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  • Bartolomé Moya, Andreas Dötsch, Carlos Juan, Jesús Blázquez, Laura Zamorano, Susanne Haussler +1 other
  • 2009
It has long been recognized that the modification of penicillin-binding proteins (PBPs) to reduce their affinity for beta-lactams is an important mechanism (target modification) by which Gram-positive cocci acquire antibiotic resistance. Among Gram-negative rods (GNR), however, this mechanism has been considered unusual, and restricted to clinically(More)
Pseudomonas aeruginosa is an important opportunistic pathogen causing chronic airway infections, especially in cystic fibrosis (CF) patients. The majority of the CF patients acquire P. aeruginosa during early childhood, and most of them develop chronic infections resulting in severe lung disease, which are rarely eradicated despite intensive antibiotic(More)
Bacteria with greatly elevated mutation rates (mutators) are frequently found in natural and laboratory populations, and are often associated with clinical infections. Although mutators may increase adaptability to novel environmental conditions, they are also prone to the accumulation of deleterious mutations. The long-term maintenance of high bacterial(More)
Clinical isolates of Pseudomonas aeruginosa that hyperproduce a dark-brown pigment are quite often found in the lungs of chronically infected patients, suggesting that they may have an adaptive advantage in chronic infections. We have screened a library of random transposon insertions in P. aeruginosa. Transposon insertions resulting in the hyperproduction(More)
Whether or not resistant mutants will be present before the start of antibiotic treatment of an initially susceptible population of bacteria depends on the size of the infecting population, the rate of mutation to resistance, and the amount of time that the population has been maintained. In the present investigation, we argue that for the treatment of(More)
A total of 183 patients were colonized or infected with multidrug-resistant Pseudomonas aeruginosa isolates at a hospital in Spain during 2007-2010; prevalence increased over this period from 2.8% to 15.3%. To characterize these isolates, we performed molecular epidemiologic and drug resistance analysis. Genotyping showed that 104 (56.8%) isolates belonged(More)
  • Pau Martí-Lliteras, Antonio López-Gómez, Silvia Mauro, Derek W. Hood, Cristina Viadas, Laura Calatayud +6 others
  • 2011
Non-typable Haemophilus influenzae (NTHi) is a gram negative pathogen that causes acute respiratory infections and is associated with the progression of chronic respiratory diseases. Previous studies have established the existence of a remarkable genetic variability among NTHi strains. In this study we show that, in spite of a high level of genetic(More)
The dominant paradigm for the evolution of mutator alleles in bacterial populations is that they spread by indirect selection for linked beneficial mutations when bacteria are poorly adapted. In this paper, we challenge the ubiquity of this paradigm by demonstrating that a clinically important stressor, hydrogen peroxide, generates direct selection for an(More)
  • Carla López-Causapé, Estrella Rojo-Molinero, Xavier Mulet, Gabriel Cabot, Bartolomé Moyà, Joan Figuerola +3 others
  • 2013
Chronic respiratory infection by Pseudomonas aeruginosa is a major cause of mortality in cystic fibrosis (CF). We investigated the interplay between three key microbiological aspects of these infections: the occurrence of transmissible and persistent strains, the emergence of variants with enhanced mutation rates (mutators) and the evolution of antibiotic(More)