Selectively isolate and differentiate Mycobacterium paratuberculosis from cattle and other ruminants using Thermo Scientific™ Remel™ Herrolds Medium w/Mycobactin. Mycobactins are endogenous siderophores that are produced by most mycobacteria allowing them to grow on Herrold’s medium without mycobactin. M. paratuberculosis is unable to produce siderophores and will not grow on media lacking mycobactins¹. Herrold’s Medium with mycobactin J was found to produce colonies of M. paratuberculosis that appeared earlier and were more numerous than on media supplemented with mycobactins².

Johne’s disease is a chronic granulomatous intestinal disease of ruminant animals caused by M. paratuberculosis. In 1895, Johne and Frothingham identified acid-fast bacilli in the intestinal tissues of cattle diagnosed with Johne’s disease³. Diagnosis of Johne’s disease is confirmed by the isolation of M. paratuberculosis from feces of the affected animal. In 1912, Twort discovered that M. paratuberculosis requires media supplemented with mycobactin for growth and thus successfully cultivated M. paratuberculosis⁵.

Use Herrolds Medium with mycobactin for selective isolation and differentiation of Mycobacterium paratuberculosis from cattle and other ruminants.

• Ready to use – Convenience of prepared media.
• Selective media - Malachite green is a selective agent that inhibits microorganisms other than mycobacteria. Amphotericin B inhibits fungal contaminants.

This medium contains casein peptone that supplies nitrogenous compounds, amino acids, and peptides necessary for bacterial growth. Sodium chloride provides essential electrolytes and maintains osmotic equilibrium. Beef extract supplies vitamins, carbohydrates, and nitrogenous compounds. The fatty acids and protein required for the metabolism of mycobacteria are provided by glycerol and egg mixture present in the medium. Sodium pyruvate is a source of energy for bacterial metabolism and enhances the recovery of M. paratuberculosis. Mycobactin J is required for the growth of M. paratuberculosis.