 |
Thank you for your question Ms. Baker regarding detection of vancomycin resistance in Enterococcus spp.
In my opinion, it is not necessary to set up a vancomycin resistance screening plate prior to or in addition to a MicroScan antimicrobial susceptibility test panel for enterococci. The 2007 CLSI document (M100S17) states in Table 2D entitled "MIC Interpretive Standards for Enterococcus spp." under general comment 9: "When testing vancomycin, plates should be held a full 24 hours for accurate detection of resistance." In addition, you can view the June 23, 2005 letter from the FDA to Dade Behring regarding vancomycin susceptibility testing of staphylococci, certain streptococci, and enterococci using MicroScan Dried Gram Positive MIC/Combo Panels at the following web page: http://www.fda.gov/cdrh/pdf5/K051202.pdf. In neither the CLSI nor the FDA document is there language that vancomycin screening is necessary as a supplement when testing enterococci. In addition, the once recommended practice of screening Staphylococcus aureus for vancomycin resistance is no longer necessary when using MicroScan overnight or Synergies Plus panels (see footnotes 1 & 4 at http://www.cdc.gov/ncidod/dhqp/ppt/VISA_VRSA_algo06v7.ppt#256,1,Slide 1).
|
