The study was performed on a male European bison (Bison bonasus bonasus L.) foetus spontaneously aborted at the fourth or fifth month of pregnancy in the Białowieża Forest. Serum samples from the foetus and mother revealed the presence of antibodies against T. gondii (S/P% = 88% and 75%, respectively). Mobile extracellular tachyzoites were first observed in a Vero cell culture, 110 days following inoculation of brain homogenate. PCR amplification with TGR1E1 and TGR1E2 primers confirmed the presence of T. gondii DNA, which was classified as Type I by PCR-RFLP genotyping. The sequences of 18S ribosomal RNA (18S rRNA) and 5.8S ribosomal RNA (5.8S rRNA) genes; internal transcribed spacer 1 (ITS1) and internal transcribed spacer 2 (ITS2), obtained from T. gondii isolate, have been deposited in GenBank (accession number KX459518.1). This is the first in vitro isolation and molecular identification of T. gondii from an aborted European bison foetus. The origin of this protozoan isolate indicates that the species is a significant threat to the European bison conservation program implemented in the Białowieża Forest.
Keywords: Aborted foetus; Białowieża Forest; European bison; Genetic characterization; Isolation; Toxoplasma gondii.