Project description:This transcriptional analysis is a follow up to a population genomic investigation of 3615 Streptococcus pyogenes serotype M1 strains whch are responsible for an epidemic of human invasive infections (www.pnas.org/cgi/doi/10.1073/pnas.1403138111), The goal was to assess gene expression differences between predecessor pre-epidemic M1 strains and their descendent epidemic M1 strains to gain insights into the underlying genetic basis for the shift in the frequency and severity of human infections caused by these pathogenic bacteria The transcriptomes of 7 GAS M1 strains, 4 pre-epidemic and 3 epidemic, were compared at two phases of growth, mid-exponential and early-stationary, using 3 biologial replicates, to identify genes differentially expressed between the pre-epidemic and epidemic isolates with the goal of to gaining insight into the underlying genetic basis for the evolutionary emergence, increased frequency and severity of the epidemic strains relative to the pre-epidemic strains

2015-08-10 | E-GEOD-70496 | biostudies-arrayexpress

monophasic variant of Salmonella Typhimurium outbreak in France 2020

Project description:monophasic variant of Salmonella Typhimurium outbreak in France 2020

| PRJEB40826 | ENA

Microevolution of Candida albicans in macrophages restores filamentation in a nonfilamentous mutant

Project description:Following antifungal treatment, Candida albicans, and other human pathogenic fungi can undergo microevolution, which leads to the emergence of drug resistance. However, the capacity for microevolutionary adaptation of fungi goes beyond the development of drug resistance. Here we used an experimental microevolution approach to show that one of the central pathogenicity mechanisms of C. albicans, the yeast-to-hyphae transition, can be subject to experimental evolution. The C. albicans cph1Δ/efg1Δ mutant is non-filamentous, as central signalling pathways linking environmental cues to hypha formation are disrupted. We subjected this mutant to constant selection pressure in the hostile environment of the macrophage phagosome. In a comparatively short time-frame, the mutant evolved the ability to escape macrophages by filamentation. To investigate the transcriptional response underlying the yeast-to-filament transition in the evolved strain, we applied RNA-Seq technology. Furthermore, RNA-Seq data were used to identify SNPs, which are specific for the evolved strain.

2015-03-31 | GSE56174 | GEO

Microevolution of Candida albicans in macrophages restores filamentation in a nonfilamentous mutant

Project description:Following antifungal treatment, Candida albicans, and other human pathogenic fungi can undergo microevolution, which leads to the emergence of drug resistance. However, the capacity for microevolutionary adaptation of fungi goes beyond the development of drug resistance. Here we used an experimental microevolution approach to show that one of the central pathogenicity mechanisms of C. albicans, the yeast-to-hyphae transition, can be subject to experimental evolution. The C. albicans cph1?/efg1? mutant is non-filamentous, as central signalling pathways linking environmental cues to hypha formation are disrupted. We subjected this mutant to constant selection pressure in the hostile environment of the macrophage phagosome. In a comparatively short time-frame, the mutant evolved the ability to escape macrophages by filamentation. To investigate the transcriptional response underlying the yeast-to-filament transition in the evolved strain, we applied RNA-Seq technology. Furthermore, RNA-Seq data were used to identify SNPs, which are specific for the evolved strain. For both strains, the cph1?/efg1? mutant and the Evo-strain, two conditions, one promotes yeast growth the other filamentous growth, were investigated. For each condition three biological replicates were analysed.

2015-03-31 | E-GEOD-56174 | biostudies-arrayexpress

Microevolution study of monophasic Salmonella Typhimurium circulating in Europe

Project description:The microevolution of the highly clonal monophasic Salmonella Typhimurium circulating in Europe since 1992 have been progressed. Phylogeny, presence of specific genomic sequences and Bayesian evolutionary analyses have been conduced to understand the high fitness and the evolution of this hazardous Salmonella. This work is part of a collaborative study (ANSES, AHPA, SSI, Bfr, RKI, UNIBO and Ifremer) progressed within the ‘COllaborative Management Platform for detection and Analyses of (Re-) emerging and foodborne outbreaks in Europe’ (COMPARE) project which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 643476.

| PRJEB36445 | ENA

Monophasic Salmonella isolates

Project description:Monophasic Salmonella isolates

| PRJEB2132 | ENA