Question

1. What natural defenses are present in gastrointestinal tract?

2. How does mucus defend against microbial attack?

3. How do dental caries develop?

4. What is periodontitis and describe the features of each stage?

5. How is STEC different from other E. coli? How did it acquire this ability?

6. How does a person acquire STEC?

7, How are STEC infections treated?

8. How do natural disasters contribute to the transmission of cholera?

9. What does cholera toxin do to develop the disease, cholera?

10, What causes pseudomembranous colitis?

11. How is C. diff infection transmitted in a hospital? What protective measures are taken to prevent tranismission?

12. Describe how a person taking antibiotics is prone to C. diff infection.

13. What causes hepatitis B?

14, How is HBV transmitted?

15. When is the vaccination for HBV given? What types of vaccines are available?

16. How is HBV infection diagnosed and differentiated between acute and chronic disease?

Answer 1

1. What natural defenses are present in gastrointestinal tract?

Gastrointestinal tract has several non-immunological barriers like intestinal flora of different microorganisms, Gastric barriers, Gastric juice secretions and antibacterial properties of bile salts, lysozyme and antibodies.

2. How does mucus defend against microbial attack?

Mucus lines several body cavities and it acts on the pathogen by trapping it and preventing it from entering our body. Mucus also possess antibacterial properties and immune cells.

3. How do dental caries develop?

It developes when the processed sugars present in our food and drinks react with the bacterial biofilm present on our tooth surface which initiates action of different acids on the enamel of tooth. A good and healthy oral hygiene can prevent them.

4. What is periodontitis and describe the features of each stage?

Periodontitis is a type of infection that develops due to the accumulation of bacteria on our teeth and gums. Stage are as follows:

1. Inflammation: Also known as gingivitis. The gum swell up and bleed during brushing and flossing.
2. Early periodontal diseases: Gums shift back from the teeth and small pockets are formed between gums and teeth.
3. Moderate periodontal disease: If left as such the bleeding and inflammation id accompanied with pain, teeth also start to loose bone support and become loose.
4. Advanced periodontal disease: The connective tissues that hold teeths in place are degraded causing severe pain while chewing and bad breath.

5. How is STEC different from other E. coli? How did it acquire this ability?

We huamn have friendly E.coli in our intestines and it is non-pathogenic. But there are several pathogenic forms of E. coli like Shiga toxin producing E. coli (STEC). STEC is a pathogenic form of E. coli that cause diarrhea and stomach disorders and it trasmitted by contaminated food and wanter and also by coming in contact with infected organisms.

STECare different from the E. coli found in out intestines as it secrets a Shiga toxin that causes diseases.

6. How does a person acquire STEC?

STEC can be transmitted from contaminated food, water, unpasteurised milk and by coming in contact with infected organisms. Also coming in contact with infected feaces.

7, How are STEC infections treated?

Non-specific supportive therapy that included hydration. Hydration places a major role in treatment to this infection. Antibiotics and Antidiarrheal agents should not be used.

8. How do natural disasters contribute to the transmission of cholera?

Cholera spreads by contaminated food and water and prior to a natural disastor or during a natural disaster contamination of both food and water is very common.

9. What does cholera toxin do to develop the disease, cholera?

Cholera toxin is a ADP-ribosylating AB toxin which increases intracellular levels of cyclicAMP in the intestinal epithelium causing hypersecretion of electrolytes and water along with severe painful diarrhea that could lead to hypovolemic shock that leads to death.

10, What causes pseudomembranous colitis?

Sweiiling of large intestines due to an overgrowth of Clostridioides difficile bacteria. This causes dues to diarrhea after consuming antibiotics.