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  2. 2. • Scientific classification • Kingdom: Bacteria • Phylum: Proteobacteria • Class:Gamma Proteobacteria • Order:Pasteurellales • Family:Pasteurellaceae • Genus:Haemophilus • Species:H. influenzae• Binomial name Haemophilus influenzae Dr.T.V.Rao MD 2
  3. 3. History• Pfeiffer 1892 Mistaken as causative of Human Influenza• Isolated by Smith, Andrewes and Laidlaw in 1933• Need one or both of Accessory growth factors X and V present in the Blood Dr.T.V.Rao MD 3
  4. 4. Overview- Haemophilus• Small• Non-motile• Gram-negative rods• Transmitted via respiratory droplets, or direct contact with contaminated secretions• Normal flora of the human respiratory tract and oral cavity. Dr.T.V.Rao MD 4
  5. 5. Haemophilus species of clinical importance1. H. influenzae -type b is an important human pathogen2. H. ducreyi -sexually transmitted pathogen (chancroid)3. Other Haemophilus are normal flora - H. parainfluenzae – pneumonia & endocarditis - H. aphrophilus – pneumonia & endocarditis - H. aegyptius – pink eye (purulent conjunctivitis) Dr.T.V.Rao MD 5
  6. 6. Haemophilus Influenza• Aerobic gram-negative bacteria• Polysaccharide capsule• Six different serotypes (a-f) of polysaccharide capsule• 95% of invasive disease caused by type b (Hib) Dr.T.V.Rao MD 6
  7. 7. Genus Haemophilus• Small, Non motile, Non sporing• Oxidase test positive• Pleomorphic• Gram Negative Dr.T.V.Rao MD 7
  8. 8. Haemophilus Influenza (Pfeiffer Bacillus )• The size is 3 x 0.3 microns• Gram negative• Non Motile• Non sporing• Pleomorphic• Appear as clusters or Coccobacillary forms in infected CSF• When isolated capsulated• Stained with Lofflers Dr.T.V.Rao MD 8 methylene blue
  9. 9. Microscopic Appearance by Gram staining Dr.T.V.Rao MD 9
  10. 10. Haemophilus influenza Dr.T.V.Rao MD 10
  11. 11. Haemophilus Species H. influenzae satellitism around and between the large, white, hemo lytic staphylococciHaemophilus species require hemoglobin for growth: X-factor ( hemin): Heat-stable substance V-factor (NAD): Heat- labile, coenzyme I, nicotinamide adenine dinucleotide, found in blood or secreted by certain organisms
  12. 12. Haemophilus InfluenzaeMode of Transmission: Droplet infection and discharge from the upper respiratory tract during the infectious period.Incubation Period Unknown, probably short, 2-4 days.Infectious Period - As long as the organism is present, even in the absence of nasal discharge. - Noninfectious within 24 to 48 hours after the start of effective antibiotics. MD Dr.T.V.Rao 12
  13. 13. Cultural Characteristics• Fastidious growth requirements• Factors X and V are essential for growth• X is Hemin heat stable• Porphyrins for synthesis of Cytochromes• V factor Coenzyme Nicotinamide adenine dinucleotide or NAD phosphate acts as hydrogen acceptor• Aerobic 370c• Grows in Blood agar Dr.T.V.Rao MD 13
  14. 14. H. influenzae on a blood agar plate.H. influenza, in a Gram stainof a sputum sample, appear as Gram-negative coccobacilli. Haemophilus influenza requires X and V factors for growth. In this culture Haemophilus has only grown around the paper disc that has been impregnated with X and V factors. There is no bacterial growth around the discs that only contain either X or V factor. Dr.T.V.Rao MD 14
  15. 15. Satellitisim• When Staph aureus is streaked across plate of Blood agar with a species containing H Influenza the colonies which are large develop along the streak of Staphylococcus and small further away Dr.T.V.Rao MD 15
  16. 16. Biochemical Characters• Glucose +• Xylose +• Lactose –• Sucrose –• Mannitol –• Nitrites reduced• Indole differs on• B type causes Meningitis Dr.T.V.Rao MD 16
  17. 17. Resistance• Heating at55 0cfor 30mt destroys• Drying and Disinfectants destroy Dr.T.V.Rao MD 17
