Epidemiology and isolation of viable strain from macropods.

Wallabies and other marsupials are highly susceptible to . In this study, 26 macropod samples were collected (8 red kangaroos, 4 Parma wallabies, 8 red-necked wallabies, 5 albino red-necked wallabies and 1 Eastern grey kangaroo), including tissue (n = 9) and serum (n = 17) samples. According to the modified agglutination test (MAT) results (cutoff 1:25), 50% (95% Cl: 32.06-67.94%) of the macropods had antibodies. Among them, species, survival state, and sampling date were risk factors for susceptibility ( < 0.05). DNA was detected in two (cases #14 and #15) of the nine cases obtained from macropod tissues. One viable strain (TgRooCHn4) was isolated from an albino red-necked wallaby ( case #14) via bioassay in mice. TgRooCHn4 belongs to ToxoDB genotype #3, using the 10 multilocus PCR-RFLP markers. The ROP18 and ROP5 gene allele types of TgRooCHn4 were 2/2, which was predicted to be non-lethal to mice. The virulence of TgRooCHn4 tachyzoites was avirulent in mice. Most macropods sampled from Hernan province in 2021 and 2022 were positive with infection A flood occurred in July 2021 in Zhengzhou from Henan province may promote the transmission of oocysts. To our knowledge, this is the first strain isolated from albino red-necked wallaby. However, further investigation is required to enhance our understanding of the transmission and prevention of toxoplasmosis in sensitive zoo animals.