Surveillance of Carbapenem-Resistant Klebsiella pneumoniae: Tracking Molecular Epidemiology and Outcomes through a Regional Network

<jats:title>ABSTRACT</jats:title> <jats:p> Carbapenem resistance in Gram-negative bacteria is on the rise in the United States. A regional network was established to study microbiological and genetic determinants of clinical outcomes in hospitalized patients with carbapenem-resistant (CR) <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Klebsiella pneumoniae</jats:named-content> in a prospective, multicenter, observational study. To this end, predefined clinical characteristics and outcomes were recorded and <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">K. pneumoniae</jats:named-content> isolates were analyzed for strain typing and resistance mechanism determination. In a 14-month period, 251 patients were included. While most of the patients were admitted from long-term care settings, 28% of them were admitted from home. Hospitalizations were prolonged and complicated. Nonsusceptibility to colistin and tigecycline occurred in isolates from 7 and 45% of the patients, respectively. Most of the CR <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">K. pneumoniae</jats:named-content> isolates belonged to repetitive extragenic palindromic PCR (rep-PCR) types A and B (both sequence type 258) and carried either <jats:italic>bla</jats:italic> <jats:sub>KPC-2</jats:sub> (48%) or <jats:italic>bla</jats:italic> <jats:sub>KPC-3</jats:sub> (51%). One isolate tested positive for <jats:italic>bla</jats:italic> <jats:sub>NDM-1</jats:sub> , a sentinel discovery in this region. Important differences between strain types were noted; rep-PCR type B strains were associated with <jats:italic>bla</jats:italic> <jats:sub>KPC-3</jats:sub> (odds ratio [OR], 294; 95% confidence interval [CI], 58 to 2,552; <jats:italic>P</jats:italic> < 0.001), gentamicin nonsusceptibility (OR, 24; 95% CI, 8.39 to 79.38; <jats:italic>P</jats:italic> < 0.001), amikacin susceptibility (OR, 11.0; 95% CI, 3.21 to 42.42; <jats:italic>P</jats:italic> < 0.001), tigecycline nonsusceptibility (OR, 5.34; 95% CI, 1.30 to 36.41; <jats:italic>P</jats:italic> = 0.018), a shorter length of stay (OR, 0.98; 95% CI, 0.95 to 1.00; <jats:italic>P</jats:italic> = 0.043), and admission from a skilled-nursing facility (OR, 3.09; 95% CI, 1.26 to 8.08; <jats:italic>P</jats:italic> = 0.013). Our analysis shows that (i) CR <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">K. pneumoniae</jats:named-content> is seen primarily in the elderly long-term care population and that (ii) regional monitoring of CR <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">K. pneumoniae</jats:named-content> reveals insights into molecular characteristics. This work highlights the crucial role of ongoing surveillance of carbapenem resistance determinants. </jats:p>