Clinical Evaluation and Cost Analysis of Great Basin Shiga Toxin Direct Molecular Assay for Detection of Shiga Toxin-Producing Escherichia coli in Diarrheal Stool Specimens
| Autor: | Brenda R. Alkins, Nathan A. Ledeboer, Blake W. Buchan, Jennifer Dien Bard, Jessica Connolly, Paul A. Granato, Stephen Young, Judy A. Daly, Matthew L. Faron |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Microbiology (medical) Serotype Time Factors 030106 microbiology Biology medicine.disease_cause Sensitivity and Specificity Microbiology Shiga Toxin Immunoenzyme Techniques 03 medical and health sciences Feces 0302 clinical medicine fluids and secretions STX2 medicine Humans 030212 general & internal medicine Prospective Studies Escherichia coli Escherichia coli Infections Transaminases Retrospective Studies Bacteriological Techniques medicine.diagnostic_test Shiga-Toxigenic Escherichia coli Shiga toxin Bacteriology Amplicon Molecular diagnostics Molecular Diagnostic Techniques Immunoassay Nucleic acid biology.protein Costs and Cost Analysis Carbohydrate Epimerases |
| Zdroj: | Journal of clinical microbiology. 55(2) |
| ISSN: | 1098-660X |
| Popis: | The Shiga Toxin Direct molecular assay (ST Direct) relies on nucleic acid amplification and solid array-based amplicon detection to identify Shiga toxin-producing Escherichia coli (STEC) in preserved stool specimens. Genes encoding Shiga toxin ( stx 1 and stx 2 ), as well as the E. coli serotype O:157-specific marker rfbE , are simultaneously detected within 2 h. ST Direct was evaluated using 1,084 prospectively collected preserved stool specimens across five clinical centers. An additional 55 retrospectively collected, frozen specimens were included to increase the number of positive specimens evaluated. Results were compared to results from routine culture and an enzyme immunoassay (EIA) specific for the recovery and identification of STEC. ST Direct was found to be 93.2% sensitive and 99.3% specific for detection of stx 1 and stx 2 and 95.7% sensitive and 99.3% specific for detection of E. coli serotype O:157. All specimens with false-positive results were found to contain stx 1 or stx 2 or were found to be positive for serotype O:157 when analyzed using alternative molecular methods. All 4 false-negative stx 1 or stx 2 results were reported for frozen, retrospectively tested specimens. In all cases, the specimens tested positive for stx by an alternative FDA-cleared nucleic acid amplification test (NAAT) but were negative for stx 1 and stx 2 following nucleic acid sequence analysis. Based on these data, culture and EIA-based methods for detection of STEC are only 33% sensitive compared to molecular tests. A retrospective cost analysis demonstrated 59% of the cost of routine stool culture to be attributable to the identification of STEC. Taken together, these data suggest that ST Direct may provide a cost-effective, rapid molecular alternative to routine culture for the identification of STEC in preserved stool specimens. |
| Databáze: | OpenAIRE |
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