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Gauthier, L.

Publications and source records attributed to Gauthier, L..

2 recordsLinked to original sources

Stepwise evolution and convergent recombination underlie the global dissemination of carbapenemase-producing Escherichia coli

Carbapenem-resistant Enterobacteriaceae are considered by WHO as \"critical\" priority pathogens for which novel antibiotics are urgently needed. The dissemination of carbapenemase-producing Escherichia coli (CP-Ec) in the community is a major public health concern. However, the global molecular epidemiology of CP-Ec isolates, as well as the genetic bases for the emergence and global dissemination of specific lineages, remain largely unknown. Here, by combining a thorough genomic and evolutionary analysis of Ec ST410 isolates with a broad analysis of 12,584 E. coli and Shigella genomes, we showed that the fixation of carbapenemase genes depends largely on a combination of mutations in ftsI encoding the penicillin binding protein 3 and in the porin genes ompC and ompF. Mutated ftsI genes and a specific ompC allele inducing reduced susceptibility to diverse {beta}-lactams spread across the species by recombination. The selection of CP-Ec lineages able to disseminate is more complex than the mere acquisition of carbapenemase genes.

microbiology

SodaPop: A computational suite for simulating the dynamics of asexual populations

MotivationSimulating protein evolution with realistic constraints from population genetics is essential in addressing problems in molecular evolution, from understanding the forces shaping the evolutionary landscape to the clinical challenges of antibiotic resistance, viral evolution and cancer.\n\nResultsTo address this need, we present SodaPop, a new forward-time simulator of large asexual populations aimed at studying their structure, dynamics and the distribution of fitness effects with flexible assumptions on the fitness landscape. SodaPop integrates biochemical and biophysical properties in a cell-based, object-oriented framework and provides an efficient, open-source toolkit for performing large-scale simulations of protein evolution.\n\nAvailability and implementationSource code and binaries are freely available at https://github.com/louisgt/SodaPop under the GNU GPLv3 license. The software is implemented in C++ and supported on Linux, Mac OS/X and Windows.\n\nContactadrian.serohijos@umontreal.ca\n\nSupplementary informationSupplementary information is available on the Github project page.

bioinformatics