Identification of DNA sequence variation in Campylobacter jejuni strains associated with the Guillain-Barre syndrome by high-throughput AFLP analysis.

BACKGROUND: Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious neuropathies such as the Guillain-Barre (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides (LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular. RESULTS: We compared 6 different isolates of the "genome strain" NCTC 11168 obtained from different laboratories. HtAFLP analysis generated approximately 3000 markers per stain, 19 of which were polymorphic. The DNA polymorphisms could not be confirmed by PCR-RFLP analysis, suggesting a baseline level of 0.6% AFLP artefacts. Comparison of NCTC 11168 with 4 GBS-associated strains revealed 23 potentially GBS-specific markers, 17 of which were identified by DNA sequencing. A collection of 27 GBS/MFS-associated and 17 enteritis control strains was analyzed with PCR-RFLP tests based on 11 of these markers. We identified 3 markers, located in the LOS biosynthesis genes cj1136, cj1138 and cj1139c

Interspecies discrimination of A. fumigatus and siblings A. lentulus and A. felis of the Aspergillus section Fumigati using the AsperGenius® assay

The AsperGenius® assay detects several Aspergillus species and the A. fumigatus Cyp51A mutations TR34/L98H/T289A/Y121F that are associated with azole resistance. We evaluated its contribution in identifying A. lentulus and A. felis, 2 rare but intrinsically azole-resistant sibling species within the Aspergillus section Fumigati. Identification of these species with conventional culture techniques is difficult and time-consuming. The assay was tested on (i) 2 A. lentulus and A. felis strains obtained from biopsy proven invasive aspergillosis and (ii) control A. fumigatus (n=3), A. lentulus (n=6) and A. felis species complex (n=12) strains. The AsperGenius® resistance PCR did not detect the TR34 target in A. lentulus and A. felis in contrast to A. fumigatus. Melting peaks for L98H and Y121F markers differed and those of the Y121F marker were particularly suitable to discriminate the 3 species. In conclusion, the assay can be used to rapidly discriminate A. fumigatus, A. lentulus and A. felis.

Validation of a new Aspergillus real-time PCR assay for direct detection of Aspergillus and azole resistance of Aspergillus fumigatus on bronchoalveolar lavage fluid

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Presence of Genetic Variants Among Young Men With Severe COVID-19

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Genomic Designing for Climate-Smart Tomato

Tomato is the first vegetable consumed in the world. It is grown in very different conditions and areas, mainly in field for processing tomatoes while fresh-market tomatoes are often produced in greenhouses. Tomato faces many environmental stresses, both biotic and abiotic. Today many new genomic resources are available allowing an acceleration of the genetic progress. In this chapter, we will first present the main challenges to breed climate-smart tomatoes. The breeding objectives relative to productivity, fruit quality, and adaptation to environmental stresses will be presented with a special focus on how climate change is impacting these objectives. In the second part, the genetic and genomic resources available will be presented. Then, traditional and molecular breeding techniques will be discussed. A special focus will then be presented on ecophysiological modeling, which could constitute an important strategy to define new ideotypes adapted to breeding objectives. Finally, we will illustrate how new biotechnological tools are implemented and could be used to breed climate-smart tomatoes