Prolonged Bacteroides pyogenes infection in a patient with multiple lung abscesses

Bacteroides pyogenes is naturally found in the oral microbiome of cats and dogs and hence exposure, especially bites from these animals, is a major risk factor for human infections. B pyogenes is known to cause infections that persist despite antibiotic treatment and can have serious clinical outcomes. We present a novel case of complex lung abscesses associated with B pyogenes infection. A 55 year old man presents with a 3‐month history of productive cough, night sweats, and 5 kg weight loss. An initial chest radiograph revealed mass‐like opacities in the right upper lobe (RUL), right middle lobe (RML), and left lower lobe (LLL). Over the next 4 years the patient underwent multiple investigations and antimicrobial treatments until resolution of the abscesses. We believe that metronidazole in combination with moxifloxacin was a key component in the clinical cure of this patient. We report a case of multiple lung abscesses associated with polymicrobial infection, including B. pyogenes, which were slow to resolve despite multiple courses of antibiotics . We believe that metronidazole in combination with moxifloxacin was a key component in the clinical cure of this patient.