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Chitosan and its antimicrobial potential--a critical literature survey.

Raafat D, Sahl HG - Microb Biotechnol (2009)

Bottom Line: The term 'chitosan' describes a heterogeneous group of polymers combining a group of physicochemical and biological characteristics, which allow for a wide scope of applications that are both fascinating and as yet uncharted.However, understanding the various factors that affect its antimicrobial activity has become a key issue for a better usage and a more efficient optimization of chitosan formulations.Moreover, the use of chitosan in antimicrobial systems should be based on sufficient knowledge of the complex mechanisms of its antimicrobial mode of action, which in turn would help to arrive at an appreciation of its entire antimicrobial potential.

View Article: PubMed Central - PubMed

Affiliation: Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany. dina_raafat@yahoo.com

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The staphylococcal cell envelope. The staphylococcal cell wall is composed of multilayers of glycan strands of alternating N‐acetylglucosamine (GlcNAc) and N‐acetylmuramyl‐pentapeptide (MurNAc‐PP), cross‐linked by pentaglycine side‐chains. For clarity, only one layer of peptidoglycan is depicted here. Teichoic acids, polyanionic surface polymers extending through the peptidoglycan layer, contribute to the negative charge of the cell wall. The cytoplasmic membrane is a selectively permeable membrane lying internal to the cell wall.
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f2: The staphylococcal cell envelope. The staphylococcal cell wall is composed of multilayers of glycan strands of alternating N‐acetylglucosamine (GlcNAc) and N‐acetylmuramyl‐pentapeptide (MurNAc‐PP), cross‐linked by pentaglycine side‐chains. For clarity, only one layer of peptidoglycan is depicted here. Teichoic acids, polyanionic surface polymers extending through the peptidoglycan layer, contribute to the negative charge of the cell wall. The cytoplasmic membrane is a selectively permeable membrane lying internal to the cell wall.

Mentions: The term cell envelope comprises both the cell wall and the cytoplasmic membrane of a bacterial cell; it also includes the semi‐permeable lipid bilayer (outer membrane) of Gram‐negative bacteria, which acts as an additional diffusion barrier. The staphylococcal cell wall is composed of multilayers of murein, where glycan strands of alternating β‐1→4‐linked GlcNAc–MurNAc disaccharides are cross‐linked by short peptides. Extending to the surface of the peptidoglycan layer are teichoic acids, which are essential polyanionic polymers found only in the cell wall of Gram‐positive bacteria that contribute to the negative charge of the cell wall (Fig. 2); similar polymeric structures, referred to as lipopolysaccharides (LPS), are found in the outer membrane of Gram‐negative bacteria. The Staphylococcus aureus cell membrane consists of three major phospholipid (PL) species: negatively charged phosphatidylglycerol and cardiolipin, and positively charged lysyl‐phosphatidylglycerol (LPG), the latter accounting for 14–38% of the total PL content of the S. aureus cytoplasmic membrane (Peschel et al., 2001).


Chitosan and its antimicrobial potential--a critical literature survey.

Raafat D, Sahl HG - Microb Biotechnol (2009)

The staphylococcal cell envelope. The staphylococcal cell wall is composed of multilayers of glycan strands of alternating N‐acetylglucosamine (GlcNAc) and N‐acetylmuramyl‐pentapeptide (MurNAc‐PP), cross‐linked by pentaglycine side‐chains. For clarity, only one layer of peptidoglycan is depicted here. Teichoic acids, polyanionic surface polymers extending through the peptidoglycan layer, contribute to the negative charge of the cell wall. The cytoplasmic membrane is a selectively permeable membrane lying internal to the cell wall.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3815839&req=5

f2: The staphylococcal cell envelope. The staphylococcal cell wall is composed of multilayers of glycan strands of alternating N‐acetylglucosamine (GlcNAc) and N‐acetylmuramyl‐pentapeptide (MurNAc‐PP), cross‐linked by pentaglycine side‐chains. For clarity, only one layer of peptidoglycan is depicted here. Teichoic acids, polyanionic surface polymers extending through the peptidoglycan layer, contribute to the negative charge of the cell wall. The cytoplasmic membrane is a selectively permeable membrane lying internal to the cell wall.
Mentions: The term cell envelope comprises both the cell wall and the cytoplasmic membrane of a bacterial cell; it also includes the semi‐permeable lipid bilayer (outer membrane) of Gram‐negative bacteria, which acts as an additional diffusion barrier. The staphylococcal cell wall is composed of multilayers of murein, where glycan strands of alternating β‐1→4‐linked GlcNAc–MurNAc disaccharides are cross‐linked by short peptides. Extending to the surface of the peptidoglycan layer are teichoic acids, which are essential polyanionic polymers found only in the cell wall of Gram‐positive bacteria that contribute to the negative charge of the cell wall (Fig. 2); similar polymeric structures, referred to as lipopolysaccharides (LPS), are found in the outer membrane of Gram‐negative bacteria. The Staphylococcus aureus cell membrane consists of three major phospholipid (PL) species: negatively charged phosphatidylglycerol and cardiolipin, and positively charged lysyl‐phosphatidylglycerol (LPG), the latter accounting for 14–38% of the total PL content of the S. aureus cytoplasmic membrane (Peschel et al., 2001).

Bottom Line: The term 'chitosan' describes a heterogeneous group of polymers combining a group of physicochemical and biological characteristics, which allow for a wide scope of applications that are both fascinating and as yet uncharted.However, understanding the various factors that affect its antimicrobial activity has become a key issue for a better usage and a more efficient optimization of chitosan formulations.Moreover, the use of chitosan in antimicrobial systems should be based on sufficient knowledge of the complex mechanisms of its antimicrobial mode of action, which in turn would help to arrive at an appreciation of its entire antimicrobial potential.

View Article: PubMed Central - PubMed

Affiliation: Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany. dina_raafat@yahoo.com

Show MeSH