Cultivation of mycobacterium paratuberculosis

The paper presents a new solid growth medium for the cultivation of Mycobacterium paratuberculosis consisting of organic and inorganic ingredients. The study of diagnostic informative value and effectiveness of solid growth media used for cultivation of Mycobacterium Paratuberculosis was carried out in the laboratory conditions. Extract from birch-wood ash of 3% concentration and a growth stimulant of biological origin, peat oxide, were introduced as a mineral salt bases into the developed medium. When constructing the test medium, Lоwenstein–Jensen egg growth medium with the addition of mycobactin, which is an extract from Mycobacterium. phlei and contains substances necessary for the nutrition and reproduction of Mycobacterium paratuberculosis on artificial nutrient media, was used as an analogue. A test on compatibility and solubility of the components was done in distilled water in accordance with the generally accepted guidelines. The duration of observation ranged from 60 to 90 days. A comparison was made between the time of appearance of the primary and intensive growth of mycobacteria of paratuberculosis on the experimental medium and the Lоwenstein–Jensen control medium with mycobactin. Colonies of primary and intensive growth of standardized M. paratuberculosis strain and M. paratuberculosis isolate obtained from the cattle biomaterial on experimental egg growth medium appeared 3-7 days faster than on Lоwenstein–Jensen control medium with mycobactin. When inoculating biomaterial from cattle (lymph nodes and intestine), the primary growth of M. paratuberculosis on the experimental medium was noted 7 days earlier than on the control one, and the intensive growth was 3 days earlier. The experimental growth medium is cheaper and simpler to prepare than Lоwenstein–Jensen control medium with mycobactin, whose preparation is a rather laborious technological process.

Investigation of Mycobacterium paratuberculosis in Arabian dromedary camels (Camelus dromedarius)

Aim: Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants. This study aimed to investigate Mycobacterium paratuberculosis infection in clinically infected camels on the immunological, conventional bacteriological, and molecular biological basis. Materials and Methods: A total of 30 Arabian camels (Camelus dromedarius) were examined in this study. The camels were suffering from signs ranging from mild to severe infections (that did not respond to antibiotic treatment) to chronic or intermittent diarrhea. Camels were grouped into three groups based on their age, sex, and breed. Detection of anti-MAP antibodies in camels' serum, Ziehl-Neelsen (ZN) staining technique on rectal scraps, direct recognition of MAP in stool and tissue specimens by IS900 polymerase chain reaction (PCR) assay, and finally isolation and molecular description of MAP from fecal and tissue samples were carried out. Results: Five MAP isolates were recovered from these investigated camel samples giving an isolation rate of 16.6%, while eight camels were identified by PCR (26.6%). Five camels yielded MAP in their feces by ZN fecal staining (16.6%), whereas ELISA detected anti-MAP antibodies in nine camels only (30%). Conclusion: From the obtained results, we concluded that the gold standard for the diagnosis of MAP is the culture method despite its limitations. Molecular diagnosis (PCR) could be a useful tool in the identification of truly positive and negative camels; however, great care should be given regarding the primers specificity and sensitivity.

Possible association between Mycobacterium paratuberculosis infection and Crohn's disease in human

Crohn's disease is a granulomatous ileocolitis of humans, of unknown aetiology, which generally manifests itself during the prime of life. The chronic, progressive clinical course and histological findings are consistent wiht a mycobacterial aetiology. Evidence supporting a pathogenic role for a mycobacterium has become available only in the last decade with the isolation of this microorganism from Crohn's disease tissue. M. paratuberculosis, which is the causative agent of Johne's disease in animals, has been identified in patients with Crohn's disease by PCR and DNA hybridisation techniques. It has been shown that isolates of M. paratuberculosis from Crohn's disease are indentical with pathogenic strains in ruminants.