A5000220498- Vibrio bacteria research studies
- Escherichia coli research studies
- Bacterial Genetics and Biotechnology
- Bacterial Infections and Vaccines
- Antibiotic Resistance in Bacteria
- Pneumonia and Respiratory Infections
- Lipid Membrane Structure and Behavior
- Bacterial biofilms and quorum sensing
- Yersinia bacterium, plague, ectoparasites research
- Streptococcal Infections and Treatments
- Bacteriophages and microbial interactions
- Bacterial Identification and Susceptibility Testing
- Cephalopods and Marine Biology
- Plant Pathogenic Bacteria Studies
- Microbial Metabolic Engineering and Bioproduction
- Medical Device Sterilization and Disinfection
- Adenosine and Purinergic Signaling
- Cystic Fibrosis Research Advances
- Inhalation and Respiratory Drug Delivery
- Micro and Nano Robotics
- Bacillus and Francisella bacterial research
- Cancer Research and Treatments
- Antimicrobial Resistance in Staphylococcus
- Carbohydrate Chemistry and Synthesis
- Biochemical and Structural Characterization
Karolinska Institutet
2017-2025
Princip (Czechia)
2025
Karolinska University Hospital
2017-2021
University of Wisconsin–Madison
2015-2020
Singapore Centre for Environmental Life Sciences Engineering
2020
Nanyang Technological University
2020
Centre National de la Recherche Scientifique
2008-2019
Aix-Marseille Université
2010-2019
Institut de Microbiologie de la Méditerranée
2010-2019
Laboratoire d'Ingénierie des Systèmes Macromoléculaires
2010-2016
ABSTRACT Enteroaggregative Escherichia coli (EAEC) is a pathogen implicated in several infant diarrhea or diarrheal outbreaks areas of endemicity. Although multiple genes involved EAEC pathogenesis have been identified, the overall mechanism virulence not well understood. Recently, novel secretion system, called type VI (T6S) system (T6SS), has identified and most animal plant gram-negative pathogens. T6SSs are multicomponent cell envelope machines responsible for at least two putative...
Summary The Type VI secretion system (T6SS) is a multiprotein machine that delivers protein effectors in both prokaryotic and eukaryotic cells, allowing interbacterial competition virulence. mechanism of action the T6SS requires contraction sheath‐like structure propels needle towards target delivery effectors. Here, we provide evidence entero‐aggregative Escherichia coli Sci‐1 required to eliminate competitor bacteria. We further identify Tle1, toxin effector encoded by this cluster showed...
Type VI secretion systems (T6SS) are multi-component machines encoded within the genomes of most Gram-negative bacteria that associate with plant, animal and/or human cells, and therefore considered as potential virulence factors. We recently launched a study on Sci-1 T6SS enteroaggregative Escherichia coli (EAEC). The is composed all or subset 21 gene products cluster, 13 which shared by identified so far. In present work, we focussed our attention SciZ protein. first showed required for...
Type VI secretion systems (T6SS) are trans-envelope machines dedicated to the of virulence factors into eukaryotic or prokaryotic cells, therefore required for pathogenesis and/or competition towards neighboring bacteria. The T6SS apparatus resembles injection device bacteriophage T4, and is anchored cell envelope through a membrane complex. This complex composed TssL, TssM TagL inner proteins TssJ outer lipoprotein. Here, we report crystal structure enteroaggregative Escherichia coli Sci1...
Type VI secretion systems (T6SS) are macromolecular complexes present in Gram-negative bacteria. T6SS structurally similar to the bacteriophage cell-puncturing device and have been shown mediate bacteria-host or bacteria-bacteria interactions. assemble from 13 20 proteins. In enteroaggregative Escherichia coli (EAEC), one of subassemblies is composed four proteins that form a trans-envelope complex: TssJ outer membrane lipoprotein, peptidoglycan-anchored inner TagL protein, two putative...
ABSTRACT Using the squid-vibrio association, we aimed to characterize mechanism through which Vibrio fischeri cells signal morphogenesis of symbiotic light-emitting organ. The symbiont releases two cell envelope molecules, peptidoglycan (PG) and lipopolysaccharide (LPS) that, within 12 h light organ colonization, act in synergy trigger normal tissue development. Recent work has shown that outer membrane vesicles (OMVs) produced by V. are sufficient induce PG-dependent morphogenesis; however,...
AbstractThe recently identified bacterial type VI secretion system (T6SS) has rapidly become one of the most interesting areas research in microbiology. In a relatively short period time relationship between T6SS and bacteriophage T4 tail baseplate been established. However, number questions concerning remain focus large researchers worldwide. Key that need to be addressed include how this assembles cell envelope mechanism by which it translocates effector proteins across two membranes,...
