牙髓卟啉单胞菌是一种革兰阴性厌氧杆菌，常见于口腔正常菌群中。牙髓卟啉单胞菌主要引起牙源性感染，由其引发的颅内感染则极为罕见。1例10岁男性患儿因“反复高热伴面部肿胀3天，抽搐1次”收治入院。入院时患儿嗜睡，面部及颈部肿胀，布氏征阳性。实验室检查示白细胞计数26.16×10⁹/L，C反应蛋白279.57 mg/L，降钙素原>100 ng/mL；脑脊液检查示白细胞45×10⁹/L，蛋白945 mg/L；头颅磁共振成像示双侧额叶脓肿形成。宏基因组二代测序检测血液、脑脊液及脓液均提示牙髓卟啉单胞菌及多种厌氧菌序列。基于上述检验和检查结果，患儿明确诊断为牙髓卟啉单胞菌脑脓肿，并采用万古霉素、美罗培南、利奈唑胺及甲硝唑等抗感染治疗。使用抗生素后，患儿的临床症状一度好转，但热度反复，影像学提示脓肿扩大伴中线移位。于入院第14天为患儿行颅骨硬膜下及硬膜外脓肿清创术。术后继续抗感染治疗6周，患儿体温恢复正常，脓肿吸收，痊愈出院。

Porphyromonas endodontalis is a Gram-negative anaerobic bacterium commonly found in the normal oral flora and is primarily associated with odontogenic infections. Intracranial infections caused by this bacterium are extremely rare. In January 2023, a 10-year-old male was admitted to hospital due to recurrent high fever accompanied by facial swelling for 3 days and one episode of convulsion. Physical examination revealed drowsiness, swelling of the face and neck, and a positive Brudzinski's sign. Laboratory tests showed a white blood cell count of 26.16×10⁹/L, C-reactive protein of 279.57 mg/L, and procalcitonin >100 ng/mL. Cerebrospinal fluid analysis indicated a white blood cell count of 45×10⁹/L and a protein level of 945 mg/L. Head magnetic resonance imaging revealed the formation of bilateral frontal lobe abscesses. Metagenomic next-generation sequencing of blood, cerebrospinal fluid, and pus detected sequences of Porphyromonas endodontalis and various other anaerobic bacteria. A definitive diagnosis of a brain abscess caused by Porphyromonas endodontalis was established. Although initial antimicrobial therapy with vancomycin, meropenem, linezolid, and metronidazole led to transient clinical improvement, the patient experienced recurrent fever, and follow-up imaging showed abscess enlargement with a midline shift. Subsequently, surgical debridement of the subdural and epidural abscesses was performed on the 14th hospital day. Postoperative anti-infective therapy was continued for 6 weeks, resulting in the resolution of fever, absorption of the abscess, and eventual recovery upon discharge.