Validation and evaluation of the performance of QIAstat-Dx gastrointestinal panel in pooled stool samples.

Abstract

In the current study, the analytical sensitivity, analytical specificity, reproducibility, anti-interferences ability, and clinical performance of the QIAstat-Dx Gastrointestinal Panel (GIP) system were evaluated using pooled stool samples. Results showed that the pooled sample test detected the selected ten targets exclusively, with no cross reaction with any other targets of common enteropathogens. The analytical sensitivity of the pooled sample test on QIAstat-Dx GIP system was 10² CFU/ml for Shigella spp., 10³ CFU/ml for Salmonella spp., Y. enterocolitica, Enterotoxigenic Escherichia coli, Enteropathogenic E. coli, 10⁴ CFU/ml for V. cholerae, 10² copies/ml for Norovirus, 10³ copies/ml for Rotavirus, Astrovirus, Sapovirus, respectively. The Coefficients of variation (CV) during the detection of V. cholerae, Salmonella spp., Y. enterocolitica, Enterotoxigenic E. coli, Enteropathogenic E. coli, Shigella spp., Rotavirus, Norovirus, Astrovirus, and Sapovirus detection was 2.3 %, 2.7 %, 3.9 %, 4.2 %, 1.7 %, 2.6 %, 6.7 %, 1.4 %, 1.3 % and 2.7 %, respectively, indicating the high reproducibility of the pooled sample test, except for Rotavirus. When potentially interfering agents were added, the shifted Ct value was less than the cut off value, suggesting the good anti-interferences ability. During clinical evaluation, the pooled sample test was 97.8 % concordant with gold standard methods (bacterial culture for bacteria and qPCR for viruses). Our results suggest that QIAstat-Dx GIP system could be used for pooled sample test for enteropathogens screening, which would be more economical and could improve throughput while provide comparable test performance.