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For the most part, the genetic approach is the most extensive way in identifying the bacterial virulence factors. Bacterial DNA can be altered from pathogenic to non-pathogenic, random mutations may be introduced to their genome, specific genes encoding for membrane or secretory products may be identified and mutated, and genes that regulate ...
For example, a common bacterial strategy is to produce proteins that bind host antibodies. The polysaccharide capsule of Streptococcus pneumoniae inhibits phagocytosis of the bacterium by host immune cells. [citation needed] Toxins Many virulence factors are proteins made by bacteria that poison host cells and cause tissue damage.
Bacteria use quorum sensing to regulate certain phenotype expressions, which in turn, coordinate their behaviors. Some common phenotypes include biofilm formation, virulence factor expression, and motility. Certain bacteria are able to use quorum sensing to regulate bioluminescence, nitrogen fixation and sporulation. [16]
Bacterial adhesins are cell-surface components or appendages of bacteria that facilitate adhesion or adherence to other cells or to surfaces, usually in the host they are infecting or living in. Adhesins are a type of virulence factor. Adherence is an essential step in bacterial pathogenesis or infection, required for colonizing a new host. [1]
Rhodococcus equi virulence plasmid pathogenicity island encodes virulence factors for proliferation in macrophages. The SaPI family of Staphylococcus aureus pathogenicity islands, mobile genetic elements, encode superantigens, including the gene for toxic shock syndrome toxin, and are mobilized at high frequencies by specific bacteriophages. [10]
Bacterial virulence factors include adherence factors to attach to host cells, invasion factors supporting entry into host cells, capsules to prevent opsonization and phagocytosis, toxins, and siderophores to acquire iron. [15] A photomicrograph of a stool that has shigella dysentery. These bacteria typically cause foodborne illness.
Bacterial secretion systems are protein complexes present on the cell membranes of bacteria for secretion of substances. Specifically, they are the cellular devices used by pathogenic bacteria to secrete their virulence factors (mainly of proteins) to invade the host cells. They can be classified into different types based on their specific ...
E.coli was an example of why this is important, with genes encoding virulence factors in two strains of the species differing by at least thirty percent. [19] Such knowledge, along with more thorough study of genome gain, loss, and change, is giving researchers valuable insight into how pathogens interact in host environments and how they are ...