Comparative Evaluation of Conventional Stool Testing and Multiplex Molecular Panel in Outpatients With Relapse of Inflammatory Bowel Disease

The impact of multiplex nested gastrointestinal PCR panel in children with gastroenteridis requiring pediatric infectious disease consultation

Infectious gastroenteritis is an important cause of morbidity and mortality, especially in nations with middle and low incomes. In a pediatric gastroenteritis patient, the aim was to determine the therapeutic impact of using the Gastrointestinal Panel in our clinical practice. A single-center retrospective study was designed to evaluate children who were admitted to the hospital for gastroenteritis and had a gastrointestinal panel between August 2021 and January 2024. 103 patients who had gastrointestinal (GI) panel results were included in the study. The GI Panel positivity rate among 103 patients was 55.3% (n = 57). Bacterial agents were positive in 25 patients (43.8%), viral agents were found in 11 patients (19.2%), and polymicrobial agents were found positive in 21 patients (36.8%). Escherichia coli (9.1%) was the most common bacterial pathogen, and viral pathogens most frequently included Rotavirus (11.6%) and Norovirus (11.6%). When the effect of the GI Panel test on treatment was determined, the treatment of 51 (49.5%) patients was changed according to GI Panel.

CONCLUSIONS

In our study, the treatment regimen of many patients was adjusted based on the GI panel results in patients presenting with gastroenteritis. GI panel had an important impact on the patients care and optimization according to the principles of antimicrobial treatment. GI panel tests had several advantages such as speed and diagnostic accuracy as good as stool culture.

WHAT IS KNOWN

• Infectious gastroenteritis is a major cause of morbidity and mortality, especially in middle- and low-income countries. • BioFire® FilmArray, Gastrointestinal Panel (BioFire- Biomerieux, France) is a rapid and simple technique that uses nested multiplex PCR to detect gastrointestinal pathogens rapidly.

WHAT IS NEW

  • In this study, the GI Panel test was found to have a cumulative impact on 49.5% (n=51) of the clinician's treatment modalities. • With its speed and diagnostic sensitivity, the GI Panel may provide clinicians with an important tool in the fight against antibiotic resistance by decreasing antimicrobial drug treatment at the children with gastroenteritis.

Enteric Infection at Flare of Inflammatory Bowel Disease Impacts Outcomes at 2 Years

BACKGROUND

Outcomes of inflammatory bowel disease (IBD) following flare complicated by enteric infection (EI) are limited by follow-up duration and insufficient assessment of the role of non-Clostridioides difficile pathogens. We compared 2-year IBD outcomes following flare with and without EI.

METHODS

We performed a retrospective cohort study of adults evaluated with stool PCR testing for IBD flare. Subjects were stratified by presence of EI at flare and were matched for age, sex, and date to those without EI. The primary outcome was a composite of steroid-dependent IBD, colectomy, and/or IBD therapy class change/dose escalation at 2 years. Additional analyses were performed by dividing the EI group into C. difficile infection (CDI) and non-CDI EI, and further subdividing non-CDI EI into E. coli subtypes and other non-CDI EI.

RESULTS

We identified 137 matched subjects, of whom 62 (45%) had EI (40 [29%] CDI; 17 [12%] E. coli). Enteric infection at flare was independently associated with the primary outcome (adjusted odds ratio, 4.14; 95% confidence interval [CI], 1.62-11.5). After dividing EI into CDI and non-CDI EI, only CDI at flare was independently associated with the primary outcome (adjusted odds ratio, 4.04; 95% CI, 1.46-12.6). After separating E. coli subtypes from non-CDI EI, E. coli infection and CDI at flare were both independently associated with the primary outcome; other EI was not.

CONCLUSIONS

Enteric infection at flare-specifically with CDI-is associated with worse IBD outcomes at 2 years. The relationship between E. coli subtypes at flare and subsequent IBD outcomes requires further investigation.

