Bacillus megaterium infection presenting as pulmonary alveolar proteinosis, a case report

Pulmonary alveolar proteinosis (PAP) is a special clinical presentation mostly associated with autoimmune disorders. Here we report a rare case of PAP secondary to infection of Bacillus megaterium.

A 58-year-old woman presented with intermittent cough and dyspnea for half a year. Chest CT scan showed “crazy paving” pattern. B. megaterium was identified by percutaneous CT-guided needle biopsy. She continuously received antimicrobial treatment since the diagnosis and follow-up examination suggested great improvement.

To our knowledge, this is the first case of B. megaterium infection presented with PAP pattern in healthy individuals. Attention should be paid on the secondary causes including rare pathogen infection when patients presented with PAP syndrome.