Name the common bacterial infection that leads to the formation of pustules usually on the face.

The common bacterial infection that leads to the formation of pustules usually on the face is acne vulgaris. This condition is primarily characterized by the presence of pimples, which are often filled with pus. Acne vulgaris occurs when hair follicles become clogged with oil and dead skin cells, providing an environment where bacteria can thrive. The most common bacteria involved in this process is Propionibacterium acnes, which contributes to the inflammation and formation of pustules.

In contrast, while folliculitis may also cause pustules, it typically presents as small red bumps around hair follicles and can occur anywhere on the body where hair follicles are present. Impetigo, on the other hand, is a contagious bacterial skin infection that results in honey-crusted lesions and is more common in children. Ecthyma is a deeper bacterial infection causing ulcerated and crusted lesions, primarily on the legs and feet, but is not specifically associated with pustule formation on the face. Hence, acne vulgaris is the accurate choice based on the description provided.