pcr assays based on inva gene amplification are not reliable for salmonella detection

Background: salmonella surveillance relies on inva polymerase chain reaction (pcr) assays for the rapid detection of salmonella ; however, falsepositive results have been reported using this method. objectives:to evaluate the performance and specificity of the published and validated pcr protocols targeting inva gene for the detection of salmonella . methods:the performance and specificity of 11 different pcr primer sets were evaluated using salmonella type strains and citrobacter spp., escherichia coli and serratia spp. isolates recovered during a salmonella surveillance program. results:it was revealed that the published pcr protocols using validated primers targeting inva and 16s rrna genes generated falsepositive signals. importantly, a protocol targeting the ttra/c genes was able to discriminate salmonella and non salmonella isolates. conclusions:detection of salmonella spp. by means of inva pcr amplification is not reliable. in fact, falsepositive results are commonly obtained from citrobacter , e. coli and serratia isolates. it is recommended to use other loci, such as ttra/c genes, for the accurate and reliable detection of salmonella .