Outer membrane vesicles (OMV) are critical elements in many host-cell/microbe interactions. Previous studies of the symbiotic association between Euprymna scolopes and Vibrio fischeri had shown that within 12 h colonizing crypts deep squid's light organ, symbionts trigger an irreversible programme tissue development host. Here, we report OMV produced by V. powerful contributors to this process. The first detectable host response is increased trafficking macrophage-like cells called...
Streptococcus pneumoniae evades C3-mediated opsonization and effector functions by expressing an immuno-protective polysaccharide capsule Factor H (FH)-binding proteins. Here we use super-resolution microscopy, mutants functional analysis to show how these two defense mechanisms are functionally spatially coordinated on the bacterial cell surface. We that pneumococcal is less abundant at wall septum, providing C3/C3b entry underlying nucleophilic targets. Evasion of C3b deposition division...
Article28 September 2020Open Access Source DataTransparent process Mannose receptor-derived peptides neutralize pore-forming toxins and reduce inflammation development of pneumococcal disease Karthik Subramanian orcid.org/0000-0002-4381-5037 Department Microbiology, Tumor Cell Biology, Karolinska Institutet, Stockholm, Sweden Search for more papers by this author Federico Iovino Vasiliki Tsikourkitoudi orcid.org/0000-0003-0820-3585 Padryk Merkl Sultan Ahmed Laboratory Medicine, Huddinge,...
Abstract Background and aims Our hypothesis is that Klebsiella pneumoniae (Kp) Type VI Secretion System (T6SS), normally used for bacteria competition during host colonization have a collateral impact on the inflammatory pathway (Fig1). specific are to: (i) Characterize of bacterial type (T6SS) gut inflammation (ii) Develop screen to identify T6SS inhibitors. Methods In vivo experiments involve infecting mice with Kp wild (WT) mutants evaluate immune response. Metagenomic analysis IBD CRC...
Molecular mechanisms by which sex steroids interact with P. aeruginosa to modulate its virulence have yet be reported. Our work provides the first characterization of a steroid-induced membrane stress mechanism promoting virulence, includes release proinflammatory outer vesicles, resulting in inflammation, host tissue damage, and reduced bacterial clearance. We further demonstrate that at nanomolar (physiological) concentrations, male female promote clinical strains based on their dynamic...
Biofilms are dense bacterial colonies that may adhere to the surfaces of medical devices and major contributors infections. These characterized by a self-produced matrix extracellular polymeric substances (EPS). Bacterial biofilms difficult treat with commonly used antibiotics partially because their poor diffusion through EPS therefore require new targeted strategies effectively fight them. produce an acidic microenvironment which can be exploited design such treatment strategies. However,...
Type IV pili (T4P) are remarkable bacterial surface appendages that carry out a range of functions. Various types T4P have been identified in bacteria and archaea, making them almost universal structures prokaryotes. best characterized Gram-negative bacteria, which pilus biogenesis T4P-mediated functions studied for decades. Recent advances microbial whole-genome sequencing provided ample evidence the existence also many Gram-positive species. However, comparatively little is known, just...
Abstract Increasing evidence highlights the role of bacteria in physiopathology cancer. However, underlying molecular mechanisms remains poorly understood. Several cancer-associated have been shown to produce toxins which interfere with host defense against tumorigenesis. Here, we show that lipopolysaccharides from Klebsiella pneumoniae and other Enterobacteria strongly inhibit tumor suppressor p53 pathway through a novel mechanism regulation. We found destabilize TP53 mRNA...
Extracellular bacterial symbionts communicate biochemically with their hosts to establish niches that foster the partnership. Using quantitative ion microprobe isotopic imaging (nanoscale secondary mass spectrometry [NanoSIMS]), we surveyed localization of 15 N-labelled molecules produced by bacterium Vibrio fischeri within cells symbiotic organ its host, Hawaiian bobtail squid, and compared either labelled non-specific species or amino acids. In all cases, two areas organ's epithelia were...
Neisseria meningitidis (meningococcus) is a common bacterial colonizer of the human nasopharynx but can occasionally cause very severe systemic infections with rapid onset. Meningococci are able to degrade IgA encountered during colonization mucosal membranes using their IgA1-specific serine protease. During infection, specific IgG induce complement-mediated lysis bacterium. However, meningococcal immune evasion mechanisms in thwarting remain undescribed. In this study, we report for first...
The type VI secretion system (T6SS) is an injection apparatus that uses a springlike mechanism for effector delivery. contractile tail composed of needle tipped by sharpened spike and wrapped the sheath polymerizes in extended conformation on assembly platform, or baseplate. Contraction propels effectors associated with it into target cells. passage through cell envelope attacker ensured dedicated trans-envelope channel complex. This membrane complex (MC) comprises TssJ lipoprotein TssL TssM...