Bordetella: Difference between revisions

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Bordetella pertussis

Diagram of the pertussis toxin structure

Bordetella pertussis is a Gram-negative, aerobic, pathogenic bacterium of the genus Bordetella. It is the causative agent of whooping cough (pertussis), a highly contagious respiratory disease. The bacterium is known for its ability to produce a variety of virulence factors, including the well-known pertussis toxin.

Characteristics

Bordetella pertussis is a small, encapsulated coccobacillus. It is non-motile and strictly aerobic, requiring oxygen for growth. The bacterium is fastidious, meaning it requires specific nutrients and conditions to grow in laboratory settings. It is typically cultured on Bordet-Gengou agar or Regan-Lowe medium.

Pathogenesis

Bordetella pertussis infects the respiratory tract of humans, its only known host. The infection process begins when the bacterium attaches to the cilia of the epithelial cells in the upper respiratory tract. This attachment is mediated by several adhesins, including filamentous hemagglutinin and pertactin.

Once attached, Bordetella pertussis releases toxins that interfere with the host's immune response and damage the respiratory epithelium. The most notable of these toxins is the pertussis toxin, which disrupts cellular signaling pathways and contributes to the characteristic symptoms of whooping cough.

Clinical Manifestations

The disease caused by Bordetella pertussis is characterized by severe coughing fits, which can be followed by a "whooping" sound as the patient breathes in. The disease progresses through three stages:

Catarrhal stage: Resembles a common cold with mild cough and runny nose.
Paroxysmal stage: Severe coughing fits occur, often with the characteristic "whoop."
Convalescent stage: Gradual recovery with decreasing cough severity.

Diagnosis

Diagnosis of Bordetella pertussis infection is typically confirmed through laboratory tests. These may include:

Polymerase chain reaction (PCR) testing of nasopharyngeal swabs.
Culture of the bacterium from respiratory specimens.
Serological tests to detect antibodies against pertussis antigens.

Prevention and Treatment

File:Bordetella pertussis.png

Bordetella pertussis under a microscope

Prevention of Bordetella pertussis infection is primarily achieved through vaccination. The DPT vaccine (diphtheria, pertussis, and tetanus) is administered to children to provide immunity against the disease. Booster vaccines are also recommended for adolescents and adults.

Treatment of whooping cough involves the use of antibiotics, such as azithromycin or erythromycin, to reduce the severity and duration of symptoms. Supportive care, including hydration and oxygen therapy, may be necessary in severe cases.

