Clinical characteristics and prognosis of central nervous system Klebsiella pneumoniae infection: a focus on hypervirulent and classical strains.

OBJECTIVE

To investigate the clinical characteristics, diagnosis, treatment, and prognosis of 20 cases of central nervous system (CNS) Klebsiella pneumoniae infection diagnosed by metagenomic next-generation sequencing (mNGS), and to compare the differences between classical Klebsiella pneumoniae (cKP) and hypervirulent Klebsiella pneumoniae (hvKP) in central nervous system infections.

METHODS

Retrospective single-center study of 20 mNGS-diagnosed CNS K. pneumoniae infections (January 2022 - March 2026). Univariate analysis compared hvKP and cKP groups.

RESULTS

Among 20 patients, 19 were diagnosed by CSF mNGS and 1 by abscess fluid mNGS. The cKP group had a higher proportion of tumor history (P = 0.029) and a marginally higher rate of neurosurgery history (P = 0.082). Type 2 diabetes was common in both groups (66.7% vs. 62.5%). The hvKP group had higher rates of focal neurological deficits (77.8% vs. 12.5%, P = 0.015) and bacteremia/sepsis (66.7% vs. 37.5%, P = 0.009), while the cKP group had more delirium (62.5% vs. 11.1%, P = 0.050). CSF mNGS positivity (95%) surpassed culture (23.5%, P < 0.001). Radiologically, hvKP showed more brain abscesses (P = 0.015). hvKP had worse modified Rankin Scale scores (P = 0.002) and higher mortality (44.4% vs. 0%, P = 0.002). No cKP deaths occurred.

CONCLUSION

hvKP and cKP CNS infections differ significantly. hvKP is associated with community-onset severe disease (multiple brain abscesses, pyoventricle, focal deficits) and high mortality, while cKP links to nosocomial factors and better outcomes. mNGS is key for diagnosis, offering high CSF positivity and concurrent virulence/resistance profiling. Potential prognostic factors identified include high CSF mNGS reads, resistance genes, early liver abscess drainage, timely intravitreal injection, and combination therapy.