Chapter 98 - Animal Models of Toxoplasma Infection

Abstract

Toxoplasma infections are widespread in warm-blooded animals and humans, which is caused by the protozoon parasite Toxoplasma gondii. This chapter focuses on the various models of Toxoplasma infection, which include tachyzoite infections in rodents, bradyzoite infections in rodents, connatal infections, infections in immunodeficient mice, oocyst studies in cats, and studies on other animal species. For tachyzoite infections in rodents, mice are the ideal experimental hosts, whereas white rats are less suitable. The weight, age, and sex have no influence on susceptibility for Toxoplasma infection and drug testing, but female mice are easier to keep in cages. A major problem with this model is that the BK or RH strain of Toxoplasma in particular is very virulent and kills mice within a few days. Several strains of mice have been used for the bradyzoite infections in rodents. No special housing or care or specific pretreatment is required in this model. The inoculum should contain about 20–30 cysts per mouse and they can be given to the animals intraperitoneally or orally by using a bent button needle of 1 mm diameter. They can be given to the animals intraperitoneally or orally by using a bent button needle of 1 mm diameter. In case of infections in immunodeficient mice, specialized housing and care are necessary, although no specific pretreatment is required. The animals are infected intraperitoneally and depletion of more than 88% is accomplished by treatment with hybridoma culture supernatants, containing anti L3T4 monoclonal antibody or anti-Lyt-2 monoclonal antibody, followed by incubation with complement.