Clinical characteristics and manifestations in patients with hypermucoviscous Klebsiella pneumoniae bacteremia from extra-hepatobiliary tract infection

Purpose Hypermucoviscous strains of Klebsiella pneumoniae (KP) are associated with invasive liver abscess syndrome. However, little is known about the characteristics of this phenotype in non-hepatobiliary infections. In this study, we investigated the clinical characteristics of patients with hypermucoviscous Kp (hmvKp) bacteremia from non-hepatobiliary tract infection. Methods This retrospective cohort study was implemented at Samsung Changwon Hospital. From March 2018 to December 2019, adult patients (>= 18 years) with KP bacteremia of the extra-hepatobiliary system were enrolled. Hypermucoviscosity was defined by the string test. Clinical characteristics and 30-day all-cause mortality between patients with hmvKp and non-hmvKp bacteremia were compared. Results Among 179 cases of non-hepatobiliary KP bacteremia, 67 (37.4%) and 112 (62.6%) isolates were classified as hmvKp and non-hmvKp, respectively. In the hmvKp group, metastatic infection (9.0 vs. 1.8%, P = 0.054) and purulent or necrotizing infection (31.3 vs. 9.8%, P < 0.001) were more frequently observed. Additionally, non-hmvKp had more frequent resistance to cefotaxime (11.9 vs. 38.4%, P < 0.001). Thirty-day all-cause mortality was similar in the hmvKp (41.8%) and non-hmvKp (39.3%) groups (P = 0.643). In multivariable analysis, septic shock (adjusted hazard ratio [aHR] = 3.05, 95% confidence interval [CI]: 1.22-7.63) and Pitt bacteremia score (aHR = 1.23 per 1 point, 95% CI 1.14-1.33) were associated with increased mortality in patients with Kp bacteremia, while urinary-tract infection (aHR = 0.38, 95% CI 0.18-0.76) was associated with decreased mortality. Conclusion hmvKp was associated with less frequent drug resistance and metastatic-purulent presentation in non-hepatobiliary infection like in hepatobiliary infection. However, hmvKp was not associated with clinical outcomes.

Automated summary

This study investigated the clinical characteristics of patients with hypermucoviscous Klebsiella pneumoniae (hmvKp) bacteremia from non-hepatobiliary tract infection. The results showed that hmvKp was associated with less frequent drug resistance and metastatic-purulent presentation, but not with clinical outcomes.