Bordetella Flashcards
General characteristics of Bordatella
- Fam: Pateurellaceae
- GNCB
- Oxidase pos
- 3 human pathogens (1 animal + 2 humans)
Epidemiology/Pathogenesis of Bordetella pertussis
- Whooping cough
- Humans are only known reservoir
- Vaccinate!
What is the mode of transmission? (Bordetella pertussis)
Person to person
Inhalation of respiratory droplets
Name virulence factors of B.pertussis
- Adhesions (binds and paralyzes beating cilia)
- Toxicity (Pertussis toxin and adenylate cyclase toxin)
- Outer membrane
- Siderophore production (limits iron)
Factors affecting B.pertussis infection.
Age, previous immunization/infection, passively acquired antibody, antibiotic treatment.
What are the 3 types of whooping cough?
Catarrhal - mild cold sympt, lasts several weeks
Paroxysmal - severe + violent coughing, lasts 2-4 weeks
Convalescent - lymphocytosis, no fever or signs/symptoms, lasts 1-4 weeks
What 2 organisms can cause whooping cough?
B. pertussis and B. parapertussis
What is the epidemiology of B. bronchiseptica?
- Not NF of humans
- Normal NF of mammals such as dogs, cats and rabbits
Mode of transmission of B. bronchiseptica?
Exposure to respiratory droplets, close contact to infected animals
What are the virulence factors of B. bronchiseptica?
Low virulence in humans, several factors similar to B. parapertussis
B. bronchiseptica; spectrum of disease?
Opportunistic infections, some uncommon infections are: pneumonia, bacteremia, UTI, meningitis and endocarditis
How and when is a Bordetella specimen collected?
- Collect early in illness (sensitivity lost after 2 week symptoms)
- Nasopharyngeal aspirate or swab (x2)
- Swabs must be made of calcium alginate or Dacron/Rayon (PCR) for culture (NOT COTTON)
How do you transport a Bordetella specimen?
- Innoculate immediately to selective media at bedside
- Use transport medium: Regan-Lowe, cold casein hydrolysate, casamino acid broth
- Dry swabs for PCR
Describe DFA (Direct Fluorescent Antibody)
- Polyclonal antibodies against both species or separate monoclonal reagents against each species.
- Limited sensitivity/ variable specificity
- Always done with a culture
Describe Nucleic acid amplification. (PCR)
- Sensitivity as good as culture
- DNA detected up to 4 wks after symptoms.
- Must be correlated w/ symptoms to ID species.
What media is used for B. parapertussis?
- BA, CHOC (after 2-4 days)
- MAC - NLF
- Grows best on enrichment media
What media is used for B. bronchiseptica?
- BA, CHOC (after 1-2 days)
- MAC - NLF
Enrichment/ selective media for Bordetella spp.?
- Bordet-Gengou agar
- Regan-Lowe agar
- Stainer Scholte synthetic medium
What is in Bordet-Gengou agar?
- Potato glycerol based (source of starch)
- Glycerol agar base is stabilizing agent
- 15-20% sheep blood (enrichment)
- Methicillin (inhibits contaminants)
What is in Regan-Lowe agar?
- Charcoal agar w/ 10% horse blood
- Beef extract, starch, casein digest
- Cephalexin (inhibits GP NF’s
- Amphotericin B (optional)
- Enriched and selective
What are the incubation requirements of Bordetella spp.?
35-37 C in O2 (NO CO2!), humidified
pertussis 3-6 days
parapertussis 2-3 days
How can you differentiate B. pertussis from B. parapertussis?, rule out Haempophilus sp.?
B. pertussis is:
Ox-pos, urea-neg
B. parapertussis is:
Ox-neg, urea-pos
BaSS rules out Haem spp.
AMS for B. bronchiseptica?
No definitive guide
MAY be sensitive to amoxicillin-clavulanic acid, tetracycline, gentamicin or quinolones
Likely resistant to beta-lactamase, penicillins and cephalosporines, Mostly resistant to SXT
AMS for B. pertussis & B. parapertussis?
Erythromycin, newer macrolides, ketolides, quinolones, tetracyclines, chloramphenicol, SXT
