160 research outputs found

    SARS-CoV-2 nanobodies 2.0.

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    Accelerating CBPP research towards a better vaccine through the application of genome transplantation

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    Complete genome sequences of virulent mycoplasma capricolum subsp. capripneumoniae strains F38 and ILRI181

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    Contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subsp. capripneumoniae is a severe epidemic affecting mainly domestic Caprinae species but also affects wild Caprinae species. M. capricolum subsp. capripneumoniae belongs to the “Mycoplasma mycoides cluster.” The disease features prominently in East Africa, in particular Kenya, Tanzania, and Ethiopia. CCPP also endangers wildlife and thus affects not only basic nutritional resources of large populations but also expensively built-up game resorts in affected countries. Here, we report the complete sequences of two M. capricolum subsp. capripneumoniae strains: the type strain F38 and strain ILRI181 isolated druing a recent outbreak in Kenya. Both genomes have a G+C content of 24% with sizes of 1,016,760 bp and 1,017,183 bp for strains F38 and ILRI181, respectively

    In-yeast reconstruction of the African swine fever virus genome isolated from clinical samples.

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    This protocol describes a synthetic genomics pipeline to clone and engineer the entire 190-kbp genome of the African swine fever virus (ASFV) genotype II in yeast using transformation-associated recombination cloning. The viral genome was cloned using DNA directly extracted from a clinical sample. In addition, the precise deletion of a non-essential gene and its replacement by a synthetic reporter gene cassette are presented. This protocol is applicable to other ASFV genotypes and other large DNA viruses

    Draft genome sequence of the first human isolate of the ruminant pathogen <i>Mycoplasma capricolum</i> subsp. <i>capricolum</i>

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    Mycoplasma capricolum subsp. capricolum is a well-known pathogen of small ruminants. A recent human case of septicemia involving this agent raised the question of its potential pathogenicity to humans. We present the first draft genome sequence of a human Mycoplasma capricolum subsp. capricolum isolate

    A new duplex qPCR-based method to quantify Mycoplasma mycoides in complex cell culture systems and host tissues.

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    Bacterial pathogen-host interactions are a complex process starting with adherence and colonization followed by a variety of interactions such as invasion or cytotoxicity on one hand and pathogen recognition, secretion of proinflammatory/antibacterial substances and enhancing the barrier function of epithelial layers on the other hand. Therefore, a variety of in vitro, ex vivo and in vivo models have been established to investigate these interactions. Some in vitro models are composed of different cell types and extracellular matrices such as tissue explants or precision cut lung slices. These complex in vitro models mimic the in vivo situation more realistically, however, they often require new and more sophisticated methods for quantification of experimental results. Here we describe a multiplex qPCR-based method to quantify the number of bacteria of Mycoplasma (M.) mycoides interacting with their hosts in an absolute manner as well as normalized to the number of host cells. We choose the adenylate kinase (adk) gene from the pathogen and the Carcinoembryonic antigen-related cell adhesion molecule 18 (CEACAM18) gene from the host to determine cell numbers by a TaqMan-based assay system. Absolute copy numbers of the genes are calculated according to a standard containing a defined number of plasmids containing the sequence which is amplified by the qPCR. The new multiplex qPCR therefore allows the quantification of M. mycoides interacting with host cells in suspension, monolayer, 3D cell culture systems as well as in host tissues

    Plasma levels of TNF-α, IFN-γ, IL-4 and IL-10 during a course of experimental contagious bovine pleuropneumonia

