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Volume 45, Number 2, April 2012

Outcomes and characteristics of ertapenemnonsusceptible Klebsiella pneumoniae bacteremia at a university hospital in Northern Taiwan: A matched case-control study

Shi-Wei Liu, Hong-Jyun Chang, Ju-Hsin Chia, An-Jing Kuo, Tsu-Lan Wu, Ming-Hsun Lee

Received: December 12, 2010    Revised: April 13, 2011    Accepted: June 19, 2011   


Corresponding author:

Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, 5 Fu-Shin Street, Gueishan 333, Taoyuan, Taiwan.
E-mail address: (M.-H. Lee).


Background and purpose: 

Carbapenem-resistant Klebsiella pneumoniae is an emerging problem worldwide. The object of this study was to investigate the risk factors, characteristics and outcomes of ertapenem-nonsusceptible K pneumoniae  (ENSKp) bacteremia.



We conducted a 1:2 ratio matched case-control study. The controls were randomly selected among patients with ertapenem-susceptible K pneumoniae (ESKp) bacteremia and were matched with ENSKp cases for bacteremia.



Seventy-five patients were included in this study (25 cases and 50 controls). Bivariate analysis showed that prior exposure to either b-Lactam/b-Lactam-lactamase inhibitors (p Z 0.008) or 4th generation cephalosporins (p < 0.001), chronic obstructive pulmonary disease (COPD) (p Z 0.001), acute renal failure (p Z 0.021), chronic kidney disease without dialysis (p Z 0.021), recent hospital stay (p Z 0.016), intensive care unit stay (p Z 0.002), mechanical ventilation (p Z 0.003), central venous catheter placement (p Z 0.016), Foley indwelling (p Z 0.022), polymicrobial bacteremia (p Z 0.003) and higher Pittsburgh bacteremia
score (p < 0.001) were associated with ENSKp bacteremia. The multivariate analysis showed that prior exposure to 4th generation cephalosporins (odds ratio [OR], 28.05; 95% confidence interval [CI],  2.92e269.85; p Z 0.004), COPD (OR, 21.38; 95% CI, 2.95e154.92; p Z 0.002) and higher Pittsburgh bacteremia score (OR, 1.35; 95% CI, 1.10e1.66; p Z 0.004) were independent factors for ENSKp bacteremia. ENSKp bacteremia had a higher14-day mortality rate than ESKp bacteremia (44.0% vs. 22.0%; p Z 0.049). The overall inhospital mortality rates for these two groups were 60.0% and 40.0% respectively (p Z 0.102).



ENSKp bacteremia had a poor outcome and the risk factors were prior exposure of 4th generation  cephalosporins, COPD and higher Pittsburgh bacteremia score. Antibiotic stewardship may be the solution for the preventive strategy.


Key words:

Bacteremia; Ertapenem nonsusceptible; Klebsiella pneumoniae