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by VITEK 2 GP. Laboratories 1, 2, 5, 7, 8, 10, 11, 15, and 18 characterized B. coagulans as a Gram-positive or a Gram- positive with endospores and resulted in an Unidentified Organism reported by the VITEK 2 GP method. This is due to the fact that Bacilli are not covered in the scope of the VITEK 2 GP test system. Laboratory 13 characterized B. coagulans as Gram-positive cocci and reported the VITEK 2 GP results as Streptococcus mitis . Laboratories 10 and 14 characterized Escherichia coli as a Gram-positive organism and reported the VITEK 2 identification as Unidentified Organism. Laboratories 1 and 8 incorrectly characterized Candida albicans as a Gram-positive organism and reported the VITEK 2 identification as Kocuria varians .

is not recognized, the system will suggest supplemental tests to distinguish between two or three closely related organisms, or indicate the result as an unidentified organism (either >3 organisms can exhibit the observed pattern, or the biopattern is very atypical and is not represented in the database). It is recommended that hemolysis on blood agar is reviewed for any identification of Listeria innocua. If b -hemolysis is observed, further testing must be performed to exclude Listeria monocytogenes. Reference: J. AOAC Int. 95 , 1427(2012) In the collaborative study, a total of 720 isolates were analyzed representing 12 different inclusivity species and 120 isolates screened representing six different exclusivity species. Twenty laboratories representing government, industry, and private testing laboratories throughout the United States participated. The individual isolate results for both inclusivity and exclusivity reported by each laboratory are presented in Tables 3 and 4, respectively. Tables 2011.02A and 2011.02B present a summary of the collaborative study including the number of isolates identified correctly, misidentified, unidentified, or not tested. For the purposes of this collaborative study, an unidentified or misidentified isolate was considered a missed identification. Inclusivity For the inclusivity evaluation, each laboratory identified isolates from CBA, TSA, and TSAB subculture media for each of the 12 claimed species. All of the collaborators completed all of the isolates submitted. A total of 714 strains were identified correctly by theVITEK 2 GPmethod. Six isolates were not tested by the VITEK 2 GP method due to being excluded by Gram stain reactions. For L. innocua , Laboratory 3 reported a low discrimination between L. innocua and L. welshimeri on TSA only. Laboratories 2, 3, 11, and 13 reported low discrimination between L. seeligeri, L. ivanovii, and L. welshimeri on either CBA or TSAB for L. seeligeri . Laboratories 6, 10, 11, and 14 reported low discrimination between L. innocua and L. welshimeri for L. welshimeri on TSA or TSAB. Laboratories 10, 11, and 18 reported low discrimination between S. aureus and S. intermedius for S. aureus on TSAB only. As indicated in the VITEK 2 GP method, a low discrimination result is considered a correct identification. Supplemental tests recommended on the result printout were conducted to provide a correct final identification of the species. There were zero isolates that produced a misidentified or an unidentified result for the inclusivity panel. For the exclusivity evaluation, each laboratory received six nontarget species that consisted of three Gram-negative bacteria, one Bacillus , one yeast, and one mold. All of the collaborators completed all of the isolates submitted. Of the 120 isolates screened, 106 were correctly excluded. A total of 14 isolates were incorrectly characterized as a Gram-positive organism resulting in improper analysis and misidentification Results Discussion Exclusivity

Recommendations

It is recommended that the VITEK 2 GP test card method be adopted as Official First Action for the identification of selected Gram-positive bacterium.

Acknowledgements

We would like to extend a sincere thank you to the following collaborators for their dedicated participation in this study: John Mills, Judith Colón-Reveles, and Hari P. Dwivedi, bioMérieux Industry, Hazelwood, MO Yvonne Salfinger, Sun Kim, Patricia Hanson, and Jason Crowe, Florida Department of Agriculture and Consumer Services, Tallahassee, FL Tom Sidebottom and Carol Elems, FDA San Francisco District Office, Alameda, CA Maureen Coakley, Jennifer Canale, and Gloria Parra, FDA Northeast Regional Laboratory, Jamaica, NY Sung Guk Kim and Latriana Robertson, FDANational Center for Toxicological Research, Jefferson, AR Hua Wang, FDA Center for Food Safety and Applied Nutrition, College Park, MD Leeann Johnson and Bryanne Shaw, Minnesota Department of Agriculture, St. Paul, MN Denise Toney and Marta Segarra, Division of Consolidated Laboratory Services, Richmond, VA Debra Cherney and Joanne Ruebl, Cherney Microbiological Services, Ltd, Green Bay, WI Melinda Hayman, April Garza, and Sergio Montez, Food Safety Net Services, Ltd, San Antonio, TX Jayne Finnigan and Peter Wikoff, New Hampshire Public Health Laboratories Food Safety Micro/Rabies Unit, Concord, NH Pete Dombroski, Illinois Department of Public Health Laboratory Springfield Combined Laboratory Facility, Springfield, IL Mary Ann Murphy, Jackie Glover, and Rebecca Daugherty, U.S. Department of Agriculture-Agricultural Marketing Service, National Science Laboratory, Gastonia, NC Karen Wilson and Sheri Robeson, Michigan Department of Agriculture, Lansing, MI Adam Miller, Rhode Island Department of Health Laboratories, Providence, RI Jessica Dyer and Urvashi Patel, North Carolina Department of Agriculture, Food and Drug Protection Division, Raleigh, NC

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