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بسم الله الرحمن الرحيم

بسم الله الرحمن الرحيم. GENUS: BORDETELLA Prof. Khalifa Sifaw Ghenghesh. Small, Gram-negative coccobacilli Strict aerobes. X and V factors not required for growth Three species: B. pertussis , B. parapertussis B. bronchiseptica. Bordetella species.

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بسم الله الرحمن الرحيم

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  1. بسم الله الرحمن الرحيم GENUS: BORDETELLA Prof. Khalifa Sifaw Ghenghesh

  2. Small, Gram-negative coccobacilli • Strict aerobes. • X and V factors not required for growth • Three species: • B. pertussis, • B. parapertussis • B. bronchiseptica

  3. Bordetellaspecies

  4. Bordetella bronchisepticaLeifson flagella stain

  5. Scanning electron micrograph of Bordetella bronchiseptica

  6. Bordetella pertussis • Whooping Cough • Paroxysmal coughing • Require blood, or starch or charcoal for growth • Bordet-Gengou medium (BGM) • Strict aerobe • Optimal temp. > 35-36oC

  7. ANTIGENICITY • 3 Major Agglutinogens >1, 2 and 3 • Detected by using adsorbed, single-agglutinin sera • 3 serotypes pathogenic to man • Type 1,2 • Type 1,3 • Type 1,2,3 • All 3 have a role in immunity

  8. Virulence Factors • Pertussis toxin (PT):an exotoxin which enters target cells and activates their production of cAMP, a molecule that acts as a second messenger in cell protein synthesis regulation • Tracheal cytotoxin:causes ciliated epithelial cell destruction • Hemoagglutinin:a cell surface protein which helps the bacterium bind to the host cell surface

  9. PATHOGENESIS • highly contagious bacterium • Non-invasive disease • Man > only natural host • Incubation period >> 1-2 weeks • Enters respiratory tract via inhalation > binds to and destroys the ciliated epithelial cells of the trachea and bronchi. • Symptoms last for many weeks

  10. LABORATORY DIAGNOSIS 1. Bacterial Culture: • Specimen: • Pernasal swab on flexible wire • Specimens on several successive days> higher isolation rates. • Transport media should not be used • Culture: • Immediately on BGM • Incubate for at least 1 week • Identification: • Serological

  11. 2. Detection of Bacterial Antigens • Bordetella antigens in serum and urine using specific antiserum • Immunofluorescence Technique: • Bacteria in nasopharyngeal secretions labelled with fluorescein-conjugated antiserum > examined with ultraviolet microscopy. 3. Detection of Bordetella Antibody: • Sera and nasopharyngeal secretions examined for Ab > Agglutination Tests, ELISA

  12. Bordetella pertussis

  13. TREATMENT • Erythromycin • For 2 weeks • May reduce the severity of illness if given before paroxysmal stage. • No clinical effect when the infection is established • May be given to protect non-vaccinated infants

  14. CONTROL • Vaccination: • Safe and >90% effective. • Adsorbed vaccine (i.e. with adjuvant). • Contains all 3 agglutinogens. • Minimum 3 doses. • Minor adverse reactions: • Erythema and local swelling, slight feverishness • Possible neurological sequelae - Acellular pertussis vaccine

  15. Bordetella parapertussis • a respiratory pathogen that can cause mild pharyngitis. • Bordetella bronchiseptica • a cause of pneumonia, otitis media, and other respiratory infections in animals.

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