Infect Chemother.  2006 Dec;38(6):362-366.

Susceptibility of Clinical Isolates of Acinetobacter baumannii and Pseudomonas aeruginosa to Colistin and Polymyxin B in Korea

• Song W
• Lee TJ
• Park MJ
• Kim HS
• Kim JS
• Woo HJ
• Lee KM

Abstract

BACKGROUND: The emergence of multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa has become a major problem. The use of nontraditional agents such as colistin and polymyxin B have been tried. The purpose of this study was to evaluate the colistin and polymyxin B susceptibility of A. baumannii and P. aeruginosa isolates in Korea.
MATERIALS AND METHODS
According to susceptibility of ceftazidime and imipenem, selected 93 isolates of A. baumannii and 99 isolates of P. aeruginosa were collected from 5 university hospitals in Korea. Susceptibility to colistin and polymyxin B was tested using the reference broth microdilution method.
RESULTS
The rates of other beta-lactams, aminoglycosides, and ciprofloxacin susceptibility were high (58-100%, 50-100%, and 75-100%, respectively) in ceftazidime- and imipenem-susceptible isolates but were low (< or =31%, < or =47%, and < or =18%, respectively) in ceftazidime- or imipenem-resistant isolates (P<0.05). Colistin and polymyxin B displayed a nearly identical spectrum of activity, exhibiting excellent potency against A. baumannii (MIC50/90, 1/2 microgram/mL) and P. aeruginosa (MIC50/90, 1/1 microgram/mL). Only one of the A. baumannii isolates was resistant to colistin (MIC, 4 microgram/mL), but the isolate was susceptible to polymyxin B (MIC, 2 microgram/mL).
CONCLUSION
In Korea, no A. baumannii and P. aeruginosa isolates were resistant to both colistin and polymyxin B. These data suggested that polymyxins may be alternative drugs for multidrug-resistant A. baumannii and P. aeruginosa isolates.

Keyword

Acinetobacter baumannii; Pseudomonas aeruginosa; Colistin; Polymyxin B

MeSH Terms

Acinetobacter baumannii*
Acinetobacter*
Aminoglycosides
beta-Lactams
Ceftazidime
Ciprofloxacin
Colistin*
Hospitals, University
Imipenem
Korea*
Polymyxin B*
Polymyxins*
Pseudomonas aeruginosa*
Pseudomonas*
Aminoglycosides
Ceftazidime
Ciprofloxacin
Colistin
Imipenem
Polymyxin B
Polymyxins
beta-Lactams