Table 3.
Concentrations of TcdA and TcdB (pg/ml) Produced by Isolated Clostridioides difficile Strains In Vitro at Different Time Points
| Strains | 24h | 24h | 24h | 48h | 48h | 48h | 72h | 72h | 72h |
|---|---|---|---|---|---|---|---|---|---|
| A, pg/mL | B, pg/mL | A/B ratio | A, pg/mL | B, pg/mL | A/B ratio | A, pg/mL | B, pg/mL | A/B ratio | |
| VPI 10463 | >2 000 000.0 | 887 155.4 | ~2.3 | >2 000 000.0 | 1 503 972.4 | ~1.3 | >2 000 000.0 | 1 763 053.4 | ~1.1 |
| BID-20 | 5751.8 | 275.2 | 20.9 | 27 809.8 | 1222.9 | 22.7 | 39 395.2 | 1737.2 | 22.7 |
| BID-37 | 1368.4 | 65.1 | 21 | 17 028.1 | 539.8 | 31.5 | 35 460.6 | 1095.2 | 32.4 |
| BID-71 | 1303.2 | 1.4 | 930.9 | 10 072.2 | 6 | 1678.7 | 33 629.6 | 9.4 | 3577.6 |
| M-118 | 17 278.8 | 506.3 | 34.1 | 116 582.8 | 2944.6 | 39.6 | 163 083.6 | 3750.6 | 43.5 |
| M-223 a | 2241.6 | 148.4 | 15.1 | 22 710.4 | 1186.8 | 19.1 | 30 542.6 | 1622.8 | 18.8 |
| M-391 | 2173.2 | 242.9 | 8.9 | 15 851.1 | 1554.2 | 10.2 | 18 239.2 | 1646 | 11.1 |
| M-494 | 1360.4 | 83 | 16.4 | 23 760.6 | 1063.8 | 22.3 | 29 700.4 | 1254.4 | 23.7 |
| M-639 | 3372.3 | 407.6 | 8.3 | 19 623.9 | 1891.6 | 10.4 | 22 174.6 | 1949 | 11.4 |
| M-687 | 10 598.8 | 465.7 | 22.8 | 36 865.3 | 1620.2 | 22.8 | 48 283.4 | 1876.8 | 25.7 |
| R1A-007 | 2906.2 | 167.2 | 17.4 | 14 325.6 | 676.4 | 21.2 | 18 779.4 | 713 | 26.3 |
| R1A-086 | 34 464.2 | 1000.9 | 34.4 | 161 605.4 | 5069.1 | 37.7 | 181 810.6 | 5192 | 35 |
| R1A-122 a | 20 190.4 | 886.6 | 22.8 | 65 253 | 3317.4 | 19.7 | 11 657 | 410 | 28.45 |
Strain VPI10463 (a high toxin A and B producer) was used as a control. We incubated 1 × 108 colony-forming units of the vegetative cells of the 12 clinical isolates anaerobically for 24, 48, and 72 hours in cooked meat medium or CCMB-TAL medium. Concentrations of TcdA and TcdB in the resulting conditioned media were determined by Simoa assay.
aIncubated in cycloserine-cefoxitin mannitol broth with taurocholate and lysozyme(CCMB-TAL) medium.