Bordetella pertussis


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Bordetella pertussis

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Bordetella pertussis

  3. 3. WHAT IS WHOOPING COUGH• Whooping Cough (Pertussis) is a bacterial infection of the lungs which is caused by a bacterium Bodetella pertussis. It is a very contagious disease which causes coughing with little or no fever. The coughing may be so severe that it leads to vomiting and aspiration.DR.T.V.RAO MD 3
  4. 4. HOW THE NAME WHOOPING DERIVED• Whooping cough is an infectious bacterial disease that causes uncontrollable coughing. The name comes from the noise you make when you take a breath after you cough. You may have choking spells or may cough so hard that you vomit.DR.T.V.RAO MD 4
  5. 5. IDENTIFICATION BODETELLA• Jules Bordet and Gengou contributed for discovery 1900• Identified as small bacilli in children with Whooping cough.• Bodetella pertussis ( Intense cough )• Other related Bacteria B.parapertussis B.brochoseptica B.aviumDR.T.V.RAO MD 5
  6. 6. BORDETELLA PERTUSSIS ( B G BACILLUS )• Gram negative organism• Small, ovoid,cocobacillus.• Length is 0.5 microns• Have bipolar metachromatic granules when stained with Toluidine blue DR.T.V.RAO MD 6
  7. 7. BODETELLA PERTUSSIS ( B G BACILLUS)• Small ovoid coccobacillus 0.5 microns• On repeated cultures becomes become larger thread like bacilli.• Non motile, Non sporing• Capsulated – loose on repeated culturing DR.T.V.RAO MD 7
  8. 8. OTHER CHARACTERS• Do not swell in the presence of antigen.• Loose clumps of bacilli appear as thumb print appearance with clear space between the organisms.• Freshly isolated strains have fimbria. DR.T.V.RAO MD 8
  9. 9. CULTURE CHARACTERS• Aerobic Not anaerobic• Grows optimally at 35 0 to 370 c• Preferred medium – Bordet Gengou glycerin potato blood agar• Blood for neutralizing inhibitory substances formed during bacterial growth.• Charcoal also serves the same purpose. DR.T.V.RAO MD 9
  10. 10. MERCURY DROP COLONIES ON BORDET-GENGOU MEDIUM• Growth takes longer up to 48 – 72 hours• On blood agar appear as small dome shaped opaque viscid grayish white retractile• Resembles bisected pearly or mercury drops DR.T.V.RAO MD 10
  11. 11. ALUMINUM PAINT APPEARANCE• Colonies surrounded by hazy zone of hemolysis• Confluent growth presents as aluminum paint. DR.T.V.RAO MD 11
  12. 12. BIOCHEMICAL REACTIONS• In active – do not ferment sugars• Indole test +• Reduce Nitrates• Utilize citrates• Splits urea• Catalase +• Oxidase + DR.T.V.RAO MD 12
  13. 13. RESISTANCE• Killed by heat at 550c for 30 mt• Drying and disinfectants kill the organism• Survive outside for 5 days• 3 days on cloths• Few hours on paperDR.T.V.RAO MD 13
  14. 14. ANTIGENIC CHARACTERS AND VIRULENCE• Agglutinogens - Species specific surface agglutinogens with capsule K antigens or fimbria• 14 agglutinin factors are identified• Factors 7 is common in all species• Factor 1- 6 in only B pertussis• Factor 12 in B.brochoseptica• Factor 14 in B Para pertussisDR.T.V.RAO MD 14
  15. 15. VIRULENCE FACTORS• These virulence factors include adhesions such as filamentous hem agglutinin, agglutinogens, peractin, and fimbriae as well as a number of toxins including pertussis toxin, acetylate cyclase toxin, trachael cytotoxins, Dermonecrtoic toxin and heat-labile toxin (CDC, 2005).DR.T.V.RAO MD 15
  16. 16. PATHOGENESIS OF B.PERTUSSIS• Like most Gram negative pathogens, B. pertussis also contains a Lipopolysaccharide coat that acts as an Endotoxin and can aid colonization by agglutinating human cells (Steele, 2004). DR.T.V.RAO MD 16
  19. 19. MECHANISM OF INFECTION• 1,2,3 are common infective strains vaccines contain all the three Agglutinogens promoting virulence by helping bacteria to attach to respiratory epithelial cells DR.T.V.RAO MD 19
