Prevalence in Singapore of enterococci with high-level resistance to aminoglycosides and comparison of three methods for their detection.
The first study of the prevalence in Singapore of enterococci with high-level resistance to aminoglycosides has been made in the National University Hospital. From March to June 1992, 225 isolates were studied by means of three methods: (1) use of brain-heart infusion (BHI) agar incorporating the antibiotic; (2) microdilution of the antibiotic in broth; and (3) use of high content antibiotic discs. The BHI agar was the reference method. Of the total, 49 (22%) isolates were resistant to gentamicin, 86 (38%) to streptomycin, 82 (36%) to kanamycin and 93 (41%) to one or more of the agents. Results of the disc diffusion method correlated completely with the BHI agar method. The broth microdilution method showed a 100, 90 and 96% sensitivity in relation to gentamicin, streptomycin and kanamycin, respectively, and a specificity of 100% for all three aminoglycosides. Statistical significance (P < 0.01 to P < 0.001) was demonstrated in (1) a greater incidence of enterococci with high-level resistance to aminoglycosides among blood isolates; (2) gentamicin resistance predicting kanamycin high-level resistance; and (3) more resistance to gentamicin, streptomycin and kanamycin among Enterococcus faecium isolates compared to those of Enterococcus faecalis. Beta-lactamase activity was not detected.
Chiew
Y F
YF
Department of Laboratory Medicine, National University Hospital, Singapore.
Lim
S W
SW
Kuah
B G
BG
Liew
H Y
HY
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects / Q000302:isolation & purification*; D016984:Enterococcus faecium / Q000187:drug effects / Q000302:isolation & purification*; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology*; D006801:Humans; D007613:Kanamycin Resistance; D015995:Prevalence; D012680:Sensitivity and Specificity; D012846:Singapore / Q000453:epidemiology
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents