An oxidase-positive, gram-negative coccus from a throat culture may be?

The identification of an oxidase-positive, gram-negative coccus from a throat culture points clearly to the genus Neisseria. This genus is characterized primarily by its oxidase-positive reaction, which means it produces cytochrome oxidase, a key enzyme in the electron transport chain used during respiration. Moreover, Neisseria species, such as Neisseria gonorrhoeae and Neisseria meningitidis, are known to be cocci and can be found in various clinical specimens, including throat swabs, where they may indicate an infection or carry states.

Staphylococcus, on the other hand, is a different family of bacteria characterized as being gram-positive and is typically oxidase-negative. Fusobacterium is a gram-negative bacillus rather than a coccus, and it is not known for being oxidase positive in the way Neisseria is. The term "EEC" often refers to enteric bacteria or specific classifications used in microbiology, but it does not directly relate to the characteristics of being an oxidase-positive, gram-negative coccus.

Thus, the selection of Neisseria as the answer is well-founded due to its distinct staining characteristics and its unique oxidase activity among the listed choices.