Bordetella PDF

Vaccination  Enterobacteria Pseudomonas Aerobic & Curved bacteria (spiral) : Gram f.anaerobic Vibrio - ve Helicobacter Campylobacter Ba...

Vaccination  Enterobacteria Pseudomonas Aerobic & Curved bacteria (spiral) : Gram f.anaerobic Vibrio - ve Helicobacter Campylobacter Bacilli Anaerobic Bacteroides Fusobacterium Parvobacteria Leptotrichia (coccobacilli)  Parvobacteria Coccobacilli Haemophilus Legionella Bordetella Brucella Yersinia Pasteurella Gardenerella Bordetella :-  Fastidious Gram-negative coccobacilli  Extremely small.  Aerobic non-fermenters  Classification – the genus contains three medially important species ◦ B. pertussis ◦ B. parapertussis ◦ B. bronchoseptica  Human Disease & Associated Pathogens Genus Species Disease Bordetella pertussis Pertussis parapertussis Pertussis (milder form) bronchiseptica Bronchopulmonary disease Bordetella pertussis pertussis::-  The causative agent of Pertussis (Whooping Cough) Virulence Factors:- Factors:- Fimbriae for attachment. Endotoxin. Different types of exotoxins Pertussis toxin : Increases cAMP in lung cells ( increased secretion excessive mucous and fluid build-up) Adenylate Cyclase Toxin - Also increases cAMP Dermonecrotic Toxin Tracheal cytotoxin Virulence Factors:- Factors:- Filamentous hemagglutinin (FHA) Agglutinogens. Pertactin Pathogenesis:-- Pathogenesis:  pertussis is transmitted by aerosols and infects the ciliated epithelium of the airways.  There is no further dissemination of the infection, but bacterial toxins produced in the respiratory tract contribute to local and systemic disease pathogenesis. Pathogenesis:-- Pathogenesis:  Pertussis is primarily a toxin-mediated disease.  The bacteria attach to the cilia of the respiratory epithelial cells.  Produce toxins that paralyze the cilia.  Cause inflammation of the respiratory tract, which interferes with the clearing of pulmonary secretions. Pertussis (Whooping Cough):-- Cough):  Highly contagious respiratory infection caused by Bordetella pertussis  Outbreaks first described in 16th century  Bordetella pertussis isolated in 1906  Estimated 294,000 deaths worldwide in 2002 Whooping Cough :- :-  Epidemiology Humans only reservoir 60,000,000 cases annually world wide 2000-6000 cases annually in US Occur primarily in non-immune children Adults with waning immunity milder disease Misdiagnosed as cold or flu Whooping Cough :- :-  Three stages of Whooping Cough:-  Catarrhal stage  Paroxysmal stage  Convalescent stage Catarrhal stage:-  First stage as bacteria just start to die and release toxin  Mild cold symptoms, coughing, sneezing  Child is not that sick so parent thinks they have a common cold and don’t isolate from other children  This is the MOST contagious stage since many bacteria still alive in respiratory tract and all the coughing and sneezing spread live bacteria easily to other children. Paroxysmal stage:-  Maximum cell death and toxin release  Severe Cough:-  40 – 50 cough spells/day  20-30 coughs in a row with no chance to breath  Coughing causes stomach upset and vomiting  Dyspnea  Subconjunctival hemorrhage. Paroxysmal stage:-  Mucous build-up in Lungs (tenacious sputum):-  Air blockage can in rare cases lead to death  Secondary pneumonia is biggest threat, Caused by other bacterial pathogens H. influenzae, S. aureus, and S. pneumoniae Video:- Convalescent stage:-  Coughing spells diminish slowly, decrease in number of spells and severity  Possible CNS complications in some children. (The pathogenesis is not clear). Complications:-  Air blockage & death.  Secondary pneumonia.  CNS complications. Laboratory diagnosis:- diagnosis:-  Diagnosis is usually clinical.  Specimen : pernasal swab: passed gently along the floor of the nose to sample nasopharyngeal secretions.  Cough plate: held in front of the mouth during a paroxysm Laboratory diagnosis:- diagnosis:-  Microscopically: Gram-negative coccobacilli  Nonmotile  Culture :-  Fastidious and slow-growing  Charcoal blood agar  Bordet-Gengou medium  Incubate for 3-5 days  colonies: moist, mercury drop  Identification:  slide agglutination  FAT Bordetella spp :- Bordet--Gengou medium Bordet Mercury drops colonies Treatment:-- Treatment:  Self-limiting in majority of children  Supportive treatment (O2 , sucction & nebulizer).  Antibiotics only speed up the process.  Erythromycin (Macrolides) prevention:-- prevention:  Vaccination (DPT – diphtheria, pertussis, tetanus)  Antibiotics to contacts.  Early diagnosis & treatment & Isolation.