Micro 28 Flashcards

Which morphology describes Campylobacter?

_______-shaped _______-negative rod

Which Campylobacter species most commonly cause gastroenteritis?

A) C. fetus and H. pylori

B) C. fetus and C. coli

C) C. jejuni and C. coli

D) C. fetus and C. jejuni

Which Campylobacter species causes septicemia and meningitis?

A) C. fetus

B) C. jejuni

C) C. jejuni O:19

D) C. coli

Which growth conditions favor C. jejuni?

A) 42°C with 15–20% oxygen

B) 30–37°C with 5–7% oxygen

C) 42°C with 5–7% oxygen

D) 30–37°C with 15–20% oxygen

Which capsule molecules characterize C. jejuni and H. pylori, respectively?

A) Lipopolysaccharide; lipooligosaccharide

B) Lipopolysaccharide; lipopolysaccharide

C) Lipooligosaccharide; lipooligosaccharide

D) Lipooligosaccharide; lipopolysaccharide

Which bacterial component has endotoxin activity according to the notes?

A) Lipooligosaccharide (LOS)

B) CagA protein

C) Lipopolysaccharide (LPS)

D) S protein

Which small-intestinal region is most commonly affected by C. jejuni?

A) Terminal ileum

B) Jejunum

C) Ileum

D) Duodenum

What epithelial lesion can C. jejuni cause in the jejunum?

A) Villous atrophy

B) Mucosal polyps

C) Crypt abscesses

D) Glandular hyperplasia

Which C. jejuni serotype is associated with Guillain-Barré syndrome?

A) O:18

B) O:11

C) O:16

D) O:19

What mechanism explains C. jejuni-associated Guillain-Barré syndrome?

A) LOS–ganglioside cross-reactivity produces neural antibodies

B) S protein activates complement against neurons

C) CagA disrupts neural cytoskeletal structure

D) IL-8 directly destroys nerve gangliosides

Which host phenotype is associated with C. jejuni reactive arthritis?

A) RAD51

B) O:19

C) HLA-B27

D) p53

Which heat-stable factor protects C. fetus against complement?

A) Urease

B) S protein

C) CagA

D) IL-8

What food exposure commonly transmits C. jejuni?

A) Raw seafood

B) Undercooked beef

C) Unwashed produce

D) Undercooked poultry

Which diarrhea is associated with C. jejuni gastroenteritis?

A) Fatty malabsorptive diarrhea

B) Bloody diarrhea

C) Watery nonbloody diarrhea

D) Painless nonbloody diarrhea

Which condition can C. jejuni mimic with right lower quadrant pain?

A) Appendicitis

B) Gastritis

C) Cholecystitis

D) Pancreatitis

Which stool finding supports C. jejuni infection?

A) Round, clustered cocci

B) Thin, S-shaped organisms

C) Thick, straight rods

D) Large, branching bacilli

Which antibiotics are first-line for C. jejuni?

A) Erythromycin or azithromycin

B) Tetracyclines or fluoroquinolones

C) Clarithromycin or amoxicillin

D) Omeprazole or clarithromycin

Which antibiotic groups are secondary options for C. jejuni?

A) Omeprazole or clarithromycin

B) Erythromycin or azithromycin

C) Clarithromycin or amoxicillin

D) Tetracyclines or fluoroquinolones

Which organ does H. pylori most commonly infect?

A) Colon

B) Stomach

C) Esophagus

D) Jejunum

Which enzyme is positive in H. pylori and enables urea metabolism?

A) Urease

B) Catalase

C) Oxidase

D) Amylase

Which additional enzyme results characterize H. pylori?

A) Catalase-negative; oxidase-negative

B) Catalase-positive; oxidase-negative

C) Catalase-negative; oxidase-positive

D) Catalase-positive; oxidase-positive

At what temperatures does H. pylori grow?

A) 20–25°C

B) 5–10°C

C) 30–37°C

D) 40–45°C

Which H. pylori factor disrupts epithelial cytoskeletal structure?

A) LOS

B) IL-8

C) CagA

D) S protein

Which mediator induced by H. pylori contributes to gastritis and gastric ulcers?

A) IL-2

B) IL-10

C) IL-4

D) IL-8

Which lymphoma can develop from H. pylori infection?

A) MALT lymphoma

B) Follicular lymphoma

C) Hodgkin lymphoma

D) Burkitt lymphoma

Which peptic ulcer locations are associated with H. pylori?

A) Gastric and colonic

B) Gastric and duodenal

C) Colonic and ileal

D) Duodenal and esophageal

Which H. pylori virulence factor raises gastric cancer risk?

A) Urease

B) CagA

C) LOS

D) S protein

Which stain is most sensitive for H. pylori on gastric biopsy?

A) Warthin-Starry silver stain

B) Wright stain

C) Gram stain

D) Acid-fast stain

Which breath-based test detects H. pylori?

A) Hydrogen breath test

B) Lactose breath test

C) Acetone breath test

D) Urea breath test

Which antibodies are detectable in H. pylori serology?

A) IgA and IgM

B) IgG and IgE

C) IgA and IgG

D) IgM and IgE

Why can H. pylori antibodies not distinguish active from past infection?

A) Antibodies disappear within days

B) Titers fluctuate hourly

C) Antibodies appear only after eradication

D) Antibodies persist for years

Which medications comprise H. pylori triple therapy?

A) Omeprazole, clarithromycin, amoxicillin

B) Clarithromycin, erythromycin, amoxicillin

C) Omeprazole, azithromycin, tetracycline

D) Azithromycin, tetracycline, fluoroquinolone