Comparison of pyogenic liver abscesses caused by hypermucoviscous Klebsiella pneumoniae and non-Klebsiella pneumoniae pathogens in Beijing: A retrospective analysis

Objective: To perform a retrospective comparison of the clinical and radiological features of Klebsiella pneumoniae (KP)-associated and non-KP-associated pyogenic liver abscesses (PLA) in Chinese patients. Methods: Patients with confirmed diagnoses of bacterial liver abscess at three Beijing hospitals were enrolled. Clinical isolates from liver abscesses were used to determine serology and expression of hypermucoviscosity genes. Basic clinical, ultrasonographic (US) and computed tomography (CT) data were recorded and compared between patients with KP- and non-KP-associated PLA. Results: A total of 101 (77.10%) and 30 (22.90%) cases were due to KP and non-KP pathogens, respectively. Compared with the non-KP cohort, the KP cohort demonstrated a significantly higher incidence of underlying diabetes mellitus, and more gas-forming abscesses, as demonstrated by US and CT examinations. Prior abdominal surgery or chemoradiation therapy was significantly associated with non-KP cases. The non-KP group had a higher chance of a clear edge, compared with the KP group, on pre-contrast CT images. Conclusion: KP and non-KP-associated PLA have distinctive risk factors and unique US and CT features, in Chinese patients.