Archives of Hellenic Medicine

Last update:

08-Jul-2009

Arch Hellen Med, 26(3), May-June 2009, 374-383

ORIGINAL PAPER

Prospective study of Klebsiella pneumoniae bacteremia:
Risk factors and clinical significance of type VIM-1 metallo-beta-lactamases

P. PETRIKKOS,¹C. KOSMIDIS,¹M. PSICHOGIOU,¹ P. TASSIOS,² L. TZOUVELEKIS,² A. AVLAMIS,³ I. STEFANOU,³ E. PLATSOUKA,⁴
O. PANIARA,⁴ A. XANTHAKI,⁵ M. TOUTOUZA,⁵ E. VRIONIS,⁶ A. SkOUTELIS,⁶ K. GEORGOUSI,⁷ C. BAMIA,⁸ G. PETRIKKOS,¹ G.L. DAIKOS¹
¹1st Department of Propedeutic Medicine, University of Athens, Athens,
²Laboratory of Microbiology, University of Athens, Athens,
³Laboratory of Microbiology, "Laiko" General Hospital, Athens,
⁴Laboratory of Microbiology, "Evangelismos" General Hospital, Athens,
⁵Laboratory of Microbiology, "Ippokrateion" General Hospital, Athens,
⁶5th Department of Medicine, "Evangelismos" General Hospital, Athens,
⁷2nd Department of Medicine, "Ippokrateion" General Hospital, Athens,
⁸Department of Hygiene and Epidemiology, University of Athens, Athens, Greece

OBJECTIVE VIM-1-producing K. pneumoniae (VPKP) is an emerging pathogen causing life-threatening infections. This study was conducted to identify the factors associated with bloodstream infections (BSI) caused by VPKP and to evaluate the importance of VIM production on outcome.

METHOD A prospective observational study was conducted in three tertiary care hospitals located in Athens, Greece, from 2004 to 2006. Consecutive patients with K. pneumoniae BSI were identified and monitored until discharge or death. Pertinent information was abstracted in a predesigned form. Antimicrobial susceptibility testing was performed by Etest. Microbial characteristics, including MBL production, blaVIM gene carriage and chromosomal types were examined. The data were analyzed to assess for risk factors associated with VPKP BSIs and 14-day mortality.

RESULTS A total of 178 patients with Klebsiella pneumoniae BSIs were identified; 67 (37.6%) were infected with a VPKP and 111 with a non-VPKP. MICs of imipenem for VPKP varied from the susceptible range to high-level resistance; 19 isolates were resistant to imipenem and 48 susceptible, whereas none of the non-VPKP exhibited resistance to carbapenems. VPKP were invariably multi-drug resistant. Prior use of carbapenems (OR 4.14; 95% CI 1.75-9.81; P=0.001) and stay in an intensive care unit (ICU) (OR 9.32; 95% CI 3.91-22.20; P<0.01) were independently associated with VPKP BSIs. Overall, patients infected with a VPKP had mortality rates similar to those infected with a non-VPKP. MIC of imipenem >4 μg/mL (OR 4.27; 95% CI 1.41-12.95; P=0.01), older age (OR 1.03; 95% CI 1.00-1.05; P=0.03) and rapidly fatal underlying disease (OR 3.15; 95% CI 1.23-8.04; P=0.016) were independently associated with 14-day mortality.

CONCLUSIONS VPKP have spread widely in Greece and cause life-threatening infections, mainly in ICU patients who have had prior exposure to carbapenems. VPKP BSIs are associated with high mortality rates when the infecting organism is resistant to carbapenems.

Key words: Bacteremia, Klebsiella, Metallo-beta-lactamases.