Microbe-Human Interactions

These flashcards cover key terms related to the interactions between microbes and humans, focusing on microbiology concepts relevant to health science.

Colonization

Establishment of a population of microbes in or on the body.

Infection

Condition in which pathogenic microorganisms penetrate host defenses, enter tissues, and multiply.

Disease

Any deviation from health caused by infections, diet, genetics, or aging.

Normal microbiota

Large and diverse collection of microbes living on and in the body.

Resident biota

Microbiota that remain and establish themselves in a host over time.

Transient biota

Microbes that are temporary residents and are often cleared.

Pathogen

A microbe whose relationship with its host is parasitic, causing disease.

Virulence

Degree of pathogenicity; ability to establish and cause damage in the host.

Endogenous infection

Infection caused by biota already present in the body.

Exogenous infection

Infection arising from outside the host's own biota.

Transmission

The methods by which infectious agents are spread to new hosts.

Zoonoses

Infections indigenous to animals that can be transmitted to humans.

Opportunistic pathogen

Microbes that cause disease when host defenses are compromised.

Incubation period

Time after exposure to a microbe before symptoms appear.

Primary infection

Initial infection in an otherwise healthy individual.

Secondary infection

Infection that occurs after or due to a primary infection.

Acute infection

Infection that comes on rapidly with short-lived effects.

Chronic infection

Infection that progresses and persists over a long period.

Infectious disease

Disruption of tissues or organs caused by microbes or their products.

Phagocyte

White blood cell that engulfs and destroys pathogens.

Exotoxin

Toxin secreted by living bacterial cells that affects host tissues.

Endotoxin

Toxin that is part of the outer membrane of gram-negative bacteria.

Microbial antagonism

The effect that resident microbes have in preventing the establishment of intruder microbes.

Signs of disease

Objective evidence of disease noted by an observer.

Symptoms of disease

Subjective evidence of disease sensed by the patient.

Inflammation

Initial response of body to damage or infection characterized by redness, swelling, and pain.

Reservoir

Primary habitat in the natural world from which a pathogen originates.

Carrier

An individual that inconspicuously shelters a pathogen and can spread it to others.

Vector

Live animal that transmits an infectious agent from one host to another.

Focal infection

Infection where the infectious agent breaks loose from a local infection and spreads to other tissues.

Local infection

Infection that is confined to a specific tissue.

Systemic infection

Infection that spreads to several sites and tissues throughout the body.

Contagious disease

Highly communicable disease that easily spreads from one individual to another.

Communicable disease

Disease that can be transmitted from an infected host to another host.

Vertical transmission

Transmission of infection from parent to offspring.

Horizontal transmission

Spread of disease through a population.

Healthcare-associated infections (HAIs)

Infections acquired during a hospital stay.

Microbial load

The quantity of microbes present in a given environment.

Medical asepsis

Practices that lower the microbial load among patients and caregivers.

Surgical asepsis

Sterile conditions maintained during surgical procedures.

Normal flora

Another term for the collection of microorganisms that normally inhabit the human body.

Transmission vehicle

A means by which pathogens are transmitted from reservoir to host.

Bacterial virulence factors

Characteristics or structures that allow a pathogen to infect and cause disease.

Quorum sensing

Chemical communication between bacteria that aids in establishing infections.

Microbiota

Microorganisms, including bacteria, fungi, and viruses, that inhabit a specific environment.

Infection control officer

Responsible for implementing and monitoring procedures to prevent infections.

Acquired immunity

Immunity developed after exposure to a pathogen or through vaccination.

Genetic immunity

Inborn resistance to certain infections based on genetic makeup.

Mucous membranes

Tissue lining various cavities and covering organs, serving as protective barriers.

Antiphagocytic factors

Virulence factors that prevent phagocytosis by immune cells.

Chronic carrier

An individual who harbors a pathogen for a long period after recovery.

Incubating carrier

An infected person who shows no symptoms of disease but can still transmit the pathogen.