Risk factors and clinical outcomes associated with multiple as opposed to single pathogens detected on the gastrointestinal disease polymerase chain reaction assay

BACKGROUND

The use of gastrointestinal disease multiplex polymerase chain reaction (GI PCR) testing has become common for suspected gastrointestinal infection. Patients often test positive for multiple pathogens simultaneously through GI PCR, although the clinical significance of this is uncertain.

METHODS

This retrospective cohort study investigated risk factors and clinical outcomes associated with detection of multiple (as opposed to single) pathogens on GI PCR. We included adult patients who underwent GI PCR testing from 2020 to 2023 and had one or more pathogens detected. We compared patients with multiple versus those with single pathogens and hypothesized that immunosuppression would be a risk factor for detection of multiple pathogens. We further hypothesized that, during the 90 days after GI PCR testing, patients with multiple pathogens would have worse clinical outcomes such as increased rates of emergency department (ED) visits, death, hospitalization, or ambulatory care visits.

RESULTS

GI PCR was positive in 1341 (29%) of tested patients; 356 patients had multiple pathogens and 985 had one pathogen. The most common pathogens included Enteropathogenic Escherichia coli (EPEC, 27%), norovirus (17%), and Enteroaggregative E. coli (EAEC, 14%) in both multi- and singly positive patients. Immunosuppression was not associated with multiple pathogens (adjusted odds ratio [aOR] 1.35, 95% CI 0.96, 1.86). The factors most associated with multiple pathogens were Hispanic ethnicity (OR 1.86, 95% CI 1.42, 2.45) and chronic kidney disease (OR 1.69, 95% CI 1.13, 2.49). Patients with multiple pathogens were more likely to have ED visits during the 90 days after GI PCR testing (40% vs. 32%, p < 0.01), but they were not more likely to die, be hospitalized, or to have ambulatory medical visits.

CONCLUSIONS

Immunosuppression was not associated with detection of multiple as opposed to single pathogens on GI PCR testing. There were worse clinical outcomes associated with detection of multiple pathogens, although these effects were modest.

Is the Medium Still the Message? Culture-Independent Diagnosis of Gastrointestinal Infections

Infectious diarrhea is caused by a variety of pathogens, including viruses, bacteria, and parasitic organisms. Though the causative agent of diarrhea has historically been evaluated via stool cultures, recently, culture-independent diagnostic tests (CIDT) have been developed and utilized with increasing frequency. Current practice guidelines recommend their use as adjuncts to stool cultures for diagnosing acute and chronic diarrhea. The three principal CIDT are microscopy, enzyme-based immunoassays (EIAs), and molecular based polymerase chain reaction (PCR). This review explores the common causes of infectious diarrhea, the basics of stool culture, the diagnostic utility of these three culture-independent modalities, and the strengths and weaknesses of all currently available clinical techniques. It also outlines considerations for specific populations including returning travelers and those with inflammatory bowel disease.

The role of gastrointestinal pathogens in inflammatory bowel disease: a systematic review

The inflammatory bowel diseases (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), are chronic, progressive, inflammatory conditions of the gastrointestinal tract. Imbalance in the gut microbial community, or dysbiosis, and the subsequent immune response, represent the critical relationship between genetic susceptibility, microbes, and environment factors, that result in IBD. Gastrointestinal pathogens - a common cause of dysbiosis - have been implicated as an environmental trigger in new onset IBD, as well as flare of existing IBD. In this article, we systematically review clinical data regarding the association between specific gastrointestinal pathogens and IBD. Numerous bacteria, viruses, fungi, and parasites have been implicated in the pathogenesis of IBD, and exacerbations of existing disease. In this article, we will also specifically discuss the less recognized microbes that have an inverse association with IBD, including certain bacterial pathogens, such as Helicobacter pylori, and parasites, such as Trichuris species. Future prospective and experimental studies are required to establish causality and clarify potential mechanisms of enteric pathogens in modifying the risk and course of IBD.