micro chapter 14

Microbiome

Organisms that colonize the body's surface without causing disease; microorganisms that live in and on the body.

Resident Microbiota

Normal microbiota that are present throughout life, mostly commensal.

Transient Microbiota

Microbiota that remain in the body for a short period; cannot persist due to competition, elimination by defense cells, or body changes.

Opportunistic Pathogens

Normal microbiota that can cause disease under certain circumstances.

Zoonoses

Diseases that are naturally spread from animals to humans.

Human Carriers

Humans with active diseases or who are asymptomatic but can still transmit diseases to others.

Nonliving Reservoirs

Infectious agents found in the environment, such as soil, water, and food.

Infection

A pathogenic organism evades the body's external defenses, multiplies, and establishes itself in the body.

Portals of Entry

Sites through which pathogens enter the body.

Symptoms

Subjective characteristics felt only by the patient.

Signs

Objective manifestations of disease that can be observed or measured by others.

Syndrome

A combination of symptoms and signs that characterize a disease.

Etiology

The study of the cause of disease.

Koch’s Postulates

A set of criteria established to prove that a specific pathogen causes a specific disease.

Virulence Factors

Characteristics of pathogens that enhance their ability to cause disease.

Exotoxins

Toxins released by pathogens that can cause damage to the host.

Endotoxins

Toxins that are part of the gram-negative bacteria's structure and released when bacteria die.

Epidemiology

The study of how diseases occur and spread within populations.

Endemic

A disease that normally occurs in a given area.

Epidemic

A disease that occurs at a greater than normal frequency in a given area.

Pandemic

An epidemic that occurs on more than one continent.

Incidence

The number of new cases of a disease in a given area during a specific time period.

Prevalence

The total number of cases of a disease in a given area during a specific time period.

Healthcare-Associated Infections (HAIs)

Infections that patients acquire while receiving treatment in a healthcare facility.