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Antibiotic Resistance and Sensitivity Testing of Bacteria

Does ATCC test for antibiotic resistance/sensitivity of the bacteria in its collection? Can MIC (minimum inhibitory concentration) values be obtained from the ATCC for each strain?

ATCC only tests those bacterial strains considered to be “quality control strains” by the Clinical Laboratory Standards Institute (CLSI).  CLSI lists breakpoint limits for antibiotics which are considered to be clinically relevant for each quality control strain.  The MIC value allows one to quantify antibiotic resistance/sensitivity. ATCC does not routinely test to obtain MIC values for each antibiotic used on each quality control strain.  Customers who wish to find out if a particular strain is resistant or sensitive to an antibiotic should check the CLSI standards tables.   Customers who wish to obtain the entire antibiotic profile of a particular bacteria will need to refer to CLSI.  ATCC does not routinely provide this and in some cases, may not test every antibiotic against the particular strain.  If only the results for one antibiotic test in particular is needed, we may be able to look up those results and forward it to the customer.

We employ a variety of methods for detecting susceptibility/resistance to antibiotics, including Kirby-Bauer, disc diffusion and Vitek. Which test(s) is used is dependent on the strain. In some cases, if a strain is found to be resistant to a particular antibiotic we would perform an ‘E’ test to determine the MIC.

MIC screening is done only for the strains that are noted in the CLSI as being the standard for sensitivity testing.     We do not provide the specific test results to the customer, but as long as the our strain produces a reaction that falls within the range noted in the CLSI, we say that the strain passed the test.

Date Created11/05/2013 11:48 AM
Date Updated11/05/2013 11:51 AM

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