Infections of the gastrointestinal (GI) tract can be caused by a wide variety of bacteria, viruses or parasites. Conventionally, the gold standard for detecting gut pathogens is stool culture. This is usually complicated by the presence of a large amount of intestinal flora, which requires the use of selective media to identify potential pathogens. The Biofire FilmArray Gastrointestinal (GI) Panel tests for 22 pathogens found in stool specimens collected in Cary Blair transport medium and is designed for use with the integrated FilmArray multiplex PCR system. This evaluation focuses on the comparisons between FilmArray GI Panel and current in-house laboratory tests, in terms of turnaround time, effort, and accuracy.
GI Panel evaluation was done alongside 84 concurrent stool cases, 43 positives and 41 negatives, which were analyzed by the in-house stool culture and/or a commercial Rotavirus antigen test kit.
The turnaround time for the Rotavirus Antigen test was the shortest, followed by GI panel, with stool culture being the longest. Rotavirus antigen testing was performed using the Rapigen BIOCREDIT Rota Antigen kit. Stool culture involves plating of specimens onto agar plates, incubation, reading of colonies, followed by identification and antibiotic susceptibility testing. The FilmArray system can perform automated nucleic acid extraction, multiplex PCR, and detection. In terms of accuracy, 97% of the FilmArray GI Panel test results were in agreement with the in-house laboratory tests.
Overall, the FilmArray GI Panel has an advantage in turnaround time and technologist’s effort required, which is critical for the management of critically ill patients. However, due to a relatively small number of different organisms detected, further evaluation is necessary.