First isolation and molecular characterization of Toxoplasma gondii from a human placenta in Argentina

Genetic characterization of Toxoplasma gondii from human and chicken isolates from Argentina

This study aimed to determine the nPCR-RFLP genotypes of newly obtained T. gondii isolates from human congenital toxoplasmosis cases in Argentina and to determine their allelic profiles for virulence genes ROP18/ROP5. In addition, the ROP18/ROP5 profiles were also determined for previously characterized T. gondii samples. Isolation from congenital toxoplasmosis cases was carried out in mouse bioassay from two placentas (P1 and P2). Genotyping for the new human isolates was performed by nPCR-RFLP using 10 markers. The samples analyzed for ROP18/ROP5 included the two newly obtained isolates (from the congenital toxoplasmosis cases) and nine previously genotyped T. gondii DNA samples from humans and chickens. The results for P1 and P2 named as TgHm18-02Arg and TgHm19-01Arg showed ToxoDB genotypes #14 (non-archetypal) and #2 (clonal type III), respectively. Non-archetypal #14 has been isolated from human cases before in Argentina. However, this is the first report of T. gondii clonal type III in a human case in the country. The ROP18/ROP5 combination was detected in nine samples: 3/3 (n = 1), 4/3 (n = 4), 4/4 (n = 3), and 3-4/4 (n = 1). Notably, the 4/4 profile was identified for the first time and exclusively in T. gondii samples from Misiones province (which borders southern Brazil). Further studies are required to corroborate the regionalization of the ROP18/ROP5 profiles in Argentina.

Genetic characterization of Toxoplasma gondii isolates from human spontaneous aborted fetuses in Jahrom, southern Iran

Toxoplasma gondii (T. gondii) is an intracellular protozoan that infects the fetus through the placenta and leads to severe complications in the fetus. One of the complications of congenital toxoplasmosis is spontaneous abortion. The prevalence of toxoplasmosis infection was investigated among spontaneously aborted fetuses (SAFs), and the genotypes of parasite isolates were determined in the present study. Placentas from 330 samples of SAFs were collected in Jahrom (Fars province) from February to September 2018. DNA was extracted from each placental tissue. The T. gondii infection was detected using nested polymerase chain reaction (Nested-PCR) assay based on a 529 bp repeat element (RE) gene. Afterward, Toxoplasma was genotyped using PCR-restriction fragment length polymorphism (PCR-RFLP) based on the GRA6 gene. The frequency of T. gondii infection was found to be 14.5% (48 out of 330 samples). Genotyping of nine T. gondii isolates revealed that all belonged to genotype II. Statistically, the prevalence of T. gondii infection was significantly correlated with the education levels of the mothers and the age of the fetus (P < 0.05). The lowest prevalence of Toxoplasma infection belonged to mothers with university education and the highest frequency of infection was observed among the fetuses in the age group of 8-9 weeks. The findings of the present study suggest a significant role for toxoplasmosis in SAFs in Jahrom city.

ROP18 and ROP5 alleles combinations are related with virulence of T. gondii isolates from Argentina

The allelic combination of ROP18/ROP5 genes of Toxoplasma gondii has been shown to be highly predictive of mouse virulence in canonical isolates and strains. The aims of this study were to analyze the alleles present in the ROP18/ROP5 genes from T. gondii isolates obtained in Argentina, to associate the results with the virulence registered in mouse model, and to compare with other isolates and reference strains using a phylogenetic network. Fourteen T. gondii isolates from Argentina were analyzed by nPCR-RFLP for ROP18/ROP5. Phylogenetic network analysis was inferred using the ToxoDB genotypes and the ROPs molecular markers. All isolates and reference strains were categorized as lethal or non-lethal. As results, combinations 2/2, 3/3 and 4/3 for ROP18/ROP5 were detected in 12 isolates, whereas only alleles 1 and 2 of ROP5 were detected in 2 isolates. The majority of the isolates had a mouse virulence matching to that predicted by the ROP18/ROP5 allele combination. The 3 isolates that differed from the expected virulence presented non-clonal genotypes. ROPs incorporation increased the accuracy of the phylogenetic network relations among the T. gondii samples, prevailing the clustering according to regions. Our results indicate a predominance of type 3 allele in both ROP18 and ROP5 markers and an association of allelic profiles 3/3 and 4/3 of non-clonal genotypes from Argentina, both with virulent and avirulent profiles in mice.

