Table 5. Costs and processing times of the different methods, based on 2014–2015 summer monitoring.
All values were estimated on the assumption that a batch of 15 samples are analysed. Consumable costs were estimated as a ratio in comparison to IDEXX consumables.
| Method | Organism | Pre-processing | Post-result | Average | Cost | Rs, p |
|---|---|---|---|---|---|---|
| operator time | operator time | turnaround time | ||||
| [min/sample] | [min/sample] | [hours] | $/$IDEXX | (vs. IDEXX) | ||
| IDEXX | Total coliform | 5 | 2 | 24 | 1.0 | – |
| E. coli | 5 | 2 | 24 | 1.0 | – | |
| enterococci | 5 | 2 | 24 | 1.0 | – | |
| TECTA™ | Total coliform | 5 | 0 | 13 | 0.8 | Rs = 0.70; p<0.001 |
| E. coli | 5 | 0 | 12 | 0.8 | Rs = 0.72; p<0.001 | |
| enterococci | 6 | 0 | 12 | 0.7 | Rs = 0.52; p<0.001 | |
| Method 1611 | enterococci | 20 | 5 | 6 | 3.3 | Rs = 0.72; p<0.001 |
| NGS | - | 601 | 302 | 603 | 30.0 | – |
1 Processing time for NGS includes filtration and DNA extraction.
2 Analysis time includes the running of scripts to pull out FIO and pathogen lists.
3 Average turnaround time includes all required steps to produce NGS data, including: filtration, DNA extraction, PCR amplification, Illumina MiSeq v2 sequencing, and closed OTU picking.