Corynebacterium species — Flashcards

Flashcard 1: Which gram-positive bacteria contains granules that stain with aniline dyes (ie: methylene blue)?_____

Answer: Corynebacterium diphtheriae

Flashcard 2: The enterotoxins of Staphylococcus aureus are _____, therefore they have a rapid-onset of action

Answer: preformed

Flashcard 3: _____ is a filamentous-branching gram-positive organism that can cause brain abscess.

Answer: Nocardia

Flashcard 4: Staphylococcus epidermidis is gram _____

Answer: positive

Flashcard 5: Clostridium _____ results in rigid muscles

Answer: tetani

Flashcard 6: Which gram-positive rod produces an exotoxin that ADP-ribosylates EF-2?

Answer: Corynebacterium diphtheriae

Flashcard 7: Gas gangrene

Answer: Clostridium perfringens

Extra: alpha toxin causes myonecrosis and hemolysis

Flashcard 8: Gram stain status of Clostridium perfringens

Answer: Gram-positive (+)

Extra: Characteristics: - Morphology: Large, box-car shaped Gram-positive bacilli - Oxygen requirement: Anaerobe - Pathogenesis: Alpha toxin (lecithinase) - Clinical: Gas gangrene (myonecrosis), food poisoning

Flashcard 9: Characteristics of Clostridium botulinum:

Answer: Gram-positive bacilli, anaerobic, spore-forming

Extra: Clinical features: Botulism (descending paralysis), Floppy baby syndrome (infant botulism from honey). Toxin: Botulinum toxin (protease that cleaves SNARE proteins, preventing ACh release).

Flashcard 10: What are the key microbiological characteristics and toxins of Clostridium tetani?

Answer: Gram-positive, anaerobic, spore-forming bacilli (drumstick appearance)

Extra: - Tetanospasmin: Neurotoxin that blocks release of inhibitory neurotransmitters (GABA and glycine) from Renshaw cells in spinal cord. - Clinical features: Trismus (lockjaw), Risus sardonicus (raised brows, open grin), Opisthotonus (back arching). - Spores are found in soil; enter via penetrating wounds.