Listeria, Erysipelothrix, and other gram-positive bacilli

• Aerobic
  
• Gram-positive bacilli
  
• Resembles Corynebacterium organisms
  
• Including:
  
  • Listeria
    
  • Erysipelothrix
    
  • Arcanobacterium
    
  • Gardnerella
    
• LISTERIA:
  
  • Capable of causing meningitis and bacteremia
    
  • Small coccobacilli may resemble:
    
    • Corynebacteria
      
    • Gram positive diplococci(e.g., Strep pneumoniae,, enterococcus)
      
  • Characteristic tumbling motion
    
  • Attack specific populations:
    
    • Neonates
      
    • Elderly
      
    • Pregnant women
      
    • Immunocompromised (cell-mediated)
      
• Erysipelothrix
  
  • E. rhusiopathiae
    
  • Ubiquitous
    
  • Eryssipeloid is an occupational disease: swine and fish workers
    
  • Absence of motility and catalase difference between Listeria
    
• Arcanobacterium
  
  • A. haemolyticus
    
  • Causes pharyngitis with or without scarlet-like fever
    
• Gardnerella
  
  • G. vaginalis
    
  • Part of the normal vaginal flora
    
  • The number of Gardnerella and other obligate anerobes (Bacteroides, Mobiluncus, and peptostreptococcus) significantly increases in bacterial vaginosis