Microbe-Human Interactions Review

Flashcards covering key vocabulary, definitions, and concepts related to microbe-human interactions, infection processes, transmission, virulence factors, and epidemiology from the lecture notes.

Initial Colonization of the Newborn

The process where fetuses start developing normal microbiota in utero and receive massive exposure during birth.

Normal Flora

The microbes that colonize the human body without causing disease under normal conditions.

Infection

The multiplication of microbes that leads to host tissue damage.

Sterile Body Areas

Parts of the body that are typically free of microbes, such as blood, cerebrospinal fluid (CSF), bone, and internal organs.

Viremia

The presence of viruses in the blood.

Fungemia

The presence of fungi in the blood.

Bacteremia

The presence of bacteria in the blood.

Sepsis (Septicemia)

A severe medical condition where organisms are actively multiplying in the blood, leading to a systemic inflammatory response.

Septic shock

A dramatic drop in blood pressure due to the uncontrolled inflammatory response of sepsis, which may be fatal.

Transmission (Infection Step)

The first step in causing an infection, involving the spread of a pathogen to a host.

Adherence (Infection Step)

The process by which microbes gain a more stable foothold on or in a host.

Invasion (Infection Step)

The third step in causing an infection, where a pathogen breaches anatomical barriers.

Colonization (Infection Step)

The multiplication of microbes in the body once established.

Exit (Infection Step)

The final step in an infection, where microbes leave the host body.

Noncommunicable disease

A disease that is not spread from one host to another.

Communicable disease

A disease that is spread from one host to another.

Contagious infection

A communicable infection where the spread from one host to another is rapid.

Vertical transmission

The transmission of a disease from parent to offspring via ovum, sperm, placenta, or milk.

Horizontal transmission

The spread of a disease through a population from one infected individual to another.

Direct contact transmission

The physical contact between an infected individual and another person (e.g., touching, kissing, sex, animal bites).

Indirect contact transmission

Disease transmission from a reservoir to a fomite and then to a new host.

Droplet transmission

Transmission that occurs when large droplets from the mouth or nose enter the air and land on another person.

Airborne transmission (Vehicle)

A type of vehicle transmission where small droplets or dust particles float in the air for an extended period, spreading infection.

Waterborne transmission (Vehicle)

A type of vehicle transmission typically from drinking water contaminated with sewage.

Foodborne transmission (Vehicle)

A type of vehicle transmission that results from improperly prepared or stored food.

Biological vector

A live animal, usually an arthropod, that transmits an infectious agent and serves as a site for pathogen multiplication or completion of its life cycle.

Mechanical vector

A live animal, usually an arthropod, that merely transports a pathogen without being infected itself.

Adhesins

Specific components of pathogens that bind to complementary receptors on host cells, enabling adherence.

Glycocalyx

A viscous, gelatinous, and sticky outer layer used by pathogens for adherence and to prevent phagocytosis.

Exotoxins

Bacterial virulence factors made inside bacterial cells then secreted, capable of harming the host even without the bacteria present.

Neurotoxins

Exotoxins that affect the nervous system, often causing paralysis.

Enterotoxins

Exotoxins that affect the gastrointestinal tract, causing symptoms like vomiting and diarrhea.

Cytotoxins

Exotoxins that interfere with general cell function or cause cell lysis.

LD50 (Lethal Dose 50%)

The amount of toxin that is lethal for 50% of the sample population, used to measure toxin potency.

Fecal-Oral Route

A mode of transmission where a host contaminates a surface or food with feces, and another person ingests the fecal microbes.

Local infection

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

Systemic infection

An infection where the infectious agent has spread or disseminated throughout the body.

Nosocomial infection

An infection acquired while receiving treatment in a health care facility.

Incubation period

The interval between the initial infection and the first appearance of signs and symptoms.

Pandemic

An epidemic that has spread to multiple countries or continents across the world.