Brain abscess caused by Paenibacillus lactis

We present a case of a 30-year-old male patient who was admitted to our institution with a 4-month history of persistent headache, pain in the left half of the face and the left ear. The initial magnetic resonance imaging detected an inflammatory process in the left pyramid interpreted as petrous apicitis. Subsequently, he developed generalized seizures. Follow-up computed tomography scanning with contrast enhancement demonstrated newly-formed brain abscess in the basal region of the left temporal lobe. The patient underwent microsurgical evacuation and resection of the abscess. Microbiological examination isolated Paenibacillus lactis as a causative microorganism. During the postoperative period, the patient further developed life-threatening meningitis that was successfully managed with prolonged intravenous antimicrobial treatment. Six-months follow-up examination confirmed complete neurological recovery with no signs of recurrence based on Magnetic Resonance Imaging (MRI). To the best of our knowledge, this is the first reported case of brain abscess caused by Paenibacillus lactis in the medical literature.