Genetic diversity of Toxoplasma gondii isolates obtained from free-living wild birds rescued in Southeastern Brazil

Abstract

Recent studies carried out in Brazil have shown that strains from the same Toxoplasma gondii genotype can infect humans, domestic animals (dogs and cats) and animals slaughtered for human consumption (pigs, sheep, goats, and chickens), suggesting a common infection route. However, little is known about the importance of free-living wild birds within this epidemiological context. The objective of this work was to isolate, genotype, and evaluate the virulence for mice of new isolates of T. gondii obtained from free-living wild birds from the state of Minas Gerais, Southeastern Brazil. From August 2016 to June 2017, T. gondii was isolated from the hearts and brains collected from 6 out of 45 free-living wild birds, namely, a roadside hawk (Rupornis magnirostris), a campo flicker (Colaptes campestris), a southern caracara (Caracara plancus) and a tropical screech-owl (Megascops choliba), all rescued in Belo Horizonte. One isolate was obtained from a toco toucan (Ramphastos toco), rescued in Cristiano Otoni, and another was obtained from southern caracara, rescued in Santa Luzia. Five different genotypes were identified by PCR-RFLP. A unique genotype was shared in two different isolates obtained from a southern caracara and a toco toucan. This genotype has never been previously described in any other host or place. Three isolates were classified as of intermediary virulence and three isolates as avirulent for mice. The combined analysis of alleles ROP18/ROP5 (a serine/threonine kinase, and a polymorphic pseudokinase, respectively) was effective in determining the virulence of five of all the isolates with the exception of that from R. magnirostris. Atypical isolates of T. gondii obtained from free-living wild birds rescued in the state of Minas Gerais share the same genotypes of strains that infect humans, domestic animals, and animals slaughtered for human consumption.

Interaction of diet and habitat predicts Toxoplasma gondii infection rates in wild birds at a global scale

“…Although important for other inferences, such as strain determination, we also found that parasite isolation methods were less sensitive for detecting infections. Failure of detection can occur if tissue cysts are very small and/or are not included in the sampled tissue, and although T. gondii has a predilection for the brain and the heart, the success of isolation can differ between these tissues even within the same individual (Rêgo et al, 2018), possibly owing to varying stages of infection (Ingram, Goodrich, Robey, & Eisen, 2013). Although seroreversion and detection failure decrease prevalence estimates, this influence should be equal across species regardless of trophic guild, habitat or scavenging tendency.…”

Sarcocystidae in wild birds of southeastern Brazil

“…Toxoplasma gondii was isolated from six of the 44 birds. Rêgo et al (2018) genotyped these isolates and identified five different genotypes by PCR-RFLP. A unique genotype, not previously described was common to two isolates.…”

Relationship between Toxoplasma gondii exposure and Forest Cover and Precipitation in Neotropical Primates of Costa Rica

“…Additionally, Toxoplasma genotypes produce different degrees of virulence in humans and mice (Xiao & Yolken, 2015), and given the high diversity recently found in Central and South America (Ajzenberg et al, 2004;Lehmann et al, 2004;Rajendran et al, 2012;Vitaliano et al, 2014;Rego et al, 2018;Vethencourt et al, 2019) the observed differences in seroprevalence between wild and captive NP might be due to different genotypes. Little is known about the genotypes circulating in wildlife, and associations between strain type, lesion patterns and clinical outcome have not been reported in wildlife frequently.…”