Isolation, genetic and immunohistochemical identification of Toxoplasma gondii from human placenta in a large toxoplasmosis outbreak in southern Brazil, 2018

The present study aimed to describe a molecular analysis of environmental and pork samples, the isolation, genetic identification and immunohistochemistry (IHC) of Toxoplama gondii from placenta and amniotic fluid from five pregnant women that miscarried during a toxoplasmosis outbreak in 2018, Santa Maria, Rio Grande do Sul. Environmental and pork samples were submitted to polymerase chain reaction (PCR); placenta and amniotic fluid samples to histopathology, IHC, mouse bioassay and PCR. All samples were genotyped by PCR-RFLP with 11 loci. Histopathologic and IHC were compatibles with toxoplasmosis. All pregnants were positive in PCR and bioassay, the genotypes were compared, and all were equal suggesting a same source of infection. Among the environmental and food samples, a sludge sample from a water tank and two porks samples were positive in PCR, and the genotypes were different from the pregnant women isolates. It is concluded that obtain and compare isolates is essential to elucidate outbreak source.

Isolation and molecular characterization of Toxoplasma gondii from placental tissues of pregnant women who received toxoplasmosis treatment during an outbreak in southern Brazil

Toxoplasma gondii is a protozoan that has great genetic diversity and is prevalent worldwide. In 2018, an outbreak of toxoplasmosis occurred in Santa Maria, Brazil, which was considered the largest outbreak ever described in the world. This paper describes the isolation and molecular characterization of Toxoplasma gondii from the placenta of two pregnant women with acute toxoplasmosis who had live births and were receiving treatment for toxoplasmosis during the outbreak. For this, placental tissue samples from two patients underwent isolation by mice bioassay, conventional PCR and genotyping using PCR-RFLP with twelve markers. Both samples were positive in isolation in mice. The isolate was lethal to mice, suggesting high virulence. In addition, the samples were positive in conventional PCR and isolates submitted to PCR-RFLP genotyping presented an atypical genotype, which had never been described before. This research contributes to the elucidation of this great outbreak in Brazil.

Human toxoplasmosis: a systematic review for genetic diversity of Toxoplasma gondii in clinical samples

Toxoplasma gondii (T. gondii) as an obligate intracellular protozoan with a worldwide distribution can infect virtually all warm-blooded animals and humans. This study aims to provide a summary of the available data on genotypes of T. gondii in human. Five databases including MEDLINE in PubMed, Scopus, Science Direct, Web of Science and Google Scholar were searched for the T. gondii genotyping in human during 1995-August 2017. Next, we screened all the articles based on the inclusion and exclusion criteria. Overall, 26 studies were eligible regarding genotyping T. gondii in human samples. In clonal genotyping, 167 out of 286 cases (58%) were infected with type II. Genetic characterisation of T. gondii isolates displayed that type II was the most predominant genotype in human with the prevalence of 64.3%, 62.1% and 41.7% in patients with AIDS, congenital and ocular toxoplasmosis, respectively. In ToxoDB genotyping, most individuals were infected with genotypes #9 and #65 (21.2%). Based on these results, genotype profile of T. gondii isolates is different throughout the world. The strains in Asian and African countries are characterised by low genetic diversity, while in North and South America a wide diversity of this parasite is found. In countries without any data (e.g. Australia, Western and Southern Africa and Western Asia), identification of T. gondii genotypes might discover higher genetic diversity.

