Comparison of the BAX System PCR Method to Brazil's Official Method for the Detection of Salmonella in Food, Water, and Environmental Samples
Authors: Tomazelli, Ingrid Boesche1; de Freitas, Josinete Barros2; Fabbi, Leania Maria1; Filipini, Terezinha Agnese1; da Silva, Cláudia Maria1; Bedin, Janaina Müssnich1; Duarte, Dalila Angélica Moliterno3; dos Santos, Amaury4; Baccarin, Aldo5; Higa, Lígia Rossi Garcia5; Yano, Dirce Mithico Yamaoka6; Killner, Mário6; Frezza, Andréa Leão Cameiro7; de Gosztonyi Abecia, Eduardo Carlos7; Tronco, Vânia Maria7; Júnior, Osmar Tomazelli8; Júnior, Waldomiro Barioni9
Source: Journal of Food Protection®, Volume 71, Number 12, December 2008 , pp. 2442-2447(6)
Abstract:
A two-stage study compared the BAX system PCR method with the reference culture method used by the Brazilian Ministry of Agriculture and Food Supply for the detection of Salmonella in food, water, and environmental samples. In stage 1, fish matrix samples (n = 258) were spiked at several levels with Salmonella and a combination of Salmonella and non-Salmonella competitive organisms. Replicates were analyzed by the BAX system PCR method and the reference method with comparable results (sensitivity ≥ 97.5%, specificity ≥ 83.3%) from both methods at the limit of detection. In stage 2, a total of 1,988 samples with 70 product types were analyzed with both methods. Five laboratories were involved in this study, and the samples used were from routine analyses. The BAX system PCR method was shown to be comparable to the reference method, with a limit of detection of 1.0 to 2.0 CFU/25 g of sample. Analysis of the results obtained in stage 2 and in the combination of stages 1 and 2 for the BAX system showed the following performance: sensitivity ≥ 99.0%, specificity ≥ 97.2%, false-negative rate ≤ 1.1%, and false-positive rate ≤ 2.8%. Therefore, the BAX system appears to be equivalent to the reference method, with ≥97.3% agreement.Document Type: Research article
Affiliations: 1: National Industrial Apprenticeship Service (SENAI), Food Technology Center (LANAL)-Microbiology, Rua Frei Bruno, 201E-Bairro Jardim América, CEP 89.803-800, Chapecó, Santa Catarina, Brazil 2: Ministry of Agriculture and Food Supply-Animal Laboratory Coordination, Brazil, Distrito Federal, Brazil 3: Ministry of Agriculture and Food Supply (LAPA/PE), Recife, Pernambuco, Brazil 4: Ministry of Agriculture and Food Supply (LARA/SP), Campinas, São Paulo, Brazil 5: Food Intelligence (FI), São Paulo, São Paulo, Brazil 6: Products Analysis Laboratory (SFDK), São Paulo, São Paulo, Brazil 7: Madasa, Brasil 8: Epagri, Chapecó, Santa Catarina, Brazil 9: Embrapa, Concórdia, Santa Catarina, Brazil

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