Which cell type is the primary phagocyte during the early stage of bacterial infection?

• A. Lymphocyte
• B. Neutrophil
• C. Monocyte
• D. Eosinophil

Answer: (B)

Neutrophils are the main phagocytes in the early stage of a bacterial infection. They are the most abundant white blood cells and are rapidly recruited to the infection site by chemotactic signals. There they quickly engulf bacteria and kill them using antimicrobial enzymes and reactive oxygen species stored in their granules. Their fast response and short lifespan make them ideal for the immediate containment of bacterial invaders. Monocytes can become macrophages later to continue phagocytosis and assist with cleanup and antigen presentation, while lymphocytes are part of the adaptive immune response and arrive later. Eosinophils are more involved in responses to parasites and allergies, not the primary players in early bacterial phagocytosis.