What organism is primarily associated with nonbullous impetigo?

Nonbullous impetigo is primarily associated with Streptococcus pyogenes, also known as Group A Streptococcus. This organism is commonly responsible for the localized skin infections that characterize nonbullous impetigo, which typically presents as crusted sores or lesions around the mouth and nose.

While Staphylococcus aureus can also contribute to impetigo and is often implicated in bullous impetigo, Streptococcus pyogenes is the classical organism for nonbullous impetigo. Therefore, in the context of this question, Streptococcus pyogenes is the correct answer because it is the organism most frequently responsible for this specific form of the infection.

The other organisms listed, such as Escherichia coli and Neisseria gonorrhoeae, are not typically associated with impetigo, thus they are less relevant to the question regarding nonbullous impetigo.