Final answer:
Anti-dandruff products contain anti-fungal agents that suppress the growth of the fungus Malassezia, which is linked to dandruff. These products often encompass topical agents due to the similarity between fungal and human cells, which limits the number of drug targets.
Step-by-step explanation:
Modern anti-dandruff shampoos, conditioners, and topical lotions contain anti-fungal agents that control dandruff by suppressing the growth of a type of fungi. The correct answer to the question of which bacteria is suppressed by these agents is C) Malassezia, a fungus that can lead to dandruff when it grows out of balance on the scalp.
Anti-fungal agents work by either killing fungi or by inhibiting their growth. In the context of microbial control protocols, the term 'fungicidal' refers to substances that kill fungi, whereas 'fungistatic' refers to substances that inhibit their growth without necessarily killing them.
Anti-fungal drugs have limited targets compared to antibiotics or anti-viral medications because human cells are much more similar to fungi cells than to bacteria or viruses. This similarity limits the number of targets for drugs that could attack the fungus without harming human cells. Hence, many anti-fungal treatments are applied topically to target the fungal cells directly at the site of infection, such as with dandruff or athlete's foot, where extracellular enzymes breakdown keratin.