Congenital human toxoplasmosis caused by non-clonal Toxoplasma gondii genotypes in Argentina

Toxoplasmosis, a worldwide distributed zoonosis, can be transmitted congenitally affecting fetuses and developing variable clinical signs. Different Toxoplasma gondii genotypes and infective dose are related factors with different clinical manifestations. Several studies indicate that atypical strains could produce more severe clinical manifestations compared to typical strains. Umbilical cord blood (n = 37) and placenta (n = 19) were collected at birth from women with acute T. gondii infection and processed for isolation by mice bioassay. Six isolates were obtained and identified as TgHm14-4Arg, TgHm15-02Arg, TgHm16-01Arg, TgHm16-02Arg, TgHm17-01Arg and TgHm17-02Arg. Three genotypes described previously on Toxo-DB were identified: #138 identified in chickens from Brazil, #182 isolated from eared doves from Brazil, #14 from wallaby kangaroos and chickens from Argentina, chickens from Brazil, Colombia, Chile and Venezuela, cats and dogs from Brazil and Colombia and also coyotes from USA indicating worldwide distribution of these genotypes. Two new allele combinations were obtained showing high genotypes diversity in Argentina. Four of the isolates (TgHm14-4Arg, TgHm15-02Arg, TgHm16-01Arg, TgHm16-02Arg) and two of them (TgHm17-01Arg, TgHm17-02Arg) produced chronic and acute infections in mice, respectively. Until now, seven T. gondii isolates have been obtained from humans in Argentina, and all were atypical or non-clonal genotypes. The identification of atypical strains causing congenital toxoplasmosis and circulating in our region, make important to perform the serological screenings according Argentine Consensus of Toxoplasmosis and to apply and monitoring treatments earlier in pregnancy. To achieve this aim, it is necessary to inform general population about T. gondii infection, diagnostics and control measures. These results should serve to generate awareness about congenital toxoplasmosis in South America.

Population structure of Toxoplasma gondii in Argentina

The protozoan Toxoplasma gondii is worldwide distributed showing a particular population structure that may differ among continents and countries. The aim of this study was to analyze the T. gondii population structure in Argentina and compare it with genotyping information from other South American countries. For the analysis, 39 samples from Argentina (isolates from the provinces of Buenos Aires, Misiones, Entre Ríos and San Luis) were genotyped using 10 multilocus PCR-RFLP markers including SAG1, SAG2 (5'-3'SAG2, alt. SAG2), SAG3, BTUB, GRA6, C22-8, C29-2, L358, PK1, and Apico. The T. gondii DNA samples were obtained from domestics animals (chickens n = 20; cats n = 3; pigs n = 2; goat n = 1; rabbit n = 1), humans (n = 6), zoo animals (n = 5) and a rat (n = 1). Phylogenetic relationship of these Argentinean isolates together with representative reference genotypes was determined by phylogenetic network analysis. Thirty-seven Argentinean samples belonged to 21 genotypes and two samples were genotyped at 8 of the 10 loci and considered incomplete characterized. Among these 37 typed samples, five genotypes were not previously reported. The majority of the samples grouped with the Type III (ToxoDB PCR-RFLP genotype #2) lineage. The clonal Type II (ToxoDB genotypes #1 and #3) was also identified. Our results suggest a unique population structure with combination of unique genotypes and the common Type II and Type III lineages in Argentina. Nevertheless, different regions showed distinctive pattern of genotypes, revealing a higher variability in Northern provinces.

