VITEK MS Collaborative Study Outline - eBook
unknown organism and every organism or organism groups of the knowledge base. Then thresholds 1 were applied in order to retain only the more significant organisms or organism groups. 2 (a) A single identification is displayed with confidence value between 60 to 99.9 when one significant 3 organism or organism group are retained. 4 (b) Low Discrimination identifications are displayed when more than one significant organism or 5 organism group are retained, but not more than 4. In this case, the sum of confidence values is 6 equal to 100. 7 (c) When more than 4 organisms or organism groups are found, the organism is considered as non‐ 8 identified. In this case, a list of possible organisms is displayed and the sum of confidence values 9 is less than 100. 10 (d) When no match is found, the organism is considered as non‐identified 13 This validation study was conducted under the AOAC Research Institute Performance Tested Method SM 14 program and the AOAC INTERNATIONAL Methods Committee Guidelines for Validation of 15 Microbiological Methods for Food and Environmental Surfaces (1). Two studies were conducted to 16 comprise the Internal Validation portion of the PTM study: a Food Drug and Administration (FDA) 17 Clinical Trial (2, 3) and a study at bioMerieux. University of Guelph Laboratory Services Division 18 performed the Independent laboratory study. The VITEK MS system identified blind‐coded organisms, 19 either unknown clinical isolates or previously characterized organisms by comparing the characteristics 20 of the obtained spectrum to the VITEK MS knowledge base. A percent agreement calculation was 21 performed. 24 The majority of the claimed organism data included in this study was collected in a FDA Clinical Trial to 25 evaluate the ability of the VITEK MS to identify microorganisms. There were 359 different organisms 26 tested with multiple strains of each organism resulting in a total of 6344 VITEK MS results. The clinical 27 trial data was augmented with 193 blind coded organisms tested at bioMérieux in St. Louis, MO. These 28 two internal studies generated 6413 VITEK MS results. 31 An FDA‐approved protocol was provided to five independent clinical laboratories. Each laboratory 32 tested any unknown clinical isolates using the VITEK MS and DNA sequencing. If there was a shortage of 33 strains for a specific claimed organism, bioMérieux provided stock isolates to each laboratory for 34 analysis. 35 Unknown clinical isolates stored on an agar plate or slant, never frozen. Frozen stock isolates, provided 36 by bioMérieux , were subcultured twice prior to testing. For this validation study report, organisms from 37 the FDA Clinical Trial that will be claimed for industry use are presented. There were others tested but 38 only claimed for clinical use. 39 11 12 Validation Study 22 23 Internal Validation Study 29 30 FDA Clinical Trial
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