Toxoplasma gondii Genotyping: A Closer Look Into Europe

Abstract

Toxoplasma gondii is a major zoonotic agent which may cause harmful effects mainly in pregnant and immunocompromised hosts. Despite many efforts on its genetic characterization, an entirely clear picture of the population structure in Europe has not been achieved yet. The present study aimed to summarize the available genotyping information and to map the distribution of circulating strains. There is consensus on type II T. gondii genotypes prevailing in Europe, but the absence of harmonization in the use of typing methods limits detailed knowledge. Standardized, high-end typing tools and integrative strategies are needed to fill the gaps and complete an accurate image of the T. gondii genetic population in Europe.

Prevalence and molecular characterization of Toxoplasma gondii in different types of poultry in Greece, associated risk factors and co-existence with Eimeria spp.

“…T. gondii presents a complex population structure, with three clonal lineages, type I, II, and III prevailing in Europe and North America (Howe and Sibley 1995;Fernández-Escobar et al 2022). Globally, a number of studies revealed a much greater genetic diversity of the parasite (Khan et al 2006(Khan et al , 2007Lehmann et al 2006;Pena et al 2008;Su et al 2012;Lorenzi et al 2016), subdivided by geographical region and by the existence of non-clonal lineages in areas such as South America, Africa and Asia (Shwab et al 2014;Galal et al 2019).…”

Archetypal type II and III Toxoplasma gondii oocysts induce different immune responses and clinical outcomes in experimentally infected piglets

“…In the present study, two low-passage (not lab-adapted) isolates were used: TgShSp1 (Type II) and TgShSp24 (Type III), which possess genetic profiles representing those that circulate in swine (an in other hosts) in Europe ( 14 ). These two isolates of different genotypes exhibit low virulence and moderate-high capacity to form tissue cysts in mice.…”

“…The population structure of T. gondii is predominantly clonal in the Northern Hemisphere. Regarding clonal types that circulate in European livestock, several genotyping-based studies have demonstrated the predominance of type II strains, which coexist with lower percentages of type III and recombinant strains ( 14 ). Previous studies in rodents highlighted marked differences in virulence depending on the clonal type, primarily related to specific mechanisms to subvert host proinflammatory immune responses ( 15 – 17 ).…”

Toxoplasma gondii in Foods: Prevalence, Control, and Safety

“…These molecular techniques detected the DNA of the parasite, and genotyping is possible with them. However, different available genotyping methodologies have been irregularly applied in different geographic areas and over different matrices [ 71 ]. The main drawback of these molecular techniques is that it only allows the DNA of the parasite to be detected, but the viability of T. gondii is unknown.…”