Improved Detection of Bacterial Pathogens in Patients Presenting with Gastroenteritis by Use of the EntericBio Real-Time Gastro Panel I Assay

Abstract

bIn this study, we evaluated the use of EntericBio real-time Gastro Panel I (Serosep, Limerick, Ireland) for routine use in a clinical microbiology laboratory for simultaneous detection of Campylobacter jejuni, coli, and lari, Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., and Shigella spp. in feces. This system differs from its predecessor (the EntericBio Panel II system, Serosep) in that it allows real-time detection of pathogens directly from feces, without pre-enrichment. It also specifically detects Campylobacter jejuni, coli, and lari rather than all Campylobacter species, as is the case with the previous system. A total of 528 samples from patients presenting with acute gastroenteritis were screened prospectively with this assay, and results were compared with those of the current method, which combines screening the samples with a molecular assay (the EntericBio Panel II assay) and retrospective culture of the specimens in which the target was detected. Discrepancy analysis was conducted using culture and molecular methods. A cute infectious gastroenteritis is common and has important economic and social consequences for both communities and health systems due to its high rate of occurrence (1). Worldwide, it is associated with a high incidence of morbidity and mortality (2), particularly among children (3).Most clinical microbiology laboratories still use traditional, culture-based diagnostic techniques for routine detection of bacterial enteric pathogens. These are both time-consuming and laborious and, in addition, have a prolonged delay in the reporting of results. This can have a significant impact on institutions such as hospitals or nursing homes, where early detection and prevention of disease spread is crucial. Molecular detection of pathogens has, however, been shown to be faster and more sensitive than traditional culture (4, 5). It is especially important where culturebased pathogen detection is problematic or lacks sensitivity. The best example of this is the genus Campylobacter, certain members of which, such as C. jejuni, can remain viable but noncultivable (6), therefore producing false-negative results if detection is based solely on a culture. Moreover, some species which can cause gastroenteritis, such as C. upsaliensis, are unlikely to be correctly isolated and identified on common media (7). Furthermore, the exact role of some fastidious Campylobacter spp. (such as C. ureolyticus or C. concisus) in gastroenteritis is still under investigation despite their being detected in large proportions of samples from patients with gastroenteritis (8, 9).Here, we present a validation study of EntericBio real-time Gastro Panel I (Serosep, Limerick, Ireland), a commercial realtime PCR system (CE marked for in vitro use) for simultaneous detection of Campylobacter jejuni, coli, and lari, Shiga toxin-producing Escherichia coli (STEC) (through detection of Stx1 and Stx2), Shigella spp., and Salmonella spp. directly from patients' feces. MATERIALS AND METHODSPatient samples. Between ...

Global Epidemiology of Campylobacter Infection

“…This is in line with results from Portugal, where Campylobacter species were detected in 31.9% of diarrheic fecal samples, with C. jejuni and C. concisus being the most prevalent species (13.7% and 8.0%, respectively) (56). Furthermore, based on PCR analysis, the prevalences of C. ureolyticus in gastroenteritis cases in Ireland in the period from 2009 to 2012 ranged from 1.15 to 1.30% (57,58). Furthermore, molecular screening for seven members of the Campylobacter genus by using PCR revealed the overall prevalence of Campylobacter species in patients with gastroenteritis from southern Ireland to be 4.7%, with C. jejuni being the predominant species, accounting for 66% of all Campylobacter species detected, followed by C. ureolyticus (22.3% of all Campylobacter species detected), C. coli (6.7%), C. fetus (2.1%), C. hyointestinalis (1.3%), C. upsaliensis (1.1%), and C. lari (0.5%) (59 (61).…”

“…A recent study by Granato and colleagues compared three commercially available kits with culture-based techniques and found that the three immunoassays had sensitivities that ranged from 98.5 to 99.3% and specificities that ranged from 98.0 to 98.2%, while standard culture had a sensitivity of 94.1% (275). Furthermore, a number of real-time assays are also available for the detection of Campylobacter species, some of which are capable of detecting more than one species at a time, including C. jejuni, C. coli, and C. lari (57). Interestingly, Javed and colleagues also described an assay to detect C. jejuni and C. coli based on the ability of recombinant receptor binding proteins from the C. jejuni bacteriophage NCTC12673 to agglutinate in the presence of these species (276).…”

Use of the EntericBio Gastro Panel II in a diagnostic microbiology laboratory: challenges and opportunities

“…7 Since we did not perform confirmatory molecular testing for this target, the significance of these results remains uncertain. EIEC is thought to be uncommon in high-income countries, but few epidemiological studies have been undertaken because of shared phenotypic and genetic characteristics with Shigella and non-enteropathogenic E. coli.…”

“…3 Three studies have been published to date on the performance of EntericBio assays. 2,7,10 Two of these compared the performance of different versions of the same assay, and did not address Salmonella sensitivity versus culture. O'Leary et al 2 tested only four of 773 samples positive by culture for Salmonella, insufficient to identify performance issues for this target.…”

“…7 Briefly, this includes inoculation of sample into a sample processing solution, followed by heating at 97 C for 30 min. The samples were then prepared for PCR using an automatic pipetting station (epiMotion 5070; Eppendorf, Germany) and run on a Lightcycler 480 II instrument (Roche; New Zealand).…”