28 documents found, page 1 of 3
Clonal interference and genomic repair during strain coexistence in the gut
Frazão, Nelson; Seixas, Elsa; Mischler, Manolo; Moura-de-Sousa, Jorge; Barreto, Hugo C.; Gordo, IsabelHumans and other mammals are colonized by multiple strains of Escherichia coli, but the tempo and mode of evolution of different coexisting strains, between whom horizontal gene transfer (HGT) can occur, is poorly understood. Here, we follow in real time the evolution of two phylogenetic distinct strains of E. coli that co-colonize the mouse gut with different population sizes. We find qualitative differences i...
Evolution of Escherichia coli strains under competent or compromised adaptive i...
Ameline, Camille; Seixas, Elsa; Barreto, Hugo C.; Frazão, Nelson; Rodrigues, Miguel V.; Ventura, M. Rita; Lourenço, Marta; Gordo, IsabelEscherichia coli is a commensal of the intestine of most mammals, but also an important human pathogen. Within a healthy human its population structure is highly dynamic, where typically a dominant E. coli strain is accompanied by several low abundance satellite strains. However, the factors underlying E. coli strain dynamics and evolution within hosts are still poorly understood. Here, we colonised germ-free i...
SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal
Borges, Vítor; Isidro, Joana; Trovão, Nídia Sequeira; Duarte, Sílvia; Cortes-Martins, Helena; Martiniano, Hugo; Gordo, Isabel; Leite, RicardoGenomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introd...
Diet leaves a genetic signature in a keystone member of the gut microbiota
Dapa, Tanja; Ramiro, Ricardo Serotte; Pedro, Miguel Filipe; Gordo, Isabel; Xavier, Karina BivarSwitching from a low-fat and high-fiber diet to a Western-style high-fat and high-sugar diet causes microbiota imbalances that underlay many pathological conditions (i.e., dysbiosis). Although the effects of dietary changes on microbiota composition and functions are well documented, their impact in gut bacterial evolution remains unexplored. We followed the emergence of mutations in Bacteroides thetaiotaomicro...
The selective advantage of the lac operon for Escherichia coli is conditional o...
Pinto, Catarina; Melo-Miranda, Rita; Gordo, Isabel; Sousa, AnaThe lac operon is one of the best known gene regulatory circuits and constitutes a landmark example of how bacteria tune their metabolism to nutritional conditions. It is nearly ubiquitous in Escherichia coli strains justifying the use of its phenotype, the ability to consume lactose, for species identification. Lactose is the primary sugar found in milk, which is abundant in mammals during the first weeks of l...
Massive dissemination of a SARS-CoV-2 Spike Y839 variant in Portugal
Borges, Vítor; Isidro, Joana; Cortes-Martins, Helena; Duarte, Sílvia; Vieira, Luís; Leite, Ricardo; Gordo, Isabel; Caetano, Constantino P.Genomic surveillance of SARS-CoV-2 was rapidly implemented in Portugal by the National Institute of Health in collaboration with a nationwide consortium of >50 hospitals/laboratories. Here, we track the geo-temporal spread of a SARS-CoV-2 variant with a mutation (D839Y) in a potential host-interacting region involving the Spike fusion peptide, which is a target motif of anti-viral drugs that plays a key role in...
Specific Eco-evolutionary Contexts in the Mouse Gut Reveal Escherichia coli Met...
Barroso-Batista, João; Pedro, Miguel F; Sales-Dias, Joana; Pinto, Catarina J G; Thompson, Jessica A; Pereira, Helena; Demengeot, Jocelyne; Gordo, IsabelMembers of the gut microbiota are thought to experience strong competition for nutrients. However, how such competition shapes their evolutionary dynamics and depends on intra- and interspecies interactions is poorly understood. Here, we test the hypothesis that Escherichia coli evolution in the mouse gut is more predictable across hosts in the absence of interspecies competition than in the presence of other m...
Massive dissemination of a SARS-CoV-2 Spike Y839 variant in Portugal
Borges, Vítor; Isidro, Joana; Cortes-Martins, Helena; Duarte, Sílvia; Vieira, Luís; Leite, Ricardo; Gordo, Isabel; Caetano, Constantino P.Genomic surveillance of SARS-CoV-2 was rapidly implemented in Portugal by the National Institute of Health in collaboration with a nationwide consortium of >50 hospitals/laboratories. Here, we track the geotemporal spread of a SARS-CoV-2 variant with a mutation (D839Y) in a potential host-interacting region involving the Spike fusion peptide, which is a target motif of anti-viral drugs that plays a key role in ...
Evolutionary Mechanisms Shaping the Maintenance of Antibiotic Resistance
Durão, Paulo; Balbontín, Roberto; Gordo, IsabelAntibiotics target essential cellular functions but bacteria can become resistant by acquiring either exogenous resistance genes or chromosomal mutations. Resistance mutations typically occur in genes encoding essential functions; these mutations are therefore generally detrimental in the absence of drugs. However, bacteria can reduce this handicap by acquiring additional mutations, known as compensatory mutati...
Evolution of commensal bacteria in the intestinal tract of mice
Sousa, Ana; Frazão, Nelson; Ramiro, Ricardo S; Gordo, IsabelHundreds of different bacterial species inhabit our intestines and contribute to our health status, with significant loss of species diversity typically observed in disease conditions. Within each microbial species a great deal of diversity is hidden and such intra-specific variation is also key to the proper homeostasis between the host and its microbial inhabitants. Indeed, it is at this level that new mechan...