Gram Positive Rods

  1. Medically Important Gram Positive Rods (Aerobic)
    • Bacillus
    • Corynebacterium
    • Erysipelothrix
    • Listeria
    • Gardnererlla
  2. Bacillus Virulence Factors
    • Endospores
    • Enterotoxins
  3. Etiological Agent of Anthrax
    B. anthracis
  4. Clinical Presentations of Anthrax
    • Cutaneous
    • Gastroenteritis
    • Inhalation (100% fatality)
  5. Clinical Presentations of B. cereus
    • Gastroenteritis (mediated by enterotoxins)
    • Ocular (rapid, progressive destruction following trauma)
  6. Severity of B. Cereus Gastroenteritis
    • Mild, self-limiting disease.
    • N/V or diarrhea.
    • Often ignored as food bug
  7. Etiological Agent of Diphtheria
    Corynebacterium diphtheriae
  8. Diphtheroids
    Non-pathogen species that often find their way into lab media
  9. Microscopic Morphology of Erysipelothrix
    Small, thin rods that form long filaments
  10. Microscopic Morphology of Listeria
    Small, paired coccobacilli
  11. Erysipelothrix associated with human disease
    E. rhusiopathiae
  12. Ersipelothrix disease
  13. #1 Cause of mortality in foodborne illnesses
    Listeria monocytogenes
  14. Methods of transmission for Listeria monocytogenes
    • Contaminated food (unpasteurized milk)
    • Vertical
    • zoonotic.
  15. Medically Important Gram Positive Rods
    • Actinomyces
    • Clostridium
    • Lactobacillus
    • Mobiluncus
    • Propionibacterium
  16. Gram positive Rod genus with filamentous morphology
    Actinomyces (resembles hyphae)
  17. Actinomyces species most commonly involved in human infections
    A. israelii
  18. Spore forming genera
    • Bacillus
    • Clostridium
  19. Virulence of serotypes of Clostridium perfringens
    • 5 serotypes
    • type A most responsible for human disease
  20. Virulence factors of Clostridium perfringens
    • Arsenal of toxins known as lethal toxins.
    • A-toxin (lecithinase)
  21. Virulence factors of C. tetani
    • Hemolysin
    • neurotoxin (tetanospasmin) responsible for clinical expression of tetanus by blocking neurotransmitter release
  22. Clinical presentations of botulism
    • Food borne (foods with low acid content)
    • infant botulism (used to be caused by giving kids honey)
    • Wound botulism
  23. Virulence factors of C. diff
    • Enterotoxin
    • Cytotoxin
  24. Clinical presentations of Lactobacillus
    • Transient bacteremia
    • Endocarditis
    • opportunistic septicemia
  25. Gram staining of Mobiluncus and Gardnerella
    On gram stain appear Gram - or gram variable, but have a gram positive cell wall, show antibiotic susceptibility similar to Gram + bacteria, lack endotoxin.
  26. Colonization of Mobiluncus and Gardnerella
    Colonize female genital tract in large numbers
  27. Most medically important species of Propionibacterium
    P. acnes.
Card Set
Gram Positive Rods
Gram Positive Rods