Microbial Mechanism of Pathogenicity

These flashcards cover key terms and concepts related to microbial pathogenicity, including definitions and mechanisms.

Pathogenicity

The ability of a microbe/pathogen to cause disease in a host.

Virulence

The enhanced ability of a pathogen to cause infection or disease.

Virulence factor

A characteristic or trait of a pathogen that makes it harmful.

ID 50

Infectious Dose 50; the number of pathogens required to make 50% of the population sick, indicating virulence.

LD 50

Lethal Dose 50; the amount of toxin required to kill 50% of the population, measuring the potency of a toxin.

Adhesion Factors

The ability of pathogens to attach to host tissues/cells.

Bacterial adhesins (ligands)

Substances on the pathogen that bind to receptors on host cells to facilitate adherence.

Exotoxins

Toxins secreted by living cells, usually made of protein, causing a strong immune response.

Endotoxins

Toxins that are part of the outer layer of gram-negative bacterial cell walls and cause fever.

Antigenic variation

The ability of pathogens to change their surface antigens through genetic mutations, evading the immune response.

Toxemia

The presence of toxins in the bloodstream.

Toxigenicity

The ability of a pathogen to produce a toxin.

Superantigens

A type of exotoxin that causes a very strong immune response, leading to the release of cytokines.

Cytokines

Small proteins released by immune cells that have an effect on other cells, often involved in the inflammatory response.

Fungi pathogenic properties

Some fungal toxins can contaminate food supplies, provoke allergic responses, and are carcinogenic.

Protozoan pathogenic properties

Protozoa can cause damage to host tissues, and some can grow within phagocytes.

Helminths pathogenic properties

Helminths are worms that can interfere with host food absorption without killing the host.

Portal of exit

The route through which pathogens leave the host, often the same as the portal of entry.