What typically causes an acute, localized infection of a hair follicle?

An acute, localized infection of a hair follicle is most commonly caused by bacteria, particularly staphylococci. When bacteria enter the hair follicle, often through minor injuries or blockages, they can multiply and lead to inflammation, pus formation, and pain, characterizing conditions such as folliculitis.

While viral agents may lead to other skin infections or conditions, they do not specifically target hair follicles in the same way bacteria do. Fungal organisms can cause skin and nail infections but are less commonly associated with hair follicle infections. Parasitic organisms, such as lice, may infest hair but do not typically cause acute infections in the hair follicles themselves. Thus, bacteria are recognized as the main culprits of infections in this context, leading to the conclusion that it is the correct answer.