TABLE 2.
Reproducibility of detection of the entire molecular process (nucleic acid extraction, PCR amplification, and SERS detection) by testing simulated samples with various concentrations of fungal burden
| Target | Load (GE) by sample type at the indicated copy no. |
|||||
|---|---|---|---|---|---|---|
| Serum/plasma |
EDTA whole blood |
Combined |
||||
| 50–100 | 10–20 | 50–100 | 10–20 | 50–100 | 10–20 | |
| C. albicans | 4/4 | 4/4 | 1/1 | 2/2 | 5/5 | 6/6 |
| C. glabrata | 4/4 | 2/4 | 1/1 | 2/2 | 5/5 | 4/6 |
| C. krusei | 3/4 | 3/4 | 1/1 | 2/2 | 4/5 | 5/6 |
| C. guilliermondii | 2/2 | 3/3 | 2/2 | 3/3 | ||
| C. parapsilosis | 4/4 | 3/3 | 4/4 | 3/3 | ||
| C. lusitaniae | 4/4 | 3/3 | 4/4 | 3/3 | ||
| C. tropicalis | 2/2 | 2/2 | 2/2 | 2/2 | ||
| C. dubliniensis | 2/2 | 2/2 | 2/2 | 2/2 | ||
| A. fumigatusa | 1/1 | 8/9 | 4/4 | 4/4 | 5/5 | 12/13 |
| A. terreus | 2/3 | 2/2 | 4/5 | |||
| A. niger | 3/3 | 1/2 | 4/5 | |||
| A. flavus | 3/3 | 2/2 | 5/5 | |||
| Overall | 26/27 | 38/43 | 7/7 | 15/16 | 33/34 | 53/59 |
a
For comparative purposes, the mean number of copies of the rRNA genes per genome of A. fumigatus is 54 (16). Consequently, 10 genomes per sample equates to 540 copies per sample. When testing a sample with a 10 GE or conidial burden and assuming 100% extraction efficiency, combined with an elution volume of 60 μl and a PCR template input volume of 10 μl, the total input equals 90 copies or 1.6 GE/conidia per reaction. One A. fumigatus conidium contains one genome.