Related Experiment Videos
Prophylactic effect of monensin sodium against experimentally induced paratuberculosis in mice
G W Brumbaugh1, P F Frelier, A J Roussel
1Department of Large Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77843.
Abstract:
Monensin sodium (0, 15, or 30 mg/kg of complete feed) was fed ad libitum for 1 week to female mice (strain C57BL6/J) that were genetically susceptible to infection with Mycobacterium paratuberculosis. Ten mice in each of the 3 groups were inoculated intraperitoneally with M paratuberculosis (10(9) organisms). Sterile saline solution was injected intraperitoneally into 10 other mice in each group. Rations were continued for 50 days, then mice were euthanatized, and body weight, splenic weight, and hepatic weight for each mouse were recorded. Ratios of body weight to splenic weight and of body weight to hepatic weight were calculated for each mouse. Hepatic granulomas in 50 light microscopic fields were counted, and presence of acid-fast organisms in those granulomas was recorded. Infected mice given monensin had higher body weight and fewer hepatic granulomas than did mice not given monensin. Although hepatic granulomas were fewer in these mice, they contained acid-fast organisms. Effects of 15 mg of monensin and those of 30 mg of monensin/kg of complete feed were not different.
Insights
Monensin sodium reduced hepatic granulomas in mice infected with Mycobacterium paratuberculosis. However, acid-fast organisms remained present in these granulomas, indicating potential for continued infection.
Area of Science:
- Immunology
- Microbiology
- Pharmacology
Background:
- Mycobacterium paratuberculosis causes Johne's disease, a chronic infection.
- Genetic susceptibility in C57BL6/J mice models M. paratuberculosis infection.
- Monensin sodium is an ionophore with potential antimicrobial properties.
Purpose of the Study:
- To investigate the effect of monensin sodium on M. paratuberculosis infection in mice.
- To evaluate monensin's impact on host immune response and bacterial load.
Main Methods:
- Female C57BL6/J mice were fed diets with 0, 15, or 30 mg/kg monensin sodium.
- Mice were inoculated intraperitoneally with M. paratuberculosis.
- Body weight, splenic weight, hepatic weight, and hepatic granulomas were assessed after 50 days.
Main Results:
- Monensin-treated mice exhibited higher body weight compared to controls.
- Infected mice receiving monensin had significantly fewer hepatic granulomas.
- Acid-fast organisms were detected within the hepatic granulomas of monensin-treated mice.
Conclusions:
- Monensin sodium may modulate the host response to M. paratuberculosis, reducing granuloma formation.
- The presence of acid-fast organisms in granulomas suggests monensin does not eliminate the infection.
- Further research is needed to understand monensin's therapeutic potential and mechanisms in M. paratuberculosis infection.