**Please forward this to other appropriate personnel within your institution**
This is a laboratory advisory from the Minnesota Department of Health (MDH) and the Minnesota Laboratory System (MLS). This message is being sent to MLS laboratory contacts serving Minnesota residents. You are not required to reply to this message.
VRSA confirmed in Michigan
The Michigan Department of Community Health (MDCH) has confirmed its second case of vancomycin-resistant Staphylococcus aureus (VRSA). This represents the fourth U.S. case of VRSA confirmed by the Centers for Disease Control and Prevention (CDC).
The VRSA case-patient is a 78 year old male with a history of coronary artery disease, non-insulin-dependent diabetes mellitus, peripheral vascular disease, neuropathy, chronic renal insufficiency and obstructive uropathy. From October through December 2004, the patient spent four weeks in a hospital and five weeks in a nursing home following surgery for an aortic valve replacement. The patient received vancomycin for most of those nine weeks. He was discharged home in early December 2004. Following discharge, a small toe wound developed on the patient’s foot, progressed, and became infected. At a hospital emergency room in early February 2005 the toe wound was found to be gangrenous and arrangements were made for toe amputation. Cultures taken prior to surgery grew Morganella morganii, Enterococcus faecalis, and VRSA (MIC=256 mg/mL). Post-operative wound cultures continue to grow out VRSA. The patient is currently on linezolid, to which this organism is susceptible.
In the LABORATORY, the VRSA isolate grew on vancomycin screening agar and was reported as vancomycin resistant (MIC >32 mg/mL) using MicroScan panels. Additional testing showed MICs of >256 mg/mL using E-test and 256 mg/mL by broth microdilution. Vitek2 failed to detect resistance with a reported MIC of < 1 mg/mL.
Recommendations and Resources
Laboratories that use automated methods or disk diffusion should also include a vancomycin screen plate for enhanced detection of vancomycin intermediate S. aureus (VISA) and VRSA. You can access links for procedures and information by visiting the MLS website at www.health.state.mn.us/mls and clicking on “Disease Specific Information” and scrolling down to “VISA/VRSA Vancomycin Intermediate/Resistant S. aureus”.
For those laboratories that participated in Challenge Set 3, you will also find an extensive write-up on this topic in your Participant Summaries.
Referral of Isolates to MDH: As stated in the CLSI (formerly NCCLS) guidelines: “Send any staphylococci determined to have an elevated MIC for vancomycin (MIC ≥ 4 μg/mL) to a reference laboratory”; you may use MDH as your reference lab for this purpose, if you choose. Please report and submit isolates of vancomycin intermediate and resistant Staphylococcus aureus to MDH. Please refer to new disease reporting rule when it is finalized, for updated information.
Paula M. Snippes, MT (ASCP)
Program Advisor, Minnesota Laboratory System
Public Health Laboratory, Minnesota Department of Health
612‑676‑5258 (phone), 612‑676‑4074 (fax)
www.health.state.mn.us/mls