Corynebacterium

Corynebacterium Species commonly associated with human disease
Organism	Diseases
C. diphteriae	Diphteria(respiratory, cutaneous)
C. jeikeium (Group JK)	Septicemia, soft tissue infections, other opportunistic infections
C. urealyticum	UTI, opp inf
C. minutissimum	Erythrasma, opp inf
C. Xerosis	Opp inf
C. pseudodiphtericum	Endocarditis, opp inf
C. Striatum	Opp inf

• Non-spore forming
  
• Gram positive bacilli
  
• Called also diphteorids
  

Similar bacterias:

Nocardia

Rhodococcus

Mycobacterium

Bacillus

• Endospore-forming bacteria classified in the family of Bacillaceae
  
• 2 clinically important genera:
  
  • Bacillus
    
  • Clostridium
    
• Aerobic
  
• Most are motile
  
• Catalase positive
  
• Saprophyte
  
• Found in soil worldwide
  

Bacilus Species
ORGANISM	DISEASE
B. anthracis	Anthrax (cutaneous, inhalation, GI)
B. Cereus	Gastroenteritis(emetic, diarrhea), ocular infections, catheter-related spesis, opp
B. circulans	Opportunistic infections
B. licheniformis	Opportunistic infections
B. subtilis	Opportunistic infections

Enterococcus and Other Gram positive Cocci

Classification of Streptococci

Lancfield Group	Representative	Hemolytic	Typical Infections
A	S. pyogenes	β	Pharyngitis, impetigo, cellulitis, scarlet fever
B	S. agalactiae	β	Neonatal sepsis and meningitis, puerperal infection, urinary tract infection, diabetic ulcer infection, endocarditis
C, G	S. dysgalactiae subsp. equisimilis	β	Cellulitis, bacteremia, endocarditis
D	Enterococci: E. faecalis; E. faecium	Usually nonhemolytic	Urinary tract infection, nosocomial bacteremia, endocarditis
	Nonenterococci: S. bovis	Usually nonhemolytic	Bacteremia, endocarditis
Variable or non goupable	Viridans streptococci: S. sanguis; S. mitis	α	Endocarditis, dental abscess, brain abscess
	Intermedius or milleri group: S. intermedius, S. anginosus, S. constellatus	Variable	Brain abscess, visceral abscess
	Anaerobic streptococci: Peptostreptococcus magnus	Usually nonhemolytic	Sinusitis, pneumonia, empyema, brain abscess, liver abscess

Staphylococcus and related organisms

• Catalase-positive genera:
  
  • Staphylococcus
    
  • Micrococcus
    
  • Stomatococcus
    
• Catalase-negative genera:
  
  • Streptococcus
    
  • Enterococcus
    
  • Others
    
• Staphylococcus:
  
  • Nonmotile
    
  • Facultatively anaerobic
    
  • Catalase positive
    
  • Grow in medium containing 10% sodium chloride
    
  • S. aureus colonies are golden, coagulase positive
    
  • Coagulase negative Staphylococcus:
    
    • Epidermidis
      
    • Saprophyticus
      
    • Haemolyticus
      
    • Lugdunensis
      
    • Schleiferi
      
  • Micrococcus almost invariably represents contamination with skin flora
    
  • Stomatococcus mucilaginosus may cause endocarditis, septicemia, and catether related infections
    
    • Mucoid capsule allows adherence to catheters, shunts, valaves, joints.
      

    Human Colonization and diseases
    

Species	Human Colonization	Human disease
Stapylococcus
S. aureus S.epidermidis S.saprophyticus	Common Common Common	Common Common Common
S.haemolyticus S.lugdunensis S.schleiferi	Common Common Common	Uncommon Uncommon Uncommon
S.saccharolyticus S.warneri S. hominis S.auricularis S. xylosus S.simulans S.capitis S.cohini	Common Common Common Common Common Common Common Common	Rare
Micrococcus	Human Colonization	Human disease
M. luteus M.varians	Common	Rare
M.agilis M.kristinae M.lylae M.roseus M.Sedentarius	Uncommon	Rare
Stomatococcus mucilaginosus	Common	Uncommon

Brainstorming infectious diagnosis

When brainstorming bacterial diagnosis think:

Bacteria:

1. Gram positive Cocci
   
2. Gram negative Cocci
   
3. Gram positive bacilli
   
4. Gram negative bacilli
   
5. Anaerobes
   
6. Fungi-like
   
7. Spirochetes
   
8. Atypicals
   
9. Mycobacteria
   
10. Zoonosis(ticks, mosqitos, birds, dogs, cats, meats…)
    
11. STD
    
12. Travel related
    

    Viruses
    

    Fungi:
    

    endemic v/s opportunistic
    

    Parasites

Gram-Negative Cocci and Bacilli

Aerobic Gram negative Cocci	Anaerobic Cocci
Neisseriaceae Neisseria species Moraxella Moraxella Branhamella	Megasphaera species Veillonella species
Aerobic Gram-negative Bacilli	Anerobic Gram-negative Bacilli
Enterobacteriaceae Citrobacter Enterobacter Escherichia Klebsiella Morganella Proteus Salmonella Shigella Serratia Yersinia Vibrionaceae Vibrio species Aeromonadaceae Aeromonas species Plesiomonadaceae Plesiomonas Campylobacteriaceae Campylobacter Arcobacter Pasteurellaceae Haemophilus Actinobacillus Pasteurella Legionellaceae Legionella Miscellaneous genera Acinetobacter Bartonella Bordetella Brucellae Burkholderia Calymmatobacterium Cardiobacterium Eikenella Francisella Helicobacter Kingella Pseudomonas Spirillium Streptpbacillus	Fusobacterium Bacteroides Bilophila Parphyromonas Prevotella