Introduction to Microbial Pathogenesis

These flashcards cover key terms and concepts from the lecture on microbial pathogenesis and its related processes.

Pathogen

Microbial parasite that causes disease (damage to host).

Opportunistic pathogen

Causes disease only in the absence of normal host resistance.

Colonization

When a microorganism is established and growing in a host, but not harming the host.

Infection

When a microorganism penetrates host defenses to actively grow within a host and cause damage or impair host cell processes.

Disease

Damage or injury to the host that impairs host function.

Symptom

Subjective experiences felt by the patient that cannot be directly observed by others.

Clinical Sign of Disease

Objective indicators of disease that can be observed or measured, not influenced by the patient's perception.

Virulence

The ability of a microorganism to inflict damage on the host.

Virulence Factor

A specific molecule that aids in virulence/pathogenicity, not essential for survival in non-infection situations.

Infectious Dose

The number of organisms needed to establish an infection.

Lethal Dose (LD50)

The lethal dose of a toxin/agent that kills 50% of the hosts in a test population.

Antiseptic

Decreases the number of microorganisms on living things.

Disinfectant

Decreases the number of microorganisms on non-living things.

Toxin

A biologically produced poison that aids in pathogenicity.

Exotoxin

A toxin that is secreted from the cell.

Endotoxin

A toxin that is a component of the cell wall of certain bacteria, released upon cell lysis.

Capsule

A protective layer that prevents phagocytosis by macrophages.

Sialic Acid

A small sugar attached to many proteins on the surface of respiratory epithelial cells, involved in pathogen adherence.

Botulinum Toxin

A toxin produced by Clostridium botulinum that blocks the release of acetylcholine, causing flaccid paralysis.

Tetanus Toxin

A toxin produced by Clostridium tetani that prevents relaxation of muscles, causing rigid paralysis.