Bordetella,

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Bordetella,

  1. 2. <ul><li> </li></ul><ul><li>GENUS BORDETELLA </li></ul>
  2. 3. Bordetella is a genus of small (0.2 - 0.7 µm), Gram-negative coccobacilli of the phylum proteobacteria. Obligate aerobes , non fermentative & highly fastidious. Three species are human pathogens B. pertussis , B. parapertussis , B. bronchiseptica ); B. bronchiseptica is motile.
  3. 4. B. pertussis and occasionally B. parapertussis cause pertussis. Some B. parapertussis strains can colonise sheep. B. bronchiseptica rarely infects healthy humans. It causes several diseases like kennel cough and atrophic rhinitis in dogs and pigs, respectively. Causes several diseases in human and animals
  4. 5. <ul><li>Obligate Aerobe. Fastidious. </li></ul><ul><li>Complex medium. </li></ul><ul><li>“ Bordet – Gengou – </li></ul><ul><li>Glycerin – Potato Blood </li></ul><ul><li>Agar”. </li></ul><ul><li>Charcoal agar with 10% blood </li></ul>Cultural characters <ul><li>Can’t grow on Mac Conkey agar. </li></ul><ul><li>Growth is slow (3 – 10 days).Small, smooth, dome shaped & opaque. </li></ul><ul><li>Viscid, grayish white and refractile. </li></ul><ul><li>Bisected pearls / Mercury drop. </li></ul><ul><li>Confluent growth: </li></ul><ul><li>“ Aluminum paint” “Thumb print” appearance. </li></ul>
  5. 6. <ul><li>Heat 55 0 C /30 minutes. </li></ul><ul><li>Drying , disinfectants. </li></ul><ul><li>Storage: At 0 – 4 0 C. </li></ul><ul><li>On dried droplets survive upto Hours to days. </li></ul><ul><li>Non fermentor. </li></ul><ul><li>Biochemically inert </li></ul><ul><li>Oxidase positive. </li></ul><ul><li>Catalase positive. </li></ul>Survival conditions and Biochemical tests for identification
  6. 7. <ul><li>1. Pertussis toxin: </li></ul><ul><ul><ul><ul><li>Protein. M.W. 1,17,000 , A & B units. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Can be toxoided. Antibody is protective. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Increased concentration of cAMP in the cell. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Lymphocytosis </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Increased sensitivity to histamine . </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Islet cell activation leads to insulin secretion. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Hemaggulatinating property. </li></ul></ul></ul></ul>Virulence factors contributing their pathogenesis Lipopolysacharide , Activates the alternative pathway of complement and release cytokines.
  7. 8. <ul><li>Present on bacillary surface. </li></ul><ul><li>Facilitates adhesion of bacilli to ciliated columnar epithelium of respiratory tract. </li></ul><ul><li>Promotes secondary infection </li></ul><ul><li>“ Piracy of adhesions” phenomenon. </li></ul>2.Filamentous haemaggutinin :
  8. 9. <ul><li>4. Invasive Adenylate cyclase: </li></ul><ul><ul><ul><li>Responsible for hemolysis on blood agar . </li></ul></ul></ul><ul><ul><ul><li>Activated by Calmodulin. </li></ul></ul></ul><ul><ul><ul><li>Release of cAMP . </li></ul></ul></ul><ul><li>5. Lethal toxin: Inflammation & Necrosis. </li></ul><ul><li>6. Tracheal cytotoxin: </li></ul><ul><ul><ul><li>Normal product of breakdown of the cellwall. </li></ul></ul></ul><ul><ul><ul><li>Induces production of IL-1  fever. </li></ul></ul></ul><ul><ul><ul><li>Induces paralysis of ciliary escalator. </li></ul></ul></ul><ul><ul><ul><li>Inhibits DNA synthesis. </li></ul></ul></ul>
  9. 10. <ul><li>Pertussis </li></ul><ul><li>An acute, highly contagious respiratory pediatric disease. Source is patient in early stage Droplets, contaminated fomites. Incubation period is </li></ul><ul><li>1 – 2 weeks. </li></ul><ul><li>Onset is insidious. </li></ul>Pathogenesis: They share everything including Bordetella
  10. 11. <ul><li>1.Catarrhal stage: </li></ul><ul><li>Stage of infectivity. </li></ul><ul><li>Like common cold. </li></ul><ul><ul><li>Low grade fever, running nose, nasal congestion, Sneezing. </li></ul></ul><ul><ul><li>Dry irritating cough. </li></ul></ul><ul><ul><li>Clinical diagnosis difficult. </li></ul></ul><ul><ul><li>Respond to antibiotics . </li></ul></ul>
  11. 12. <ul><li>2. Paroxysmal phase </li></ul><ul><li>Bouts (paroxysms) of coughing: </li></ul><ul><li>At the end of each bout a long inspiratory effort is usually accompanied by a characteristic high-pitched sound “whoop”. </li></ul><ul><li>Duration of this stage is 1 – 6 weeks. </li></ul><ul><li>( Due to difficulty in expelling thick mucus from the airways in the lungs. More in first 1-2 wks. and constant for another 2 wks). </li></ul>
