Q.Which bacterium has been used as a clot buster? What is its mode of action.

The bacterium used as a clot buster is Streptococcus (specifically Streptococcus species that produce the enzyme streptokinase). This enzyme has been modified through biotechnology to serve as an effective clot-dissolving agent in patients who have suffered a myocardial infarction (heart attack).

Streptokinase works by activating the fibrinolytic system in blood. When a clot forms, fibrin strands create a mesh that traps blood cells. Streptokinase binds to plasminogen, a naturally occurring inactive enzyme in blood, and converts it into plasmin. Plasmin is a proteolytic enzyme that breaks down fibrin, the structural protein of blood clots. By dissolving the fibrin network, streptokinase helps restore blood flow through blocked coronary arteries, reducing damage to heart muscle tissue during a heart atta …

The discovery that certain bacterial products could dissolve blood clots revolutionized emergency medicine, particularly in treating heart attacks and strokes. When a clot blocks a coronary artery or a vessel in the brain, time is critical—restoring blood flow quickly can mean the difference between life and death, or between full recovery and permanent damage.

The bacterium in question is a species of Streptococcus, and the enzyme it produces is called streptokinase. This enzyme has been genetically engineered and produced on a large scale for medical use. Streptokinase is administered intravenously to patients suffering from acute myocardial infarction (heart attack) or other thrombotic conditions where a clot is obstructing blood flow.

How Streptokinase Works

The mode of action is elegantly simple yet highly effective. Our blood contains an inactive protein called plasminogen. Under normal circumstances, when a clot has served its purpose and needs to be removed, the body converts plasminogen into its active form, plasmin, which is a natural clot-dissolving enzyme.

Streptokinase acts as a catalyst in this conversion. When injected into the bloodstream, it binds to plasminogen and activates it into plasmin. This plasmin then breaks down fibrin, the protein mesh that forms the structural framework of blood clots. As the fibrin dissolves, the clot disintegrates, and blood flow is restored to the affected tissue. …

Write it as a biochemical reaction sequence (fibrinolysis cascade), rather than a descriptive paragraph.

Streptokinase + Plasminogen → Plasmin (active)

Plasmin + Fibrin (clot mesh) → Fibrin degradation products (clot dissolves)

Reading the two steps in sequence: streptokinase itself does NOT dissolve the clot directly -- it is an activator that converts the body's own inactive plasminogen into active plasmin, and it is plasmin (a protease) that actually breaks down the fibrin mesh holding the clot together. …