Spiral Bacteria and Enterobacteriaceae

Vocabulary practice flashcards covering medical bacteriology topics including spiral bacteria (Treponema, Borrelia, Leptospira, Campylobacter, Helicobacter) and the family Enterobacteriaceae.

Treponema pallidum

A slender, tightly coiled spirochete with endoflagella that causes syphilis, transmitted predominantly through sexual contact or transplacentally.

Chancre

A painless, indurated, highly infectious ulcerative lesion that typically develops at the site of inoculation during primary syphilis.

Condylomata Lata

Flat, moist, highly infectious wart-like papules rich in spirochetes that appear in intertriginous areas during secondary syphilis.

Gumma

A localized, destructive granulomatous lesion characteristic of tertiary syphilis that can form in the skin, bones, and internal organs.

Darkfield Microscopy

A diagnostic microscopic technique used to directly visualize live, motile Treponema pallidum spirochetes from primary or secondary lesion exudates.

VDRL and RPR

Nontreponemal serologic screening tests that detect reaginic antibodies directed against cardiolipin-lecithin-cholesterol antigen complexes.

FTA-ABS

Fluorescent Treponemal Antibody Absorption; a confirmatory treponemal serologic test used to detect specific antibodies against Treponema pallidum.

Jarisch-Herxheimer Reaction

An acute, self-limiting systemic inflammatory response characterized by fever, chills, and tachycardia occurring shortly after initiating antibiotic therapy for spirochetal infections.

Borrelia burgdorferi

A loosely coiled spirochete transmitted by Ixodes ticks that serves as the causative agent of Lyme disease.

Erythema Migrans

An expanding, annular, 'bull's-eye' erythematous skin rash characteristic of early localized stage 1 Lyme disease.

Borrelia recurrentis

A spirochete transmitted by the human body louse (Pediculus humanus) that serves as the etiologic agent of epidemic relapsing fever.

Antigenic Variation

The programmed genetic rearrangement and variable expression of surface outer membrane lipoproteins (variable major proteins) in Borrelia that produces recurrent cycles of bacteremia and fever.

Leptospira interrogans

A finely coiled, thin spirochete with hooked ends transmitted to humans via water or soil contaminated with infected animal urine.

Weil Disease

A severe, icteric form of leptospirosis characterized by profound jaundice, hepatic dysfunction, acute renal failure, and widespread hemorrhages.

Conjunctival Suffusion

Bilateral erythema of the bulbar conjunctiva occurring without inflammatory exudate, serving as a hallmark diagnostic finding in leptospirosis.

Campylobacter jejuni

A curved, gull-wing-shaped, microaerophilic Gram-negative rod that grows optimally at $42\,^\circ\text{C}$ and causes acute inflammatory diarrhea.

Guillain-Barré Syndrome

An acute post-infectious demyelinating polyneuropathy triggered by cross-reactive autoimmune antibodies against peripheral nerve gangliosides following Campylobacter jejuni enteritis.

Helicobacter pylori

A curved, spiral-shaped Gram-negative microaerophilic bacterium that colonizes the gastric antrum and is associated with chronic gastritis, peptic ulcers, and gastric carcinoma.

Bacterial Urease

A nickel-dependent metalloenzyme produced in large quantities by Helicobacter pylori that hydrolyzes urea into ammonia and carbon dioxide to neutralize gastric acidity.

Urea Breath Test

A non-invasive diagnostic method that detects active Helicobacter pylori colonization by measuring labeled $CO_2$ in expired air after oral ingestion of isotope-labeled urea.

Enterobacteriaceae

A large family of Gram-negative bacilli that are facultative anaerobes, ferment glucose, reduce nitrate to nitrite, and are oxidase-negative.

MacConkey Agar

A selective and differential medium containing bile salts and crystal violet that separates Gram-negative bacteria into lactose fermenters (pink) and non-fermenters (colorless).

Triple Sugar Iron (TSI) Agar

A differential slant medium containing glucose, lactose, sucrose, phenol red, and ferrous sulfate used to determine carbohydrate fermentation patterns and $H_2S$ gas production.

Salmonella enterica serovar Typhi

A motile, $H_2S$-producing Gram-negative bacillus containing a capsular Vi antigen that causes typhoid (enteric) fever and persists chronically in the gallbladder.

Shigella dysenteriae

A non-motile, non-lactose-fermenting, non-$H_2S$-producing Gram-negative rod with an extremely low infectious dose that produces Shiga toxin and causes bacillary dysentery.

Yersinia pestis

A non-motile Gram-negative coccobacillus with distinctive bipolar 'safety-pin' staining, transmitted by rodent fleas (Xenopsylla cheopis) to cause bubonic and pneumonic plague.

Yersinia enterocolitica

A psychrotrophic Gram-negative bacillus capable of replication at $4\,^\circ\text{C}$ that causes acute enteritis and mesenteric lymphadenitis mimicking acute appendicitis.

Proteus mirabilis

A peritrichously flagellated Gram-negative rod that exhibits dramatic swarming motility on solid media and produces potent urease, promoting struvite renal calculi.

Klebsiella pneumoniae

An encapsulated, non-motile, lactose-fermenting Gram-negative bacillus producing mucoid colonies, known for causing destructive lobar pneumonia with 'currant jelly' sputum.

IMViC Tests

A series of four biochemical assays (Indole, Methyl Red, Voges-Proskauer, and Citrate) used collectively to differentiate coliforms and other members of the family Enterobacteriaceae.