Rapid Identification of Gastro Pathogens Directly from Stool

The Luminex xTAG Gastrointestinal Pathogen Panel (GPP)—approved by the FDA in January, 2013—allows detection of up to 11 different bacterial viral and parasitic pathogens from a single stool sample. The pathogens that it commonly detects are mostly grouped and listed below alphabetically.

Bacteria and toxins

  • Campylobacter
  • Clostridium difficile toxin A/B
  • Enterotoxigenic E. coli (ETEC) LT/ST
  • Escherichia coli O157
  • Salmonella
  • Shiga-like toxin producing E. Coli stx 1/stx 2
  • Shigella


  • Norovirus GI/GII
  • Rotavirus A


  • Cryptosporidium
  • Entamoeba histolytica
  • Giardia

The FDA, which approved the device on Jan. 14, 2013, writes “the manufacturer demonstrated the performance of the xTAG GPP by collecting samples from 1407 patients with suspected infectious gastroenteritis and comparing the xTAG GPP results to individual tests that are known to separately and reliably detect the 11 viruses, bacteria, or parasites associated with the xTAG GPP.”

After describing the conduction of the trials, the FDA admitted that the “results were comparable to the individual tests.” It later cautioned, however, that the “risk of false positives” necessitated “additional testing” to back up the xTAG’s initial positive results. The company claims in Europe that tests conducted repeatedly demonstrate that the device’s detective sensitivity for individual pathogens is between 87.5% and 100%. Testing devices and systems like the xTAG GPP are significant progress and emblematic of serious advancement in the field of diagnostics, but they can only be truly impactful if they are easily accessible to practicing clinicians and are not unreasonably priced.