Fusobacterium Nucleatum Infection Leading to Rare Hepatorenal Abscess: A Case Report

Lei JinChangkang ChenHong ZhaoLei ChenXian WangQin WangJi YuanJinjin LiShen XuRunzhen ZhangWenwen ChuNaifang YeGuizhou ZouJun Ye^*

• Second Hospital of Anhui Medical University, Hefei, China

Fusobacterium nucleatum is a gram-negative anaerobic bacterium commonly associated with periodontal disease. However, its role in extraoral infections, particularly in immunocompetent individuals, is increasingly recognized. We report a rare case of hepatorenal abscess caused by F. nucleatum in a previously healthy woman, initially suspected to have a malignant tumor based on PET-CT findings. Next-generation sequencing (NGS) of abscess aspirate confirmed the pathogen. The patient responded well to targeted antibiotic therapy. This case highlights the importance of considering anaerobic pathogens in deep-seated abscesses and the utility of NGS in achieving accurate microbial diagnosis. Key words. Fusobacterium nucleatum; hepatorenal abscess; metagenomic next-generation sequencing (mNGS); Infectious disease diagnosis; oral cavity infection 1.Introduction Fusobacterium nucleatum is a Gram-negative anaerobic bacterium that is commonly found as the normal flora in the oral cavity, gastrointestinal tract, and reproductive tract. It typically exists as acommensal organism and sometimes acts as a pathogenic agent leading to infections [1]. Although F. nucleatum infections are most frequently observed in the oral cavity and head and neck region, particularly in periodontal disease, there are also reports showing that F. nucleatum can cause lung abscess, brain abscess, and sepsis [1][2][3][4]. However, the liver remains a common site for intra-abdominal abscess formation. This is attributed to its dual blood supply from the hepaticartery, hepatic veins, and portal vein. Studies have shown that 48% of intra-abdominal abscesses occur in the liver [5].What is of particular scientific interest is that cases of disseminated abscesses