Abstract
•The patient presented with pneumonia and gram-negative diplococci on sputum smear.•Neisseria meningitidis and Moraxella catarrhalis are both gram-negative diplococci.•Both bacteria can cause pneumonia but can be differentiated by culture.•Colonies of N. meningitidis are mucoid and translucent.•Colonies of M catarrhalis are firm and white.