  18. 18. Antigenic Properties• Contains 3 Major surface antigens 1 Capsular polysaccharide 2 Outer membrane proteins (OMP) 3 Lipopolysaccharides ( LPS ) Dr.T.V.Rao MD 18
  19. 19. Pittman Classification• The major antigenic determinant of capsulated strains into six capsular types type a to fTyping by agglutination Quelling reactions precipitation and co agglutination or ELISA 95% of H, Influenza isolates belong to type b Dr.T.V.Rao MD 19
  20. 20. Type b characteristics• Has unique characters contains Pentose sugars Ribose Ribitol, instead of Hexose in others and hexosamines The capsular polyribosyl ribitol phosphate ( PRP ) of Hib induces IgG IgM and IgA antibodies –Bactericidal and opsonic and protective. So Hib PRP employed for Immunization Dr.T.V.Rao MD 20
  21. 21. Haemophilus influenzae type b Clinical Features* Epiglottitis 17% Meningitis 50% Pneumonia 15% Osteomyelitis 2% Arthritis 8% Cellulitis Bacteremia 6% 2%*prevaccination era Dr.T.V.Rao MD 21
  22. 22. Non typable Strains• H Influenza lacking capsule are non typable are most relevant in clinical infections• Outer membrane proteins OMP of Hib are classified into 13 subtypes• H Influenza lipo polysaccharides are more complex• Genome of the organism is sequenced Dr.T.V.Rao MD 22
  23. 23. Pathogenicity• A Human pathogen• Can produce invasive and Non invasive lesions• Prominent organism in producing Meningitis• Can produce laryngoepiglottitis,Conjuctivitis,Bactereima Pneumonia, Arthritis Endocarditis, Pericarditis Dr.T.V.Rao MD 23
  24. 24. Most strains are opportunistic Pathogens• Most strains of H. influenza are opportunistic pathogens; that is, they usually live in their host without causing disease, but cause problems only when other factors (such as a viral infection or reduced immune function) create an opportunity. Dr.T.V.Rao MD 24
  25. 25. Most Important Clinical Illness associated with H influenzae Dr.T.V.Rao MD 25
  26. 26. Clinical PresentationPneumonia: Severe shortness of breath, rapid heart rate, fever, cough and evidence of pneumonia by chest radiograph.Septic Arthritis: Swelling, warmth, pain with movement and decreased mobility of a single large weight-bearing joint. Dr.T.V.Rao MD 26
  27. 27. Haemophilus influenzae type b Clinical Manifestations* E p ig lo ttitis 17% M en in g itis 50% P n eu m o n ia 15% O steo m yelitis 2% A rth ritis 8% C ellu litis B acterem ia 6% 2% Dr.T.V.Rao MD 27*prevaccination era
  28. 28. Haemophilus InfluenzaMode of Transmission: Droplet infection and discharge from the upper respiratory tract during the infectious period.Incubation Period Unknown, probably short, 2-4 days.Infectious Period - As long as the organism is present, even in the absence of nasal discharge. - Noninfectious within 24 to 48 hours after the start of effective antibiotics. MD Dr.T.V.Rao 28
  29. 29. Haemophilus influenza type b Meningitis• Accounted for approximately 50%-65% of cases in the prevaccine era• Hearing impairment or neurologic sequelae in 15%-30%• Case-fatality rate 2%-5% despite of effective antimicrobial therapy Dr.T.V.Rao MD 29
  30. 30. Secondary Infections• Respiratory tract infections,• Otitis media• Sinusitis• Chronic Bronchitis Dr.T.V.Rao MD 30
  31. 31. Haemophilus Meningitis• Carries a High Mortality of 90% if not treated• The Bacteria reach Meninges from nasopharynx Dr.T.V.Rao MD 31
  32. 32. Laryngo epiglottitis• Causes Epiglottis• Obstructive Laryngitis• > 2 years children are vulnerable• Can be fatal in 2 hours Dr.T.V.Rao MD 32
  33. 33. Pneumonia• Pneumonia along with Meningitis• Lobar Pneumonia• Bronchopneumonia• Can present with Empyema Dr.T.V.Rao MD 33
  34. 34. Suppurative Lesions• Arthritis• Endocarditis• Pericarditis• Haematogenous dissemination• Otitis Media• Cellulitis Dr.T.V.Rao MD 34
  35. 35. Laboratory Diagnosis• On Microscopy Gram Negative Pleomorphic organisms are seen• Capsulated with polysaccharide antigen in CSF• Urine also detect Antigen Dr.T.V.Rao MD 35
