Changing susceptibilities of coagulase-negative staphylococci to teicoplanin in a teaching hospital.
The susceptibility of two collections of coagulase-negative staphylococci (CNS) isolated from clinical specimens for teicoplanin and vancomycin were compared. They comprised 91 and 101 isolates, collected in 1985 and 1994 respectively, from different departments of a teaching hospital. MICs of vancomycin and teicoplanin were determined by a modified Etest method. Additionally, a disc diffusion test was performed for teicoplanin. All isolates were susceptible to vancomycin (MIC < or = 4 mg/L). Two of the 91 isolates collected in 1985 were intermediate to teicoplanin (MIC between 8 and 32 mg/L), whereas in 1994 the number of intermediate isolates was 20 out of 101 (P < 0.01). The correlation between MICs, as determined by the modified Etest assay, and disc diffusion zones was poor (r = -0.35). Results show that resistance to teicoplanin in CNS has increased in the study hospital over a period of 9 years. This increase is likely to be correlated with the introduction of teicoplanin. Furthermore, a disc diffusion method does not appear to be the first method of choice for detection of strains of CNS with diminished susceptibility to teicoplanin.
Sloos
J H
JH
Department of Medical Microbiology, Leiden University Medical Center, The Netherlands.
van de Klundert
J A
JA
Dijkshoorn
L
L
van Boven
C P
CP
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003030:Coagulase / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D006784:Hospitals, Teaching; D006801:Humans; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000382:microbiology*; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification; D017334:Teicoplanin / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D003030:Coagulase; D017334:Teicoplanin; D014640:Vancomycin