Microbial Mechanisms of Pathogenicity

These flashcards cover key vocabulary related to the study of pathogens, their mechanisms of action, and disease processes.

Pathology

The study of disease, its causes, and its effects on the body.

Etiology

The study of the cause or origin of a disease.

Infection

The invasion of the body by pathogenic microorganisms that multiply and cause disease.

Disease

A disorder of structure or function in a human, animal, or plant that produces specific symptoms.

Commensalism

A type of symbiotic relationship where one organism benefits and the other is neither helped nor harmed.

Mutualism

A type of symbiotic relationship where both organisms benefit.

Parasitism

A type of symbiotic relationship where one organism benefits at the expense of another.

Normal microbiota

The microorganisms that are normally present in a specific site, providing certain benefits.

Transient microbiota

Microorganisms that are temporarily present in a particular environment but do not establish permanent residence.

Opportunistic microorganisms

Microorganisms that cause disease when the body's defenses are compromised.

Koch's postulates

A set of criteria for establishing a causative relationship between a microbe and a disease.

Communicable disease

A disease that can be transmitted from one person to another.

Noncommunicable disease

A disease that is not transmitted from one person to another.

Reservoir of infection

The natural host or habitat of a pathogen where it normally lives and multiplies.

Healthcare-associated infections (HAIs)

Infections that patients acquire while receiving treatment for medical or surgical conditions.

Compromised host

An individual whose immune system is weakened or not functioning properly.

ID50 (Infectious Dose 50)

The quantity of a microbial agent required to infect 50% of a population.

LD50 (Lethal Dose 50)

The amount of a toxin required to kill 50% of a test population.

Exotoxins

Toxic substances released by bacteria that cause damage to the host by destroying cells or disrupting normal cellular metabolism.

Endotoxins

Toxins that are part of the cell wall of gram-negative bacteria and are released when the bacteria die.

Siderophores

Molecules that bind and transport iron in microorganisms, aiding in nutrient acquisition.

Antigenic variation

The mechanism by which pathogens alter their surface proteins to evade the host immune response.

Adhesins

Molecules on the surface of pathogens that allow them to adhere to host tissues.

Biofilms

Complex communities of microorganisms that adhere to surfaces and are encased in a protective matrix.

Cytopathic effects (CPE)

Visible effects of viral infections on host cells.

Virulence

The degree of pathogenicity of a microbe, indicating its ability to cause disease.

Toxigenicity

The ability of a microorganism to produce toxins that affect the host.