Bloodstream infections due to Klebsiella pneumoniae in an intensive care unit in Greece: susceptibility patterns and clinical characteristics

Abstract number: 1732_202

Pavleas J., Skiada A., Salatas K., Koufakos K., Rigas A., Archontoulis N., Vernikos P., Mega A., Thomopoulos G., Rigas K.

Objectives: In recent years K. pneumoniae has been shown to have increasing resistance, due to production of extended-spectrum b-lactamases (ESBLs) or metallo-b-lactamases (MBLs). The aim of this study was to record the bacteraemias due to K. pneumoniae in our ICU, to analyse the patterns of resistance, as well as the clinical characteristics of the ensuing infections.

Methods: Prospective observational study in patients who were hospitalised in the ICU, from September 2004 to October 2006. The demographic characteristics of all patients admitted were recorded, as well as the underlying diseases, disease severity as estimated by the APACHE II score and possible factors predisposing to infections, such as previous consumption of antibiotics. Susceptibility testing of culture isolates was performed by MicroScan autoSCAN4. The outcome of all bacteraemias was recorded. Statistical analysis was done with ESPSS v.12.

Results: During the study period 290 patients were admitted to the ICU and 160 episodes of bacteraemia were recorded. Of these, 29 (18%) were due to K. pneumoniae. The isolates were resistant as follows: 100% to ampicillin, 72% to b-lactamase inhibitors, 90% to 3rd-generation cephalosporins, 41% to imipenem (MIC > 4 mg/L), 41% to aztreonam, 86% to quinolones and 31% to aminoglycosides. All isolates were susceptible to colistin (MIC ≤ 2 mg/L). The carbapenem-resistant isolates (CRKP) were also resistant to all other antibiotics tested, except aztreonam and gentamicin (75% and 58% sensitive respectively). The bacteria were isolated in 23 patients (mean age 67 years, 69% male) of whom 56% were surgical. Their mean APACHE II score was 19. Ten bacteraemias were primary, 5 secondary to ventilator-associated pneumonia and 14 catheter-related. The 14-days mortality of patients with bacteraemia due to CRKP was 53%, while in those with sensitive strains it was 28% (p = 0.2). Outcome was significantly related to the APACHE II score (p = 0.02). Of the patients who had bacteraemia due to CRKP, 77% had been previously receiving a carbapenem. Of those who had a carbapenem-sensitive isolate, 35% had been receiving a carbapenem (p = 0.4)

Conclusions: Infections due to K. pneumoniae resistant to carbapenems represent a serious clinical problem in our ICU and are associated with a high mortality rate. It seems that previous use of carbapenems leads to increased resistance. Larger studies are needed in order to obtain statistically significant results.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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