Characterization of Toxoplasma gondii isolates from herds of sheep in southern Brazil reveals the archetypal type II genotype and new non-archetypal genotypes

Recent studies have demonstrated that, in Brazil and South America, strains of Toxoplasma gondii are often genotypically and biologically different from those found in countries on other continents. The objective of this study was to genotypically characterize T. gondii isolates from naturally infected sheep in herds in the southern region of the state of Rio Grande do Sul, Brazil, by means of the polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP). Five T. gondii isolates obtained from sheep in five municipalities in the state of Rio Grande do Sul were used. Application of multilocus PCR-RFLP multilocus using 12 genetic markers (SAG1, 5'3' SAG2, alt. SAG2, SAG3, BTUB, c22-8, c29-2, GRA6, L358, PK1, APICO and CS3) revealed four different genotypes in the five isolates studied: clonal type II (TgOvBrRS4), type BrIV (TgOvBrRS2 and TgOvBrRS3) and two new non-archetypal genotypes, ToxoDB-RFLP#270 and #271 (TgOvBrRS1 and TgOvBrRS5, respectively). The genotype structure found in the T. gondii isolates from naturally infected sheep in the southern region of Brazil was revealed to have high diversity. This study confirms the presence of rare circulation of the clonal type II genotype in Brazil.

Is Toxoplasma gondii type related to clinical outcome in human congenital infection? Systematic and critical review

In human congenital toxoplasmosis the effects of parasite burden and pregnancy time at infection on clinical outcome are well known, but there is controversy regarding the role of Toxoplasma gondii type. Through a systematic review of the literature, we aimed to discern if T. gondii type has a role on clinical outcome in human congenital toxoplasmosis. We built up a database of congenital toxoplasmosis from reports of cases, case series and screening-based cohorts, which had information about parasite type, gestation time at maternal infection and/or clinical outcome in the product. Then, we obtained frequencies for loci used to genotype geographical origin of cases and types found. Also, odds ratios were calculated for association between time of maternal infection or parasite type on outcome. Type II parasites were the most common in Europe, Asia and Africa, while in America there were mainly atypical strains. More newborns with clinical problems were born from mothers infected during the first half of gestation than from those acquiring the parasite after week 24, regardless of parasite genotype (92.9 vs. 16.1 %, OR = 67.9, CI95 25.4-181.6). Type I and atypical parasites were associated with clinical problems as opposed to types II and III, regardless of pregnancy period at infection (86.9 vs. 72.9 %, OR = 2.47, CI95 1.1-5.4). A significant and remarkable tendency of type I parasites to be present during early pregnancy was also observed (94.4 vs. 5.6 %, P < 0.009). In addition to parasite burden and period of gestation, T. gondii genotype seems involved in CT clinical outcome.

Prematurity and Low Birth Weight did not Correlate with Anti-Toxoplasma gondii Maternal Serum Profiles--a Brazilian Report

Gestational Toxoplasma gondii infection is considered a major risk factor for miscarriage, prematurity and low birth weight in animals. However, studies focusing on this topic in humans are scarce. The objective of this study is to determine whether anti-Toxoplasma gondii maternal serum profiles correlate prematurity and low birth weight in humans. The study examined 213 pregnant women seen at the High-Risk Pregnancy Hospital de Base, São José do Rio Preto, São Paulo, Brazil. All serological profiles (IgM-/IgG+; IgM-/IgG-; IgM+/IgG+) were determined by ELISA commercial kits. Maternal age, gestational age and weight of the newborn at birth were collected and recorded in the Statement of Live Birth. Prematurity was defined as gestational age <37 weeks and low birth weight ≤ 2499 grams. The t-test was used to compare values (p < 0.05). The mean maternal age was 27.6±6.6 years. Overall, 56.3% (120/213) of the women studied were IgM-/IgG+, 36.2% (77/213) were IgM-/IgG- and 7.5% (16/213) were IgM+/IgG+. The average age of the women with serological profile IgM+/IgG+ (22.3±3.9 years) was different from women with the profile IgM-/IgG+ (27.9±6.7 years, p = 0.0011) and IgM-/IgG- (27.9±6.4 years, p = 0.0012). There was no statistically significant difference between the different serological profiles in relation to prematurity (p = 0.6742) and low birth weight (p = 0.7186). The results showed that prematurity and low birth weight did not correlate with anti-Toxoplasma gondii maternal serum profiles.