Related Pages

@@ Line 1: / Line 1: @@
-'''Bordetella''' is a [[genus]] of small (0.2–0.7 µm), [[Gram-negative]] [[coccobacilli]] that are predominantly [[aerobic]]. They are pathogenic to humans and other animals, causing a range of respiratory diseases. The most well-known species within this genus is ''[[Bordetella pertussis]]'', the causative agent of [[whooping cough]] or pertussis, a highly contagious disease primarily affecting children.
+{{DISPLAYTITLE:Bordetella pertussis}}
-==Classification and Structure==
+== Bordetella pertussis ==
-''Bordetella'' species are classified under the [[Proteobacteria]] phylum, within the [[Betaproteobacteria]] class. Their cell walls are characteristic of Gram-negative bacteria, consisting of a thin layer of [[peptidoglycan]] surrounded by an outer membrane containing [[lipopolysaccharide]] (LPS). This structure contributes to their pathogenicity and the immune response they elicit in hosts.
-==Pathogenesis==
+[[File:Pertussis_toxin.png|thumb|right|Diagram of the pertussis toxin structure]]
-The pathogenesis of ''Bordetella'' infections involves adherence to the ciliated epithelial cells of the respiratory tract, mediated by various [[adhesins]] and [[toxins]]. ''B. pertussis'', for example, produces several virulence factors, including pertussis toxin, filamentous hemagglutinin, and adenylate cyclase toxin, which disrupt host cell functions and evade the immune system. The bacteria's ability to form [[biofilms]] also plays a crucial role in its survival and persistence in the host.
-==Diseases==
+'''Bordetella pertussis''' is a Gram-negative, aerobic, pathogenic bacterium of the genus [[Bordetella]]. It is the causative agent of [[whooping cough]] (pertussis), a highly contagious respiratory disease. The bacterium is known for its ability to produce a variety of virulence factors, including the well-known [[pertussis toxin]].
-''Bordetella'' species are responsible for a spectrum of respiratory diseases:
-* ''[[Bordetella pertussis]]'' causes whooping cough, a disease characterized by severe coughing fits and a distinctive "whooping" sound during inhalation. It primarily affects infants and young children.
+== Characteristics ==
-* ''[[Bordetella parapertussis]]'' is associated with a milder form of pertussis.
-* ''[[Bordetella bronchiseptica]]'' can cause infectious [[bronchitis]] in various animals and occasionally in humans, particularly those with compromised immune systems.
-* ''[[Bordetella holmesii]]'' and ''[[Bordetella hinzii]]'' have been identified in respiratory infections, though they are less commonly implicated than the other species.
-==Diagnosis and Treatment==
+Bordetella pertussis is a small, encapsulated coccobacillus. It is non-motile and strictly aerobic, requiring oxygen for growth. The bacterium is fastidious, meaning it requires specific nutrients and conditions to grow in laboratory settings. It is typically cultured on Bordet-Gengou agar or Regan-Lowe medium.
-Diagnosis of ''Bordetella'' infections typically involves culture from a nasopharyngeal swab or molecular methods such as [[PCR]] to detect bacterial DNA. Treatment usually includes antibiotics such as [[macrolides]], which are effective against ''B. pertussis'' and other species. Prevention of whooping cough is primarily through vaccination with the [[DPT vaccine]], which offers protection against ''Diphtheria'', ''Pertussis'', and ''Tetanus''.
-==Prevention==
+== Pathogenesis ==
-Vaccination is the most effective method for preventing ''Bordetella'' infections, particularly whooping cough. The [[DPT vaccine]] is recommended for children and is part of routine immunization schedules in many countries. Booster shots are also advised for adults to maintain immunity, especially those in close contact with infants and young children.
-==Epidemiology==
+Bordetella pertussis infects the respiratory tract of humans, its only known host. The infection process begins when the bacterium attaches to the cilia of the epithelial cells in the upper respiratory tract. This attachment is mediated by several adhesins, including filamentous hemagglutinin and pertactin.
-''Bordetella pertussis'' is highly contagious and spreads through respiratory droplets. Despite widespread vaccination, outbreaks of whooping cough continue to occur, highlighting the need for continued surveillance and booster vaccination programs. Other ''Bordetella'' species have a broader host range, affecting various animals and occasionally humans.
-==Research Directions==
+Once attached, Bordetella pertussis releases toxins that interfere with the host's immune response and damage the respiratory epithelium. The most notable of these toxins is the [[pertussis toxin]], which disrupts cellular signaling pathways and contributes to the characteristic symptoms of whooping cough.
-Current research on ''Bordetella'' focuses on understanding the mechanisms of pathogenesis, improving diagnostic methods, and developing more effective vaccines. Studies on the genetic variability of ''B. pertussis'' strains are also crucial for addressing vaccine-driven evolution of the pathogen.
-[[Category:Bacteria]]
+== Clinical Manifestations ==
-[[Category:Proteobacteria]]
-[[Category:Betaproteobacteria]]
+The disease caused by Bordetella pertussis is characterized by severe coughing fits, which can be followed by a "whooping" sound as the patient breathes in. The disease progresses through three stages:
+* '''Catarrhal stage''': Resembles a common cold with mild cough and runny nose.
+* '''Paroxysmal stage''': Severe coughing fits occur, often with the characteristic "whoop."
+* '''Convalescent stage''': Gradual recovery with decreasing cough severity.
+== Diagnosis ==
+Diagnosis of Bordetella pertussis infection is typically confirmed through laboratory tests. These may include:
+* [[Polymerase chain reaction]] (PCR) testing of nasopharyngeal swabs.
+* Culture of the bacterium from respiratory specimens.
+* Serological tests to detect antibodies against pertussis antigens.
+== Prevention and Treatment ==
+[[File:Bordetella_pertussis.png|thumb|left|Bordetella pertussis under a microscope]]
+Prevention of Bordetella pertussis infection is primarily achieved through vaccination. The [[DPT vaccine]] (diphtheria, pertussis, and tetanus) is administered to children to provide immunity against the disease. Booster vaccines are also recommended for adolescents and adults.
+Treatment of whooping cough involves the use of antibiotics, such as [[azithromycin]] or [[erythromycin]], to reduce the severity and duration of symptoms. Supportive care, including hydration and oxygen therapy, may be necessary in severe cases.
+== Related Pages ==
+* [[Whooping cough]]
+* [[Pertussis toxin]]
+* [[DPT vaccine]]
+* [[Bordetella]]
+[[Category:Bordetella|Pertussis]]
+[[Category:Gram-negative bacteria]]
 [[Category:Pathogenic bacteria]]
-{{Bacteria-stub}}