

Genome sequences from 47 monkeypox virus infections detected in a German university virology laboratory were analyzed in context of other sequences from the 2022 outbreak and earlier monkeypox genomes. Identical non-synonymous amino acid changes in six genes and the signature of APOBEC editing match other sequences from the European outbreak. Non-synonymous changes that were present in one to three sequences were found in 34 other genes. In sequences from two lesions of one patient, an 856 nucleotide translocation between genome termini resulted in the duplication of an initial 5 gene, and the disruption or complete deletion of four genes near the 3 genome end. Orthopoxvirus genome rearrangements of this nature are known to confer fitness advantages in the face of selection pressure. This change may therefore represent an early virus adaptation in the novel widespread and sustained human-to-human context of the current monkeypox outbreak.

bioinformatics↗