A5085786872- Antibiotic Resistance in Bacteria
- Antimicrobial Resistance in Staphylococcus
- Bacterial biofilms and quorum sensing
- Bacterial Identification and Susceptibility Testing
- Bacteriophages and microbial interactions
- Vibrio bacteria research studies
- Antibiotic Use and Resistance
- Enterobacteriaceae and Cronobacter Research
- Gut microbiota and health
- Clostridium difficile and Clostridium perfringens research
- Antimicrobial Peptides and Activities
- Probiotics and Fermented Foods
- Bacterial Genetics and Biotechnology
- Pneumonia and Respiratory Infections
- Genomics and Phylogenetic Studies
- Escherichia coli research studies
- Mycobacterium research and diagnosis
- Antifungal resistance and susceptibility
- Biochemical and Structural Characterization
- Streptococcal Infections and Treatments
- Pharmaceutical and Antibiotic Environmental Impacts
- Microbial infections and disease research
- Bacterial Infections and Vaccines
- SARS-CoV-2 detection and testing
- Infections and bacterial resistance
Walter Reed Army Institute of Research
2020-2024
Massachusetts Eye and Ear Infirmary
2015-2024
Harvard University
2015-2024
Institut de recherche en horticulture et semences
2022
Broad Institute
2013-2022
Université de Caen Normandie
2009-2013
Centre Hospitalier Universitaire de Caen
2011
ABSTRACT Enterococcus faecium , natively a gut commensal organism, emerged as leading cause of multidrug-resistant hospital-acquired infection in the 1980s. As living record its adaptation to changes habitat, we sequenced genomes 51 strains, isolated from various ecological environments, understand how E. hospital pathogen. Because scale and diversity sampled were able resolve lineage responsible for epidemic, human other strains measure evolutionary distances between groups. We found that...
Hypervirulent Klebsiella pneumoniae (hvKp) is a concerning pathogen that can cause life-threatening infections in otherwise healthy individuals. Importantly, although strains of hvKp have been acquiring antimicrobial resistance, the effect on virulence unclear. Therefore, it critical importance to determine whether given resistant K. isolate hypervirulent. This report determined which combination genotypic and phenotypic markers could most accurately identify with acquired resistance. Both...
Enterococci are gut microbes of most land animals. Likely appearing first in the guts arthropods as they moved onto land, diversified over hundreds millions years adapting to evolving hosts and host diets. Over 60 enterococcal species now known. Two species,
Enterococcus faecium UCN71, isolated from a blood culture, was resistant to low levels of vancomycin (MIC, 16 μg/ml) but susceptible teicoplanin 0.5 μg/ml). No amplification observed with primers specific for the previously described glycopeptide resistance ligase genes, PCR product corresponding gene called vanN obtained using degenerate and sequenced. The deduced VanN protein related (65% identity) d-alanine:d-serine VanL ligase. organization cluster, determined by thermal asymmetric...
Klebsiella pneumoniae, which is frequently associated with hospital- and community-acquired infections, contains multidrug-resistant (MDR), hypervirulent (hv), non-MDR/non-hv as well convergent representatives. It known that mostly international high-risk clonal lineages including sequence types (ST) 11, 147, 258, 307 drive their global spread. ST395, was first reported in the context of a carbapenemase-associated outbreak France 2010, less well-characterized, yet emerging lineage.
ABSTRACT Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in variety antibiotic refractory infections and is interest treating LVAD infections. We performed retrospective review four patients that underwent five separate courses intravenous (IV) phage with concomitant treatment endovascular Pseudomonas aeruginosa infection. assessed susceptibility, bacterial strain...
ABSTRACT Enterococcus faecalis is an opportunistic pathogen that causes numerous infectious diseases in humans and a major agent of nosocomial infections. In this work, we showed the recently identified transcriptional regulator Ers (PrfA like), known to be involved cellular metabolism virulence E. , acts as repressor ace which encodes collagen-binding protein. We characterized promoter region analysis by reverse transcription-quantitative PCR mobility shift protein-DNA binding assays...
