Optimization of murine model for Besnoitia caprae

Area of Science:

• Veterinary Parasitology
• Immunology
• Animal Models

Background:

• Apicomplexan parasites, including Besnoitia caprae, can infect mice.
• BALB/c mice are known to be susceptible to certain apicomplexan infections.
• Understanding host susceptibility and optimal inoculation methods is crucial for studying parasitic diseases.

Purpose of the Study:

• To compare the susceptibility of inbred BALB/c, outbred BALB/c, and C57 BL/6 mice to Besnoitia caprae.
• To determine the lethal dose 50 (LD50) of Besnoitia caprae in different mouse strains.
• To evaluate the impact of various inoculation routes on Besnoitia caprae infection in the most susceptible mouse strain.

Main Methods:

• Three mouse strains (inbred BALB/c, outbred BALB/c, C57 BL/6) were inoculated intraperitoneally with varying doses of Besnoitia caprae tachyzoites.
• LD50 was calculated for each mouse strain.
• Inbred BALB/c mice were further inoculated via subcutaneous, intramuscular, intraperitoneal, infraorbital, and oral routes with a high dose of tachyzoites.

Main Results:

• Inbred BALB/c mice exhibited the highest susceptibility to Besnoitia caprae.
• The LD50 values were determined as 12.5 × 10^3.6 for inbred BALB/c, 25 × 10^3.4 for outbred BALB/c, and 5 × 10^4 for C57 BL/6 mice.
• Intramuscular inoculation in inbred BALB/c mice led to rapid mortality and severe lesions, while oral and infraorbital routes resulted in survival.

Conclusions:

• Inbred BALB/c mice serve as a suitable laboratory model for Besnoitia caprae infection.
• Intramuscular inoculation is an effective method for inducing besnoitiosis in this model.
• This model and inoculation method can be utilized for testing treatments, prevention strategies, and vaccine efficacy against besnoitiosis.