Gram Positive Bacilli Rapid Review

Flashcards created from the lecture notes on Gram Positive Bacilli, covering key organisms, their traits, diseases, and treatments.

What is the oxygen requirement for Bacillus anthracis?

Aerobic

What are the key morphological traits of Bacillus anthracis?

Non-motile, boxcar-shaped rods, 'Medusa head' colonies, capsule (poly-D-glutamate)

What major disease is caused by Bacillus anthracis?

Anthrax (cutaneous, pulmonary 'Woolsorter's,' GI)

What is a common source of Bacillus anthracis spores?

Spores from soil and animal products (wool, hides)

What are the virulence factors of Bacillus anthracis?

Anthrax toxin = PA + EF + LF (increases cAMP → edema; LF → necrosis)

How is Bacillus anthracis diagnosed?

Gram stain, BAP (non-hemolytic), Ascoli test, PCR

What is the recommended treatment for Bacillus anthracis infection?

Ciprofloxacin / Doxycycline; vaccine for high-risk groups

What is the oxygen requirement for Bacillus cereus?

Aerobic

What are the key traits of Bacillus cereus?

Motile rods, β-hemolytic, grows in 7% NaCl, associated with 'reheated fried rice'

What major diseases does Bacillus cereus cause?

Food poisoning (emetic, diarrheal), eye/CNS/systemic infections

What is a common transmission source for Bacillus cereus?

Spores in reheated rice, meat, and vegetables

What are the virulence factors of Bacillus cereus?

Emetic toxin (heat-stable), Enterotoxin (heat-labile), phospholipases

How is Bacillus cereus diagnosed?

Clinical culture on BAP/SDA

What is the treatment for Bacillus cereus food poisoning?

Supportive; for severe cases: Clindamycin, Aminoglycosides

What is the oxygen requirement for Clostridium botulinum?

Anaerobic

What are the key morphological traits of Clostridium botulinum?

Large rods, spores in food ('bulging cans')

What major disease is caused by Clostridium botulinum?

Botulism (flaccid paralysis), Infant botulism ('floppy baby')

What is a common source of Clostridium botulinum spores?

Improperly canned/vacuum-packed food, honey (in infants)

What are the virulence factors of Clostridium botulinum?

Botulinum neurotoxin (A–G): blocks ACh release → paralysis

How is Clostridium botulinum diagnosed?

Detect toxin in serum/stool/food; mouse bioassay

What is the treatment for botulism caused by Clostridium botulinum?

Antitoxin (A,B,E), ventilation, avoid honey in infants

What is the oxygen requirement for Clostridium tetani?

Anaerobic

What are the key morphological traits of Clostridium tetani?

Drumstick / tennis racket shape, swarming

What major disease does Clostridium tetani cause?

Tetanus (spastic paralysis, lockjaw, risus sardonicus, opisthotonos)

What is the common mode of transmission for Clostridium tetani?

Spores from soil enter wounds, umbilical stump

What is the virulence factor of Clostridium tetani?

Tetanospasmin: blocks GABA & glycine → spasm

How is Clostridium tetani diagnosed?

Clinical diagnosis

What is the treatment for tetanus caused by Clostridium tetani?

Debridement + Penicillin + TIG; Toxoid vaccine (DTP)

What is the oxygen requirement for Clostridium perfringens?

Anaerobic

What are the key morphological traits of Clostridium perfringens?

Boxcar-shaped rods, double-zone hemolysis, stormy fermentation

What major diseases does Clostridium perfringens cause?

Gas gangrene (myonecrosis), food poisoning

What is a common source of Clostridium perfringens infection?

Soil contamination, wounds, contaminated food

What are the virulence factors of Clostridium perfringens?

Alpha toxin (lecithinase), theta toxin, enterotoxin

How is Clostridium perfringens diagnosed?

Gram stain, culture (egg yolk agar, milk stormy fermentation)

What is the treatment for Clostridium perfringens gas gangrene?

Surgery + Penicillin + Hyperbaric O₂; food poisoning = supportive

What is the oxygen requirement for Clostridium difficile?

Anaerobic

What are the key morphological traits of Clostridium difficile?

Non-motile rods, pseudomembrane in colon

What major diseases does Clostridium difficile cause?

Pseudomembranous colitis, antibiotic-associated diarrhea

What is a common cause of Clostridium difficile infection?

After broad-spectrum antibiotics (clindamycin, cephalosporins, fluoroquinolones)

What are the virulence factors of Clostridium difficile?

Toxin A (enterotoxin), Toxin B (cytotoxin)

How is Clostridium difficile diagnosed?

Stool toxin assay, PCR, colonoscopy

What is the treatment for Clostridium difficile infection?

Stop antibiotic, Metronidazole / Oral Vancomycin, FMT (for recurrent cases)

What is the oxygen requirement for Corynebacterium diphtheriae?

Aerobic

What are the key morphological traits of Corynebacterium diphtheriae?

Club-shaped rods, 'Chinese letters,' Babes-Ernst granules

What major disease does Corynebacterium diphtheriae cause?

Diphtheria (respiratory pseudomembrane, myocarditis, neuropathy)

What is the common transmission method for Corynebacterium diphtheriae?

Droplet/contact from carriers

What is the virulence factor of Corynebacterium diphtheriae?

Diphtheria toxin: inhibits EF-2 → stops protein synthesis

How is Corynebacterium diphtheriae diagnosed?

Loeffler’s/tellurite medium (black colonies), Elek’s test

What is the treatment for diphtheria caused by Corynebacterium diphtheriae?

Antitoxin + Penicillin / Erythromycin; DPT vaccine

What is the oxygen requirement for Erysipelothrix rhusiopathiae?

Aerobic

What are the key morphological traits of Erysipelothrix rhusiopathiae?

Thin, Gram (+/variable), 'test tube brush,' H₂S (+)