Where is Bordetella pertussis found in nature?
The mucous membranes of the human respiratory tract are the natural habitat for B pertussis and B parapertussis.
What is the characteristic appearance of the colony of Bordetella pertussis?
7.3 Colonial appearance Colonies of B. pertussis on charcoal blood agar with cefalexin are smooth, convex, pearly and glistening, greyish-white and butyrous and appear in 3 days on subculture, longer on primary isolation. Colonies of B. parapertussis are similar but larger, duller and become visible within two days.
What is the nature pertussis?
Pertussis is a highly contagious respiratory disease that is transmitted directly from human to human1, probably via aerosolized respiratory droplets. The primary causative agent, Bordetella pertussis, is a Gram-negative bacterium that was first described by Bordet and Gengou in 1906 (Ref. 2).
What is the bacterial morphology of Bordetella?
MICROSCOPIC APPEARANCE
| Gram Stain: | Negative. |
|---|---|
| Morphology: | Coccobacilli or short rods. |
| Size: | 0.2-0.5 micrometers by 0.5-2.0 micrometers. |
| Motility: | Non-motile or motile. |
| Capsules: | No. |
Where is pertussis most common in the world?
While Bordetella pertussis circulates worldwide, disease rates are highest among young children in countries where vaccination coverage is low, primarily in the developing world. In developed countries, the incidence of pertussis is highest among unvaccinated babies and increases again among teens.
What are the pathogenic mechanisms of Bordetella pertussis?
These virulence factors include adhesins such as filamentous haemagglutinin, fimbriae and pertactin, which allow B. pertussis to bind to ciliated epithelial cells in the upper respiratory tract.
What are the pathogenic mechanisms of Bordetella pertussis what are its virulence factors?
pertussis virulence factors. These virulence factors include adhesins such as filamentous haemagglutinin, fimbriae and pertactin, which allow B. pertussis to bind to ciliated epithelial cells in the upper respiratory tract.
What are the four methods used to identify Bordetella pertussis?
Common laboratory diagnostic methods used for pertussis diagnosis include culture, direct-fluorescent-antibody testing (DFA), serology and polymerase chain reaction (PCR). Culture of Bordetella pertussis is highly specific but fastidious and has limited sensitivity.
How does Bordetella pertussis bacteria reproduce?
Bordetella pertussis bacteria Whooping cough is caused by bacteria called Bordetella pertussis. The bacteria are spread from one person to another when someone with the infection coughs and fine droplets that contain the bacteria spread into the surrounding air. The bacteria are breathed in by others who are nearby.
What does Bordetella pertussis cause?
Pertussis, also known as whooping cough, is a highly contagious respiratory disease. It is caused by the bacterium Bordetella pertussis. Pertussis is known for uncontrollable, violent coughing which often makes it hard to breathe.
How does Bordetella pertussis spread?
Pertussis spreads from person to person. People with pertussis usually spread the disease to another person by coughing or sneezing or when spending a lot of time near one another where you share breathing space.
What is the mechanism of action of pertussis whooping cough )?
The toxin kills ciliated cells and causes their extrusion from the mucosa. It also stimulates release of cytokine IL-1, and so causes fever. It produces the pertussis toxin, PTx, a protein that mediates both the colonization and toxemic stages of the disease.
How big is the bacterium Bordetella pertussis?
Description and significance. Bordetella pertussis is a small, Gram-negative, coccoid bacterium about the size of 0.8 µm by 0.4 µm. It is an encapsulated immotile aerobe that does not make spores.
What kind of disease does Bordetella parapertussis cause?
Bordetella pertussis. Both species cause pertussis (whooping cough) in humans and are separated merely by the toxins they release during infection. B. parapertussis releases toxins that seem to cause a milder form of pertussis (whooping cough). B. bronchiseptica causes respiratory disease in various mammals and occasionally in humans.
How many species of Bordetella bacteria are there?
There are currently eight species in the Bordetella genus. Three species in this genus are known to be pathogenic to humans. B. pertussis and B. parapertussis are very similar species. Both species cause pertussis (whooping cough) in humans and are separated merely by the toxins they release during infection.
How is camp produced in Bordetella pertussis?
It begins by using hemoagglutinin, a protein, which aids the bacteria in binding to the cilia surface. Next, the pertussis toxin, an exotoxin, enters the cells and activates the production of cAMP.