Bacterial Virulence Factors: A Minor Cause of Periodontal Destruction
Mechanisms that allow biofilm bacteria to colonize and to invade the periodontal tissues
are called virulence factors (table. 6-3). The Virulence factors can be structural characteristics of the bacteria themselves or substances produced and released into the environment by bacteria.
A. Bacteriological Characteristics
1. Bacterial invasion factors
a. Periodontal pathogens have the opportunity to actively penetrate the epithelium lining the pocket wall and to intrude in the connective tissue of the gums [36,37].
B. Both gram-positive and gram-negative bacteria occurs in the intercellular space of the connective tissue of the gums and near the alveolar bone.
1) bacteria can invade the connective tissue of the gums through ulcers in the pocket of the epithelium.
2) A. actinomycetemcomitans, P. gingivalis, F. nucleatum, and Treponema denticoia were demonstrated directly to invade host tissue cells.
3) the ability to invade host tissue cells, is considered a key factor that distinguishes from pathogenic pathogenic Gram-negative bacteria .
4) Presence of bacteria within the tissues makes periodontitis more resistant to treatment.
2. Peptide protein in the bacterial cell membranes
a. Previously, researchers believed that inflammation is something to do with the lipopolysaccharide (LPS). Lipopolysaccharide make up the cell membrane of gram-negative bacteria.
B. Recently researchers have found a new class of proteins called peptides. Peptides are short chains of amino acids found in living bacterial cell membranes that control the transport of molecules in a bacterial cell.
c. T cells-a Type of white blood cells can identify peptides in cell membranes and the castle in peptide. After locking in peptide t cells, prevents the rest of the immune system bacterial invasion.
d. When the bacteria are killed, peptides unlink and become one amino acid again. There is nothing to t cells to block it, and the immune response is silence.
B. Bacterial Products
1. Exotoxin production
a. Exotoxins harmful proteins released from bacterial cells that operate on the host cell in the distance.
B. For example, A. actinomycetemcomitans produces leukotoxin (LT), an exotoxin, which can help to kill the bacteria cells in the furrow or pocket.
2. Bacterial enzyme production. Bacterial enzymes are agents that are harmful or destructive host cell.
a. Various enzymes produced pathogens of diseases of parodont important in tissue destruction [39,40].
B. Enzymes function in different ways using bacteria invading the tissues. After the liberation, bacterial enzymes are able
1) increase in the permeability of the epithelium lining the groove (allowing bacteria to penetrate sulcular epithelium more easily).
2) to contribute to the breakdown of collagen fibers of the connective tissue of the gums.
3) promote the apical migration paroxizmalnaya form epithelium along the surface of the root.
4) call the extension intercellular spaces.
5) reduce the ability of antibodies and other proteins of the body to protect the host.