Clinical, microbiological, and prognostic differences between hypermucoviscous and non-hypermucoviscous community-acquired Klebsiella pneumoniae infections.

Objective: This study investigates the clinical, microbiological, and prognostic variations between hypermucoviscous Klebsiella pneumoniae (hmKp) and non-hypermucoviscous Kp (n-hmKp) infections.

Methods: A total of 381 cases of community-acquired Klebsiella pneumoniae (cKp) infections at Zhongshan People's Hospital between January 2019 and November 2024 were analyzed. Infection characteristics, mortality risk factors, and antimicrobial susceptibility profiles were compared between hmKp and n-hmKp groups.

Results: No significant differences were observed between patients infected with n-hmKp and hmKp in terms of median age, gender, underlying conditions, hospital stay, ICU stay, and hospital mortality rates (all P > 0.05). However, the SOFA score was higher, and shock occurred more frequently in hmKp infections (all P < 0.05). In addition, hmKp exhibits a higher propensity for inducing invasive infections (P = 0.000). Multivariable logistic regression identified higher median age (OR: 1.08, P = 0.005), and tumors (OR: 5.73, P = 0.035) as risk factors for mortality in n-hmKp infections. Conversely, higher SOFA scores (OR: 2.08, P = 0.000), shock (OR: 48.55, P = 0.001), and elevated levels of procalcitonin (OR: 0.96, P = 0.019), lactic acid (OR: 1.78, P = 0.015), and troponin T (OR: 1.01, P = 0.029) were associated with mortality in hmKp infections. Both hmKp and n-hmKp strains exhibited varying degrees of antibiotic resistance, with n-hmKp strains demonstrating higher resistance to common antibiotics, especially for ceftriaxone, imipenem, and piperacillin-tazobactam compared to hmKp strains (all P < 0.05).

Conclusions: N-hmKp and hmKp exhibit significant differences in both clinical and microbiological characteristics. Heightened awareness of them is essential for effective management.