Performance of different commercial methods for determining minimum inhibitory concentrations of glycopeptides and linezolid against blood isolates of Staphylococcus aureus
Performance of different commercial methods for determining minimum inhibitory concentrations of glycopeptides and linezolid against blood isolates of Staphylococcus aureus
(2013)
Performance of different commercial methods for determining minimum inhibitory concentrations of glycopeptides and linezolid against blood isolates of Staphylococcus aureus
The aim of this study was to determine the accuracy of commercial
systems (VITEK (R) 2, Etest and Sensititre (R)) in determining the
minimum inhibitory concentrations of vancomycin, teicoplanin and
linezolid of Staphylococcus aureus strains and to evaluate the
reproducibility of each system in a clinical microbiology laboratory. In
total, 115 strains of S. aureus isolated from blood cultures were tested
with all three commercial methods as well as the broth microdilution
method, which is designated as the standard for glycopeptides and
linezolid. Fourteen different S. aureus strains were included in a
reproducibility test for all methods and antibiotics. For these strains,
antimicrobial susceptibility testing was repeated 10 times on different
days with all four methods, each time using the same inoculum. All three
commercial methods exhibited similar performance in categorisation of
nearly all of the meticillin-susceptible S. aureus (MSSA) isolates.
Discrepancies were registered for meticillin-resistant S. aureus (MRSA);
2.5\% of the strains in the intermediate or resistant category with the
VITEK 2 system were not recognised as resistant by Etest and Sensititre.
Moreover, none of the three commercial methods provided accurate results
compared with homemade broth microdilution. Reproducibility of
vancomycin and teicoplanin was 100\% with VITEK 2 and Sensititre and
98.75\% with Etest. Microdilution showed a reproducibility of 95.6\%
with vancomycin and 83.1\% with teicoplanin. In contrast to previous
reports, the best agreement with microdilution was exhibited by VITEK 2
both for MSSA and MRSA. For the antibiotics tested, the best
reproducibility was obtained with the VITEK 2 and Sensititre systems.
(C) 2013 International Society for Chemotherapy of Infection and Cancer.
Published by Elsevier Ltd. All rights reserved.
Id prodotto:
89623
Handle IRIS:
11562/932621
ultima modifica:
1 dicembre 2022
Citazione bibliografica:
LO CASCIO, Giuliana; Balzaj, A; Maccacaro, L; Fontana, Roberta; Centonze, Anna Rita; Sorrentino, A; Mazzariol, Annarita,
Performance of different commercial methods for determining minimum inhibitory concentrations of glycopeptides and linezolid against blood isolates of Staphylococcus aureus«JOURNAL OF GLOBAL ANTIMICROBIAL RESISTANCE»
, vol. 1
, n. 3
, 2013
, pp. 163-169