Write briefly about the following : (a) SV40 Virus (b) Amoebiasis (c) MTB Complex. (d) Mechanisms of bacterial drug resistance

SouravSeptember 4, 2024

Answer

(a) SV40 Virus: The Simian Virus 40 (SV40) is a small DNA virus that was originally discovered in rhesus monkeys. It is known for its role in cancer research due to its ability to transform cells and its use in studying viral oncogenesis. SV40 can cause tumors in laboratory animals and is used as a model to understand cancer mechanisms and gene regulation.

(b) Amoebiasis: Amoebiasis is an infection caused by the protozoan parasite Entamoeba histolytica. It primarily affects the intestines, leading to symptoms like diarrhea, abdominal pain, and in severe cases, liver abscesses. It is transmitted through contaminated food or water and can be treated with antiparasitic medications.

(c) MTB Complex: The Mycobacterium tuberculosis complex (MTBC) includes several species of mycobacteria that cause tuberculosis (TB) in humans and animals. The main member of this complex is Mycobacterium tuberculosis, but it also includes Mycobacterium bovis, Mycobacterium africanum, and Mycobacterium microti. These bacteria are characterized by their slow growth and resistance to many conventional disinfectants.

(d) Mechanisms of Bacterial Drug Resistance: Bacterial drug resistance occurs through various mechanisms, including:

1. Enzymatic Degradation: Bacteria produce enzymes that inactivate the drug (e.g., beta-lactamases that destroy beta-lactam antibiotics).
2. Efflux Pumps: Bacteria actively pump out drugs before they can act.
3. Altered Targets: Bacteria modify the drug’s target site so that the drug can no longer bind effectively.
4. Reduced Permeability: Bacteria reduce the uptake of drugs by altering their membrane permeability.
5. Alternative Pathways: Bacteria develop or acquire alternative metabolic pathways that bypass the drug’s effects.

These mechanisms can be intrinsic or acquired through genetic mutations or horizontal gene transfer.