Background: A rapid molecular test for identifying cases of infectious diarrhea might be beneficial for patients.
Methods: We established a LightMix modular multiplex PCR assay for rapid detection of Campylobacter, Salmonella, Yersinia, and Shigella species from fecal samples.
Results: Unlike Campylobacter sp., direct detection of Salmonella from feces by multiplex PCR was significantly less sensitive than culture. Only 11 out of 21 (52%) Salmonella culture positive specimens were positive for Salmonella in the direct multiplex PCR assay (Campylobacter: 52/53 samples [98%]). In contrast, an overnight selenite enrichment step prior to multiplex PCR increased the Salmonella assay sensitivity significantly: 18 out of 18 Salmonella culture positive samples were then also detected by PCR.
Conclusions: An overnight enrichment step is necessary for reliable PCR detection of Salmonella from fecal samples.