To characterize the clinical manifestations, virulence factors, and antimicrobial resistance profiles of hypervirulent Klebsiella pneumoniae (hvKp) infections, thereby improving the understanding of hvKp and informing evidence-based strategies for early diagnosis and precise antimicrobial therapy.

A retrospective analysis of 14 patients with hvKp infection admitted to the emergency department of peking university first hospital between April 2021 and May 2023 was performed. Data on clinical characteristics, laboratory results, virulence genes, and antimicrobial susceptibility were collected and analyzed.

All 14 patients with hvKp infections had community-acquired cases, predominantly male (71.43%, 10 cases/14 cases), with a median age of 69 years. Diabetes mellitus was present in 78.57% (11 cases/14 cases) of the patients. Clinical features included varying degrees of liver injury and bacteremia in all cases, with 71.43% (10 cases/14 cases) complicated by liver abscesses, 78.57% (11 cases/14 cases) by pulmonary infections, 57.14% (8 cases/14 cases) by acute kidney injury, 35.71% (5 cases/14 cases) requiring mechanical ventilation, and 35.71% (5 cases/14 cases) resulting in mortality. Laboratory findings showed significantly elevated C-reactive protein (CRP) and neutrophil to lymphocyte ratio (NLR) levels, which were 150.00~356.00 mg·L^-1and 9.04%~66.97%, respectively. 92.86% (13 cases/14 cases) exhibiting decreased albumin levels upon admission, of which 50% demonstrated a >20% decline by the next day. The string test was positive in 69.23% (9 cases/13 cases) of cases. Virulence and resistance profiling via mNGS on three isolated strains revealed the presence of iutA, iucABD, fimH, and gaLF genes in all isolates, with two (66.67%) carrying rmpA2. Among the 14 isolates, antimicrobial susceptibility testing of 12 hvKp strains indicated high susceptibility to most antibiotics; however, two (14.29%) were identified as multidrug-resistant (MDR) including one extended spectrumβ lactamases (ESBLs) producing strain and one carbapenem resistant carbapenem resistant klebsiella pneumoniae (CRKP) strain.

HvKp infections predominantly affect male patients with diabetes, characterized by liver abscesses leading to metastatic infections at multiple sites, rapid progression, and high mortality. Dynamic monitoring of albumin levels, the string test, and imaging studies facilitate early detection. Although most hvKp strains remain highly susceptible to commonly used antibiotics, vigilance against MDR strains is essential. Enhanced surveillance of high-risk populations and individualized antimicrobial strategies are recommended.