  20. 20. PERTUSSIS TOXIN• Pertussis toxin – MW 1,17,000• Hexamer protein composed of 6 subunits with A – B structure• A has enzymatic activity it can be toxoided• Pertussis toxin is the major component of Acellular Pertussis vaccine.DR.T.V.RAO MD 20
  21. 21. NATURE OF TOXIN• It produces a highly lethal toxin (formerly called Dermonecrtoic toxin) which causes inflammation and local necrosis adjacent to sites where B. pertussis is located. The lethal toxin is a 102 kDa protein composed of four subunits, two with a mw of 24kDa and two with mw of 30 kDa.DR.T.V.RAO MD 21
  22. 22. PERTUSSIS TOXIN• Causes pathogenesis• Present only in B.pertussis• Pertussis toxin is expressed on the surface, secreted into the surrounding medium• Posses Biochemical and Biological activity of producing lymphocytosis producing factor causes Lymphocytosis• Acts as Histamine sensitizing factor• Islet activating function – causes excessive Insulin secretion.DR.T.V.RAO MD 22
  23. 23. FILAMENTOUS HEMAGGLUTININ• One of the Hemagglutinins produced by B.pertussis• Filamentous Haemagglutinnins adheres to cilia of the respiratory epithelium and to erythrocytes• Helps in binding to respiratory epitheliumDR.T.V.RAO MD 23
  24. 24. OTHER TOXINS Adenylate cyclase• Enters the target cells and acts as toxin• It acts by catalyzing the production of cAmp by various types of cells. Heat labile Toxin• Cytoplasmic protein present in Bordetella• Dermonecrtoic and lethal in MiceDR.T.V.RAO MD 24
  25. 25. TRACHEAL TOXIN• L M W – peptidoglycan• Causes ciliary damage, produced by all Bodetella• It induces ciliary damage in hamster tracheal ring• Lipolysacchardie acts as in Gram –ve bacilli• Pertactin – OMP produces immunity in mice.DR.T.V.RAO MD 25
  26. 26. VARIATION SMOOTH TO ROUGH• B pertussis may alter from smooth to rough variation• Phase I to Phase II Phase III Phase IV( rough stage ) which is rough and avirulent formDR.T.V.RAO MD 26
  27. 27. PATHOGENICITY• An obligate parasite• Intranasal inoculation in mice induces a characteristic patches and intensive pneumonia like In humans• Incubation is 1 to 2 weeks DR.T.V.RAO MD 27
  28. 28. INCUBATION IN WHOOPING COUGH• The incubation period (the time between infection and the onset of symptoms) for whooping cough is usually 7 to 10 days, but can be as long as 21 days.DR.T.V.RAO MD 28
  29. 29. STAGES OF INFECTION• 1 Catarrhal• 2 Paroxysmal• 3 Convalescent Each stage lasts 2 weeks Catarrhal stage is Maximal infective Antibiotics are useful.DR.T.V.RAO MD 29
  30. 30. PAROXYSMAL STAGE• Cough increases – distinctive bouts• Violent spasms of continuous coughing• With violent act of cough, air enters into empty lung with characteristic whoop Enters into next stage• Leads to convalescence• And severity of cough decreases• Total disease lasts for 6- 8 weeks.DR.T.V.RAO MD 30
  32. 32. COMPLICATIONS• The violent bouts of cough leads to Subconjuctival hemorrhage Subcutaneous emphysema Bronchopneumonia Lung collapse Neurological complications Epilepsy, paralysis, mental retardation, blindness, deafness.DR.T.V.RAO MD 32
  33. 33. EPIDEMIOLOGY• Predominately a pediatric disease• Highest in the 1st year of life• Maternal antibodies are not protective.• Females suffers more than males.• World wide in distribution• Epidemics occurs periodically.• In early stage of infection droplets and fomites contaminated by oropharengeal secretion are infective.• Non immune rarely escape infectionDR.T.V.RAO MD 33
  34. 34. EPIDEMIOLOGY• House hold contacts at risk• Chronic carriers are not known• B.pertussis - 95 %• B.parapertussis – 5%• B.brochoseptica occasionally occur• Some times Adenovirus, Mycoplasma pneumonia may mimics whooping cough.DR.T.V.RAO MD 34
