Bordetella pertussis

Bordetella pertussis

Q. 1

What is true about Bordetella pertussis 

 A

Adheres to normal mucosa

 B

Destroys cilia

 C

Local tissue destruction

 D

All of the above

Q. 1

What is true about Bordetella pertussis 

 A

Adheres to normal mucosa

 B

Destroys cilia

 C

Local tissue destruction

 D

All of the above

Ans. D

Explanation:

Ans. is ‘d’ i.e., All of the above 


Q. 2

Pertusis toxin acts by all of the following mechanisms except ?

 A

ADP ribosylation of proteins associated with receptors

 B

Increase cyclic AMP

 C

Increased calcium release from sarcoplasmic reticulum

 D

Acts through G alpha subunit

Q. 2

Pertusis toxin acts by all of the following mechanisms except ?

 A

ADP ribosylation of proteins associated with receptors

 B

Increase cyclic AMP

 C

Increased calcium release from sarcoplasmic reticulum

 D

Acts through G alpha subunit

Ans. C

Explanation:

Ans. is ‘c’ i.e., Increased calcium release from saroplasmic reticulum 

Pertusis toxin

.  Pertussis toxin is an exotoxin that has A and B subunits.

.   B subunit binds to the target cells whereas A subunit acts on the target.

.  First, the pertussis toxin itself gets activated by glutathione and ATP.

.   Once the toxin gets activated it activates cell membrane bound G proteins.

.  Pertussis toxin catalyzes the ADP ribosylation of the G proteins and activates them.

. The activated G protein in turn activates adenylate cyclase, this results in an outpouring of cAMP which activates protein kinase and other intracellular messangers.


Q. 3

Mouse is used for pathogenicity testing in ‑

 A

M. Tuberculosis

 B

C diptheriae

 C

Bordetella pertussis

 D

Brucella

Q. 3

Mouse is used for pathogenicity testing in ‑

 A

M. Tuberculosis

 B

C diptheriae

 C

Bordetella pertussis

 D

Brucella

Ans. C

Explanation:

Ans. is ‘c’ i.e., Bordetella pertussis 

  • Bordetella pertussis is an obligate human parasite, but infection can be produced experimentally in several species of animals, the white mouse being most often employed.
  • Intranasal inoculation produces a patchy interstitial pneumonia.
  • Intraperitoneal inoculation of large doses is fatal due to toxemia.
  • Intracerebral inoculation causes a fatal infection. Immunized mice are protected. This forms the basis for intracerebral mouse potency assay for pertussis vaccines.

Q. 4

Culture media for pertusis is:     

September 2004

 A

LJ medium

 B

Chocolate agar

 C

Wilson Blair medium

 D

Bordet gengou medium

Q. 4

Culture media for pertusis is:     

September 2004

 A

LJ medium

 B

Chocolate agar

 C

Wilson Blair medium

 D

Bordet gengou medium

Ans. D

Explanation:

Ans. D i.e. Bordet gengou medium


Q. 5

Identify the organism by appearance of colonies on Regan-Lowe medium as shown in the  photograph below? 

 A

HemoPhilus influenzae.

 B

Bordetella Pertussis.

 C

Brucella melitensis.

 D

MYcobacterium tuberculosis.

Q. 5

Identify the organism by appearance of colonies on Regan-Lowe medium as shown in the  photograph below? 

 A

HemoPhilus influenzae.

 B

Bordetella Pertussis.

 C

Brucella melitensis.

 D

MYcobacterium tuberculosis.

Ans. B

Explanation:

Bordetella Pertussis is an organism which shows Bisected pearls/ Mercury drops appearance of colonies on Regan-Lowe medium as shown in the  photograph above.

B. pertussis  is a very small Gram-negative aerobic coccobacillus that appears singly or in pairs. Its metabolism is respiratory, never fermentative, and taxonomically, Bordetella is placed among the “Gram-negative Aerobic Rods and Cocci” in Bergey’s Manual. Bordetella is not assigned to any family. The bacteria are nutritionally fastidious and are usually cultivated on rich media supplemented with blood. They can be grown in synthetic medium, however, which contains buffer, salts, an amino acid energy source, and growth factors such as nicotinamide (for which there is a strict requirement). Even on blood agar the organism grows slowly and requires 3-6 days to form pinpoint colonies.

Bordetella pertussis colonizes the cilia of the mammalian respiratory epithelium. Generally, it is thought that B. pertussis does not invade the tissues, but some recent work has shown the bacterium in alveolar macrophages. The bacterium is a pathogen for humans and possibly for higher primates, and no other reservoir is known. Whooping cough is a relatively mild disease in adults but has a significant mortality rate in infants. Until immunization was introduced in the 1930s, whooping cough was one of the most frequent and severe diseases of infants.


Q. 6

Pattern in culture as shown in the photograph below is characteristic of ? 

 A

Bacillus anthracis.

 B

Brucella.

 C

Bordetella pertussis.

 D

Clostridium welchii.

Q. 6

Pattern in culture as shown in the photograph below is characteristic of ? 

 A

Bacillus anthracis.

 B

Brucella.

 C

Bordetella pertussis.

 D

Clostridium welchii.

Ans. C

Explanation:

Pattern in culture as shown in the photograph above is characteristic of  Bordetella pertussis.

B. pertussis, a pathogen only for humans, is transmitted by airborne droplets produced during the severe coughing episodes.

The organisms attach to the ciliated epithelium of the upper respiratory tract but do not invade the underlying tissue.

Decreased cilia activity followed by death of the ciliated epithelial cells are important aspects of pathogenesis.

The organism can be isolated from nasopharyngeal swabs taken during the paroxysmal stage.
Bordet-Gengou medium used for this purpose contains a high percentage of blood (20%–30%) to inactivate inhibitors in the agar.

Q. 7

Thumb print appearence in culture film smear is seen ‑

 A

Bacillus antracis

 B

Brucella species

 C

Bordetella pertussis

 D

Clostridum Welchii

Q. 7

Thumb print appearence in culture film smear is seen ‑

 A

Bacillus antracis

 B

Brucella species

 C

Bordetella pertussis

 D

Clostridum Welchii

Ans. C

Explanation:

Ans. is ‘c’ i.e., Bordetella pertussis 

  • In culture smears, the bacilli are arranged in loose clumps with clear spaces in between giving a thumb print appearance.


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