Final answer:
Clostridium perfringens causes target hemolysis through the production of hemolysins, which form pores in cell membranes and lead to cell lysis.
Step-by-step explanation:
Clostridium perfringens causes target hemolysis through the production of hemolysins, which are membrane-disrupting exotoxins. These hemolysins can form pores in cell membranes, including those of red blood cells (erythrocytes). When the hemolysins bind to the cholesterol moieties in the host cell membrane, they create pores that cause leakage of the cytoplasmic contents and ultimately lead to cell lysis. This process results in the characteristic target hemolysis observed in infections caused by C. perfringens. Clostridium perfringens is a gram-positive, spore-forming anaerobic bacterium that can cause a variety of illnesses, ranging from mild gastrointestinal conditions to more severe diseases like gas gangrene.
One of the ways this bacterium affects the human body is by producing toxins that disrupt the plasma membranes of host cells. Among the many proteins it produces, C. perfringens creates toxins such as phospholipases, which degrade the phospholipid bilayer of erythrocytes (red blood cells), leading to cell membrane rupture and the subsequent release of hemoglobin—a process known as hemolysis. Target hemolysis by C. perfringens can be observed on a Blood Agar Plate (BAP), where the hemolytic activity of the bacteria creates a clear zone around the colonies, indicative of β-hemolysis (beta hemolysis). This clear area is due to the complete lysis of red blood cells by the bacterial toxins. In the case of food poisoning caused by Type A strains of C. perfringens, an enterotoxin is also produced, which triggers the unpleasant symptoms associated with the gastrointestinal form of the illness.