Figure 1.

Semilogarithmic graph comparing enumeration of three Mycobacterium avium subsp. paratuberculosis (MAP) isolates. White symbols represent absolute MAP numbers of three MAP isolates gained by F57 based qPCR for the respective OD and dark symbols represent CFU numbers gained by culture. Error bars represent standard deviations obtained from three independent physical replicates. McFarland standards 0.5, 1 and 2 are shown by grey symbols. The OD of each McFarland standard was determined in this study; theoretical number of bacterial cells was adopted according to the standard formula for E. coli: McFarland 0.5 = 1.5 × 10⁸ CFU/ml [9].