Question

1. (a)

(b) Define immunodeficiency and hypersensitivity

(c) Explain MDR & XDR -TB

(d) Discuss briefly similarities between TB & COVID-19

Explain with examples cocci, bacilli and vibrio

Answer 1

a) immunodeficiency

Immunodeficiency means malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. it  usually result from use of a drug or from a long-lasting serious disorder (such as cancer) but occasionally are inherited. Immunodeficiency disorders impair the immune system’s ability to defend the body against foreign or abnormal cells that invade or attack it (such as bacteria, viruses, fungi, and cancer cells). As a result, unusual bacterial, viral, or fungal infections may develop.2 types of immunodeficiency disorder are there

1)Primary: These disorders are usually present at birth and are genetic disorders that are usually hereditary. They typically become evident during infancy or childhood.

2)Secondary: These disorders generally develop later in life and often result from use of certain drugs or from another disorder, such as diabetes or human immunodeficiency virus (HIV) infection. They are more common than primary immunodeficiency disorders.

hypersensitivity

it means the reaction produced by our immune system to protect from the external virus or something attacks.like allergy autoimmune system.Examples include anaphylaxis and allergic rhinoconjunctivitis. and contact dermatitis from poison ivy or nickel allergy.4 types of hypersensitivity

• Type I: Immediate Hypersensitivity (Anaphylactic Reaction) These allergic reactions are systemic or localized, as in allergic dermatitis (e.g., hives, wheal and erythema reactions).
• Type II: Cytotoxic Reaction (Antibody-dependent)
• Type III: Immune Complex Reaction.
• Type IV: Cell-Mediated (Delayed Hypersensitivity)

(b) MDR & XDR -TB

Extensively drug resistant tuberculosis (XDR-TB) is a form of TB caused by bacteria that are resistant to several of the most effective anti-TB drugs.When a single bacterium is resistant to more than one antibiotic it is said to be multidrug-resistant. This can occur in two distinct ways. A bacterium can have several different resistance genes, each providing resistance to a particular antibiotic.Multidrug-resistant TB (MDR TB) is caused by an organism that is resistant to at least isoniazid and rifampin, the two most potent TB drugs. These drugs are used to treat all persons with TB disease.Multidrug resistant tuberculosis (MDR-TB) is a strain of TB that cannot be treated with the two most powerful first-line treatment anti-TB drugs

c)similarities between TB & COVID-19

mostly both will be serious when it affected to the lungs.People ill with COVID-19 and TB show similar symptoms such as cough, fever and difficulty breathing. Both diseases attack primarily the lungs and although both biological agents transmit mainly via close contact, the incubation period from exposure to disease in TB is longer, often with a slow onset

.the mode of transmision is in the case of tb it is TB bacilli remain suspended in the air in droplet nuclei for several hours after a TB patient coughs, sneezes, shouts, or sings, and people who inhale them can get infected. The size of these droplet nuclei is a key factor determining their infectiousness. Their concentration decreases with ventilation and exposure to direct sunlight.

COVID-19 transmission has primarily been attributed to the direct breathing of droplets expelled by someone with COVID-19.Droplets produced by coughing, sneezing, exhaling and speaking may land on objects and surfaces, and contacts can get infected with COVID-19 by touching them and then touching their eyes, nose or mouth

The diagnostic methods for tuberculosis (TB) and COVID-19 are quite distinct and commonly require different specimens.  Sputum, as well as many other biological specimens, can be used to diagnose TB using culture or molecular techniques.Tests for COVID-19 are done most commonly by nasopharyngeal or oropharyngeal swab or wash in ambulatory patients, but sputum or endotracheal aspirate or bronchoalveolar lavage may be used in patients with severe respiratory disease.

d) cocci

The cocci are spherical or oval bacteria having one of several distinct arrangements,such as a staphylococcusCompare bacillus.examples:Diplococci are pairs of cocci (e.g. Streptococcus pneumoniae and Neisseria gonorrhoeae) Streptococci are chains of cocci (e.g. Streptococcus pyogenes). Staphylococci are irregular (grape-like) clusters of cocci (e.g. Staphylococcus aureus).

bacilli

Bacilli are rod-shaped gram-positive usually aerobic bacteria producing endospores and including many saprophytes and some parasites.one example is B. anthracis of anthrax broadly : a straight rod-shaped bacterium.Bacillus anthracis  is resistant to beta-lactam antibiotics; it is usually susceptible to treatment with clindamycin, vancomycin, gentamicin, chloramphenicol, and erythromycin.

vibrio

Vibrio is a Gram-negative bacteria, a curved-rod shape, which can cause foodborne infection, usually cause by eating undercooked seafood which is Typically found in salt water.Most common examples is V. cholerae.V. halioticoli, V. harveyi, V. hepatarius, V. aerogenes, V. aestivus, V. aestuarianus, V. agarivorans, V. albensis, V. alfacsensis, V. alginolyticus, V. anguillarum, V. areninigrae.Treatment is not necessary in mild cases, but patients should drink plenty of liquids to replace fluids lost through diarrhea.