Risk factors for carbapenem-resistant<i>Klebsiella pneumoniae</i>infection/colonization and predictors of mortality: a retrospective study

Abstract

OBJECTIVE: To identify risk factors associated with carbapenem-resistant Klebsiella pneumoniae (CRKP) infection/colonization and death and to investigate the resistance and homology of CRKP. METHODS: A retrospective 1:1 case-control study was conducted at Changhai Hospital, China, from January 2010 to December 2011.The study population included 30 patients with CRKP infection/colonization and 30 matched patients with carbapenem-susceptible K. pneumoniae (CSKP) infection/colonization at the same site. Homology analysis was conducted by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Potential resistance genes were detected by PCR. RESULTS: Independent risk factors for CRKP infection/colonization were admission to exposure to glycopeptides [Odds ratio (OR): 43.84, 95% confidence interval (CI): 1.73-1111.91, P = 0.020], cefoperazone plus sulbactam (OR: 49.56, 95% CI: 1.42-1726.72, P = 0.030) and tracheostomy (OR: 677.82, 95% CI: 2.76-1667, P = 0.020). Age (OR: 1.07, 95% CI: 1.00-1.14, P = 0.04), renal dysfunction (OR: 17.63, 95% CI: 2.34-132.87, P = 0.005) and exposure to cefoperazone plus sulbactam (OR: 8.87, 95% CI: 1.29-61.07, P = 0.026) were independent risk factors for the death of patients with K. pneumoniae infection/colonization. Older age (OR: 1.16, 95% CI: 1.01-1.39, P = 0.011) was an independent risk factor for the death of patients with CRKP infection/colonization. Thirty CRKP strains were all KPC-2-producing resistant strains with genotype of ST-11. CONCLUSION: Exposure to glycopeptides, cefoperazone plus sulbactam and tracheostomy were independent risk factors for CRKP infection/colonization, and older age was an independent risk factor for CRKP infection/colonization caused death.