ABSTRACT
Salmonella is the leading cause of food-borne diarrhoeas in the US. In recent years polymerase chain reaction (PCR) has become the method of choice for rapid and sensitive detection of Salmonellae in contaminated foods. As a result, several different primer sets have been reported for use in PCR-based assay systems. In order to identify an optimal primer set from among the wide range of primers reported in the literature, we synthesized five different pairs and evaluated their relative performance in PCR under uniform assay conditions using a common panel of the target (Salmonella) and non-target (non- Salmonella) bacterial strains. Of the five sets of primers tested, the one designed on the basis of a 199 bp repeat sequence of S. weltevreden[Jitrapakdee et al. (1995) Molecular and Cellular Probes 9, 375-382] gave optimal results with most bacterial strains examined.
Subject(s)
DNA Primers/standards , DNA, Bacterial/analysis , Salmonella/genetics , Animals , Polymerase Chain Reaction/instrumentation , Polymerase Chain Reaction/methods , Sensitivity and SpecificityABSTRACT
Escherichia coli O157:H7 in spiked samples of raw milk and ice-cream was enriched in tryptic soy broth for 4 h, captured by immunomagnetic separation, subjected to amplification by polymerase chain reaction of parts of the verotoxin genes (SLT-I and SLT-II), and detected by agarose gel electrophoresis. Using this method, as few as 1 cfu Esch. coli O157:H7/g food could be detected in < 10 h.
