Necrotizing pneumonia and empyema caused by Neisseria flavescens infection.

Neisseria flavescens is an uncommon pathogen of human infection, pneumonia and empyema caused by N. flavescens is rarely reported. Herein, we report a 56-year-old diabetic patient presenting necrotising pneumonia and empyema due to N. flavescens infection. The main clinical manifestation of this patient was high fever, sticky pus and gradually aggravating dyspnea. The chest computed tomography (CT) scan showed there are mass of high density areas around hilus of the left lung, hollow sign with inflammation also appeared. A biopsy specimen was taken from the left principal bronchus by lung puncture biopsy and showed necrosis and inflammation. Microscopic examination of direct smear and culture of sticky pus, much more gram-negative diplococcus was present, pathogen was further identified by Vitek NH card, Vitek MS and confirmed as N. flavescens by 16S rRNA gene sequencing finally. Anti-infection therapy following the antimicrobial susceptibility test results was effectively. To our knowledge, this is the first report of pulmonary infection caused by N. flavescens.