Simultaneous and sensitive detection of three foodborne pathogens by multiplex PCR, capillary gel electrophoresis, and laser-induced fluorescence.
The simultaneous detection of Staphylococcus aureus, Listeria monocytogenes, and Salmonella spp. has been approached by a new multiplex PCR-based procedure followed by capillary gel electrophoresis with laser-induced fluorescence detection (multiplex-PCR-CGE-LIF). As compared to slab gel electrophoresis, the use of CGE-LIF improved from 10- to 1000-fold the sensitivity of the multiplex PCR analysis, allowing the detection of 2.6 x 10(3) cfu mL(-1) of S. aureus, 570 cfu mL(-1) of L. monocytogenes, and 790 cfu mL(-1) of Salmonella in artificially inoculated food, without enrichment. Following 6 h of enrichment, as low as 260, 79, and 57 cfu mL(-1) of S. aureus, L. monocytogenes, and Salmonella, respectively, were detected. The CGE-LIF method is shown to be reproducible, providing relative standard deviation (RSD) values lower than 0.8% for analysis time and lower than 5.8% for peak areas. The multiplex-PCR-CGE-LIF proved a powerful analytical tool to detect various food pathogens simultaneously in a fast, reproducible, and sensitive way.
Alarcón
Benito
B
Departamento de Microbiología y Ecología, Universitat València, Burjassot E-46100, Valencia, Spain.
García-Cañas
Virginia
V
Cifuentes
Alejandro
A
González
Ramón
R
Aznar
Rosa
R
D019075:Electrophoresis, Capillary / Q000379:methods*; D005453:Fluorescence; D005516:Food Microbiology; D007834:Lasers; D008089:Listeria monocytogenes / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012475:Salmonella / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000302:isolation & purification