Open AccessInvestigation of Staphylococcus aureus Isolates Identified as Erythromycin Intermediate by the Vitek-1 System: Comparison with Results Obtained with the Vitek-2 and Phoenix Systems
Author(s) -
Patrick Tang,
Donald E. Low,
Sandra Atkinson,
Karen Pike,
Aisha Ashi-Sulaiman,
Andrew E. Simor,
Susan E. Richardson,
Barbara M. Willey
Publication year - 2003
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.41.10.4823-4825.2003
Subject(s) - erythromycin , staphylococcus aureus , microbiology and biotechnology , broth microdilution , biology , micrococcaceae , antibacterial agent , antibiotics , minimum inhibitory concentration , bacteria , genetics
We identified 69 Staphylococcus aureus isolates that were erythromycin intermediate as reported by the Vitek-1 system using the GPS-105 card. Of the 57 strains that were available for further testing, all were erythromycin resistant by broth microdilution and the Phoenix system, while the Vitek-2 system identified 55 of 57 strains (96%) as erythromycin resistant. The majority of isolates (54 of 57 [95%]) exhibited the inducible MLS (macrolide-lincosamide-streptogramin family) phenotype, as shown by the double-disk test. We recommend that all S. aureus strains determined as erythromycin intermediate by the Vitek-1 system be interpreted as resistant to erythromycin.