  12. 13. <ul><li>During an attack, the individual may become cyanotic due to lack of oxygen . </li></ul><ul><li>Children and young infants appear especially ill and distressed. </li></ul>Conjunctival hemorrhages & cyanotic patches on the face
  13. 14. <ul><li>Convalescent stage (Recovery stage) </li></ul><ul><li>3 – 4 weeks after an acute illness paroxysms are decreased. </li></ul><ul><li>Complications: </li></ul><ul><ul><li>Subconjunctival & </li></ul></ul><ul><ul><li>Cerebral hemorrhage. </li></ul></ul><ul><ul><li>Subcutaneous emphysema. </li></ul></ul><ul><ul><li>Bronchopneumonia & </li></ul></ul><ul><ul><li>Lung collapse. </li></ul></ul><ul><ul><li>Convulsions due to permanent </li></ul></ul><ul><ul><li>brain damage. </li></ul></ul><ul><ul><li>Anoxic encephalopathy. </li></ul></ul><ul><ul><li>Developmental retardation </li></ul></ul>
  14. 15. <ul><li>Epidemiology: </li></ul><ul><ul><li>Most infectious,air borne bacterial disease. </li></ul></ul><ul><ul><li>No reservoir. Chronic carrier state not seen. </li></ul></ul><ul><ul><li>World wide (600,000 million cases annually). </li></ul></ul><ul><ul><li>6,00,000 deaths occurs in epidemics. </li></ul></ul><ul><ul><li>Prominent in infants and children. </li></ul></ul><ul><ul><li>In adolescents & adults present </li></ul></ul><ul><ul><li>atypically as bronchitis. </li></ul></ul>
  15. 16. <ul><li>Lab diagnosis : </li></ul><ul><li>1. Demonstration of antigen: </li></ul><ul><ul><li>Nasopharyngeal secretions. </li></ul></ul><ul><ul><li>By using calcium alginate /Dacron swab </li></ul></ul><ul><ul><li>Urine and Serum. </li></ul></ul><ul><li>Immunofluorecent method. </li></ul><ul><li>False positive : </li></ul><ul><li>Staphylococci, Yeasts, </li></ul><ul><li>Hemophilus, Moraxella. </li></ul>
  16. 17. <ul><li> 3. Culture </li></ul><ul><li>Best in early stages of disease. </li></ul><ul><li>No use with Transport medium. </li></ul><ul><li>Requires 3 -10 days. </li></ul><ul><li>Specimens: </li></ul><ul><li>1. Cough plate method: </li></ul><ul><li>2. Per oral swab: </li></ul><ul><li>secretions from </li></ul><ul><li>posterior pharyngeal wall. </li></ul><ul><li>3. Per nasal swab: Better. </li></ul><ul><li> With highest yields . </li></ul>
  17. 18. <ul><li>2. Demonstration of antibody (late). </li></ul><ul><ul><li>Serum, Nasopharyngeal secretions ( Ig A). </li></ul></ul><ul><ul><li>Useful for retrospective diagnosis. </li></ul></ul><ul><ul><li>Increased antibody titer. </li></ul></ul><ul><ul><li>Method: Agglutination, ELISA. </li></ul></ul>
  18. 19. <ul><li>IgM and IgA antibodies are diagnostic. Early/acute infection and followed by vaccination. </li></ul><ul><li>PCR testing: Quite sensitive. (Be aware of cross reaction with Bordetella holmesii.) </li></ul><ul><li>CBC : Elevated WBC count with lymphocytosis. </li></ul>
  19. 20. <ul><li>Specific immunization: </li></ul><ul><li>Killed vaccine ( smooth phase I strain) </li></ul><ul><li> (Detoxication with 0.2% merthiolate) . </li></ul><ul><li>Types: </li></ul><ul><li>1. Whole cell vaccine. </li></ul><ul><li>2. Acellular vaccine for below 7 yrs age </li></ul><ul><li> protective components. </li></ul><ul><li>(PT + FHA + Factors 1,2,3) </li></ul>Prevention of spreading and Vaccine availability
  20. 21. <ul><li>Available as: </li></ul><ul><li>1. Plain vaccine </li></ul><ul><li>2. Alum absorbed vaccine PT </li></ul><ul><li>3. Triple vaccine DPT or DTaP </li></ul><ul><li>Dosage: </li></ul><ul><li>‘ 3’ injections IM at 4 – 6 weeks. </li></ul><ul><li>1 st dose at the age of 2 months. </li></ul><ul><li>Vaccination is safe with protection rate of 90%. </li></ul>
  21. 22. <ul><li>Local soreness , fever , shock, Convulsions, encephalopathy </li></ul><ul><li>Provocate the poliomyelitis. </li></ul><ul><li>Contra indicated incase of severe side effects with previous dose. </li></ul>Side effects followed by vaccination
  22. 23. <ul><ul><li>Erythromycin for 14 </li></ul></ul><ul><ul><li>days. </li></ul></ul><ul><ul><li>Cough suppressants. </li></ul></ul><ul><ul><li>Corticosteroids. </li></ul></ul><ul><ul><li>Pertussis i mmunoglobulins </li></ul></ul><ul><ul><li>:Limited success </li></ul></ul>Treatment for acute case
  23. 24. <ul><li>During epidemics: </li></ul><ul><li>Immunization is not 100% effective and slowly becomes less effective. </li></ul><ul><li>Health care providers, adolescents & others at risk are advised to receive a booster dose. </li></ul><ul><li>Un immunized children < 7 yrs should be excused from school and public gatherings for 14 days. </li></ul><ul><li>Health warning announcements. </li></ul>
  24. 25. PREVENTIVE MEASURES
  25. 26. Created by Dr P.S.Reddy MD Professor, Dept. of Microbiology Narayana Medical College, Nellore AP, INDIA For e -learning

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