[6] The genus Bordetella contains nine species: B. pertussis, B. parapertussis, B. bronchiseptica, B. avium, B. hinzii, B. holmesii, B. trematum, B. ansorpii, and B.

It is believed that the genus Bordetella may have evolved from ancestors that could survive in the soil according to 16S rRNA gene sequencing data.

Over time, Bordetella, like B. pertussis, has adapted to specifically infect humans and they are still able to multiply and thrive in soil conditions.

[9] Bordetella pertussis prefers aerobic conditions in pH range of 7.0–7.5,[11] optimal to thrive in the human body.

It has been identified that the growth of the bacteria is hindered in the presence of fatty acids, peroxide media, metal ions, and sulfides.

Elevated glutamate levels were found to slow growth due to oxidative stress, revealing a complex relationship.

This effect is compounded by observations suggesting that a small starting population could amplify oxidative stress through quorum sensing, a phenomenon deserving further investigation.

Cultivating B. pertussis in this medium resulted in some production of polyhydroxybutyrate but no excretion of β-hydroxybutyrate, indicating a more efficient conversion of carbon into biomass compared to existing media formulations.

[16] In biofilm conditions, B. pertussis cells exhibited increased toxin levels alongside reduced expression of certain proteins, indicating a metabolic shift towards utilizing the full tricarboxylic acid (TCA) cycle over the glyoxylate shunt.

[17] These changes correlated with heightened polyhydroxybutyrate accumulation and superoxide dismutase activity, potentially contributing to prolonged survival in biofilms.

[17] The interplay between protein expression and metabolic responses highlights the intricate mechanisms influencing B. pertussis growth and adaptation.

[18] Despite a less negative energy profile compared to host tissues like the human respiratory system, B. pertussis efficiently couples biosynthesis with catabolism, sustaining robust growth even after extended incubation periods.

[19] Outbreaks of whooping cough have been observed among chimpanzees in a zoo, and wild gorillas; in both cases, it is considered likely that the infection was acquired as a result of close contact with humans.

The bacterium contains a surface protein, filamentous haemagglutinin adhesin, which binds to the sulfatides found on cilia of epithelial cells.

The signs and symptoms are similar to a common cold: runny nose, sneezing, mild cough, and low-grade fever.

Transmission rates are expected to rise as the host experiences their most contagious stage when the total viable count of B. pertussis is at its highest.

After the host coughs, the bacteria in their respiratory airways will be exposed to the air by way of aerosolized droplets, threatening nearby humans.

[31] A human host can exhibit a range of physical reactions as a result of the  B. pertussis pathogen, depending on how well their body is equipped to fight infection.

[32] However, for B. pertussis to persist in a population the bacterium needs an uninterrupted chain of transmission as there are no animal reservoirs and the bacteria do not survive in the environment.

B. pertussis primarily spreads through respiratory droplets, requiring direct contact between individuals due to its short survival time outside the body.

The dynamic progression of pertussis, characterized by its distinct phases from incubation to paroxysmal coughing, underscores the complexity of the disease's clinical manifestations and highlights the potential significance of toxin release in driving symptoms.

Endotracheal tube aspirates or bronchoalveolar lavage fluids are preferred for laboratory diagnostics due to their direct contact with the ciliated epithelial cells and higher isolation rates of the pathogen.

Some kits use a combination of antigens which leads to a higher sensitivity, but might also make the interpretation of the results harder since one cannot know which antibody has been detected.

[42] These acellular vaccines are also intramuscular and are composed of purified surface antigens, mainly fimbriae, filamentous hemagglutinin, pertactin and pertussis toxin.