Skip directly to site content

Panel:   Vancomycin Intermediate Staphylococcus aureus (VISA)
AR Bank # 0221 Staphylococcus aureus
Study ID: VISA-07

Biosample Accession #: SAMN04901611


MICs obtained by broth microdilution. Modal MIC is reported.

MIC results for each antimicrobial agent for an isolate may commonly be ± 1 log2 (doubling dilution) different than what is posted on the FDA & CDC AR Bank website because this is the normal technical variability of antimicrobial susceptibility testing (see J. H. Jorgensen. 1993. J Clin Microbiol. Vol 31[11]: 2841-2844).

Panel:  Vancomycin Intermediate Staphylococcus aureus (VISA)

MIC (μg/ml) Results and Interpretation
Drug MIC (μg/ml) INT
Cefoxitin 2>16R
Ceftaroline 0.5S
Clindamycin <=0.25S
Daptomycin 4NS
Doxycycline 4S
Erythromycin 0.5S
Gentamicin 16R
Levofloxacin >16R
Linezolid 2S
Mupirocin <=4---
Oxacillin 8R
Penicillin >2R
Rifampin 1S
Tetracycline >16R
Trimethoprim/sulfamethoxazole 1>8R
Vancomycin 4I
S – I –R Interpretation (INT) derived from CLSI 2021 M100 S31
NS = Nonsusceptible

1 Reflects MIC of first component
2 Cefoxitin is tested as a surrogate for mecA-mediated oxacillin resistance
Molecular Mechanisms of Resistance
Aminoglycoside aac(6')-aph(2''), aph-STPH
Beta-lactam blaI, mecA, Z
Fosfomycin fosB
Tetracyclines tet(M)
The resistance mechanisms listed were identified by analysis of whole genome sequence using the ResFinder database (last updated June 2, 2016 and accessed on October 25, 2016). This analysis does not include mutations that may result in antibiotic resistance or resistance determinants added to newer versions of the ResFinder database or other antimicrobial resistance gene databases. Biosample accession numbers have been provided so that users can analyze the data on their own if so desired.
Medium: Trypticase Soy Agar with 5% Sheep Blood (BAP)

Temperature: 35°C
Atmosphere: Aerobic


Remove the sample vial to a container with dry ice or a freezer block. Keep vial on ice or block. (Do not let vial content thaw)

Open vial aseptically to avoid contamination

Using a sterile loop, remove a small amount of frozen isolate from the top of the vial

Aseptically transfer the loop to BAP

Use streak plate method to isolate single colonies

Incubate inverted plate at 35°C ± 2°C for 18-24 hrs.

Storage Temperature & Biosafety

Appropriate safety procedures should always be used with this material. Laboratory safety is discussed in the current publication of 'BioSafety in Microbiological and Biomedical Laboratories' from the U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, and National Institutes of Health.

This product is sent with the condition that you are responsible for its safe storage, handling, and use. All materials are the property of the Centers for Disease Control and Prevention (CDC) and have been made available on behalf of the Food and Drug Administration (FDA). This material is not for use in human subjects and may not be redistributed. While CDC uses reasonable efforts to include accurate and up-to-date information on this product sheet, CDC makes no warranties or representations as to its accuracy. CDC is not liable for damages arising from the misidentification or misrepresentation of cultures. Please refer to the Standard Letter Agreement (SLA) for further details regarding the use of this product.
Isolate History
Date Action Performed
10/17/22Gene was added
10/17/22Gene was removed
08/01/22Gene was added
08/01/22Category was added
Top of Page