  36. 36. Culturing and Isolation• Can be grown on Blood agar and Chocolate agar• Need 5 – 10 % carbon dioxide• A streak of Staphylococcus should be streaked across the plate at 370c• Opaque colonies appear shows as Satellitisim• Iridescence Demonstrates on Leviathan medium• Blood culture Dr.T.V.Rao MD 36
  37. 37. Detection of Antigen• Capsular polysaccharide antigen can be detected in CSF of Meningitis and Urine from systemic infections• By Latex agglutination• Counter Immuno Electrophoresis Dr.T.V.Rao MD 37
  38. 38. Treatment• Cefotaxime• Ceftazidime• Ampicicillin, Contrimixazole• Plasmid born resistance set in Ampicillin• Amoxycillin with Clavulanate• Clarithromycin Dr.T.V.Rao MD 38
  39. 39. Haemophilus influenza type b Medical Management• Hospitalization required• Treatment with an effective 3rd generation cephalosporin, or chloramphenicol plus ampicillin• Ampicillin-resistant strains now common throughout the United States Dr.T.V.Rao MD 39
  40. 40. Epidemiology and Prevention• Similar to Pneumococci• Infection enters through Respiratory tract• Immunity is type specific• HIB is protected by PRP vaccine• Poorly immunogenic in children below 2 years• Rifampicin can be given for 4 days and prevents secondary infection and eradicates carrier state. Dr.T.V.Rao MD 40
  41. 41. Public Health Action Dr.T.V.Rao MD 41
  42. 42. Current Vaccines• Haemophilus B conjugate vaccine• Wide spread use of H influenza type b vaccine has reduced H influenza type b meningitis in children by 95% Dr.T.V.Rao MD 42
  43. 43. Newer vaccines• The previous vaccines PRP is immunogenic in older children• PRP is poorly immunogenic in children below two years• Immunogenicity can be improved when coupled with Protein carriers like diphtheria and tetanus Toxoid• Used in young children Dr.T.V.Rao MD 43
  44. 44. Dr.T.V.Rao MD 44
  45. 45. Public Health Aspect of other Haemophilus strains• H. ducreyi – Sexually transmitted disease - chancroid• H. influenzae biogroup aegyptius – Brazilian Purpuric Fever• H. aegyptius – “pink eye” (purulent conjunctivitis)• H. aphrophilus – pneumonia – Infective endocarditis Dr.T.V.Rao MD 45
  46. 46. H,influenzae and other Species Dr.T.V.Rao MD 46
  47. 47. Haemophilus ducreyi- Chancroid~5,000 cases per yearin the USMajor cause os STD’s Dr.T.V.Rao MD 47
  48. 48. Haemophilus ducreyi• Ducrey 1890• Produces Chancroid lesions• Chancroid or soft sore – A Venereal disease• Tender non indurated irregular ulcers of Genetalia• Infection is localized spreading to only to regional lymph nodes• Lymph nodes enlarged and painful Dr.T.V.Rao MD 48
  49. 49. H.ducreyi• Short ovoid bacilli• 1 – 1.5 x 0.6 microns• End to end pairing in short chains• Gram –ve appear as Gram +ve• Bipolar staining• Bacilli in small groups appear as parallel chains giving school of fish appearance Dr.T.V.Rao MD 49
  50. 50. Growth and Culturing• Grows on Fresh clotted Rabbit blood• Grows on Chorioallontoic membrane of chick embryo• Small grey translucent colonies are produced Dr.T.V.Rao MD 50
  51. 51. Chemotherapy for H ducrei• Sulphonamides• Erythromycin• Contrimixazole• Ciprofloxacin• Ceftriaxone Dr.T.V.Rao MD 51
  52. 52. Haemophilus aegypticus• Also called Koch - Weeks Bacillus• Identified as Bio type of H influenza• Produces pink eye• Sulphonamides and Gentamycin effective Dr.T.V.Rao MD 52
  53. 53. H.parainflunza•Requires only V factor and not X factor Dr.T.V.Rao MD 53
  54. 54. H.aphrophilus• Requires X and V factors• Produces Bacterial endocarditis• Brain abscess• Sinusitis• Abscess Dr.T.V.Rao MD 54
  55. 55. HACEK GROUP• Haemophilus Para influenza• H paraphorophilus• Actinobacillus• Cardiobacterium homnis• Eikenella corrodens• Kingela kingie Dr.T.V.Rao MD 55
  56. 56. • Programme Created by Dr.T.V.Rao MD for Medical and Paramedical Students in the Developing World • Email • doctortvrao@gmail.com Dr.T.V.Rao MD 56