Penicillin-binding proteins (PBPs) are enzymes involved in the assembly of bacterial cell wall, a major target for antibiotics. These classified by mass into high-molecular-weight PBPs, which transpeptidases that form peptidoglycan cross-links, and low-molecular-weight typically hydrolases. We report functionally unique family PBPs act as rather than hydrolases, but they do not cross-link peptidoglycan. show these can exchange d-amino acids bearing chemical tags or affinity handles...
In the context of great concern about impact human activities on environment, we studied 403 commensal Escherichia coli/Escherichia clade strains isolated from several animal and populations that have variable contacts to one another. Multilocus sequence typing (MLST) showed a decrease diversity 1) in animals had an increasing contact with humans 2) all increased antimicrobial resistance. A specific B1 phylogroup clonal complex (CC87, Institut Pasteur schema nomenclature) origin was...
Over the past two decades, Acinetobacter baumannii has emerged as a leading cause of nosocomial infections worldwide. Of particular concern are panresistant strains, World Health Organization (WHO) to designate carbapenem-resistant A. priority 1 (critical) pathogen for research and development new antibiotics. A key component in supporting this effort is accessibility diverse clinically relevant strains testing. Here, we describe panel 100 use endeavor. Whole-genome sequencing was performed...
Significance Carbapenem-resistant Klebsiella pneumoniae belongs to the “critical-priority” tier of bacterial pathogens as identified by World Health Organization. Emerging “high-risk” lineages are responsible for difficult-to-treat, hospital-acquired infections and outbreaks around globe. By integrating genomic epidemiological data isolates collected over 20 mo, this study revealed both high, regional prevalence rapid spread, within a single hospital, K. ST-147 in Italy. Besides resistance...
The pathogenic potential of hvKp strains is primarily mediated by a large virulence plasmid. minimal set genes required for the full expression hypervirulent phenotype undefined.
are a leading cause of healthcare-associated infections worldwide. In particular, strains expressing extended-spectrum β-lactamases (ESBLs) and carbapenemases pose serious treatment challenges, the World Health Organization (WHO) to designate ESBL carbapenem-resistant Enterobacteriaceae as 'critical' threats human health. Research efforts combat these pathogens can be supported by accessibility diverse clinically relevant isolates for testing novel therapeutics. Here, we describe panel 100
Quantitating the contribution of phenotype-responsible elements in hypervirulent Klebsiella pneumoniae is needed.
Oxidative stress serves as an important host/environmental signal that triggers a wide range of responses in microorganisms. Here, we identified oxidative sensor and response regulator the multidrug-resistant nosocomial pathogen Enterococcus faecium belonging to MarR family called AsrR (antibiotic regulator). The used cysteine oxidation sense hydrogen peroxide which results its dissociation promoter DNA. Transcriptome analysis showed regulon was composed 181 genes, including representing...
Multidrug-resistant Enterococcus faecalis possess numerous mobile elements that encode virulence and antibiotic resistance traits as well new metabolic pathways, often constituting over one-quarter of the genome. It was interest to determine how this large accretion affects competitive growth in gastrointestinal (GI) tract consortium. We unexpectedly observed prototype clinical isolate strain V583 actively killed by GI flora, whereas commensal enterococci flourished. found killing resulted...
Extra-intestinal pathogenic Escherichia coli (ExPEC) are a leading cause of bloodstream and urinary tract infections worldwide. Over the last two decades, increased rates antibiotic resistance in E. have been reported, further complicating treatment. Worryingly, specific lineages expressing extended-spectrum β-lactamases (ESBLs) fluoroquinolone proliferated now considered serious threat. Obtaining contemporary information on epidemiology prevalence these circulating is critical for...
Blood and surveillance cultures from an injured service member Ukraine grew Acinetobacter baumannii, Klebsiella pneumoniae, Enterococcus faecium, 3 distinct Pseudomonas aeruginosa strains. Isolates were nonsusceptible to most antibiotics carried array of antibiotic resistant genes, including carbapenemases (blaIMP-1, blaNDM-1, blaOXA-23, blaOXA-48, blaOXA-72) 16S methyltransferases (armA rmtB4).
Worldwide, Escherichia coli is the leading cause of neonatal Gram-negative bacterial meningitis, but full understanding pathogenesis this disease not yet achieved. Moreover, to date, no vaccine available against meningitis.