O-antigen protects gram-negative bacteria from histone killing
Catherine Chaput1, Eileen Spindler, Ryan T Gill
1Department of Cellular Microbiology, Max-Planck Institute for Infection Biology, Berlin, Germany. catherine.chaput@charite.de
Plos One
|August 17, 2013
Summary
Histones have antibacterial properties. Researchers found that bacterial exopolysaccharides and O-antigen lipopolysaccharides provide resistance against histones, a finding relevant for pathogens like Shigella and Klebsiella.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Histones, primarily known for DNA organization, exhibit antimicrobial activity against various bacteria.
- Understanding bacterial resistance mechanisms to host defense factors like histones is crucial for combating infections.
Purpose of the Study:
- To identify bacterial factors conferring resistance to histone challenge.
- To investigate the role of specific bacterial surface components in histone resistance.
Main Methods:
- Utilized Escherichia coli mutant libraries to screen for genes involved in histone resistance.
- Analyzed genes related to exopolysaccharide and lipopolysaccharide (LPS) O-antigen synthesis.
- Tested the effect of O-antigen and exopolysaccharide on histone resistance in pathogenic bacteria.
Main Results:
- Identified genes essential for exopolysaccharide production and O-antigen synthesis as key to histone resistance.
- Demonstrated that both exopolysaccharide and O-antigen significantly enhance bacterial survival against histones.
- Confirmed that O-antigen confers cross-resistance to histones in pathogens Shigella flexneri and Klebsiella pneumoniae.
Conclusions:
- Bacterial exopolysaccharides and O-antigen are critical determinants of resistance to histones.
- These findings highlight novel targets for therapeutic strategies against bacterial infections involving host histones.
More Related Videos
Related Concept Videos
01:23Antimicrobial Proteins
Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
01:22Bacterial Cell Wall
The bacterial cell wall is an essential structural component that encases the plasma membrane, preserving cellular integrity, determining shape, and protecting against osmotic stress. This rigid yet flexible structure primarily comprises peptidoglycan, a polymer that forms a mesh-like matrix conferring mechanical strength and flexibility.Peptidoglycan Composition and StructurePeptidoglycan, the core of the bacterial cell wall, comprises alternating units of N-acetylglucosamine (NAG) and...
01:23Inhibitors of Gram-positive Cell Wall Synthesis
Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
01:25Inhibitors of Bacterial Protein Synthesis
Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
01:31Defense Against Bacterial Pathogens
The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
01:26Antibody Actions
Antibodies, or immunoglobulins, are critical players in the immune system's arsenal against invading pathogens. Produced by B cells and plasma cells, their primary role is to detect and bind to specific antigens, molecules found on the surface of pathogens like bacteria or viruses. Beyond antigen recognition, antibodies perform several vital functions that contribute to immune defense.
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...