Isolation and molecular characterization of Toxoplasma gondii from fatal cases of generalized toxoplasmosis in captive wild animals in Argentina

BASSO W.; MORÉ G.; QUIROGA M.A.; PARDINI L.; BACIGALUPE D.; VALENZUELA M.C.; VENTURINI M.C.; VENTURINI L.; SCHARES G.

Innsbruck, Austria

Congreso; 42° Congress of the Austrian Society of Tropical Medicine and Parasitology.; 2008

Toxoplasma gondii infection is frequently asymptomatic; however, it can produce severe disease or be even fatal in some hosts. Some species like New World monkeys, lemurs, Pallas’ cats and some Australian marsupials are considered highly susceptible to clinical toxoplasmosis, but little is known on the T. gondii genotypes affecting these species. In this study, T. gondii was isolated from two Bennett’s wallabies (Macropus rufogriseus), one red kangaroo (Macropus rufus), one eastern grey kangaroo, one Squirrel monkey (Saimiri boliviensis), and three slender tailed meerkats (Suricata suricatta) with fatal generalized toxoplasmosis, in the zoo of La Plata, Argentina. In most of the cases death occurred suddenly without previous signs of disease. The diagnosis of toxoplasmosis was made by histological, immunohistochemical and molecular methods. Toxoplasma gondii DNA was demonstrated using the specific primers B22/B23 and TOX4/TOX5 in tissues of all animals. The parasite was isolated by bioassay in Swiss mice and was transferred into bovine monocytes cultures from tissues of all animal species. The isolates were cryopreserved. For the molecular characterization of the isolates, markers based in the loci SAG2, BTUB, GRA6, SAG3, c22-8, L358, PK1, c29-2 and Apico of T. gondii were analysed by PCR-RFLP. Toxoplasma gondii isolated from the eastern grey Kangaroo were classified as genotype II, the isolates from the red Kangaroo and the three meerkats, corresponded to the genotype III, and the isolates from the Bennett’s Wallabies and the Squirrel monkey were atypical; however, both wallabies shared the same marker pattern, and this same pattern was observed in isolates from free ranging chickens from Brazil. In this study, T. gondii genotypes considered avirulent in the mouse model like genotypes II and III were responsible for fatal cases in other species like Bennett’s Wallaby, red kangaroo, eastern grey kangaroo, Squirrel monkey and slender tailed meerkat.