[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Other Gram-negative rods](https://durgical.com/en/microbiology/groups/other-gram-negative-rods/) › Bordetella pertussis

[Microbiology](https://durgical.com/en/microbiology/) · [Other Gram-negative rods](https://durgical.com/en/microbiology/groups/other-gram-negative-rods/)

# Bordetella pertussis

- Bacterium
- Gram-negative
- Droplet
- Exam priority: medium

The whooping cough bacterium: coughing fits that last weeks. In babies under one year it can cause apnea and death.

Updated 2026-11-01

Also called: whooping cough bacillus

## Key points

- Three stages: catarrhal (most contagious), paroxysmal (whoop) and convalescent.
- Pertussis toxin: ADP-ribosylates Gi, raises cAMP, marked lymphocytosis.
- Infant with apnea and coughing fits: pertussis; the whoop may be absent.
- Treatment and prophylaxis with macrolides.
- NCLEX: droplet precautions until 5 days of antibiotics; Tdap in every pregnancy.

## At a glance

**Gram**
Gram-negative

**Shape**
Small coccobacillus

**Oxygen**
Strict aerobe

**Family**
Alcaligenaceae

**Stain**
Gram: small red coccobacilli

## Morphology

- Small encapsulated Gram-negative coccobacillus
- Fastidious: Bordet-Gengou or Regan-Lowe media
- Attaches to ciliated respiratory cells

## Transmission

- Respiratory droplets from coughing or sneezing; very contagious, especially in the catarrhal stage
- Babies usually catch it from siblings, parents or caregivers with mild symptoms
- Droplet (on top of standard) until 5 days of effective antibiotics are completed

**Reservoir:** Humans only

### Isolation precautions

What the care team adds to standard precautions.

**Droplet**
Surgical mask within about a metre; single room.

## Virulence factors

- Pertussis toxin: ADP-ribosylates Gi, raises cAMP and causes lymphocytosis, hyperinsulinemia and impaired defenses
- Adenylate cyclase toxin: raises cAMP inside phagocytes
- Tracheal cytotoxin: kills ciliated cells
- Filamentous hemagglutinin and pertactin: attachment to ciliated epithelium

## Diseases it causes

- Whooping cough (pertussis) [Pertussis (whooping cough) →](https://durgical.com/en/conditions/pertussis/)

## Clinical picture

- Catarrhal stage of 1 to 2 weeks: a common cold, the most contagious stage
- Paroxysmal stage: coughing fits followed by an inspiratory whoop and vomiting
- Convalescent stage: the cough fades over weeks or months
- Infants: apnea, cyanosis, pneumonia and death; often no whoop

## Diagnosis

- PCR of a nasopharyngeal swab or aspirate: fast and sensitive
- Culture on Regan-Lowe or Bordet-Gengou: specific but difficult
- Marked lymphocytosis on the infant's blood count
- Serology useful late in the illness

## Treatment

Macrolides (azithromycin; clarithromycin or erythromycin as alternatives), and trimethoprim-sulfamethoxazole when macrolides are not tolerated. Early antibiotics can soften the illness and always reduce spread; close contacts get prophylaxis.

Drug class only; doses and regimens are set by the clinician from the current guideline.

In Pharmacology:

- [Azithromycin](https://durgical.com/en/pharmacology/azithromycin/)
- [Clarithromycin](https://durgical.com/en/pharmacology/clarithromycin/)
- [Erythromycin](https://durgical.com/en/pharmacology/erythromycin/)

## Prevention

- DTP or DTaP vaccination in childhood with boosters
- Tdap in every pregnancy to protect the newborn
- Antibiotic prophylaxis for close contacts
- Droplet precautions

**Vaccine:** Pertussis vaccine is in Colombia's PAI: within the pentavalent or hexavalent vaccine in the first months, DTP boosters, and acellular Tdap for pregnant women.

## In Colombia

Whooping cough is a notifiable event in SIVIGILA (INS); the most severe burden falls on infants under one year, which is why pregnant women are vaccinated.

## Memory aid

"The hundred-day cough": a cold for a week or two, whooping for weeks, and a recovery measured in months.

## Test yourself

Think of the answer, then tap the question to see it.

## Which stage of whooping cough is the most contagious?

The catarrhal stage, when it looks like a common cold.

## How does pertussis toxin work?

It ADP-ribosylates and inactivates Gi, raises cAMP and, among other effects, causes lymphocytosis.

## Which test is preferred to confirm pertussis in the first weeks?

PCR of a nasopharyngeal sample.

## Why are pregnant women given Tdap?

To pass antibodies to the baby and protect it in the first months, when pertussis is most dangerous.

## Which isolation precaution does a patient with pertussis need?

Droplet precautions, on top of standard, until 5 days of effective antibiotics are completed.

[Add to my cards (5)](https://durgical.app/estudiar/?add=/en/microbiology/bordetella-pertussis/)

## Related

- [Haemophilus influenzae](https://durgical.com/en/microbiology/haemophilus-influenzae/)

## Related conditions

- [Pertussis (whooping cough)](https://durgical.com/en/conditions/pertussis/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

**Contact**
Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing.

**Droplet**
Surgical mask within about a metre; single room.

**Airborne**
N95 respirator and a negative-pressure room.

[← Back to the group: Other Gram-negative rods](https://durgical.com/en/microbiology/groups/other-gram-negative-rods/)

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Chapter 16: Pertussis](https://www.cdc.gov/pinkbook/hcp/table-of-contents/chapter-16-pertussis.html) (CDC, 2024); [About Whooping Cough](https://www.cdc.gov/pertussis/about/index.html) (CDC, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

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Source: https://durgical.com/en/microbiology/bordetella-pertussis/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/bordetella-pertussis/