Infection and Pathogenicity Lecture Note Practice Flashcards

Comprehensive vocabulary flashcards covering the major concepts of infection development, pathogenicity, virulence factors, stages of disease, and transmission patterns based on Chapter 11 lecture notes.

True pathogens

Microbes that cause disease in people with normal immune defenses, such as Influenzavirus and Salmonella.

Opportunistic pathogens

Microbes that cause disease in immunocompromised individuals or when they grow in a part of the body that is not natural to them, such as Pseudomonas sp and Candida albicans.

Virulence factor

Any characteristic or structure that contributes to the ability of a microbe to cause disease.

Portal of entry

The route that a microbe follows to enter tissues of the body, such as the skin, GI tract, respiratory tract, or urogenital tract.

Infectious Dose (ID)

The minimum number of microbes required for infection to proceed; microbes with smaller values have greater virulence.

Adhesion

The binding between specific molecules on both the host and the pathogen to gain a foothold.

Fimbriae

Surface structures used for attachment, such as those used by Neisseria gonorrhoeae to attach to genital epithelium.

Leukocidins

Toxic substances produced by species of Staphylococcus and Streptococcus that are harmful to white blood cells.

STORCH

The acronym for pathogens that infect during pregnancy: Syphilis, Toxoplasmosis, Other diseases (hepatitis B, AIDS and Chlamydia), Rubella, Cytomegalovirus, and Herpes simplex virus.

Exoenzymes

Secreted bacterial products that dissolve extracellular barriers and penetrate through or between cells.

Toxigenicity

The capacity of a microorganism to produce toxins at the site of multiplication.

Endotoxin

A toxin not secreted but released after the cell is damaged; composed of lipopolysaccharide (LPS) from the outer membrane of Gram-negative cell walls.

Exotoxin

A toxin molecule secreted by a living bacterial cell into the infected tissue that has strong specificity for a target cell.

Hemolysins

A type of exotoxin that disrupts the cell membrane of red blood cells.

A-B toxins

Exotoxins consisting of two parts: an active component (A) and a binding component (B).

Incubation period

The time from initial contact with the infectious agent to the appearance of first symptoms, where damage is insufficient to cause symptoms.

Prodromal stage

The stage of infection characterized by vague feelings of discomfort and nonspecific complaints.

Period of invasion

The stage where a pathogen multiplies at high levels, becomes well-established, and causes more specific signs and symptoms.

Convalescent period

The stage as a person begins to respond to the infection and symptoms decline.

Localized infection

An infection where microbes enter the body and remain confined to a specific tissue.

Systemic infection

An infection that spreads to several sites and tissue fluids, usually through the bloodstream.

Focal infection

Occurs when an infectious agent breaks loose from a local infection and is carried to other tissues.

Mixed infection

Also known as polymicrobial, this occurs when several microbes grow simultaneously at the same infection site.

Primary infection

The initial infection in a host.

Secondary infection

A subsequent infection by a different microbe following a primary infection.

Acute infection

An infection that comes on rapidly with severe but short-lived effects.

Chronic infection

An infection that progresses and persists over a long period of time.

Symptom

A manifestation of disease that is apparent to the patient.

Sign

A manifestation of disease that a physician or healthcare worker perceives.

Septicemia

A clinical sign where microorganisms are multiplying in the blood and are present in large numbers.

Bacteremia

Small numbers of bacteria present in the blood that are not necessarily multiplying.

Viremia

Small numbers of viruses present in the blood that are not necessarily multiplying.

Leukocytosis

An increase in the total number of white blood cells.

Leukopenia

A decrease in the total number of white blood cells.

Sequelae

Long-term or permanent damage to tissues or organs, such as Post Polio Syndrome or COVID "long haulers".

Latency

A state where a microbe periodically becomes active and produces recurrent disease after the initial symptoms of a chronic disease have subsided.

Reservoir

The primary habitat of a pathogen in the natural world, which can be a human, animal, soil, water, or plants.

Source

The individual or object from which an infection is actually acquired.

Communicable disease

A disease where an infected host can transmit the infectious agent to another host and establish infection.

Non-communicable infectious disease

A disease that does not arise through transmission from host to host, often caused by a person's own normal microflora.

Passive carrier

A contaminated healthcare provider who picks up pathogens and transfers them to other patients without being infected themselves.

Asymptomatic carrier

An individual who spreads infection even though they show no symptoms.

Vector

A live animal, typically an arthropod like a flea or tick, that transmits an infectious agent from one host to another.

Biological vector

An animal vector that actively participates in the life cycle of the pathogen.

Mechanical vector

A vector that transports an infectious agent without being infected and is not necessary to the pathogen's life cycle.