Table 4.
Comparison of LAMP and qPCR assays in human stool specimens spiked with 103 and 104 CFU/0.5 g of STEC O157 strain EDL933 based on two independent repeats
Cell level (no. of CFU/0.5 g) | Target gene | LAMP Tt (min) after enrichment ofb: |
qPCR CT (cycles) after enrichment ofb: |
||||||
---|---|---|---|---|---|---|---|---|---|
0 h | 4 h | 6 h | 8 h | 0 h | 4 h | 6 h | 8 h | ||
103 | stx1 | NAc | 32.0 ± 2.6A | 20.9 ± 1.5B | 17.3 ± 1.6B | NA | 37.9a | 34.1 ± 1.5A | 29.1 ± 1.4A |
stx2 | NA | 33.9 ± 2.3A | 23.9 ± 1.1B | 21.0 ± 1.3B | NA | NA | 34.3 ± 1.5A | 29.4 ± 1.5A | |
eae | NA | 27.8 ± 2.1A | 19.0 ± 2.0B | 15.9 ± 1.8B | NA | 37.2a | 32.3 ± 1.4A | 26.6 ± 1.5A | |
104 | stx1 | NA | 22.9 ± 0.8A | 18.9 ± 0.4B | 18.2 ± 0.5B | NA | 34.5 ± 1.4A | 31.3 ± 1.5A | 30.2 ± 1.4A |
stx2 | NA | 26.6 ± 1.3A | 23.2 ± 0.5AB | 21.5 ± 1.3B | NA | 34.5 ± 1.2A | 31.2 ± 1.4AB | 30.3 ± 1.3B | |
eae | 26.9a | 19.8 ± 3.0A | 17.5 ± 1.4A | 17.0 ± 1.1A | NA | 33.5 ± 1.8A | 29.7 ± 1.5A | 28.8 ± 1.1A |
Only one repeat generated a positive result.
In each row within LAMP or qPCR, Tt or CT values followed by different uppercase letters are statistically significant (P < 0.05).
NA, not available.