Purpose: Hypervirulent klebsiella pneumoniae  (hvKP) is responsible for various invasive diseases and associated with high mortality. However, the clinical and microbiological factors of hvKP infection that influence prognosis have not been well studied. The purpose of this study was to evaluate the prognostic factors for in-hospital mortality of patients with hvKP infections, mainly focusing on clinical and microbiological characteristics.
Methods: A retrospective study was conducted in hvKP strains which positive for iucA  and string test. According to the clinical outcomes during hospitalization, hvKP-infected patients were divided into non-survivor and survivor groups. The clinical characteristics, capsule types, multi-locus sequence types (MLST), virulence genes and antimicrobial susceptibility were compared between those of the two groups.
Results: A total of 135 patients were demonstrated to be with hvKP infections, with a prevalence rate of 22% among all the klebsiella pneumoniae  infected cases. Sixteen of these patients died during hospitalization, with an in-hospital mortality rate of 11.9%. Univariate analysis confirmed that admission to the intensive care unit (ICU) (p=0.008), antimicrobial resistance of hvKP to ampicillin/sulbactam (p=0.028), cefepime (p=0.033), aztreonam (p=0.049) and harboring iroN  gene (p=0.023) were associated with in-hospital mortality. On the contrary, the rmpA  gene showed an inverse association with in-hospital mortality (p=0.017). Multivariate logistic regression analysis revealed that ICU admission (odds ratio [OR]=3.452, 95% confidence interval [CI]=1.052– 11.329; P=0.041) and iroN  carriage (OR=9.278, 95% CI=1.654– 52.035; P=0.011) were independent prognostic factors for the in-hospital mortality of patients with hvKP infections.
Conclusion: Emerging hvKP infection may lead to relatively high in-hospital mortality. ICU admission and iroN  carriage were independent prognostic factors for the in-hospital mortality of patients with hvKP infections.
Keywords: hypervirulent Klebsiella pneumoniae , prognostic factors, iucA , iroN , in-hospital mortality