Multicenter comparative evaluation of six commercial systems and the national committee for clinical laboratory standards m27-a broth microdilution method for XXXX susceptibility testing of Candida species.

@entity5132 @entity375 @entity7409 @entity2380
@entity2380 susceptibility among 800 clinical Candida isolates (60% @entity5132 ) and two control strains (C. krusei ATCC 6258 and @entity7409 @entity7409 ) was tested with the NCCLS M27-A method (gold standard) and six commercial products (Candifast, disk, Etest, Fungitest, Integral System @entity375 , and Sensititre YeastOne). Results were classified as susceptible, susceptible-dose dependent, or resistant using M27-A breakpoints or, for Fungitest, Integral System @entity375 , and Candifast, as susceptible, intermediate, or resistant, according to the manufacturers' instructions. Concordance with NCCLS M27-A results was analyzed with the chi(2) test. Intra- and interlaboratory reproducibility was also evaluated. NCCLS M27-A (90.1%), Etest (93.1%), Sensititre YeastOne (93.1%), disk (96.7%), Fungitest (92.6%), Integral System @entity375 (40.6%), and Candifast (6.0%) classified the indicated percentages of @entity5132 isolates as susceptible. Among non- @entity5132 strains, the percentages of susceptible isolates were as follows: NCCLS M27-A, 74.0%; Etest, 83.8%; Sensititre YeastOne, 64.1%; disk, 60.6%; Fungitest, 76.6%; Integral System @entity375 , 28.3%; and Candifast, 27.4%. All methods except Candifast and Integral System @entity375 showed good agreement with NCCLS M27-A results for both @entity5132 and non- @entity5132 isolates. Intralaboratory reproducibility was excellent for NCCLS M27-A, Etest, Sensititre YeastOne, disk, and Fungitest (88 to 91%). Similar results emerged from the interlaboratory reproducibility evaluation. Our findings indicate that some commercial methods can be useful for @entity2380 susceptibility testing of clinical Candida isolates. Those characterized by a lack of medium standardization and/or objective interpretative criteria should be avoided. Particular caution is necessary when testing is being done for clinical and epidemiological purposes.