  35. 35. HOW WHOOPING COUGH DIAGNOSED• Since the early symptoms are so non-specific, pertussis is usually not diagnosed until the appearance of the characteristic cough. Pertussis can be confirmed by taking cultures of respiratory fluids for examination in the laboratory. This involves taking a sample of secretions from the nose or throat and identifying the pertussis bacteria in the secretionDR.T.V.RAO MD 35
  36. 36. DIAGNOSIS• Isolation by culture• PCR• Direct fluorescent antibody• Serological testingDR.T.V.RAO MD 36
  37. 37. LABORATORY DIAGNOSIS• Microscopy• Culture.• Microscopy – Demonstration of Bacilli in respiratory secretions.• Florescent Antibody methodsDR.T.V.RAO MD 37
  38. 38. DR.T.V.RAO MD 38
  39. 39. COUGH PLATE METHOD• Culture plate held at 10- 15 cm infront of the mouth when the patient is coughing spontaneously or induced cough• Droplets of respiratory exhaled impinge on the media.• Helpful as bed side investigationDR.T.V.RAO MD 39
  41. 41. NASOPHARYNGEAL SWAB• Secretion from the posterior pharyngeal wall are collected with cotton swab on a bent wire passed from the oral cavity• A West’s post nasal swab is used for collection of specimen. DR.T.V.RAO MD 41
  42. 42. PER NASAL SWAB• Swab on a flexible wire is passed along the floor of the nasal cavity and material collected from Pharyngeal wall• Dacron or Calcium alginate swabs are better DR.T.V.RAO MD 42
  43. 43. TRANSPORT MEDIUM• Transferred into Casamio acid solution at pH 7.2 in modified Stuarts medium Glycerin potato blood agar of Bordet Gengou• Adding Pencillin becomes more selective DR.T.V.RAO MD 43
  44. 44. IDENTIFICATION OF BACTERIA• The culture plates are incubated at 360c• The bacteria are identified by Microscopy and slide agglutination• Immunofluorescence methods DR.T.V.RAO MD 44
  45. 45. SEROLOGY• Paired serum sample for detection of antibodies• Gel precipitation testing• Complement fixation test• Detection of Ig A by ELISA from nasopharyngeal secretions.DR.T.V.RAO MD 45
  47. 47. HOW WHOOPING PREVENTED• Pertussis can be prevented by the pertussis vaccine, which is part of the DTaP (diphtheria, tetanus, a cellular pertussis) vaccine. These important immunizations are routinely given in five doses before a childs sixth birthday. DR.T.V.RAO MD 47
  48. 48. PROPHYLAXIS• Alum absorbed vaccine is better• Administered in combination with Diphtheria, and tetanus toxoid• B pertussis acts as an adjuvant• Early immunization, is essential in prevention of infection.• Later doses are given at the interval of 4 – 6 weeks intervals, before 6 moths 3 doses are completed.DR.T.V.RAO MD 48
  49. 49. BOOSTER DOSES• A booster at the end of the 1 st year• Another dose at 4th year• Chemoprophylaxis with Erythromycin when exposed to contacts in the vicinity• Complications with vaccination Post vaccinial encephalopathy 5 – 10 million doses Neurotic complications Stop further vaccination Do not vaccinate after 7 yearsDR.T.V.RAO MD 49
  50. 50. ADVANTAGES OF ACELLULAR VACCINE• An acellular vaccine containing whole antigen has been developed and found to elicit good antibody response with fewer side effects. It has replaced the classical vaccine in Japan since 1981 with success, with fewer out breaks and less side effects. whooping cough vaccine can be made from various components of the Bodetella pertussis bacterium, rather than the whole organism. This "acellular" vaccine works well but has fewer side effects than the traditional "whole cell" version.DR.T.V.RAO MD 50
  51. 51. ACELLULAR VACCINES• Contain the Pertussis bacilli• Contain PT FHA Agglutinogens 1, 2, 3• Produces immunity in 90 % of individuals• Immunity in only 50 % by 12th yearDR.T.V.RAO MD 51
  52. 52. TREATMENT• Penicillin is not useful• 10 days of Erythromycin is useful in early infection• Chloramphenicol and Cotromoxazole are effective.DR.T.V.RAO MD 52
  53. 53. • Programme Created by Dr.T.V.Rao MD for Medical and Paramedical Students • Email • doctortvrao@gmail.comDR.T.V.RAO MD 53