A 64 year old gentleman with chronic obstructive pulmonary disease presents to the GP with increasing dyspnoea

A 64 year old gentleman with chronic obstructive pulmonary disease presents to the GP with
increasing dyspnoea. He is febrile and gives a history of a cough productive of green sputum over the
last few days. You diagnose an infective exacerbation of his underlying lung disease. After sending a
sputum sample you make the decision to start oral steroids and appropriate antibiotics. On reviewing
the results of the sputum sample the lab has reported an initial culture of a Gram negative cocci. What
is the likely organism?

Haemophilus influenzae
Moraxella catarrhalis
Neisseria meningitidis
Pseudomonas aeruginosa
Streptococcus pneumoniae
Of all the available organisms only Neisseria and Moraxella are Gram negative cocci. Neisseria
meningitidis is not a common respiratory pathogen and therefore the likely organism in this case
is Moraxella.
Moraxella catarrhalis is a Gram negative cocci that is a common cause of respiratory infections in
patients with underlying lung disease. It also commonly causes sinusitis and middle ear infections