Genetic diversity, clonality and sexuality in Toxoplasma gondii

Ajzenberg, Daniel; Bañuls, Anne‐Laure; Su, Chunlei; Dumètre, Aurélien; Demar, Magalie; Carme, Bernard; Dardé, Marie‐Laure

doi:10.1016/j.ijpara.2004.06.007

Cited by 329 publications

(228 citation statements)

References 44 publications

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“…Typically, 95% of strains isolated in North America and Europe fall into one of three highly clonal genotypes (Howe and Sibley 1995). However, it has recently been proposed that a greater degree of genetic diversity is found among strains in some geographic areas and possibly among non-domesticated animals (Ajzenberg et al 2004). Previous studies of strains isolated in Brazil has shown that they contain unusual, recombinant genotypes when analyzed using markers based on polymorphisms identifi ed in the North American and European clonal lineages (Ferreira et al 2006, Fux et al 2000.…”

Section: Discussionmentioning

confidence: 99%

High prevalence of unusual genotypes of Toxoplasma gondii infection in pork meat samples from Erechim, Southern Brazil

Belfort-Neto

Nussenblatt

Rizzo

et al. 2007

An. Acad. Bras. Ciênc.

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Toxoplasmosis is the most common cause of infectious uveitis in Brazil, with a higher frequency in the South of the country. We have collected samples from porcine tongue and diaphragm obtained in both large and small abattoirs and used molecular biological technique to determine the prevalence of infection and RFLP analysis to type the parasites. Seventeen out of 50 (34%) samples from the diaphragm and 33 out of 50 (66%) samples from the tongue demonstrated a positive PCR reaction for T. gondii and restriction analysis of four of the positive samples revealed that all had a type I genotype at SAG2. However, when other unlinked loci were analyzed, these strains had a type III genotype at markers BTUB, SAG3, and GRA6. One of the strains (8T) had a type II allele at SAG3, indicating it has a combination of alleles normally seen in the clonal lineages. Our sampling indicates a high prevalence of infection and suggests that unusual genotypes of T. gondii are found in Brazil even among domesticated pigs.

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Section: Discussionmentioning

confidence: 99%

High prevalence of unusual genotypes of Toxoplasma gondii infection in pork meat samples from Erechim, Southern Brazil

Belfort-Neto

Nussenblatt

Rizzo

et al. 2007

An. Acad. Bras. Ciênc.

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“…These isolates showed distinct and atypical genotypes, and neither has been described previously. Although T. gondii infection is asymptomatic in most immunocompetent hosts, severe cases of toxoplasmosis caused by atypical genotypes have been described in the Amazon region of French Guiana (19) (20) (21) .…”

Section: Statistical Analysesmentioning

confidence: 99%

Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon

Vitaliano

Mendonça

Sandres

et al. 2015

Rev. Soc. Bras. Med. Trop.

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Introduction:Toxoplasma gondii infection is widely prevalent in humans and other animals worldwide. Information on the prevalence of T. gondii infection is scarce in some regions of Brazil, including riverside communities along the Amazon River basin. Methods: The prevalence of T. gondii in 231 people, aged 1-85 years, who were living in four riverside communities along the Purus River, Lábrea, State of Amazonas, Brazil, was determined. Antibodies against T. gondii were assayed using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The hearts and brains of 50 chickens, which were raised freerange in the communities, were pooled according to the community of origin and bioassayed in mice. The isolates were genotyped using polymorphisms at 12 nuclear markers (SAG1, 5' and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3). Results: The overall seroprevalence of T. gondii was 56.7% (131/231). IgG antibodies were presented by 117 (89.3%) and IgM by 14 (10.7%) of the 131 positive individuals. No association between age group and gender with prevalence was observed (chi-square test, p > 0.05); however, the comparison between localities showed that the seroprevalence of T. gondii was signifi cantly lower among the individuals living in the Boca do Ituxi (p < 0.05) community. Five isolates of T. gondii were obtained in the mouse bioassay, and genotyping revealed two complete genotypes that had not been described previously and three mixed isolates. Conclusions: These results support previous fi ndings that T. gondii population genetics are highly diverse in Brazil and that T. gondii infection is active in these riverside communities.

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“…Recently, attention has been focused on the genetic variability among T. gondii isolates from apparently healthy and sick hosts (Howe et al, 1997;Grigg and Sundar, 2009). Severe cases of toxoplasmosis have been reported in immunocompetent patients in association with atypical T. gondii genotypes (Ajzenberg et al, 2004;Demar et al, 2007;Elbez-Rubinstein et al, 2009;Grigg and Sundar, 2009;Vaudaux et al, 2010;Wendte et al, 2010).…”

Section: Genetic Diversity and Epidemiological Significancementioning

confidence: 99%

Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type

Dubey

Velmurugan

Rajendran

et al. 2011

International Journal for Parasitology

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a b s t r a c tLittle is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study wild animals, from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. gondii was isolated from 31 animals including, to our knowledge for the first time, from a bald eagle (Haliaeetus leucocephalus), five gray wolves (Canis lupus), a woodrat (Neotoma micropus), and five Arctic foxes (Alopex lagopus). Additionally, 66 T. gondii isolates obtained previously, but not genetically characterised, were revived in mice. Toxoplasma gondii DNA isolated from these 97 samples (31 + 66) was characterised using 11 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, 5 0 -and 3 0 -SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). A total of 95 isolates were successfully genotyped. In addition to clonal Types II, and III, 12 different genotypes were found. These genotype data were combined with 74 T. gondii isolates previously characterised from wildlife from North America and a composite data set of 169 isolates comprised 22 genotypes, including clonal Types II, III and 20 atypical genotypes. Phylogenetic network analysis showed limited diversity with dominance of a recently designated fourth clonal type (Type 12) in North America, followed by the Type II and III lineages. These three major lineages together accounted for 85% of strains in North America. The Type 12 lineage includes previously identified Type A and X strains from sea otters. This study revealed that the Type 12 lineage accounts for 46.7% (79/169) of isolates and is dominant in wildlife of North America. No clonal Type I strain was identified among these wildlife isolates. These results suggest that T. gondii strains in wildlife from North America have limited diversity, with the occurrence of only a few major clonal types. Ó

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Genetic diversity, clonality and sexuality in Toxoplasma gondii

Cited by 329 publications

References 44 publications

High prevalence of unusual genotypes of Toxoplasma gondii infection in pork meat samples from Erechim, Southern Brazil

High prevalence of unusual genotypes of Toxoplasma gondii infection in pork meat samples from Erechim, Southern Brazil

Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon

Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type

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