Increase of ceftazidime- and fluoroquinolone-resistant Klebsiella pneumoniae and imipenem-resistant Acinetobacter spp. in Korea: analysis of KONSAR study data from 2005 and 2007

Abstract

Purpose: Antimicrobial resistance monitoring could be a useful source of information for treating and controlling nosocomial infections. We analyzed antimicrobial resistance data generated by Korean Hospitals and by a commercial laboratory in 2005 and 2007.

Materials and methods: Susceptibility data for 2005 and 2007 were collected from 37 and 41 hospitals, respectively, and from one commercial laboratory. Intermediate susceptibility was not included in the calculation of resistance rates.

Results: Methicillin-resistant Staphylococcus aureus (MRSA) (64%), third-generation cephalosporin-resistant Klebsiella pneumoniae (29%), fluoroquinolone-resistant Escherichia coli (27%), Pseudomonas aeruginosa (33%), and Acinetobacter spp. (48%), and amikacin-resistant P. aeruginosa (19%) and Acinetobacter spp. (37%) were prevalent in hospitals in 2007. A gradual increase of vancomycin-resistant Enterococcus faecium and imipenem-resistant Acinetobacter spp. was observed. Higher incidences of thirdgeneration cephalosporin-resistant E. coli and K. pneumoniae and imipenemresistant P. aeruginosa were found in the commercial laboratory than in the hospitals.

Conclusion: Methicillin-resistant S. aureus, third-generation cephalosporin- resistant K. pneumoniae, and fluoroquinolone-resistant E. coli, P. aeruginosa and Acinetobacter spp. remain prevalent in Korea, while the incidence of vancomycin-resistant E. faecium and imipenem-resistant Acinetobacter spp. has increased gradually. The higher prevalences of third-generation cephalosporinresistant E. coli and K. pneumoniae, and imipenem-resistant P. aeruginosa in the commercial laboratory are a new concern.

Fig. 1

The resistance trends of gram-positive cocci in the hospitals. Oxacillin-resistant S. aureus, penicillin-nonsusceptible S. pneumoniae, and ampicillin-resistant E. faecium continued to have high prevalence rates, and a gradual increase in vancomycin-resistant E. faecium strains was observed. OXA, oxacillin; PEN, penicillin; AMP, ampicillin; VAN, vancomycin; R, resistant; NS, nonsusceptible; SAU, S. aureus; SPN, S. pneumoniae; EFM, E. faecium.

Fig. 2

The resistance trends of K. pneumoniae in the hospitals. The cefoxitin resistance rate remained high but stable, whereas ceftazidime, fluoroquinolone, and amikacin resistance rates increased in 2005 compared to those of previous years. CAZ, ceftazidime; FOX, cefoxitin; FQN, fluoroquinolone; AMK, amikacin.

Fig. 3

The resistance trends of P. aeruginosa isolates from hospitals. The resistance rates to fluoroquinolone and amikacin declined slightly, but those to ceftazidime and imipenem remained stable. FQN, fluoroquinolone; AMK, amikacin; CAZ, ceftazidime; IPM, imipenem.

Fig. 4

The resistance trends of Acinetobacter spp. isolates in hospitals. The resistance rates to ceftazidime, fluoroquinolone, and amikacin decreased slightly, but that to imipenem increased steadily. FQN, fluoroquinolone; AMK, amikacin; CAZ, ceftazidime; IPM, imipenem.

Fig. 5

Comparison of the prevalence of antimicrobial-organism combinations in the hospitals and the commercial laboratory (ComLab) in 2007. Penicillin-nonsusceptible S. pneumoniae and vancomycin-resistant E. faecium were more prevalent in the hospitals. Cefotaxime-resistant E. coli and K. pneumoniae and imipenem-resistant P. aeruginosa were more prevalent among isolates in the commercial laboratory. OXA, oxacillin; R, resistant; SAU, S. aureus; PEN, penicillin; NS, nonsusceptible; SPN, S. pneumoniae; AMP, ampicillin; EFM, E. faecium; VAN, vancomycin; CTX, cefotaxime; ECO, E. coli; KPN, K. pneumoniae; IPM, imipenem; ACI, Acinetobacter spp.; PAE, P. aeruginosa.