Figure 5
Bacterial yield in DCTB assays using CF containing Fatty acids and cyclic-AMP. (A) Assessment of DCTB recovery from sputum cultures using CF, fatty acid and cyclic-AMP (CAMP) supplementation. DCTB were detected using the MPN limiting dilution assay. For comparison, CF containing and deficient in Mtb Rpfs was used to compare the growth stimulatory effects of fatty acids and cAMP. To control for the effect of CF in growth stimulation, fresh Middlebrook media was used, which standardly contains oleic acid. To obtain the DCTB count, MPN values (with or without CF) were divided by CFU counts, which depict conventionally culturable bacteria. (B) Histogram depicting mean DCTB counts from MPN assays supplemented with standard media containing cAMP or select fatty acids. Statistical comparisons were conducted between CFs and the no CF or cAMP/fatty acid assays. There was an increase in bacterial recovery from MPN assays containing CF, which was not significant, most likely due to the small samples size (n = 4), no significant increase in DCTB recovery was noted in the media control and cAMP or fatty acid assays. Error bars depict the standard error of the mean. (C) Histogram depicting mean DCTB counts from assays using CF from Mtb and standard media supplemented with fatty acids. The mean DCTB counts were compared to that obtained from the media controls assay using a Wilcoxon test to determine the growth stimulatory affect of fatty acids. P-values depict the comparison of the CFs to the no CF or fatty acid assays. Graphs were generated using Graphpad Prism software, Version 6.
