A5058879928- Legume Nitrogen Fixing Symbiosis
- Bacterial biofilms and quorum sensing
- Plant nutrient uptake and metabolism
- Antibiotic Resistance in Bacteria
- Antimicrobial Peptides and Activities
- Oral microbiology and periodontitis research
- Cassava research and cyanide
- Bacterial Genetics and Biotechnology
- Vibrio bacteria research studies
- Pneumocystis jirovecii pneumonia detection and treatment
- Yersinia bacterium, plague, ectoparasites research
- Coastal wetland ecosystem dynamics
- Magnetic and Electromagnetic Effects
- Agronomic Practices and Intercropping Systems
- Trace Elements in Health
- Microbial Natural Products and Biosynthesis
- Metalloenzymes and iron-sulfur proteins
- Cellular transport and secretion
- Plant Parasitism and Resistance
- Microbial Community Ecology and Physiology
- Antibiotic Use and Resistance
- Viral Infectious Diseases and Gene Expression in Insects
- Plant Pathogenic Bacteria Studies
- Cancer therapeutics and mechanisms
- Nematode management and characterization studies
KU Leuven
2005-2023
VIB-KU Leuven Center for Microbiology
2023
Massachusetts Institute of Technology
2011
Persister cells are phenotypic variants that extremely tolerant to high concentrations of antibiotics. They constitute a fraction stationary phase cultures and biofilm populations numerous bacterial species, such as the opportunistic pathogen Pseudomonas aeruginosa. Even though persisters believed be an important cause incomplete elimination infectious by antibiotics, their nature remains obscure. Most studies on persistence have focused model organism Escherichia coli only limited number...
Swarming motility is suggested to be a social phenomenon that enables groups of bacteria coordinately and rapidly move atop solid surfaces. This multicellular behavior, during which the apparently organized bacterial populations are embedded in an extracellular slime layer, has previously been linked with biofilm formation virulence. Many population density-controlled activities involve activation complex signaling pathways using small diffusible molecules, also known as autoinducers. In...
The alarmone (p)ppGpp mediates a global reprogramming of gene expression upon nutrient limitation and other stresses to cope with these unfavorable conditions. Synthesis is, in most bacteria, controlled by RelA/SpoT (Rsh) proteins. role has been characterized primarily Escherichia coli several Gram-positive bacteria. Here, we report the first in-depth analysis (p)ppGpp-regulon an α-proteobacterium using high-resolution tiling array better understand pleiotropic stress phenotype relA/rsh...
ABSTRACT The spread of antibiotic resistance and the challenges associated with antiseptics such as chlorhexidine have necessitated a search for new antibacterial agents against oral bacterial pathogens. As result failing traditional approaches, drug repurposing has emerged novel paradigm to find agents. In this study, we examined effects FDA-approved anticancer agent toremifene bacteria Porphyromonas gingivalis Streptococcus mutans . We found that was able inhibit growth both pathogens,...
Summary In general, oxidative stress, the consequence of an aerobic lifestyle, induces bacterial antioxidant defence enzymes. Here we report on a peroxiredoxin Rhizobium etli , prxS strongly expressed under microaerobic conditions and during symbiotic interaction with Phaseolus vulgaris . The induction prxS‐rpoN 2 operon is mediated by alternative sigma factor RpoN enhancer‐binding protein NifA. RpoN‐dependent promoter also active low‐nitrogen through NtrC. An additional symbiosis‐specific...
ABSTRACT The symbiotic interaction between Rhizobium etli and Phaseolus vulgaris , the common bean plant, ultimately results in formation of nitrogen-fixing nodules. Many aspects intermediate late stages this are still poorly understood. R. relA gene was identified through a genome-wide screening for mutants. RelA has pivotal role cellular physiology, as it catalyzes synthesis (p)ppGpp, which mediates stringent response bacteria. ppGpp abolished an mutant strain under conditions amino acid...
SUMMARY Strigolactones are a class of phytohormones that involved in many different plant developmental processes, including the rhizobium–legume nodule symbiosis. Although both positive and negative effects strigolactones on number nodules have been reported, influence development is still unknown. Here, by means ramosus ( rms ) mutants Pisum sativum (pea) cv Terese, we investigated impact strigolactone biosynthesis rms1 rms5 signaling rms3 rms4 growth. The had more red, , functional,...
Rhizobium etli occurs either in a nitrogen-fixing symbiosis with its host plant, Phaseolus vulgaris, or free-living the soil. During both conditions, bacterium has been suggested to reside primarily nongrowing state. Using genome-wide transcriptome profiles, we here examine molecular basis of physiological adaptations rhizobia nongrowth inside and outside host. Compared exponentially growing cells, found an extensive overlap downregulated growth-associated genes during stationary phase,...
A major cause of treatment failure infections caused by Pseudomonas aeruginosa is the presence antibiotic-insensitive persister cells. The mechanism formation in P. largely unknown, and so far, only few genetic determinants have been linked to persistence. Based on a previous high-throughput screening, we here present dnpA (de-N-acetylase involved persistence; gene locus PA14_66140/PA5002) as new noninherited fluoroquinolone tolerance aeruginosa. Fluoroquinolone mutant strongly reduced both...
While establishing a nitrogen-fixing symbiosis with leguminous plants, rhizobia are faced the problem of penetrating plant cell wall at several stages infection process. One major components this barrier is pectin, heteropolysaccharide composed mainly galacturonic acid subunits. So far, no enzymes capable degrading pectin have been isolated from rhizobia. Here, we make an inventory rhizobial candidate pectinolytic based on available genome sequence data and present initial biochemical...
Oral infections are among the most common diseases worldwide. Many protocols for prevention and treatment of oral have been described, yet no golden standard has developed so far. The antiseptic chlorhexidine antibiotics often used in these procedures. However, long-term use can lead to side effects extensive promote development antibiotic-resistant bacteria, which turn compromise effectiveness treatment. Consequently, it remains important search new antibacterial agents infections. In this...
Antibiotics typically fail to completely eradicate a bacterial population, leaving small fraction of transiently antibiotic-tolerant persister cells intact. Persisters are therefore seen be major cause treatment failure and greatly contribute the recalcitrant nature chronic infections. The current study focused on Pseudomonas aeruginosa, Gram-negative pathogen belonging notorious ESKAPE group pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter...
Abstract Background The rel gene of Rhizobium etli ( Ret ), the nodulating endosymbiont common bean plant, determines cellular level alarmone (p)ppGpp and was previously shown to affect free-living growth symbiosis. Here, we demonstrate its role in adaptation survival response various stresses. Results Growth R. mutant strongly reduced or abolished presence elevated NaCl levels at 37°C, compared wild type. In addition, depending on cell density, decreased exponentially growing stationary...
Rhizobium etli is a Gram-negative soil-dwelling alphaproteobacterium that carries out symbiotic biological nitrogen fixation in close association with legume hosts. R. strains exhibit high sequence divergence and are geographically structured, potentially dramatic influence on the outcome of symbiosis. Here, we present genome CNPAF512, Brazilian isolate from bean nodules. We anticipate availability sequences distinctly different areas will provide valuable new insights into geographic mosaic...
Abstract Porphyromonas gingivalis is a major pathogen involved in oral diseases such as periodontitis and peri‐implantitis. Management of these typically includes mechanical debridement the colonized surfaces followed by application antiseptics or antibiotics. Disadvantages associated with use growing worldwide problem antibiotic resistance have necessitated search for alternative agents. In this study, antibacterial antibiofilm properties AM404, an active metabolite paracetamol, were tested...