First reported case of Peptostreptococcus stomatis bacteremia in left orbit apex syndrome patient after dental repair

Orbital apex syndrome is a life-threatening disease that is very rarely caused by anaerobic bacterial infections. In particular, Peptostreptococcus stomatis , a newly discovered species of Peptostreptococcus species, which is commonly thought to be associated with the development of colorectal cancer (CRC) in patients and oral squamous cell carcinoma (OSCC). However, there is no report that other site infections and bacteremia was caused by this organism. We firstly herein report a case of P.stomatis bacteremia in a 63-year-old woman who was diagnosed with left orbital apex syndrome and cellulitis of both eyelids originated from a dental reparation. This report illustrates the importance of using traditional methods and experience for identification when MALDI-TOF MS failed, which still facilitates the timely selection of appropriate antibiotics for treatment, thus achieving a favorable outcome.