The First Known Case of Liver Abscess Caused by <i>Aggregatibacter aphrophilus</i> in Japan

Abstract

A 48-year-old man presented with a sustained fever. Abdominal computed tomography revealed multilocular liver abscesses. He underwent percutaneous needle aspiration, yielding straw-colored pus. Gram staining revealed Gram-negative coccobacilli. The organism grew only on chocolate II agar in a 7% carbon dioxide atmosphere. Identification of Aggregatibacter aphrophilus was confirmed using mass spectrometry and 16S rRNA gene sequencing. He was successfully treated with antibiotics. Liver abscess caused by A. aphrophilus is extremely rare. We herein report the first such case in Japan. Even fastidious organisms, such as A. aphrophilus, should be correctly identified using mass spectrometry or 16S rRNA gene sequencing for adequate treatment.

Invasive Aggregatibacter infection: shedding light on a rare pathogen in a retrospective cohort analysis

“…A. aphrophilus is well recognized as a cause of brain abscesses and has also been implicated in a range of invasive infections, including endocarditis, spinal abscess, liver abscess and acute appendicitis [14][15][16][17][33][34][35][36]. One patient with brain abscess in this series had A. aphrophilus cultured from neurosurgical intraoperative samples, while another with A. aphrophilus endocarditis had cerebral septic emboli, highlighting the particular affinity of this species for the brain parenchyma.…”

“… A. aphrophilus is well recognized as a cause of brain abscesses and has also been implicated in a range of invasive infections, including endocarditis, spinal abscess, liver abscess and acute appendicitis [14–17, 33–36]. One patient with brain abscess in this series had A.…”

Case Report: The First Case of Bloodstream Infection Complicated with Psoas Abscess and Pulmonary Infection Caused by Aggregatibacter aphrophilus in China

“…Another reason for the negative culture could be the difficulty in culturing Aggregatibacter aphrophilus , since it was detected by nucleic acid detection in several previous studies. 5 , 13–16 The immunosuppressed status and previous invasive procedures, such as tooth manipulation, subject patients to Aggregatibacter aphrophilus infection. 17 , 18 However, in this case, the patient was not predisposed to these risk factors, implying its potential to infect immunocompetent individuals, as reported previously.…”