Clinical performance evaluation of TAQPATH Enteric Bacterial Select Panel for the detection of common enteric bacterial pathogens in comparison to routine stool culture and other qPCR-based diagnostic tests

Abstract

ABSTRACT The use of real-time PCR-based methods for the detection of enteric pathogens in routine clinical diagnostics is slowly replacing stool culture, with open questions regarding clinical performance and ease of implementation. We evaluated the clinical and analytical performance of the TAQPATH Enteric Bacterial Select Panel in comparison to routine stool culture and other multiplex diagnostic tests. Clinical stool specimens (N = 217) from symptomatic individuals were tested using the TAQPATH Enteric Bacterial Select Panel and the BD MAX Enteric Bacterial Panel, while the BIOFIRE FILMARRAY Gastrointestinal (GI) Panel was used as a resolver. This analysis demonstrated that the TAQPATH Enteric Bacterial Select Panel had clinical sensitivity and specificity of 100.00% for both Salmonella spp. and Shigella spp./Enteroinvasive Escherichia coli (EIEC) and 100.00% and 98.09% for Campylobacter, respectively. Analytical comparison of six European conformity-in vitro diagnostic (CE-IVD) tests on contrived samples showed similar performance results. In a prospective study, we tested 500 stool samples using the TAQPATH Enteric Bacterial Select Panel and routine stool culture combined with Campylobacter antigen test. In total 26/500 samples were positive for Campylobacter, 2/500 for Salmonella, and none for Shigella/EIEC using the TAQPATH kit. Routine culture and antigen testing detected only 65.4% (17/26) of Campylobacter infections. The results obtained by the TAQPATH kit were confirmed as true positive for Campylobacter using two resolver methods, indicating a significantly higher clinical sensitivity over routine stool culture. Finally, we demonstrated that the TAQPATH Enteric Bacterial Select Panel provided shorter time-to-result (<3 h vs 2–4 days), required sevenfold less hands-on time and 7.17-fold less laboratory plastic in comparison to conventional stool culture in routine diagnostics. IMPORTANCE Enteric bacterial infections caused by Salmonella, Shigella, pathogenic Escherichia coli, and Campylobacter represent one of the most common causes of infectious enteritis worldwide. The timely and accurate diagnosis of pathogens causing gastroenteritis is crucial for patient care, public health, and disease surveillance. While stool culture has long been the standard and highly specific method for detecting enteric pathogens, it is labor-intensive and time-consuming with limited sensitivity. To improve patient outcomes, there is a need to implement new cost-effective approaches for the detection of bacterial enteric pathogens with higher sensitivity and faster time to result. This study shows that multiplex real-time polymerase chain reaction-based tests, such as the TAQPATH Enteric Bacterial Select Panel, are accurate and cost-effective diagnostic alternatives for the detection and differentiation of the most common enteric bacterial pathogens, offering quicker time to result and higher sensitivity compared to routine stool culture.

Keywords

• molecular diagnostics
• gastrointestinal infections
• Campylobacter
• Salmonella
• Shigella