Rapid Molecular Detection of Gastrointestinal Pathogens and Its Role in Antimicrobial Stewardship

Abstract

We aimed to detect the etiological agents of acute diarrhea by a molecular gastrointestinal pathogen test (MGPT) and to assess the impact of MGPT on antimicrobial stewardship programs (ASP). This is a prospective observational study and was conducted between 1 January 2015 and 30 June 2017. We included consequent patients who had acute diarrhea. At the end of 2015, we implemented ASP in acute diarrhea cases and compared the outcomes in the pre-ASP and post-ASP periods. An FDA-cleared multiplexed gastrointestinal PCR panel system, the BioFire FilmArray (Idaho Technology, Salt Lake City, UT), which detects 20 pathogens in stool, was used. In 499 out of 699 patients (71%), at least one pathogen was detected. Among 314 adults with positive MGPT, 101 (32%) enteropathogenic (EPEC), 71 (23%) enteroaggregative (EAEC), 68 (22%) enterotoxigenic (ETEC), 55 (18%) Shiga toxin-producing (STEC) (17%) , 48 (15%), 21 (7%) , and 20 (6%) strains were detected. Among 185 children, 55 (30%) EPEC, 37 (20%) , 32 (17%), 29 (16%) EAEC, 22 (12%) STEC, 21 (11%) ETEC, 21 (11%) , 20 (11%), and 16 (5%) strains were detected. Inappropriate antibiotic use decreased in the post-ASP period compared with the pre-ASP period among inpatients (42.9% and 25.8%, respectively; = 0.023). Using MGPT in clinical practice significantly decreased the unnecessary use of antibiotics. Detection of high rates of in children and spp., as well as relatively high rates of spp., which were hard to isolate by routine stool culture, were remarkable.

Appropriate Use and Future Directions of Molecular Diagnostic Testing

“…EPEC was also more frequently found as part of co-detections than alone. Further studies have repeated these findings in countries across different continents and have also identified the same issues with enteroaggregative E. coli [20][21][22]. False-positive detections of Vibrio cholerae [23] and Entamoeba histolytica [24] have been reported in patients without relevant exposures.…”

“…The ASP intervention was described as "educational meetings and activities among prescribers" that took place at the end of the preintervention time period. The authors saw a significant reduction in inappropriate prescriptions even with this modest intervention [22]. Importantly, analysis was limited to adults with severe diarrhea and fever or bloody diarrhea.…”

Interplay between Rapid Diagnostic Tests and Antimicrobial Stewardship Programs among Patients with Bloodstream and Other Severe Infections

“…These results are routinely higher than the comparative conventional testing and culture methods (72)(73)(74)(75)(76). The most common organisms identified included enteropathogenic E. coli, C. difficile, norovirus, and other E. coli types (72)(73)(74). Organisms that the FA panel could identify that conventional testing missed included Campylobacter, Vibrio cholerae, Cyclospora, Shiga-like toxin-producing E. coli, Giardia, Cryptosporidium, and norovirus in 1 study (72).…”

“…Published studies indicate that pathogens are detected by GI panels in 33% to 80% of adult and pediatric patients with diarrhea (72-75), with 8% to 32% positive for multiple pathogens (72)(73)(74). These results are routinely higher than the comparative conventional testing and culture methods (72)(73)(74)(75)(76). The most common organisms identified included enteropathogenic E. coli, C. difficile, norovirus, and other E. coli types (72)(73)(74).…”

“…ASPs are crucial to realizing the benefits of GI panels. A study demonstrated that inappropriate antibiotics decreased from 42.9% with the FA alone to 25.8% with FA plus ASP intervention (P = 0.023) (74). Interestingly, a study of the FA panel on patients hospitalized for >72 h at the time of sample collection resulted in a very low yield of 6.0% after excluding C. difficile (77).…”