Fig 2. Library screen with novel axenic assay, comparison with intracellular results.

15,667 compounds were screened in the novel axenic assay at 15μM. Comparison with the intracellular assay shows that 67 of the hits are also active in the intracellular assay whereas 71 of the hits are not. 280 novel axenic assay inactive compounds were hits in the intracellular assay, 170 of these compounds showed toxicity in the intracellular assay (in single point mode, at 50μM, or less than 3-fold selectivity window in potency assay) and are therefore considered false positives in the intracellular assay. Potencies were determined for 110 non-toxic compounds in the novel axenic and intracellular assays. 13 compounds were inactive in the intracellular assay and are added to the false positive count (13 + 170 = 183). 97 compounds had confirmed activity in the intracellular assay; 42 of these compounds showed activity in the novel axenic assay, while 54 did not. (INMAC = intracellular assay). Hit criteria as described in Table A in S1 Text.