Further increase of vancomycin-resistant Enterococcus faecium, amikacin- and fluoroquinolone-resistant Klebsiella pneumoniae, and imipenem-resistant Acinetobacter spp. in Korea: 2003 KONSAR surveillance

Abstract

Monitoring temporal trends of antimicrobial resistance can provide useful information for the empirical selection of antimicrobial agents to treat infected patients and for the control of nosocomial infections. In this study, we analyzed antimicrobial resistance of clinically relevant bacteria in 2003 at Korean hospitals and at a commercial laboratory. The following organism-antimicrobial agent resistance combinations were very prevalent: oxacillin-resistant Staphylococcus aureus (68%), expanded-spectrum cephalosporin-resistant Klebsiella pneumoniae (25%), and fluoroquinolone-resistant Escherichia coli (33%), Acinetobacter spp. (58%), and Pseudomonas aeruginosa (40%). Moreover, gradual increases in vancomycin-resistant Enterococcus faecium (20%), cefoxitin-resistant E. coli (10%) and K. pneumoniae (23%), and imipenem-resistant P. aeruginosa (20%) and Acinetobacter spp. (13%) were also observed. The resistance rates of Acinetobacter spp. to most antimicrobial agents at hospitals and at the commercial laboratory were similar. Among the Acinetobacter spp. isolated at a tertiary-care hospital, 46.2% were multidrug-resistant to 9-12 of 13 antimicrobial agents, and 18.3% were panresistant. The exclusion of duplicate isolates at a tertiary-care hospital significantly lowered the proportion of oxacillin-resistant S. aureus, vancomycin-resistant E. faecium, and fluoroquinolone-resistant E. coli.

Fig. 1

The resistance trends of staphylococci to oxacillin, and E. faecium to ampicillin and vancomycin. Continued high prevalence of oxacillin-resistant staphylococci, ampicillin-resistant E. faecium, and a gradual increase of vancomycin-resistant E. faecium were observed. OXA, oxacillin; AMP, ampicillin; VAN, vancomycin; R, resistant; SAU, S. aureus; CNS, coagulase-negative staphylococci; EFM, E. faecium.

Fig. 2

The resistance trend of K. pneumoniae to cefoxitin, ceftazidime, amikacin, and fluoroquinolone. The ceftazidime resistance rate remained high, while a tendency of increasing resistance to other antimicrobial agents was observed. FOX, cefoxitin; CAZ, ceftazidime; AMK, amikacin; FQN, fluoroquinolone.

Fig. 3

The resistance trend of Acinetobacter spp. to amikacin, fluoroquinolone, and ceftazidime remained high, and a tendency for increasing imipenem-resistance was observed. AMK, amikacin; FQN, fluoroquinolone; CAZ, ceftazidime; IMP, imipenem.

Fig. 4

Antimicrobial resistances of strains isolated at three hospital groups and tested at a commercial laboratory. Resistance rates were generally higher in the large hospital group. Vancomycin-resistant E. faecium and imipenem-resistant Acinetobacter spp. were much less prevalent among the commercial laboratory tested strains. S-med, Seoul-medium; N-med, non-Seoul-medium; Comm Lab, commercial laboratory; VAN, vancomycin; FQN, fluoroquinolone; FOX, cefoxitin; IPM, imipenem; EFM, E. faecium; ECO, E. coli; KPN, K. pneumoniae; PAE, P. aeruginosa; ABA, A. baumannii.

Fig. 5

Multi-resistance of Acinetobacter spp. isolated at a tertiary-care hospital. Among the isolates 11.5% were resistant to none of the 13 antimicrobial agents tested, but 18.3% were resistant to all of the agents tested.