Which organism is likely to be identified as oxidase-positive and Gram-negative cocci from a throat culture?

The correct identification of Neisseria as oxidase-positive and Gram-negative cocci from a throat culture is fundamental in microbiology. Neisseria species, particularly Neisseria gonorrhoeae and Neisseria meningitidis, are known for their characteristic morphology as Gram-negative cocci and their ability to produce the enzyme cytochrome c oxidase, which leads to a positive oxidase reaction.

This trait is significant in differentiating Neisseria from other Gram-negative bacilli, as organisms like Escherichia coli, Klebsiella, and Proteus are typically oxidase-negative. Additionally, Neisseria species thrive in the mucosal surfaces of the throat and other epithelial tissues, aligning with their isolation from a throat culture context. This makes their identification essential for accurate diagnosis and treatment of infections caused by these organisms.