Micro Chapter 15 & 16

Microbial Mechanisms of Pathogenicity

Study of how pathogens cause diseases and spread through various mechanisms.

Dynamic Equilibrium

The balance of interactions between host health and microbial populations.

Normal Flora

Beneficial microorganisms that reside in the human body without causing disease.

Incubation Period

The period between exposure to the pathogen and the appearance of symptoms.

Prodromal Stage

Onset of general symptoms indicating the start of infection.

Period of Illness

Stage when specific symptoms manifest and active disease is present.

Convalescent Period

Recovery stage where the body returns to health after illness.

Epidemiology

The scientific study of how diseases spread and affect populations.

Pathology

Study of diseases, their causes, and effects on the organism.

Etiology

Investigation into the origins and reasons behind diseases.

Pathogen

Microorganisms, including bacteria, viruses, fungi, and parasites, that can cause disease.

Pathogenesis

Study of the development and progression of diseases.

Infection

Successful colonization of a host by pathogens.

Disease

An abnormal condition affecting normal bodily functions with specific symptoms.

Sign

Objective indication of disease that can be observed or measured.

Symptom

Subjective experience or change in bodily function reported by the patient.

Syndrome

A cluster of signs and symptoms indicating a particular disease or condition.

Cytopenia

Reduction in blood cells.

Hepatitis

Inflammation of the liver.

Infectious Diseases

Result from the action of pathogens invading the body.

Noninfectious Diseases

Conditions not caused by pathogens, often resulting from genetics or lifestyle.

Plasmodium falciparum

The organism responsible for malaria.

Sickle Cell Disease

A genetic disorder characterized by abnormal hemoglobin.

Communicable Diseases

Infectious diseases that can be transmitted from one person to another.

Noncommunicable Diseases

Conditions not spread through person-to-person contact.

Latrogenic Diseases

Disorders caused by medical treatment or procedures.

Zoonotic Diseases

Diseases transmitted from animals to humans.

Acute Disease

Characterized by a rapid onset and short duration.

Chronic Disease

Develops slowly and can last for long periods, often years.

Latent Disease

Pathogen is dormant but can reactivate and cause symptoms later.

Koch's Postulates

Criteria for establishing a causal relationship between a pathogen and a disease.

Normal Microbiota

Beneficial microorganisms that coexist in mutualistic relationships with the host.

Sterile Sites

Anatomical locations within the body typically free from microorganisms.

Microbial Antagonism

The protective role of normal flora against harmful microbes.

Primary Pathogens

Infectious agents causing disease in healthy individuals.

Opportunistic Pathogens

Microorganisms that cause disease only in a weakened immune system.

Infectious Dose (ID)

Minimum number of pathogens needed to establish an infection.

Pathogenicity

The inherent ability of a pathogen to cause disease.

Virulence

The degree of pathogenicity, determined by specific attributes of the pathogen.

Virulence Factors

Traits that enhance a pathogen's ability to invade hosts and induce damage.

Antiphagocytic Factors

Mechanisms by which pathogens evade phagocytosis.

Exoenzymes

Enzymatic substances produced by pathogens to aid in invasion.

Endotoxins

Part of the bacterial cell wall; induce general symptoms.

Exotoxins

Secreted by bacteria; cause specific cellular damage.

Cholera Toxin

Disrupts ion transport in intestinal cells.

Tetanus Toxin

Prevents muscle relaxation and causes sustained contractions.

Diphtheria Toxin

Inhibits protein synthesis in host cells.

Stages of Pathogenesis

Process through which a pathogen leads to disease.

Exogenous Pathogens

Microbes entering the body from the external environment.

Endogenous Pathogens

Microbes originating from within the host.

TORCH Infections

Pathogens causing complications during pregnancy.

Glycocalyx

A characteristic allowing pathogens to adhere effectively to body cells.

Localized Infection

Infection confined to one area (e.g., boil).

Systemic Infection

Infection that spreads throughout the body (e.g., flu).

Focal Infection

Infection starting in one location then spreading to others.

Primary Infection

Initial infection.

Secondary Infection

Infection resulting from an initial infection.

Portals of Exit

Methods by which pathogens exit their host.

Epidemiological Terminology

Key terms related to the study of disease impact and spread.

Morbidity

Rate of illness related to specific diseases.

Mortality

Rate of death related to specific diseases.

Incidence

Measure of new cases of a disease within a population.

Prevalence

Measure of existing cases of a disease within a population.

Endemic Diseases

Present in a population at relatively stable rates.

Sporadic Cases

Occasional cases occurring irregularly.

Epidemic

Rapid increase in disease occurrence above normal levels.

Pandemic

Global spread of a disease affecting multiple countries.

Reservoir

Natural habitat in which a pathogen thrives.

Carrier

Individual who harbors a pathogen and can spread it, may be symptomatic or asymptomatic.

Direct Transmission

Spread of disease via immediate contact between individuals.

Indirect Transmission

Infection transmitted through contaminated surfaces or materials.

Airborne Transmission

Pathogens suspended in air and inhaled by hosts.

Waterborne Transmission

Spread of pathogens through contaminated water sources.

Foodborne Transmission

Spread of pathogens through improperly prepared food.

Biological Vectors

Organisms that play a role in the lifecycle of pathogens.

Mechanical Vectors

Transport pathogens without being part of the pathogen life cycle.

Healthcare-Associated Infections (HAIs)

Infections acquired in medical settings, often due to increased patient vulnerability.