Mucoviscous characteristics of Klebsiella pneumoniae strains: A factor of clinical severity?

Abstract

IntroductionHypermucoviscous Klebsiella pneumoniae (KP) strains are responsible for complicated bacteremia with multiple septic sites (liver, central nervous system, muscles). We aimed to compare the clinical severity of patients presenting with KP bacteremia based on the hypermucoviscous or non-hypermucoviscous characteristic of the strains. MethodsObservational retrospective study successively including all patients with KP bacteremia from May 2013 to March 2015 at the tertiary medical center of New Caledonia. The hypermucoviscous characteristic was defined by the string test results and molecular analysis to determine the capsular serotype. ResultsA total of 55 bacteremic patients were included in the study; 27% of isolated strains were hypermucoviscous. Hypermucoviscous strains accounted for two-thirds of community-acquired infections (72.5% vs. 33.4%, p=0.01). The rate of intensive care hospitalization was high (hypermucoviscous 46.7%; standard 52.5%) without any difference between the two groups. No significant difference was observed in case fatality (hypermucoviscous 46.7% vs. standard 15%, p=0.07) but patients with hypermucoviscous strains had longer hospital stays (73.5 days versus 50.7 days, p=0.04) and longer persistence of positive blood cultures despite an appropriate treatment (OR 1.41, 95% CI: 1.0–1.96, p=0.045). ConclusionHypermucoviscous KP bacteremia account for most community-acquired Klebsiella infections in New Caledonia and are associated with longer hospital stay and persistence of positive blood cultures despite the implementation of an appropriate treatment.