Toxoplasma gondii infection in European mouflons (Ovis musimon) and captive wild felines from Puebla, México

Acute Disseminated Toxoplasmosis in Two Specimens of Macropus rufogriseus Caused by a Genotype so far Exclusive to South America

Macropods are included among the species considered highly susceptible to Toxoplasma gondii infection. Clinically, it is difficult to distinguish between acute toxoplasmosis due to primary infection and reactivation of chronic latent infection in susceptible species until pathologic studies are performed. Here, we described the clinical cases and lesions found in two deceased Bennett's wallabies (Macropus rufogriseus) with a presumptive diagnosis of toxoplasmosis, as well as the genetic characterization of the T. gondii isolates obtained from these specimens. Both animals presented acute infection lesions in the lungs, liver, spleen and lymph nodes associated to T. gondii infection. Histopathology and immunohistochemistry also demonstrated tissue cysts of different sizes, indicating that the wallabies were previously infected with this parasite. Two isolates were obtained, one from each specimen and the molecular characterization was done; both isolates were the ToxoDB #116 genotype. This is the first study that reports the isolation of this particular genotype outside South America, and given the histopathological findings, it could be considered virulent for this species. The dynamics of infection that T. gondii is causing in definitive and intermediate hosts in a region allows us to know the risks to which the animals and humans that live in the area are exposed, and in the future to implement a preventive medicine plan against this parasite.

SAG3 Toxoplasma gondii cloning reveals unexpected fivefold infection in the blood of feral cats in the Mexican Caribbean

Background

Currently, more than 300 genotypes of Toxoplasma gondii (T. gondii) have been described throughout the world, demonstrating its wide genetic diversity. The SAG3 locus is one of the genes included in the genotyping panel of this parasite. It is associated with its virulence since it participates during the invasion process of the host cells. Therefore, cloning, sequencing, and bioinformatic analysis were used to deepen the understanding of the SAG3 locus genetic diversity of T. gondii in blood samples from feral cats.

Results

Six different SAG3 sequences were detected, five of which were detected in one feline. Three sequences were first reported here; one of them was an intragenic recombinant. In the cladogram, four out of ten SAG3 sequences did not share nodes with others reported worldwide.

Conclusions

Cloning and sequencing of samples with more than one restriction pattern by PCR-RFLP were very helpful tools to demonstrate the presence of more than three genotypes of T. gondii in the blood of feral cats from southeastern Mexico. This suggests a potential mixed infection of multiple T. gondii strains and high genetic diversity of the parasites in felines in this tropical region of Mexico.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03129-9.

Serological prevalence and risk factors of Toxoplasma gondii in Zoo Mammals in Chile

Toxoplasma gondii is a zoonotic cosmopolitan protozoan that causes a high mortality rate among zoo mammals such as New World primates, meerkats, marsupials and Pallas' cat. It has been recently reported in Chile, mainly among wild populations, but also as the cause of death of a kangaroo and a mara. However, there has not been a T. gondii report at a Zoo population level in Chile in the last 35 years. The aim of the study was to estimate the seroprevalence and risk factors associated with T. gondii infection in mammals housed in a zoo located in the Metropolitan Region of Chile between 2011 and 2018. In this study, we analyzed 350 samples, from 324 animals, belonging to 57 species of carnivores, non-human primates, macropodids, ungulates and rodents to detect the presence of anti-T. gondii antibodies. Additionally, 20 animals were longitudinally sampled to evaluate intra-zoo infection. Using a commercial indirect Enzyme-Linked Immuno Sorbent Assay (ELISA) test, we detected T. gondii antibodies in 72 (22.2 %) samples. The overall seroprevalence estimates were 48.4 % in felines, 22.9 % in non-feline carnivores, 21.1 % in ungulates and 15.0 % in non-human primates. There were no positive samples from rodents or marsupials. Of animals sampled longitudinally, only a culpeo fox (Lycalopex cualpaeus) became seropositive along the study indicating exposition inside the facility. T. gondii seroprevalence differed significantly in taxonomic groups (p = 0.003), felines are statistically different from non-feline carnivores (NFC) (p = 0.040), ungulate (p = 0.027) and non-human primates (NHP) (p = 0.009). Annual prevalence comparison was performed showing no statistical difference (p = 0.941). A multivariable logistic regression was performed to ascertain the effect of taxonomic groups, proximity to water sources, diet, sex and type of housing on seropositivity. Only taxonomic group was statistically significant, indicating that NFC (OR = 0.35; 95 % CI = 0.15 - 0.83; p = 0.017), ungulates (OR = 0.30; 95 % CI = 0.13 - 0.69; p = 0.005), and NHP (OR = 0.25; 95 % CI = 0.09 - 0.72; p = 0.010) have lower risk of positivity to T. gondii compared to felines. Additionally, a black-faced spider monkey (Ateles chamek) and a siamang (Symphalangus syndactylus) were seropositive, being the first description of T. gondii infection in these species worldwide. As seen in previous studies, the widespread presence and exposure of T. gondii in zoo mammals was confirmed, and there may be contact with the agent and transmission within the zoo, which was confirmed by one animal became seropositive over the time. This fact could be a health problem for animals susceptible to fatal toxoplasmosis.