Adhesion Factors

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Adhesion Factors

  • Adherence is the initial step for the infectious process. Then it is followed by microcolonies growth (colonization).
  • After successful adherence and colonization, most of the bacteria produce microbial biofilm.
  • Biofilm is the aggregate of microorganisms, where the cells are embedded into a self-produced matrix of extracellular polymeric substances tightly attached to the adjacent tissues.
  • Biofilms create a tough polymicrobial layer poorly permeable for antimicrobial agents.
  • All these kinds of interactions ensue from the synthesis of various virulence factors by pathogenic bacteria.
  • Bacterial adhesins may be single mommeric proteins or large multimeric complexes.
  • For instance, microbial cells express a number of specific adhesins – surface molecules that bind to the host cell receptors. In this vein, many bacteria (e.g., E. coli) have 1st type pili that bind to receptors containing D-mannose.
  • Likewise, group A streptococci carry fimbriae capable of binding to certain host cell receptors. Fimbriae contain lipoteichoic acid and M-protein.
  • Also, the bacteria possess a vast number of lectins – adhesive proteins, responsible for binding to carbohydrate moiety of host membrane structures.
  • Bacterial adhesion is affected by many factors, including some characteristics of the bacteria, the chemical and physical nature of the target material surface, and factors in the bacterial suspension medium including the physical conditions of the medium and the presence of carbohydrates, proteins, serum proteins, or bactericidal substances.
Adhesion Factors
Pathogen competes against host cell binding sites

Reference

  1. https://link.springer.com/chapter/10.1007/978-1-59259-224 1_4#:~:text=Bacterial%20adhesion%20is%20a%20very,medium%20and%20the%20presence%20of
  2. https://www.sciencedirect.com/topics/immunology-and-microbiology/bacterial-adhesin