Clinical features of patients with carbapenem nonsusceptible Klebsiella pneumoniae and Escherichia coli in intensive care units: a nationwide multicenter study in Taiwan.

Patients in intensive care units (ICUs) are especially prone to colonization and infection by carbapenem-resistant Enterobacteriaceae. We conducted a multicenter investigation to study the clinical and microbiological characteristics of patients with carbapenem nonsusceptible Klebsiella pneumoniae and Escherichia coli in ICUs of Taiwanese hospitals. Patients with carbapenem nonsusceptible K. pneumoniae and E. coli in ICUs from nine medical centers and eight regional hospitals in Taiwan were enrolled in 2012. Carbapenem nonsusceptibility was defined as a minimum inhibitory concentration of at least 2 mg/L for imipenem or meropenem. Clinical characteristics and risk factors for 30-day mortality were analyzed. Isolates were screened for antibiotic susceptibility and β-lactamase genes. A total of 66 cases infected (n = 46) or colonized (n = 20) with carbapenem nonsusceptible K. pneumoniae (n = 60) and E. coli (n = 6) were identified during the study period. Nineteen isolates had genes that encoded carbapenemases (28.8%), including Klebsiella pneumoniae carbapenemase-2 (KPC-2) (n = 14), imipenemase-8 (IMP-8) (n = 1), Verona integron-encoded metallo-β-lactamase (VIM) (n = 3), and New Delhi metallo-β-lactamase-1 (NDM-1) (n = 1). The in-hospital mortality associated with non-susceptible K. pneumoniae and E. coli was 50%. The 30-day mortality of the 46 patients with infection was 50%. Septic shock was the only independent risk factor for 30-day mortality in patients with infection. The 30-day mortality rate was similar between patients with combination therapy and monotherapy. Patients who acquired carbapenem nonsusceptible K. pneumoniae and E. coli in ICUs have a high mortality rate. Further clinical study is needed to deal with this emerging challenge.