Denture-Associated Oral Microbiome and Periodontal Disease Causing an Anaerobic Pyogenic Liver Abscess in an Immunocompetent Patient: A Case Report and Review of the Literature

Abstract

Pyogenic liver abscesses (PLA) most commonly develop following peritonitis due to intra-abdominal bowel leakage with subsequent spread to the liver through the portal circulation or via direct spread from biliary infections. PLA are often polymicrobial and are uncommonly reported to be due to anaerobic species. We report the case of a previously healthy immunocompetent (IC) 63-year-old man who presented with a 4-day history of food aversion, subjective fever, chills, and epigastric pain. He had leukocytosis, elevation of his liver enzymes, and imaging that revealed several hepatic abscesses. Cultured fluid aspirated from the hepatic abscesses grew Fusobacterium Nucleatum. An extensive ID investigation was unremarkable; however, his examination was notable for removable partial dentures and advanced periodontal disease. He was managed with antibiotics, hepatic drains, teeth extractions, and removal of dentures. He was discharged home after a 4-wk hospitalization. Upon follow up at 2- and 6-wks post hospitalization, he remained asymptomatic, liver enzymes normalized, and repeat imaging demonstrated significant interval decrease of the rim enhancement and size of the known PLA, compatible with treatment response. He completed a total antibiotic course of 35 days. F. Nucleatum is an anaerobic, invasive, adherent, gram negative, spindle-shaped rod. This bacterium is indigenous to the human oral flora and plays a major role in periodontal disease. Interestingly, this anaerobe has also been associated with many other infections, including peritonsillar abscesses and appendicitis. However, with regards to liver abscesses, only 10 cases have been reported to be due to Fusobacterium in IC hosts (Table 2). Out of the 10 cases, 4/10 were polymicrobial, 6/10 were monomicrobial, 8/10 cases were F. nucleatum, while 2/10 were F. necrophorum. All cases were linked to periodontal disease, except for 3 of the cases, for which a source of the infection was unknown. In addition to our patient's periodontal disease, we believe that his partially removable dentures also played a role as a reservoir for the bacterium and source of PLA. Although anaerobic infections such as Fusobacterium most often occur in immunocompromised individuals, clinicians should have a high index of suspicion in IC patients with periodontal disease or chronic stomatitis. Additionally, as in our case, dentures may play a role in this uncommon presentation and oral hygiene should be emphasized.Table: Table. Case reports of immunocompetent patients with pyogenic liver abscess caused by Fusobacterium