Identification and Characterization of a Spore-Like Morphotype in Chronically Starved Mycobacterium avium Subsp. Paratuberculosis Cultures
Figure 3
Sporulation is reproducible on traditional sporulation medium.
Spore enrichment was independently conducted by the National Animal Disease Center (Ames, IA) using a separate MAP K-10 culture inoculated on A–K agar. MAP K-10 year old MB7H9 broth culture, B. subtilis and E. coli K-12 were inoculated on B) Potato extract agar with mycobactin J at 37°C and 39°C. MAP K-10 growth was observed after two weeks of incubation at 39°C in comparison to overnight growth of B. subtilis and E. coli K-12 controls. Biomasses were collected similarly to A–K cultures and processed for TEM (B). MAP K-10 TEM images showed similar structures as those observed in Figure 2. Furthermore, biomasses were streaked on blood agar and incubated at 37°C and 39°C for 4 weeks to confirm purity (C). MAP K-10 failed to grow for the entire duration of incubation in comparison to B. subitlis and E. coli K-12 controls.