Haemophilus and other fastidious gram negative bacilli

• Reside in human oral mucosa; causes endocarditis

  • Haemophilus
  • Aggregatibacter
  • Cardiobacterium
  • Eikenella
  • Kingella
• PASTEURELLACEAE - Genera: Haemophilus, Actinobacillus, Pasteurella, and Aggregatibacter
• PASTEURELLACEAE - Gram (-), pleomorphic, coccoid to rod-shaped cells (Generally, bacilli)
• PASTEURELLACEAE - Nonmotile and facultative anaerobic Catalase and nitrate to nitrite reduction (+) Oxidase negative (-)
• HAEMOPHILUS SPP. - Derived from Greek word meaning, “blood-lover”
• Requirement for Haemophilus

  • X- Factor
  • V-Factor
• X- Factor - contains hemin or hematin [hemoglobin] (X for “unknown”)
• V-Factor contains nicotinamide adenine dinucleotide [NAD] (V for “vitamin”)
• Blood Agar Plate - this agar has V factor dependent Haemophilus spp. growth (-)
• Blood Agar Plate - this agar has RBC are still intact and contains NADase (hydrolyze V factor) [add blood when heat is already tolerable]
• Chocolate Agar Plate - agar Lysing of the red blood cells by heat
• Chocolate Agar Plate - that Releases both the X factor and the V factor
• Chocolate Agar Plate - in the making of this agar We add blood even if the mixture or medium is still hot
• Chocolate Agar Plate - this agar has inactivates NADase [enzyme which when present, can hydrolyze the NAD]
• Satellitism - to be done when you don’t have CAP
• Satellitism - Phenomenon without helps in the recognition of Haemophilus spp. that require V factor
• Satellitism - Occurs when Staphylococcus aureus, Streptococcus pneumoniae, or Neisseria spp. produce V factor
• in satellitism

  • Organisms: source of V factor
  • BAP: source of X factor
• Haemophilus influenzae - known as Pfieffer’s bacillus
• Virulence Factor of Haemophilus influenzae

  • Capsule
  • Immunoglobulin A Proteases
  • Adherence Mechanisms
• Capsular polysaccharide plays the most significant role in the virulence factor of haemophilus influenzae
• Capsule - virulence factor of haemophilus influenzae that has Antiphagocytic property and anticomplementary activity
• serologic group of capsule (Haemophilus influenzae)

  • a
  • b
  • c
  • d
  • e
  • f
• most invasive serotype of capsule of haemophilus influenzar?

  b (Hib - also known as)
• b - serotype that is Composed of ribose, ribitol, and phosphate (polyribitol phosphate)
• Only genus that produces IgA protease: H. influenzae
• NTHi means?

  Nontypable H. influenzae
• Immunoglobulin A Proteases - virulence factor of haemophilus influenzae that Cleave secretory IgA
• Adherence Mechanisms of haemophilus inflenzae

  • NTHi strains
  • Serotype B
• NTHi strains - Adherence Mechanisms that adhere to human epithelial cells
• NTHi strains - Adherence Mechanisms that cause localized infection
• Serotype B Adherence Mechanisms that does not adhere to human epithelial cells
• Serotype B - Adherence Mechanisms that cause systemic infections
• nontypable haemophilus inflenzae - non-encapsulated haemophilus influenzae
• INFECTION OF HAEMOPHILUS INFLUENZAE [ENCAPSULATED STRAINS]

  • Septicemia
  • Septic arthritis
  • Meningitis
  • Osteomyelitis
  • Cellulitis
  • Pericarditis
  • Pneumonia
  • Epiglottitis
• INFECTION OF HAEMOPHILUS INFLUENZAE [NONENCAPSULATED STRAINS]

  • Otitis media with effusion
  • Conjunctivitis
  • Sinusitis
  • Bacteremia
  • Pneumonia
• Haemophilus aegyptius - haemophilus spp that cause Acute conjunctivitis
• Haemophilus aegyptius - also known as Koch-Weeks bacillus
• Haemophilus aegyptius - haemophilus spp that Commonly referred as “pink eye” ® sore eyes
• Counterpart in virology [study of virus] of Haemophilus aegyptius - Adenovirus