title: Comparison of the BAX system PCR method to Brazil's official method for the detection of Salmonella in food, water, and environmental samples.
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 > or = 97.5%, specificity > or = 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 > or = 99.0%, specificity > or = 97.2%, false-negative rate < or = 1.1%, and false-positive rate < or = 2.8%. Therefore, the BAX system appears to be equivalent to the reference method, with > or = 97.3% agreement.
authors.affiliation: 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. ingrid@senai-sc.ind.br
authors.forename: Ingrid Boesche
authors.initials: IB
authors.lastname: Tomazelli
authors.forename: Josinete Barros
authors.initials: JB
authors.lastname: de Freitas
authors.forename: Leania Maria
authors.initials: LM
authors.lastname: Fabbi
authors.forename: Terezinha Agnese
authors.initials: TA
authors.lastname: Filipini
authors.forename: Cláudia Maria
authors.initials: CM
authors.lastname: Silva
authors.forename: Janaina Müssnich
authors.initials: JM
authors.lastname: Bedin
authors.forename: Dalila Angélica Moliterno
authors.initials: DA
authors.lastname: Duarte
authors.forename: Amaury
authors.initials: A
authors.lastname: dos Santos
authors.forename: Aldo
authors.initials: A
authors.lastname: Baccarin
authors.forename: Lígia Rossi Garcia
authors.initials: LR
authors.lastname: Higa
authors.forename: Dirce Mithico Yamaoka
authors.initials: DM
authors.lastname: Yano
authors.forename: Mário
authors.initials: M
authors.lastname: Killner
authors.forename: Andréa Leão Cameiro
authors.initials: AL
authors.lastname: Frezza
authors.forename: Eduardo Carlos de Gosztonyi
authors.initials: EC
authors.lastname: Abecia
authors.forename: Vânia Maria
authors.initials: VM
authors.lastname: Tronco
authors.forename: Osmar
authors.initials: O
authors.lastname: Tomazelli Júnior
authors.forename: Waldomiro
authors.initials: W
authors.lastname: Barioni Júnior
mesh_terms: D001322:Autoanalysis; D015169:Colony Count, Microbial / Q000295:instrumentation / Q000379:methods; D004783:Environmental Microbiology; D005188:False Negative Reactions; D005189:False Positive Reactions; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012475:Salmonella / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D014871:Water Microbiology