Question

1. What are the microorganisms responsible for Cholera and Pertussis?

a) Where are each of these microorganisms active in the human body?

b) What are the signs and symptoms of each disease?

c) Compare G protein coupled receptor mechanism in each of these disease. Explain each mechanism and discuss if they are similar or different.

Answer 1

1) * The microorganism responsible for cholera is vibrio cholerae . It is spread by the contaminated water by the feces of infected person.

* The microorganism responsible for Pertussis is Bordetella Pertussis.

a) CHOLERA: When vibrio cholerae enters into the body through contaminated water, some of the bacteria are killed in the stomach by stomach acids. The escaped ones reach the INTESTINE, causing loss of large amounts of salt and water in the form of watery diarrhea. This results in dehydration. Vibrio cholerae active in the INTESTINE OR GASTROINTESTINAL TRACT in the human body.

  PERTUSISS: The Bordetella pertussis is active in the RESPIRATORY TRACT of the human body. The bacteria is found only in the humans and it resides in the mouth, nose and throat. When immunity is reduced, Bordetella pertussis infects the respiratory tract and affects the cilia. This causes accumulation of mucus and leads to cough. The bactera also populates in the trachea and bronchi leads to inflammation and narrowing of pathways.

b) Signs and symptoms of cholera:

1) watery diarrhea

2) rapid heart rate

3) loss of skin elasticity

4) dry mucus membranes

5) low blood pressure

6) thirst

7) muscle cramps

Signs and symptoms of Pertussis:

1) Nasal discharge

2) fever

3) vomiting

4) red watery eyes

5) cough( whooping cough)

6) apnea( pause in breath)

7) blue face because of cyanosis

c) G protein coupled receptors are membrane receptors in eukaryotes. G protein receptor interacts with G proteins in the plasma membrane and transmit signals inside the cell through a type of protein called G protein. Both works in different mechanisms.

CHOLERA PERTUSSIS Vibrio cholerae settles in the intestine and releases the toxin and it binds to the intestinal cells. These toxins released by the bacteria interupts G protein coupled receptor signaling. Vibrio cholerae causes ADP ribosylation of the stimulatory subunit of G proteins. This modification restricts the GTPase activity of gas and results in as subunit that is always in the ON or active state. The cholera toxin results in continuous stimulation of adenylyl cyclase and leads to more ions out of the cells. These changes in the GPCR causes the diarrhea and severe water loss in cholera. The pertussis toxin alters the activity of Gai by ADP ribosylation. This causes inhibition of ai subunit by preventing interaction with activated receptor. This modification inhibits the activity of the ai subunit remains GDP bound and in an OFF state unable to inhibit the activity of adenylyl cyclase. The toxins enters the intestinal cells and modifies theGTPase and results in ON or lockingg it in a permanently active state and channels open much longer and more ions are out of the cells, The ai subunit remains GDP bound and in OFF state unable to inhibit the activity of adenylyl cyclase. kindly give feedback..... Thank you