14 documents found, page 1 of 2
What Is the Impact of Antibiotic Resistance Determinants on the Bacterial Death...
Luz, Bruno T. S.; Rebelo, João S.; Monteiro, Francisca; Dionisio, FranciscoObjectives: Antibiotic-resistant bacteria are widespread, with resistance arising from chromosomal mutations and resistance genes located in the chromosome or in mobile genetic elements. While resistance determinants often reduce bacterial growth rates, their influence on bacterial death under bactericidal antibiotics remains poorly understood. When bacteria are exposed to bactericidal antibiotics to which they...
Plasmids Increase the Competitive Ability of Plasmid-Bearing Cells Even When Tr...
Rebelo, João S.; Domingues, Célia P. F.; Nogueira, Teresa; Dionisio, FranciscoBacterial cells often suffer a fitness cost after conjugative plasmids’ entry because these cells replicate slower than plasmid-free cells. Compensatory mutations may appear after tens of or a few hundred generations, reducing or eliminating this cost. A previous work based on a mathematical model and computer simulations has shown that plasmid-bearing cells already adapted to the plasmid may gain a fitness adv...
The Impact of Non-Pathogenic Bacteria on the Spread of Virulence and Resistance...
Dionisio, Francisco; Domingues, Célia P. F.; Rebelo, João S.; Monteiro, Francisca; Nogueira, TeresaThis review discusses the fate of antimicrobial resistance and virulence genes frequently present among microbiomes. A central concept in epidemiology is the mean number of hosts colonized by one infected host in a population of susceptible hosts: R0. It characterizes the disease’s epidemic potential because the pathogen continues its propagation through susceptible hosts if it is above one. R0 is proportional ...
The Impact of Non-Pathogenic Bacteria on the Spread of Virulence and Resistance...
Dionisio, Francisco; Domingues, Célia P. F.; Rebelo, João S.; Monteiro, Francisca; Nogueira, TeresaThis review discusses the fate of antimicrobial resistance and virulence genes frequently present among microbiomes. A central concept in epidemiology is the mean number of hosts colonized by one infected host in a population of susceptible hosts: R0. It characterizes the disease’s epidemic potential because the pathogen continues its propagation through susceptible hosts if it is above one. R0 is proportional ...
Plasmid Costs Explain Plasmid Maintenance, Irrespective of the Nature of Compen...
Rebelo, João S.; Domingues, Célia P. F.; Dionisio, FranciscoConjugative plasmids often carry virulence and antibiotic-resistant genes. Therefore, understanding the behavior of these extra-chromosomal DNA elements gives insights into their spread. Bacteria frequently replicate slower after plasmids’ entry, an observation inconsistent with the plasmids’ ubiquity in nature. Several hypotheses explain the maintenance of plasmids among bacterial communities. However, the num...
Plasmids Increase the Competitive Ability of Plasmid-Bearing Cells Even When Tr...
Rebelo, João S.; Domingues, Célia P. F.; Nogueira, Teresa; Dionisio, FranciscoBacterial cells often suffer a fitness cost after conjugative plasmids’ entry because these cells replicate slower than plasmid-free cells. Compensatory mutations may appear after tens of or a few hundred generations, reducing or eliminating this cost. A previous work based on a mathematical model and computer simulations has shown that plasmid-bearing cells already adapted to the plasmid may gain a fitness adv...
Multi-Drug Resistance in Bacterial Genomes—A Comprehensive Bioinformatic Analysis
Domingues, Célia P. F.; Rebelo, João S.; Dionisio, Francisco; Nogueira, TeresaAntimicrobial resistance is presently one of the greatest threats to public health. The excessive and indiscriminate use of antibiotics imposes a continuous selective pressure that triggers the emergence of multi-drug resistance. We performed a large-scale analysis of closed bacterial genomes to identify multi-drug resistance considering the ResFinder antimicrobial classes. We found that more than 95% of the ge...
Are Virulence and Antibiotic Resistance Genes Linked? A Comprehensive Analysis ...
Darmancier, Helena; Domingues, Célia P. F.; Rebelo, João S.; Amaro, Ana; Dionisio, Francisco; Pothier, Joel; Serra, Octavio; Nogueira, TeresaAlthough pathogenic bacteria are the targets of antibiotics, these drugs also affect hundreds of commensal or mutualistic species. Moreover, the use of antibiotics is not only restricted to the treatment of infections but is also largely applied in agriculture and in prophylaxis. During this work, we tested the hypothesis that there is a correlation between the number and the genomic location of antibiotic resi...
Harmful behaviour through plasmid transfer: a successful evolutionary strategy ...
Domingues, Célia P. F.; Rebelo, João S.; Monteiro, Francisca; Nogueira, Teresa; Dionisio, FranciscoConjugative plasmids are extrachromosomal mobile genetic elements pervasive among bacteria. Plasmids' acquisition often lowers cells' growth rate, so their ubiquity has been a matter of debate. Chromosomes occasionally mutate, rendering plasmids cost-free. However, these compensatory mutations typically take hundreds of generations to appear after plasmid arrival. By then, it could be too late to compete with f...
COVID-19 lockdowns may reduce resistance genes diversity in the human microbiom...
Rebelo, João S.; Domingues, Célia P. F.; Dionisio, Francisco; Gomes, Manuel C.; Botelho, Ana; Nogueira, TeresaRecently, much attention has been paid to the COVID-19 pandemic, yet bacterial resistance to antibiotics remains a serious and unsolved public health problem, which kills thousands of people annually, being an insidious and silent pandemic. In this study, we explored the idea of confinement and the tightening of the hygiene measures to contain the spreading of coronavirus, to simulate the effect that it has on ...