J Clin Pathol Qual Control.  1998 Jun;20(1):199-205.

Evaluation of Disk Screen Test for Detection of High Level Gentamicin Resistance of Enterococci

• Uh Y
• Jang IH
• Hwang GY
• Yoon KJ

Abstract

BACKGROUND: In serious enterococcal infections such as septicemia, endocarditis, and meningitis, bactericidal therapy using combination of cell wall-active agents and aminoglycosides is needed. Synergistic effect depends mainly on high-level aminoglycoside resistance. Furthermore, high-level aminoglycoside resistance of enterococci has been increasingly reported, screening of enterococci for high-level resistance to gentamicin, and streptomycin is recommended. So, we evaluated three methods for detection of high-level resistance to gentamicin.
METHODS
Disk screen with high content gentamicin, agar screen, and broth screen for detecting high-level gentamicin resistance were compared using 63 clinical isolates of enterococci. Three screen methods were performed by National Committee for Clinical Laboratory Standards recommended procedures.
RESULTS
Proportion of high-level resistance to gentamicin were 66.7% (42/63), and agreement rate of disk screen, agar screen, and broth screen method were 100%, and enterococci with zone of 7 to 9 mm indicating inconclusive result in disk screen method were absent.
CONCLUSION
Disk screen with high-content gentamicin is a simple, accurate method for the detection of high-level gentamicin resistance, and suitable to use in clinical microbiology laboratories.

MeSH Terms

Agar
Aminoglycosides
Endocarditis
Gentamicins*
Mass Screening
Meningitis
Sepsis
Streptomycin
Agar
Aminoglycosides
Gentamicins
Streptomycin