Microbial Mechanism of Pathogenicity and Host Defenses

Flashcards covering key vocabulary terms and definitions from Microbiology Unit V.

Infection

The invasion and multiplication of microorganisms in the body.

Disease

A pathological condition resulting from a sustained infection.

Sign

An objective observation of a disease, often measurable.

Symptom

A subjective experience reported by the patient.

Syndrome

A combination of signs and symptoms that occur together.

Infection vs Disease

Infection is the invasion of pathogens, while disease refers to the consequences of infection.

Signs vs Symptoms

Signs are observable evidence, while symptoms are felt experiences.

Infectious Infection

An infection caused by pathogens that can spread.

Communicable Infection

An infection that can be transmitted from one host to another.

Contagious Infection

A highly communicable infection that spreads easily.

Noncommunicable Infection

An infection that cannot be transmitted between individuals.

Noninfectious Infection

A condition not caused by pathogens.

Zoonotic Infection

An infection that is transmitted from animals to humans.

Iatrogenic Infection

An infection caused by medical interventions or treatments.

Nosocomial Infection

An infection acquired in a healthcare facility.

Stages of Disease

The phases through which a disease progresses.

Acute Disease

A disease with a rapid onset and short duration.

Chronic Disease

A long-lasting disease that develops slowly.

Latent Disease

A disease that is inactive but can reactivate.

Koch’s Postulates

Criteria to establish a causative relationship between a microbe and a disease.

Virulence

The degree of pathogenicity of a microbe.

Pathogenicity

The ability of a pathogen to cause disease.

LD50

The lethal dose of a toxin for 50% of a test population.

ID50

The infectious dose of a pathogen for 50% of a host population.

Primary Pathogen

A pathogen that can cause disease in a healthy host.

Secondary Pathogen

A pathogen that causes disease only in a compromised host.

Opportunistic Pathogen

A pathogen that exploits a weakened immune system.

Stages of Pathogenesis

The steps through which pathogens cause disease.

Local Infection

An infection confined to a specific area.

Systemic Infection

An infection that spreads throughout the body.

Focal Infection

An infection that starts locally but spreads to specific areas.

Portals of Entry

Routes through which pathogens enter the body.

Adhesins

Pathogen molecules that allow attachment to host tissues.

Biofilm

A complex aggregation of microorganisms adhering to a surface.

Extracellular Enzymes

Secreted enzymes by pathogens that aid in infection.

Toxins

Poisonous substances produced by pathogens.

Antigenic Drift

Minor antigen changes in a pathogen.

Antigenic Shift

Major changes in pathogen antigens.

Endotoxins

Toxins released upon the destruction of Gram-negative bacteria.

Exotoxins

Toxins secreted by living bacteria.

Role of CDC

To monitor and control disease outbreaks.

Role of WHO

To coordinate international public health efforts.

Epidemiology

The study of disease distribution and determinants.

Incidence

The number of new cases of a disease in a specified time.

Prevalence

The total number of cases of a disease in a population.

Morbidity

The state of being diseased or unhealthy.

Reservoir

A primary habitat where pathogens live and multiply.

Carrier

An individual who harbors a pathogen without showing symptoms.

Vertical Transmission

Transmission of pathogens from parent to offspring.

Horizontal Transmission

Transmission among individuals of the same generation.

Modes of Transmission

Methods through which pathogens spread.

Universal Precautions

Guidelines to prevent transmission of infections.

Inflammation

A localized tissue response to injury or infection.

Mechanical Barriers

Physical barriers that prevent pathogen entry.

Microbiome

The community of microorganisms living in and on the human body.

Chemical Defenses

Chemical substances that inhibit pathogen growth.

Cytokines

Proteins that mediate and regulate immunity.

Histamine

A compound released during allergic reactions and inflammation.

Leukotrienes

Mediators of inflammation and allergic responses.

Complement System

A group of proteins that assist in immune responses.

Natural Killer Cells

Immune cells that destroy infected or cancerous cells.

PAMPs

Pathogen-associated molecular patterns recognized by the immune system.

PRRs

Pattern recognition receptors that detect PAMPs.

TLRs

Toll-like receptors that play a key role in the immune response.

Pathophysiology

The study of the functional changes associated with disease.

Phagocytosis

The process by which cells engulf and digest pathogens.

Pyrogen

A substance that induces fever.

Fever

An elevated body temperature as a response to infection.