Comparison of the BAX system PCR method to Brazil's official method for the detection of Salmonella in food, water, and environmental samples.
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.
Tomazelli
Ingrid Boesche
IB
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
de Freitas
Josinete Barros
JB
Fabbi
Leania Maria
LM
Filipini
Terezinha Agnese
TA
Silva
Cláudia Maria
CM
Bedin
Janaina Müssnich
JM
Duarte
Dalila Angélica Moliterno
DA
dos Santos
Amaury
A
Baccarin
Aldo
A
Higa
Lígia Rossi Garcia
LR
Yano
Dirce Mithico Yamaoka
DM
Killner
Mário
M
Frezza
Andréa Leão Cameiro
AL
Abecia
Eduardo Carlos de Gosztonyi
EC
Tronco
Vânia Maria
VM
Tomazelli Júnior
Osmar
O
Barioni Júnior
Waldomiro
W
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