PCR Detection and Microbiological Isolation of <i>Salmonella</i> spp. from Fresh Beef and Cantaloupes
Miguel Ángel Gallegos-Robles, Alberto Morales-Loredo, María G. Álvarez-Ojeda, J. A. Osuna-García, Irma Martínez, Lilia H. Morales-Ramos +1 more
Journal of Food Science
Abstract
Species belonging to the genus Salmonella are an important cause of enteric fevers, gastroenteritis, and septicemia, and the pathogens are commonly transmitted through contaminated food. In this study, polymerase chain reaction (PCR) amplification of a 287-bp region of the invA gene was compared to a microbiological technique to determine the presence of Salmonella in retail beef and in cantaloupe rinse samples. Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42 degrees C. The presence of Salmonella was determined in 50 commercial top sirloin beef samples that were not artificially inoculated. Three samples were positive by the microbiological method, and these samples and an additional sample were positive by the PCR. Both methods were also used to test surface rinses of cantaloupes collected from 4 farms in Nayarit, Mexico. Salmonella was detected by the microbiological method in 9 of 20 samples (45%), whereas the pathogen was detected by the PCR in 11 samples (55%). This study demonstrates the utility of the PCR targeting the invA gene to determine the presence of Salmonella spp. in beef and cantaloupe samples.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
PCR targeting the invA gene detects Salmonella spp. in beef and cantaloupe samples
“This study demonstrates the utility of the PCR targeting the invA gene to determine the presence of Salmonella spp. in beef and cantaloupe samples.”
microbiological technique detects Salmonella
“Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42 degrees C.”
PCR amplification of a 287-bp region of the invA gene detects Salmonella
“Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42 degrees C.”