Table 3.
Rank order comparison of growth rate of selected M. paratuberculosis strains with drug susceptibility and colony morphology.
| Growth rate + mycobactin J (1.0 mg/ml) | Drug resistance | Predominant colony morphology | Congo Red staining | |
| MAP Ben-B | >792 ΔGI/day | AMI, CIP, GAT, RIF, STR | Rough | White |
| MAP Kay | >483 ΔGI/day | AMI, CIP, GAT, RIF, STR | Smooth opaque | Red |
| MAP 43544 (Ben-A) | >206 ΔGI/day | CIP, GAT, RIF, STR | Rough | White |
| MAP Linda | >103 ΔGI/day | CIP, GAT, RIF, STR | Smooth opaque | Red |
| MAP 47 ileum | >111 ΔGI/day | Not done* | Smooth opaque/rough | White/red |
*Not done due to erratic growth rate of this strain in the BACTEC 12B system. Differences in growth rates based on BACTEC 12B system. Published guidelines36,51 used to establish breakpoints for susceptible, moderately susceptible and resistant strains for the following drugs: AMI, amikacin; CIP, ciprofloxacin; GAT, gatifloxacin; RIF, rifampin; STR, streptomycin; and CLR, clarithromycin.
MAP, M. paratuberculosis