Lung abscess by Actinomyces odontolyticus and Parvimonas micra co-infection presenting as acute respiratory failure: A case report

RATIONALE: Actinomyces odontolyticus and Parvimonas micra are very rare causative organisms of lung abscess and acute respiratory failure. PATIENT CONCERNS: A 49-year-old male patient visited the emergency room with a complaint of sudden onset of shortness of breath, and he developed acute respiratory failure rapidly. DIAGNOSIS: An abscess in the left lower lung field was diagnosed on the computed tomography scan of chest. INTERVENTIONS: Immediate treatment with intravenous antibiotics was initiated along with a pigtail catheter insertion for pus drainage. OUTCOMES: A odontolyticus was cultured on the drained pus and P micra was identified by a blood culture. The patient was successfully weaned from the mechanical ventilator and the lung abscess was completely resolved. LESSONS: To the best of our knowledge, this is the first case report of mixed infection with A odontolyticus and P micra, which caused acute respiratory failure in an immune-competent patient. Therefore, physicians should consider the possibility of these organisms as causative pathogens of a fulminant pulmonary infection even in an immune-competent patient.