Dear all,
The person who started the project I am now working on chose to use 2
microgram penicillin disks when testing Staphylococcus aureus and 100
microgram nitrofurantoin disks for S. aureus and enterococci. She
said that this was according to NCCLS recommendations. I have checked all
NCCLS m2-a5,m2-a6 documents from 1993-1997 and CANNOT FIND THE INTERPRETIVE
STANDARDS FOR ZONES OF INHIBITION FOR THESE PARTICULAR CONCENTRATIONS !!!!!
The concentrations used in standard NCCLS testing are much higher than
those which were chosen for my project (5-fold and 3-fold for penicillin
and nitrofurantoin respectively). As this project depends on measuring
increased levels of antibiotic resistance, I don't know how to
interpret susceptibility data for antibiotic levels which are much lower
than those used to derive NCCLS tables.
Is there anywhere that I can find tables for other concentrations (even
outdated NCCLS documents)?????
please drop me a line at s666806 at uottawa.ca if you have any possible leads.
Thanks for your time,
Oksana