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    <p>Abstract</p> <p>Background</p> <p>Contagious Bovine Pleuropneumonia (CBPP), caused by <it>Mycoplasma mycoides </it>subsp. <it>mycoides</it>, is widespread in sub-Saharan Africa. The current live vaccine T1/44 has limited efficacy and occasionally leads to severe side effects in the animals. A better understanding of the immune responses triggered by <it>Mycoplasma mycoides </it>subsp. <it>mycoides </it>and their role in disease progression will help to facilitate the design of a rational vaccine. Currently, knowledge of cytokines involved in immunity and immunopathology in CBPP is rather limited. The aim of this study was to characterize the <it>in vivo </it>plasma concentrations of the cytokines TNF-α, IFN-γ, IL-4, IL-10 and the overall role of CD4<sup>+ </sup>T cells in the development of cytokine levels during a primary infection. Plasma cytokine concentrations in two groups of cattle (CD4<sup>+ </sup>T cell-depleted and non-depleted cattle) experimentally infected with <it>Mycoplasma mycoides </it>subsp. <it>mycoides </it>were measured and their relationship to the clinical outcomes was investigated.</p> <p>Results</p> <p>Plasma cytokine concentrations varied between animals in each group. Depletion of CD4<sup>+ </sup>T cells did not induce significant changes in plasma levels of TNF-α, IL-4, and IL-10, suggesting a minor role of CD4<sup>+ </sup>T cells in regulation or production of the three cytokines during the time window of depletion (1-2 weeks post depletion). Unexpectedly, the IFN-γ concentrations were slightly, but statistically significantly higher in the depleted group (p < 0.05) between week three and four post infection. Three CD4<sup>+ </sup>T cell-depleted animals that experienced severe disease, had high levels of TNF-α and IFN-γ. Only one severely diseased non-depleted animal showed a high serum concentration of IL-4 post infection.</p> <p>Conclusions</p> <p>Comparison of most severely diseased animals, which had to be euthanized prior to the expected date, versus less severe diseased animals, irrespective of the depletion status, suggested that high TNF-α levels are correlated with more severe pathology in concomitance with high IFN-γ levels.</p

    First European report of Francisella tularensis subsp. holarctica isolation from a domestic cat

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    Francisella tularensis subsp. holarctica is a select agent causing life-threatening tularemia. It has been isolated from humans and animals, mainly lagomorphs and rodents, rarely other wild carnivore species. Increasing numbers of human tularemia cases have been reported during the last 5 years in Switzerland. Here we report the first isolation of Francisella tularensis subsp. holarctica from a domestic cat in Europe and compare its genome sequence with other Swiss isolates. The cat isolate shows a close phylogenetic relationship with a contemporary hare isolate from close geographic proximity, indicating a possible epidemiological link

    Comparative genomics of Mycoplasma feriruminatoris, a fast-growing pathogen of wild Caprinae.

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    Mycoplasma feriruminatoris is a fast-growing Mycoplasma species isolated from wild Caprinae and first described in 2013. M. feriruminatoris isolates have been associated with arthritis, kerato conjunctivitis, pneumonia and septicemia, but were also recovered from apparently healthy animals. To better understand what defines this species, we performed a genomic survey on 14 strains collected from free-ranging or zoo-housed animals between 1987 and 2017, mostly in Europe. The average chromosome size of the M. feriruminatoris strains was 1,040±0,024 kbp, with 24 % G+C and 852±31 CDS. The core genome and pan-genome of the M. feriruminatoris species contained 628 and 1312 protein families, respectively. The M. feriruminatoris strains displayed a relatively closed pan-genome, with many features and putative virulence factors shared with species from the M. mycoides cluster, including the MIB-MIP Ig cleavage system, a repertoire of DUF285 surface proteins and a complete biosynthetic pathway for galactan. M. feriruminatoris genomes were found to be mostly syntenic, although repertoires of mobile genetic elements, including Mycoplasma Integrative and Conjugative Elements, insertion sequences, and a single plasmid varied. Phylogenetic- and gene content analyses confirmed that M. feriruminatoris was closer to the M. mycoides cluster than to the ruminant species M. yeatsii and M. putrefaciens. Ancestral genome reconstruction showed that the emergence of the M. feriruminatoris species was associated with the gain of 17 gene families, some of which encode defence enzymes and surface proteins, and the loss of 25 others, some of which are involved in sugar transport and metabolism. This comparative study suggests that the M. mycoides cluster could be extended to include M. feriruminatoris. We also find evidence that the specific organization and structure of the DnaA boxes around the oriC of M. feriruminatoris may contribute to drive the remarkable fast growth of this minimal bacterium
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