A5058878749- Antibiotic Resistance in Bacteria
- Antibiotics Pharmacokinetics and Efficacy
- Bacterial Genetics and Biotechnology
- Evolution and Genetic Dynamics
- Tuberculosis Research and Epidemiology
- Mycobacterium research and diagnosis
- Pharmaceutical and Antibiotic Environmental Impacts
- Bacterial biofilms and quorum sensing
- Escherichia coli research studies
- Bacteriophages and microbial interactions
- Vibrio bacteria research studies
- Pneumocystis jirovecii pneumonia detection and treatment
- Urinary Tract Infections Management
- RNA and protein synthesis mechanisms
- DNA Repair Mechanisms
- Pneumonia and Respiratory Infections
- Genomics and Phylogenetic Studies
- Cancer therapeutics and mechanisms
- Bacterial Identification and Susceptibility Testing
- Cancer Genomics and Diagnostics
- Plant Pathogenic Bacteria Studies
- Antimicrobial Resistance in Staphylococcus
- Renal and Vascular Pathologies
- Salmonella and Campylobacter epidemiology
- Gut microbiota and health
Centro Nacional de Biotecnología
2015-2024
Consejo Superior de Investigaciones Científicas
2011-2024
Hospital Clínico San Carlos
1999-2023
Universidad Autónoma de Madrid
1996-2022
Hospital Universitario Virgen del Rocío
2014-2021
Instituto de Salud Carlos III
2017-2021
Red Espanola de Investigacion en Patologia Infecciosa
2017-2021
Instituto de Biomedicina de Sevilla
2014-2018
Universidad de Sevilla
2014-2017
Hospital Universitario Ramón y Cajal
1998-2017
Regardless of their targets and modes action, subinhibitory concentrations antibiotics can have an impact on cell physiology trigger a large variety cellular responses in different bacterial species. Subinhibitory β-lactam cause reactive oxygen species production induce PolIV-dependent mutagenesis Escherichia coli. Here we show that the RpoS regulon. RpoS-regulon induction is required for because it diminishes control DNA-replication fidelity by depleting MutS E. coli, Vibrio cholerae...
It has long been recognized that the modification of penicillin-binding proteins (PBPs) to reduce their affinity for β-lactams is an important mechanism (target modification) by which Gram-positive cocci acquire antibiotic resistance. Among Gram-negative rods (GNR), however, this considered unusual, and restricted clinically irrelevant laboratory mutants most species. Using as a model Pseudomonas aeruginosa, high up on list pathogens causing life-threatening infections in hospitalized...
ABSTRACT Pseudomonas aeruginosa , a major cause of nosocomial and chronic infections, is considered paradigm antimicrobial resistance development. However, the evolutionary trajectories impact mutator phenotypes remain mostly unexplored. Therefore, whole-genome sequencing (WGS) was performed in lineages wild-type (Δ mutS ) strains exposed to increasing concentrations relevant antipseudomonal agents. WGS provided privileged perspective dramatic effect on accumulation random mutations, most...
Abstract Alterations in genes involved the repair of DNA mutations (mut genes) result an increased mutation frequency and better adaptability bacterium to stressful conditions. W-Beijing genotype strains displayed unique missense alterations three putative mut genes, including two mutT type (Rv3908 mutT2) ogt. These polymorphisms were found be characteristic phylogenetic lineage. Analysis 55 representative isolates suggests a sequential acquisition mutations, elucidating plausible pathway...
Summary We have recently described the presence of a high proportion Pseudomonas aeruginosa isolates (20%) with an increased mutation frequency (mutators) in lungs cystic fibrosis (CF) patients. In four out 11 independent P. strains, was found to be complemented wild‐type mutS gene from PAO1. Here, we report cloning and sequencing two additional mismatch repair genes characterization, by complementation deficient these putative ( mutL uvrD ). also describe alterations , responsible for...
Contrary to what was thought previously, bacteria seem be, not merely spectators their own evolution, but, through a variety of mechanisms, able increase the rate at which mutations occur and, consequently, chances becoming resistant antibiotics. Laboratory studies and mathematical models suggest that, under stressful conditions, such as antibiotic challenge, selective pressure favors mutator strains over nonmutator strains. These hypermutable have been found in natural bacterial populations...
Isolates from the Mycobacterium tuberculosis complex cultured caprine pathological tissue samples were biochemically and genetically characterized. The isolates negative for nitrate reduction niacin accumulation, they weakly hydrolysed Tween 80, sensitive to pyrazinamide (50 μg ml−1) resistant 1 2 tiophene-2-carboxylic acid hydrazide ml−1 but not 5 or 10 ml−1. Sequencing of pncA gene revealed a polymorphism characteristic M. tuberculosis, whereas oxyR, katG gyrA sequences bovis....
