Brugia malayi in Mastomys coucha: establishment in immunosuppressed animals
K Tyagi1, P K Murthy, R K Chatterjee
1Division of Parasitology, Central Drug Research Institute, Lucknow, India.
Abstract:
Investigations on various aspects of human filariasis using target filarial parasite, Brugia malayi is jeopardised to a great extent due to its prolonged incubation period and poor harvest from the existing experimental animal models. To obviate these difficulties it was contemplated to establish B. malayi infection in immunosuppressed Mastomys coucha. Cortisone, a well known immunosuppressant, was used at 10 mg/kg dose level subcutaneously in two courses each of 5 days duration. The first course was administered 1 week before and the second, a week after infective exposure. Mastomys were exposed either with 100 or 200 infective larvae (L3) each. Untreated age-matched animals were also exposed simultaneously. The minimum prepatent period was observed to be 90.7 days in immunosuppressed animals exposed to 200 L3. The course of microfilaraemia in immunosuppressed and control animals was identical up to 180 days of observation period. However, the adult worm recovery from the former group of Mastomys was higher. It is surmised that exposure with B. malayi L3 in immunosuppressed Mastomys would be of great advantage in getting larger harvests of adult worms of B. malayi.
Insights
Immunosuppression in Mastomys coucha enhances Brugia malayi worm recovery. This study utilized cortisone to improve yields of this filarial parasite in experimental models.
Area of Science:
- Parasitology
- Immunology
- Tropical Medicine
Background:
- Human filariasis research is hindered by the long incubation period and low yields of Brugia malayi in animal models.
- Developing effective experimental models is crucial for understanding filariasis and developing treatments.
Purpose of the Study:
- To establish Brugia malayi infection in immunosuppressed Mastomys coucha to overcome experimental limitations.
- To assess the impact of immunosuppression on the prepatent period and adult worm recovery of Brugia malayi.
Main Methods:
- Mastomys coucha were immunosuppressed using cortisone (10 mg/kg) in two 5-day courses.
- Animals were exposed to either 100 or 200 infective Brugia malayi larvae (L3).
- Control groups of age-matched, untreated animals were used for comparison.
Main Results:
- The minimum prepatent period in immunosuppressed Mastomys exposed to 200 L3 was 90.7 days.
- Microfilaremia levels were similar between immunosuppressed and control groups up to 180 days.
- Significantly higher adult worm recovery was observed in immunosuppressed Mastomys.
Conclusions:
- Immunosuppression of Mastomys coucha with cortisone facilitates increased adult worm yields of Brugia malayi.
- This enhanced model offers advantages for filariasis research, particularly for obtaining larger parasite harvests.
