Drug Susceptibility and Molecular Epidemiology of Klebsiella pneumoniae Bloodstream Infection in ICU Patients in Shanghai, China

Abstract

<b>Background:</b> Bloodstream infections (BSIs) are recognized as important nosocomial infections. <i>Klebsiella pneumoniae</i> is one of the major causes of bacteremia. This retrospective study focused on drug susceptibility and molecular epidemiology of <i>K. pneumoniae</i> isolated from intensive care unit (ICU) patients with BSI in Shanghai, China. <b>Methods:</b> Consecutive <i>K. pneumoniae</i> isolates were collected from ICU patients. Antibiotic susceptibility testing was conducted by the broth microdilution method. PCR was performed to detect antimicrobial resistance genes. We also completed multilocus sequence typing (MLST) and GoeBURST was used to analyze the result of MLST. <b>Results:</b> A total of 78 <i>K. pneumoniae</i> isolates were enrolled. <i>K. pneumoniae</i> from ICU-BSIs were highly resistant to almost all common antibiotics. The most frequent resistance determinants responsible for extended-spectrum β-lactamase (ESBL) producers were <i>bla</i> _CTX-M-14, <i>bla</i> _CTX-M-15, and <i>bla</i> _CTX-M-55. KPC was the only enzyme, which was detected by the carbapenemase producers. The most principal sequence types (STs) were ST11, ST15, and ST23. <b>Conclusion:</b> This study presents for the first time the antibiotic resistance phenotype and molecular epidemiology of <i>K. pneumoniae</i> isolated from ICU patients with BSIs in Shanghai. ICU-BSI <i>K. pneumoniae</i> is characteristic of a high resistance rate. The occurrence of the KPC-2 enzyme may result from nosocomial clonal dissemination of ST11 <i>K. pneumoniae</i>.