Microbe-Human Interactions

Flashcards covering key terms and concepts related to microbe-human interactions.

Symbiosis

A close interaction between two organisms where the relationship is beneficial to one or both.

Mutualism

A symbiotic relationship where both organisms benefit.

Commensalism

A symbiotic relationship where one organism benefits and the other is unaffected.

Parasitism

A relationship where one organism benefits at the expense of the other.

Microbial antagonism

A nonsymbiotic relationship where normal microbiota prevent pathogens from establishing infections.

Pathogen

A microorganism capable of causing damage to a host.

True Pathogens

Microorganisms that can cause disease in healthy individuals under the right circumstances.

Opportunistic Pathogens

Microbes that cause disease only in hosts with weakened defenses.

Pathogenicity

The ability of a pathogen to cause disease.

Virulence

The degree of severity of disease caused by a pathogen.

Exoenzymes

Enzymes secreted by pathogens that damage host tissues.

Endotoxin

The lipid A portion of lipopolysaccharides in the outer membrane of Gram-negative bacteria, which can trigger severe immune responses.

Superantigen

A type of protein that can cause an excessive immune response, leading to disease.

Synergism

A nonsymbiotic relationship where multiple organisms benefit but are not required for each other's survival.

Normal Microbiota

Microorganisms that normally reside in the body and usually do not harm the host.

Virulence Factors

Traits of pathogens that help them survive and cause disease.

Antigenic Variation

The process by which a pathogen alters its surface proteins to evade the host immune system.

Intracellular Life

The ability of pathogens to live within host cells, thereby evading immune defenses.