Pathogenic Bacteria, Toxins, and Associated Diseases

Comprehensive vocabulary flashcards detailing major bacterial pathogens, their transmission modes, virulence factors, toxins, and associated diseases from the lecture.

Campylobacter jejuni

A foodborne pathogen transmitted via the fecal-oral route that infects the small intestine and typically causes bloody dysentery.

Campylobacter fetus

A livestock pathogen that causes spontaneous abortion in cattle, sheep, and other farm animals.

Helicobacter pylori

A short, spheroid, Gram-negative bacterium that colonizes the stomach lining and causes gastric ulcers and potential stomach cancer.

Urease

An enzyme produced by Helicobacter pylori that breaks down urea into ammonia and carbon dioxide, neutralizing acid and liquefying the stomach's protective mucus layer.

Terry Marshall

An Australian microbiologist who proved in the 1980s that Helicobacter pylori causes stomach ulcers by ingesting a broth culture of the bacterium.

Borrelia burgdorferi

A Gram-negative spirochete bacterium transmitted by deer ticks that serves as the primary causative agent of Lyme disease.

Bull's-Eye Rash

A characteristic target-patterned rash featuring a central red spot encircled by an outer red ring that can appear at the site of a Borrelia burgdorferi tick bite.

Treponema pallidum

A Gram-negative spirochete bacterium that is sexually transmitted and causes syphilis.

Chancre

An open sore that develops at the site of infection during the primary stage of syphilis before eventually healing.

Latent Stage

A phase in chronic infections, such as syphilis, where the pathogen persists within the host without causing visible signs or symptoms.

Gummas

Soft tissue growths developed by the host body during tertiary syphilis in an attempt to contain the persistent pathogen.

Chlamydia trachomatis

An obligate intracellular bacterium that causes chlamydia, the most common bacterial sexually transmitted infection.

Reticulate Body

The intracellular form of Chlamydia trachomatis that actively replicates and divides inside the host cell but cannot survive outside of it.

Elementary Body

The infectious, extracellular form of Chlamydia trachomatis that is resistant to drying, capable of surviving outside the host cell, and responsible for transmitting the infection.

Trachoma

An eye infection caused by Chlamydia trachomatis that represents the leading non-genetic cause of blindness worldwide.

Genus Clostridium

A genus of Gram-positive, endospore-forming soil bacteria that are obligate anaerobes requiring an oxygen-free environment.

Botulinum Toxin

An extremely potent AB exotoxin produced by Clostridium botulinum that targets excitatory neurons and cleaves synaptobrevin, resulting in flaccid paralysis.

Synaptobrevin

A neuronal protein required for synaptic vesicles to release neurotransmitters, which is cleaved and destroyed by botulinum toxin and tetanospasmin.

Infant Botulism

A form of botulism (floppy baby syndrome) occurring when infants ingest Clostridium botulinum endospores—often from honey—which germinate in the gut due to a lack of competing normal flora.

Tetanospasmin

An AB exotoxin produced by Clostridium tetani that targets inhibitory neurons and damages synaptobrevin, preventing muscle relaxation and causing spastic paralysis (lockjaw).

Alpha Toxin

A phospholipase exotoxin secreted by Clostridium perfringens that degrades phospholipids in plasma membranes, causing cell lysis and extensive tissue necrosis.

Gas Gangrene

A condition caused by Clostridium perfringens characterized by blackened, necrotic tissue and subcutaneous gas bubbles produced by bacterial fermentation.

Crepitus

A popping or crackling sound and sensation caused by gas bubbles bursting within tissues during a Clostridium perfringens infection.

Necrotizing Fasciitis

A rapidly spreading, severe infection—commonly referred to as 'flesh-eating bacteria'—that causes necrosis of the connective tissue (fascia) binding muscles together.

Clostridioides difficile

An endospore-forming, obligate anaerobic bacterium that causes severe, recurring diarrhea, typically emerging after antibiotic use eliminates competing intestinal normal flora.