What is the virulence factor that inhibits phagocytosis?
The fimbriae of certain species of Streptococcus contain M protein, which alters the surface of Streptococcus and inhibits phagocytosis by blocking the binding of the complement molecules that assist phagocytes in ingesting bacterial pathogens.
Which of the following component prevents phagocytosis of bacterial cell?
The bacteria secrete the extracellular fibrinogen binding protein (Efb), which binds the serum protein fibrinogen (137). In this way, the bacterium creates a proteinaceous shield that covers the surface bound opsonin and prevents phagocytosis (137, 138) (Figure 4).
What is bacterial virulence factors?
Virulence factors are the molecules that assist the bacterium colonize the host at the cellular level. These factors are either secretory, membrane associated or cytosolic in nature. The cytosolic factors facilitate the bacterium to undergo quick adaptive-metabolic, physiological and morphological shifts.
Which bacterial structure interferes with phagocytosis?
Inhibition of fusion of the phagocytic lysosomes (granules) with the phagosome. The bacteria survive inside of phagosomes because they prevent the discharge of lysosomal contents into the phagosome environment. Specifically, phagolysosome formation is inhibited in the phagocyte.
How does bacterial capsule prevent phagocytosis?
Capsules can resist unenhanced attachment by by preventing pathogen-associated molecular patterns or from binding to endocytic pattern-recognition receptors on the surface of the phagocytes. The capsules of some bacteria interfere with the body’s complement pathway defenses.
What are virulence factors examples?
Factors that are produced by a microorganism and evoke disease are called virulence factors. Examples are toxins, surface coats that inhibit phagocytosis, and surface receptors that bind to host cells.
What are the examples of virulence factor?
Is lipopolysaccharide a virulence factor?
Pseudomonas aeruginosa lipopolysaccharide: a major virulence factor, initiator of inflammation and target for effective immunity.
Which of the following are examples of virulence factors?
How do bacteria resist phagocytosis?
Some bacteria resist phagocytic destruction by preventing fusion of the lysosome with the phagosome. Some bacteria resist phagocytic destruction by escaping from the phagosome before the lysosome fuses. Some bacteria resist phagocytic destruction by preventing acidification of the phagosome.
How do bacteria use virulence factors to evade phagocytosis?
Bacteria use a variety of virulence factors to evade phagocytosis by cells of the immune system. For example, many bacteria produce capsules, which are used in adhesion but also aid in immune evasion by preventing ingestion by phagocytes. The composition of the capsule prevents immune cells from being able to adhere and then phagocytose the cell.
Why do some bacteria become resistant to phagocytic ingestion?
Clearly it is the bacterial surface that matters. Resistance to phagocytic ingestion is usually due to a component of the bacterial cell surface (cell wall, or fimbriae, or a capsule). Classical examples of antiphagocytic substances on bacterial surfaces include:
What is an example of virulence factor?
Some bacteria produce virulence factors that promote infection by exploiting molecules naturally produced by the host. For example, most strains of Staphylococcus aureus produce the exoenzyme coagulase, which exploits the natural mechanism of blood clotting to evade the immune system.
What is the genetic basis for bacterial virulence?
Genetic and Molecular Basis for Virulence. Bacterial virulence factors may be encoded on chromosomal, plasmid, transposon, or temperate bacteriophage DNA; virulence factor genes on transposons or temperate bacteriophage DNA may integrate into the bacterial chromosome.