Zhihui Yan, Xiaona Qian, Yixuan Liu, Liyuan Tian
Prevotella oris is a rare but significant pathogen in pediatric empyema. A high index of suspicion should be maintained for anaerobic infections in children presenting with a history of dental procedures, abnormal immune parameters or possible immunological vulnerability, or poor response to empirical antibiotics. Traditional cultures are often inadequate; therefore, mNGS serves as a crucial tool for the early detection and precise treatment of difficult-to-culture anaerobes.
BACKGROUND: Empyema and pyopneumothorax are severe complications of pediatric community-acquired pneumonia. While typically caused by aerobic bacteria, anaerobic infections, particularly those involving Prevotella oris (P. oris), are exceedingly rare in children. This study aims to explore the clinical characteristics, diagnostic challenges, and therapeutic strategies for pediatric pyopneumothorax caused by P. oris, thereby enhancing clinical awareness of this uncommon opportunistic pathogen.
CASE PRESENTATION: We retrospectively analyzed the clinical data of a 10-year-old male admitted to the Hebei Children's Hospital in October 2025, presenting with acute chest pain and a history of tooth extraction 1 week prior to symptom onset. Radiological imaging revealed bilateral pneumonia with bilateral pleural effusions (predominantly on the left side). Pleural fluid analysis was consistent with an empyema. Traditional bacterial cultures of blood and pleural fluid yielded negative results. However, probe-based targeted metagenomic next-generation sequencing (mNGS) of the pleural fluid identified P. oris with a high relative abundance (81.86%), alongside other minor oral commensals. Based on the molecular diagnosis and the patient's ongoing clinical deterioration, cefoperazone-sulbactam was selected to strengthen coverage against anaerobic Gram-negative organisms, while linezolid was temporarily added to cover potential Gram-positive pleural co-infection during the acute deterioration phase. This was combined with closed thoracic drainage and intrapleural urokinase instillation for fibrinolysis, leading to a complete clinical recovery.
CONCLUSION: Prevotella oris is a rare but significant pathogen in pediatric empyema. A high index of suspicion should be maintained for anaerobic infections in children presenting with a history of dental procedures, abnormal immune parameters or possible immunological vulnerability, or poor response to empirical antibiotics. Traditional cultures are often inadequate; therefore, mNGS serves as a crucial tool for the early detection and precise treatment of difficult-to-culture anaerobes.