The use of non-heart-beating donors could help shorten the list patients who are waiting for a kidney transplant. Several reports describe acceptable results transplantations from had in-hospital cardiac arrest, but few arrest that occurred outside hospital (Maastricht type I and II donors).To compare graft survival rates among receiving kidneys heart-beating versus or donors.Retrospective cohort study performed January 1989 to December 2004.Kidney transplant program teaching in Madrid,...
Low concentrations of some antibiotics have been reported to stimulate mutagenesis and recombination, which may facilitate bacterial adaptation different types stress, including antibiotic pressure. However, the mutagenic effect most currently used remains untested. Furthermore, it is known that in many bacteria, Escherichia coli, stimulation mediated by SOS response. Thus, blockage or attenuation this response through inhibition RecA has proposed as a possible therapeutic adjuvant combined...
Abstract Mismatch repair (MMR) is a near ubiquitous pathway, essential for the maintenance of genome stability. Members MutS and MutL protein families perform key steps in mismatch correction. Despite major importance this MutS–MutL are absent almost all Actinobacteria many Archaea. However, these organisms exhibit rates spectra spontaneous mutations similar to MMR-bearing species, suggesting existence an alternative canonical MutS–MutL-based MMR. Here we report that Mycobacterium smegmatis...
A clinical Escherichia coli strain highly resistant to the combinations of amoxicillin-clavulanate, ampicillin-sulbactam, and piperacillin-tazobactam was isolated from a patient with community-acquired urinary tract infection who previously treated amoxicillin-clavulanate. These resistances were carried by 45-kb conjugative plasmid encoding for single beta-lactamase pI 5.4. Cloning sequencing new beta-lactamase, IRT-3, revealed identity blaT1 gene TEM-1 except replacement methionine residue...
Whether or not resistant mutants will be present before the start of antibiotic treatment an initially susceptible population bacteria depends on size infecting population, rate mutation to resistance, and amount time that has been maintained. In investigation, we argue for chronic infections caused by hypermutable Pseudomonas aeruginosa sort frequently found in cystic fibrosis patients, all single antipseudomonal drugs almost invariably a high proportion at onset treatment, consequently,...
The expression of β-lactamases is the most common form bacterial resistance to β-lactam antibiotics. To combat these enzymes, agents that inhibit (e.g. clavulanic acid) or evade aztreonam) have been developed. Both β-lactamase inhibitors and β-lactamase-resistant antibiotics are themselves β-lactams, bacteria responded compounds by expressing variant enzymes resistant inhibition IRT-3) inactivate antibiotic TEM-10). Moreover, increased frequency with intrinsically AmpC). In an effort...
Summary The widespread use and abuse of antibiotics as therapeutic agents has produced a major challenge for bacteria, leading to the selection spread antibiotic resistant variants. However, do not seem be mere selectors these Here we show that fluoroquinolone ciprofloxacin, an inhibitor type II DNA topoisomerases, stimulates intrachromosomal recombination sequences. stimulation between divergent sequences occurs via either RecBCD or RecFOR pathways is, surprisingly, independent SOS...
Objective: To assess the rate of long-term effectiveness and factors associated with response to protease inhibitor therapy in a cohort HIV-infected patients. Design setting: Prospective, non-randomized study tertiary care centre. Patients: A total 400 patients who started on (saquinavir, 28%; ritonavir, 26%; indinavir, 46%) from March 1996 1997. Main outcomes measures: Long-term virological immunological were defined as HIV RNA levels below 200 copies/ml CD4+ cell count increase greater...
Clinical isolates of Pseudomonas aeruginosa that hyperproduce a dark-brown pigment are quite often found in the lungs chronically infected patients, suggesting they may have an adaptive advantage chronic infections. We screened library random transposon insertions P. . Transposon resulting hyperproduction were to be located hmgA gene, which putatively encodes enzyme homogentisate-1,2-dioxygenase. Complementation studies indicate disruption is responsible for pyomelanin both laboratory and...
Transcription of the dinB gene, encoding DNA polymerase IV, is induced by inhibition cell wall synthesis at different levels. Using beta-lactam antibiotic ceftazidime, a PBP3 inhibitor, as model, we have shown that this induction independent LexA/RecA regulatory system. Induction transcription mediated ceftazidime produces an increase in reversion +1 Lac frameshift mutation.
Fosfomycin is transported into Escherichia coli via both glycerol-3-phosphate (GlpT) and a hexose phosphate transporter (UhpT). Consequently, the inactivation of either glpT or uhpT confers increased fosfomycin resistance in this species. The other genes, including ptsI cyaA, also significant resistance. It has been assumed that identical mechanisms are responsible for transport Pseudomonas aeruginosa cells. study an ordered library insertion mutants P. PA14 demonstrated only insertions...