Detection of Salmonella spp in fecal specimens by use of real-time polymerase chain reaction assay

Objective-To use real-time polymerase chain reaction (PCR) technology to develop a highly sensitive and specific diagnostic assay for the detection of Salmonella spp in fecal specimens. Sample Population-299 fecal specimens from cattle, horses, and dogs. Procedure-Enrichment of fecal specimens was followed by genomic DNA extraction by use of commercially available isolation kits. Real-time PCR assay was performed to target a Salmonella spp-specific DNA segment. Results of real-time PCR assay were compared with bacterial culture results to determine relative sensitivity and specificity. Results-Use of the spaQ primer-probe set resulted in a relative sensitivity of 100% and a specificity of 98.2%, compared with bacterial culture results when tested on 299 clinical fecal specimens. Conclusions and Clinical Relevance-A rapid, sensitive, and specific assay for the detection of Salmonella spp from enriched clinical fecal specimens was developed. This technique would be highly valuable in clinical settings to help avoid or mitigate the complications arising from an outbreak of salmonellosis in a herd or among patients of a veterinary hospital.