This document provides information on Bordetella, the bacteria that causes whooping cough. It discusses the three main Bordetella species (B. pertussis, B. parapertussis, B. bronchiseptica), their morphology, culture characteristics, antigenic structure, pathogenesis of whooping cough, laboratory diagnosis, and prophylaxis with DPT vaccine. The key points are that B. pertussis causes the most common form of whooping cough in children, has a distinctive paroxysmal cough stage, and is diagnosed through culture or PCR of respiratory samples and confirmed with specific staining or agglutination.

1. Bordetella
By Dr. Rakesh Prasad Sah
Associate Professor, Microbiology

2. Introduction
• Bordetella
– Highly infectious
– Very small
– Gram-negative
– Cocobacillus
– First described by Bordet and Gengou in 1906.
• Non fermenter, Family  Alcaligenaceae
• Species
– Bordetella pertussis
• Causes whooping cough in children  characterized by paroxysmal cough (frequent and
violent coughing that can make it hard for a person to breathe) ending in a high-pitched
inspiratory sound  described as “whoop”.
– B. parapertussis
• Causes a milder form of whooping cough.
– B. bronchiseptica
• Pathogen of domestic animals.

3. Morphology
• Is a small, ovoid, 1-1.5 µm x 0.3 µm
• Gram Negative coccobacillus
• Non-motile and non-sporing
• Capsulated
• Bipolar metachromatic granules  obs on toulidine blue.

4. Culture
• Obligate aerobe.
• Tempr 350C-360C.
• Fastidious organism  does not grow on N.A.
• Req. complex media
– Bordet-Gengou (Glycerol-potato-blood agar)
– I.P. 48-72hrs
• Colonies are
– Small
– Smooth
– Opaque
– Greyish white
– Refractile
– Resembling bisected pearls or mercury drops.
B. pertussis
B. parapertussis

5. • Charcoal Blood agar  Regan-Lowe (RL) medium.
• Availabe as both semisolid transport medium and as a solid medium
for the isolation of orgganism.
• Biochemical Reactions
– Biochemically inactive.
– Does not ferment sugars
– Indole +ve
– Reduces nitrates
– Urease +ve
– Citratre +ve
– Oxidase +ve
– Catalase +ve

6. Antigenic Structure
Agglutinogens
• Freshly isolated strains of B. pertussis  possess heat labile
Ags associated with the capsule (K-Ags)  designated 1 to 14
factors or agglutinogens.
• Promote virulence by helping organisms to attach to respiratory
epithelial cells.
LPS (Lipopolysaccharides)
• Heat stable LPS endotoxin of the cell wall.
• Not protective
• Is common to all smooth strains of all three species of Bordetella.

7. Heat Labile Toxin (HLT)
• +nt in all Bordetellae.
• Pathogenic role is doubtful.
• Is a cytoplasmic protein.
Tracheal Cytotoxin (TCT)
• Derived from peptidoglycan of cell wall.
• +nt in all Bordetellae.
• Damage to respiratory epithelial cells  more prone to secondary
infections.

8. Adenylate Cyclase (AC)
• Has ability to enter in the target cells.
• Known as AC toxin (ACT).
• Catalyses the production of cAMP by various cells.
Filamentous Haemagglutinin (FHA)
• Indicates attachment of the bacterium to the ciliated epithelial cells of
respiratory tract.
• Also adheres to erythrocytes.
• Abs against it is protective in nature.
• FHA used in pertussis vaccines along with PT toxoid.
Pertactin
• Is an outer membrane protein (OMP)  +nt in virulent strains of B. pertussis.
• Included in acellular vaccines of pertussis.

9. Pertussis Toxin
• Heat labile exotoxin.
• +nt only in B. pertuissis.
• Major virulence factor
– Lymphocytosis producing factor (LPF)
– Histamine sensitising factor (HSF)
– Islet activating protein (IAP)
• Causes profound lymphocytosis  pertussis patients.
• Mol wt 1,17,000.
• Has two sub units A (enzymatically active) and B (binding).
• Can be toxoided.
• Major component of acellular pertussis vaccines.

12. Pertussis Toxin

14. Pathogenesis
• Ds of childhood  known as “whooping cough” or “pertussis”.
• 95% whooping cough  B. pertussis and 5%  B. parapertussis
and only 0.1% cases  B. bronchiseptica is responsible.
• Sources of infection is the patient in the early stage
• I.P.  1 to 2 weeks.
• MOT  droplets
• Ds usually lasts for 6-8weeks.
• Consists of three stages
– Catarrhal
– Paroxysmal
– Convalescent
Each lasts for
approx 2 weeks

15. Catarrhal Stage
– Maximally infective
– Clinical diagnosis is difficult.

16. Paroxysmal Stage
– Violent spasm of continuous coughing 
followed by a long rush of air into the empty
lungs  with a characteristic of “Whoop”.

17. Convalescent Stage
– Frequency and severity of coughing gradually decreases.

19. Complications
• Subconjunctival hemorrhage due to pressure effects of violent
coughing.
• Bronchopneumonia and lung collapse.
• Convulsions and coma.

20. Laboratory Diagnosis
• Microscopy
– Demonstration of bacilli in respiratory secretions by fluorescent Ab
technique.
• Culture
– Catarrhal Stage  bacilli most abundant.

21. Laboratory Diagnosis
• The pernasal Swab
– Swab collected from nasal cavity and pharyngeal wall.
– Sample the posterior nasopharynx using a nasopharyngeal swab (NPS) or
pernasal swab (PNS).
– Inoculated on Bordet-Gengou medium or charcoal blood agar.

22. Laboratory Diagnosis
• The Cough plate method
– Bordet-Gengou culture plate  10-15cm in front of mouth asked to
cough  cough droplets directly inoculated into culture medium.

23. • The Postnasal (Peroral) swab
– Postnasal swab is passed through mouth to collect posterior phryngeal
wall secretions.
– Fatty acids +nt in cotton  inhibit growth of bacilli  better to use dacron
or calcium alginate swabs for collection.
– Swabs are plated without delay.
– Modified Stuart’s medium or charcoal agar  used as transport of swabs.

24. • Bordet and Gengou or charcoal blood agar  add diamidine,
flouride and penicillin  to make media more selective 
incubated at 35-360C for 3-5 days.  Typical pearl like colonies
of B. pertussis appear in 48-72hrs.
• Confirmed by
– Gram staining  G –ve coccobacilli arrange in loose clumps  thump print
appearance.
– Slide agglutination with specific antisera.
• PCR
• Serology
– Ab against PT
• Treatment
– Azithromycin

25. Laboratory Diagnosis

26. Prophylaxis
DPT vaccine
• Dose:- 6,10 and 14 weeks of birth. Booster dose at 16-24months
and at 5 years.
• Route:- I.M. on anteriolateral side of mid thigh.