Authors
Denise Powell, Medical Student, Sarah Kerut, MD, Alisha Parker, DO, Christian Weaver, MD, Pradeep Bathina, MD, University of Mississippi Medical Center, Jackson, MS
Introduction
Fusobacterium nucleatum is an overlooked gram-negative anaerobe that causes a wide array of life threatening infections. The variable and vague clinical presentation of this bacteria makes early diagnosis of Fusobacterium bacteremia crucial to ensure optimal treatment.
Case Presentation
A 23-year-old African-American female presented with sore throat, right lateral neck pain, and malaise. She had not received maintenance of braces or dental care for 7 months. On examination, she had blood- stained braces, gum hyperplasia, black eschars of her lips, bleeding oral ulcers, thrush, and enlarged yellow papillae on her tongue. Vitals were blood pressure of 100/63 mmHg, maximum temperature of 101.6�F, respiratory rate of 18/min, and heart rate of 114 beats/min; labs on presentation included WBC count of 20,000/uL, sodium of 127 mmol/L, anion gap of 14.0 mmol/L, BUN of 87 mg/dL, creatinine of 4.00 mg/dL, glucose of 151 mg/dL, AST of 816 U/L, ALT of 175 U/L, alkaline phosphatase of 233 U/L, total bilirubin of 7.10 mg/dL, CRP of 12.3 mg/dL, creatinine kinase of 57,040 U/L, eGFR of 17.0 mL/min/1.73m2, lipase of 553 U/L, procalcitonin of 100 ng/mL, and lactate of 2.70 mmol/L. Clinical diagnosis of severe sepsis was made, and broad spectrum antibiotics vancomycin/piperacillin-tazobactam were started. During hospital course, patient also needed vasopressors after a fluid challenge. CT showed tonsillar abscesses and distant pulmonary septic emboli. Blood cultures were positive for Fusobacterium nucleatum, and throat cultures were positive for Streptococcus pyogenes and Staphylococcus aureus. Oral Maxillofacial Surgery was consulted, and dental braces were removed for source control. Echocardiogram was done to rule out vegetations and found incidental foramen ovale. She was discharged on long-term IV ceftriaxone/metronidazole.
Discussion
This case illustrates the variability in clinical spectrum of Fusobacterium infections in patients with orthodontic fixed appliances. Fusobacterium is an obligate gram-negative anaerobic rod (GNAR), and poor care of her braces provided a foreign material that was easily colonized by other facultative species and promoted a symbiotic environment that allowed Fusobacterium to thrive. The subsequent throat infection progressed to tonsillar abscesses and bacteremia. F. nucleatum then disseminated and colonized the lungs because of its specialized virulence factor, FadA adhesin, that binds to cadherins. There was no radiological evidence of venous thrombus, but this patient's clinical presentation of septic pulmonary emboli was a rare case of septic emboli traversing the patent foramen ovale via right-to-left shunting and causing distant metastatic infections in the lung. When confronted with a sore throat and nonspecific symptoms in a young patient with braces, the possibility of anaerobes as causative agents of infection must be considered. The importance of dental follow-up and dental hygiene with braces could prevent similar clinical presentations. Early diagnosis and treatment can result in avoiding complications, such as septic shock, septic emboli, or even death.