First Isolation and Genotyping of Toxoplasma Gondii Strains From Domestic Animals in Tunisia

Abstract

The isolation and molecular typing of Toxoplasma gondii strains provides an essential basis for a better understanding of the distribution of genetic diversity and associated human health risks. In this context, we report, the molecular characterization of strains of T. gondii isolated from domestic animals infected with T. gondii in Southern and coastal area of Tunisia. This diversity is compared to that known for the Western European and Mediterranean sub-region.Blood, hearts and/or brains were collected from 766 domestic animals (630 sheep and 136 free-range chickens). Strain isolation from these samples were performed using mouse bioassay. The strains genotyping was carried out with a multiplex PCR technique using 15 microsatellite markers. Viable strains of T. gondii were isolated from 13.4% sheep and 33.3% chickens. Furthermore, the parasite was also detected in three DNA extracts from animal tissue digestates.This study showed a large predominance of type II strains (87.9%) from which two samples were type II variants for W35 locus. The other genotypes were three type III sheep isolates (9.1%) and, for the first time in Tunisia, an isolate of sheep origin of the Africa 4 genotype (3.0%). The comparison of microsatellite alleles of type II strains shows the recent migration of strains between Tunisia and other countries of the world.

First detection of Toxoplasma gondii Africa 4 lineage in a population of carnivores from South Africa

“…This is therefore the first record of the Africa 4 lineage in the region. This lineage is widespread in Africa (Egypt, Ethiopia, Senegal, Mali, Ghana, Benin, Gambia and Tunisia) and has also been reported in several Asian countries (China, Sri Lanka, United Arab Emirates) (Galal et al, 2018;Galal et al, 2019a;Galal et al, 2019b;Hamidovićet al, 2021;Lachkhem et al, 2021). Our results therefore revealed a wider distribution area of the Africa 4 lineage across the African continent.…”

“…Our results therefore revealed a wider distribution area of the Africa 4 lineage across the African continent. With the presence of the Type II lineage and now the Africa 4 lineage, the diversity in South Africa may be similar to that observed in North and East Africa, even though the Type III lineage described in these regions has not yet been found in South Africa (Galal et al, 2018;Lachkhem et al, 2021). A recent study showed that T. gondii lineages from the Old World (Africa, Asia and Europe), including the Africa 4 lineage, would be better adapted to the domestic environment, with a better potential for the sexual reproduction efficiency of these strains in the domestic cat (Galal et al, 2022).…”

“…In order to analyze the position of our strain within T. gondii genetic diversity from the African continent, a Neighbor -Joining tree was reconstructed using Populations 1.2.32 software (1999, Olivier Langella, CNRS UPR9034 http://bioinformatics.org/ ~tryphon/populations/) including Benin (Hamidovićet al, 2021), Senegal (Galal et al, 2019a;Galal et al, 2019b), Tunisia (Lachkhem et al, 2021), Egypt (Al-Kappany et al, 2010) and Gabon (Mercier et al, 2010). To do this, genetic distances based on Cavalli-Sforza and Edwards chord distance estimator (Cavalli-Sforza and Edwards, 1967) between unique haplotypes were calculated and used to reconstruct a Neighbour-Joining Tree generated with MEGA 6.05 (http://www.megasoftware.net/history.php).…”