Supplementary Material for: A Rare Case of Capnocytophaga canimorsus Meningitis in an immunocompetent Patient: A successful Outcome with a Short course of Antibiotics

Introduction: Capnocytophaga canimorsus is a gram-negative bacterium found in the oral flora of dogs and cats, transmitted to humans through bites, licks, or scratches. Infections can lead to severe manifestations, including meningitis, particularly in immunocompromised individuals.
Case presentation: A 46-year old immunocompetent man presented with somnolence, headache, and fever after being licked by his dog. Neurological examination revealed signs of meningeal irritation, and cerebrospinal fluid analysis showed an elevated white cell count and protein levels consistent with bacterial meningitis. Treatment followed Dutch guidelines with amoxicillin, ceftriaxone, and dexamethasone, resulting in rapid clinical improvement. Microbiological confirmation of C. canimorsus followed later. The patient was treated with antibiotics for the duration of one week, and remained symptom-free after being discharged.
Conclusion: C. canimorsus meningitis, although rare, poses diagnostic challenges due to its variable presentation and slow growth in culture. Empirical therapy guided by susceptibility testing contributes to favorable outcomes. This case underscores the importance of considering a C. canimorsus infection in patients with animal exposure and of taking diagnostic findings, precedent, and clinical response into account when determining the treatment duration.

引言：犬咬二氧化碳嗜纤维菌（Capnocytophaga canimorsus）是一种定植于犬、猫口腔菌群的革兰氏阴性菌，可通过咬伤、舔舐或抓伤传播给人类。该菌感染可引发严重临床表现，包括脑膜炎，尤其好发于免疫功能低下人群。
病例报告：1例46岁免疫功能正常男性，在被自家犬舔舐后出现嗜睡、头痛及发热症状就诊。神经系统检查可见脑膜刺激征，脑脊液分析显示白细胞计数及蛋白水平升高，符合细菌性脑膜炎表现。治疗参照荷兰诊疗指南，予阿莫西林、头孢曲松及地塞米松联合治疗，患者临床症状快速改善。后续经微生物学检测证实为犬咬二氧化碳嗜纤维菌感染。患者接受为期1周的抗生素治疗，出院后未再出现相关症状。
结论：犬咬二氧化碳嗜纤维菌性脑膜炎虽属罕见疾病，但因其临床表现多样且培养生长缓慢，给临床诊断带来挑战。药敏试验指导下的经验性治疗有助于获得良好预后。该病例强调，对于有动物接触史的患者，需考虑犬咬二氧化碳嗜纤维菌感染的可能；且在确定抗菌疗程时，应综合考量诊断结果、临床参考依据及治疗应答。