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• What is the family of Haemophilus?

  Pasteurellaceae

  
• What is the genus of Haemophilus?

  Haemophilus

  
• Name one species of Haemophilus.

  1. H.influenzae

  
• What type of bacteria is Haemophilus?

  Gram-negative coccobacilli

  
• What does "blood loving" refer to in Haemophilus?

  It indicates their requirement for growth factors from blood

  
• Are Haemophilus bacteria motile?

  No, they are non-motile
• What type of anaerobes are Haemophilus species?

  Facultative anaerobes
• What is the catalase and oxidase status of Haemophilus?

  Catalase positive

  Oxidase positive
• What is the "X" factor required by Haemophilus?

  Haemin, a component of elemental iron-containing part of hemoglobin.

  Heat stable

  Required for synthesis of cytochrome and other enzymes e.g. catalase, peroxidase, oxidase

  
• What is the "V" factor required by Haemophilus?

  NAD or NADP, a hydrogen acceptor

  Heat labile (destroyed at 120°C)

  Present inside RBCs

  Synthesised by some fungi and bacteria

  
• What is the growth requirement for Haemophilus species?

  Both X and V factors

  
• What are the general characteristics of Haemophilus species?

  • Blood loving
  • Gram-negative coccobacilli
  • Non-motile
  • Non-sporing
  • Facultative anaerobes
  • Catalase positive
• What is the main virulence factor of Haemophilus influenzae?

  Polyribosyl-ribitol phosphate (PRP)

  
• How does PRP contribute to virulence?

  It prevents phagocytosis and opsonization

  
• Who first described Haemophilus influenzae?

  Pfeiffer in 1892
• What are the capsular types of Haemophilus influenzae?

  Six capsular types: a-f

  
• What is the carrier rate for capsulated type b strains of Haemophilus influenzae?

  About 2-4%

  
• What infections are commonly caused by Haemophilus influenzae?

  Respiratory tract infections and otitis media
• How does the post-Hib vaccine era affect Haemophilus influenzae infections?

  Other capsulated forms are responsible for invasive disease

  
• What are the clinical implications of NTHi infections?

  • Part of normal microbial flora of the URT
  • Involved in respiratory tract infections
  • May cause invasive disease post-Hib vaccine

  
• What type of infections can Haemophilus influenzae cause?

  Localized and invasive infections

  
• What is the significance of mucociliary interactions in Haemophilus infections?

  Attachment to respiratory mucosa via adhesins

  
• What is the laboratory investigation specimen for Haemophilus influenzae?

  CSF, blood, pus aspirates

  
• Why must specimens for Haemophilus be cultured quickly?

  It does not retain viability for long
• What type of agar is used for culturing Haemophilus?

  Chocolate blood agar (CBA)

  
• What is the appearance of Haemophilus colonies on CBA?

  Semi-opaque, gray-white, convex, mucoid colonies
• What biochemical tests are positive for Haemophilus species?

  Catalase positive and oxidase positive
• What are the identification methods for Haemophilus species?

  • Growth factor requirements (X and V)
  • Satellitism
  • Biochemical tests
  • Serotyping
  • Molecular methods (PCR)

  
• What is the treatment for Haemophilus influenzae infections?

  1. Ampicillin,
  2. Chloramphenicol,
  3. Cephalosporins

  • Antimicrobial susceptibility testing important.
  • Increasing incidence of plasmid-mediated beta- lactamase production.

  
• What is the main method of prevention for Haemophilus infections?

  Vaccination with Hib conjugate vaccine
• What is the causative agent of Brazilian Purpuric Fever?

  Haemophilus influenzae biogroup aegyptius

  
• What are the symptoms of Brazilian Purpuric Fever?

  High fever

  Hemorrhagic skin lesions

  Abdominal pain

  Nausea

  Vomiting

  Septic shock

  Death

  
• What is the treatment for Brazilian Purpuric Fever?

  Ampicillin and cephalosporins

  
• What is the causative agent of chancroid?

  Haemophilus ducreyi

  May spread to other anatomical sites by autoinoculation.

  
• What is the clinical presentation of chancroid?

  Tender erythematous papule that ulcerates.

  In 50% of cases, painful, tender inguinal lymphadenitis.

  • Buboes may develop - lymphadenopathy- usually unilateral, spherical and painful

  «Lesions occur;

  • on prepuce and frenulum in men.
  • Vulva, cervix and perianal area in women.

  
• What are the methods used for diagnosis of Haemophilus ducreyi?

  Clinical history

  Specimen - Genital swab and culture

  Culture;

  - Fastidious

  -Needs special nutritive base (MH-HB, GC agar base, Iso Vitalex)

  Molecular methods- PCR
• What is the treatment for chancroid?

  Erythromycin, azithromycin, ceftriaxone

  
• What are the characteristics of HACEK organisms?

  • Fastidious, slow-growing, gram-negative bacteria
  • Normal flora in the oral cavity
  • Opportunistic microorganisms
  • Associated with bacterial endocarditis

  
• What does HACEK stand for?

  Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella

  
• What infections are associated with HACEK organisms?

  Bacterial endocarditis

  periodontal infections

  Peritonitis

  Otitis media

  Conjuctivitis

  Pneumonia

  Septic arthritis

  Osteomyelitis