Gentamicin therapy for sepsis due to carbapenem-resistant and colistin-resistant Klebsiella pneumoniae

Objectives: Antimicrobial therapy for sepsis caused by carbapenem-and colistin-resistant Klebsiella pneumoniae is not well established. We hypothesized that the early use of gentamicin in cases due to susceptible organisms would decrease the crude mortality rate of this infection. Methods: This retrospective cohort study examined 50 cases of sepsis caused by carbapenem-resistant K. pneumoniae occurring between June 2012 and February 2013 during an outbreak of K. pneumoniae ST512 producing KPC-3, SHV-11 and TEM-1. Survival curves categorized by the use of gentamicin were constructed using the Kaplan-Meier method and compared using the log-rank test. Eight multivariate models using Cox regression were designed to study the risk factors for mortality and test the hypothesis. Results: The 30 day crude mortality rate was 38%. The use of targeted gentamicin was associated with reduced mortality (20.7% versus 61.9%, P = 0.02). In all multivariate regression models, the use of gentamicin was independently associated with lower mortality until Day 30 (HR 0.17-0.29, P = 0.03-0.002 depending on the model) after controlling for other potential confounding variables such as age, optimal treatment, renal function, severity of infection, underlying disease, use of tigecycline and previous hospitalization. Conclusions: Gentamicin reduced the mortality from sepsis caused by this K. pneumoniae ST512 clone producing KPC-3, SHV-11 and TEM-1.