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

Genetic diversity of Toxoplasma gondii in South America: occurrence, immunity, and fate of infection

Toxoplasma gondii is an intracellular parasite with a worldwide distribution. Toxoplasma gondii infections are of great concern for public health, and their impact is usually most severe in pregnant women and their foetuses, and in immunocompromised individuals. Displaying considerable genetic diversity, T. gondii strains differ widely according to geographical location, with archetypal strains predominantly found in the Northern Hemisphere and non-archetypal (atypical) strains, with highly diverse genotypes, found mainly in South America. In this review, we present an overview of the identification and distribution of non-archetypal strains of T. gondii. Special attention is paid to the strains that have been isolated in Brazil, their interaction with the host immunological response, and their impact on disease outcomes. The genetic differences among the strains are pivotal to the distinct immunological responses that they elicit. These differences arise from polymorphisms of key proteins released by the parasite, which represent important virulence factors. Infection with divergent non-archetypal strains can lead to unusual manifestations of the disease, even in immunocompetent individuals.

Genetic diversity of Toxoplasma gondii in goats and sheep from the Northeast Region of Brazil destined for human consumption

This study aimed to genotype isolates of Toxoplasma gondii obtained from samples of brain, diaphragm and heart of goats and sheep intended for human consumption in the State of Paraíba, Brazil. Tissue samples from 14 animals, goats (n = 5) and lambs (n = 9), were sourced from public slaughterhouses in seven cities and bio-assayed in mice. The brains of the mice were utilized for DNA extraction. Genotyping was carried out by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) using 10 markers (SAG1, SAG2, SAG3, BTUB, c22-8, PK1, GRA6, L358, c-29-2 and Apico). A total of 10 isolates were fully genotyped (i.e. at all loci), three from goats and seven from sheep, revealing five distinct genotypes: #13 (n = 4); #48 (n = 3); #57 (n = 1); #273 (n = 1); and one new genotype that had not been previously described. Genotype #13 is frequently found in the Northeast of Brazil and represents a clonal lineage circulating in this region and was the most prevalent genotype identified (n = 4). Moreover, in the present study genotypes #13, #48, #57, and #273 were documented for the first time in sheep from Brazil, and the novel genotype was isolated from a goat. Our findings align with previous studies on T. gondii from Brazil, where new genotypes are continuously being identified, highlighting a high level of genetic diversity of T. gondii isolates in the country.

Immunological, Histopathological, Molecular Identification and Genotyping of Toxoplasma gondii in Small Ruminants in Egypt

<b>Background and Objective:</b> Toxoplasmosis is an infective zoonotic disease caused by protozoan <i>Toxoplasma gondii </i>(<i>T. gondii</i>).<i> </i>Molecular identification of <i>T. gondii</i> followed by studying the hereditary variety range of <i>T. gondii </i>isolates in Egypt was investigated. <b>Materials and Methods:</b> Blood samples were acquired from 138 live ewes and 212 she-goats from 5 governorates of Egypt, also the blood and its related tissue samples (uterus, diaphragm, heart and thigh muscles from each animal) were collected from slaughtered 180 ewes and 206 she-goats from Cairo and Giza abattoirs. <b>Results:</b> Using ELISA, the total seropositivity of live ewes and she-goats was 26.8 and 21.2%, respectively, while it was 16.6 and 33% in slaughtered ewes and she-goats, respectively. <i>T. gondii</i> tissue cysts with the associated characteristic histopathological changes were detected in different organs. Twenty-eight <i>T. gondii</i> isolates were confirmed using PCR, while among 24 milk samples from seropositive live ewes and she-goats, only 12.5 and 6.25%, were positive using PCR, respectively. Genotyping using multiple nested PCR (n-PCR) combined with restriction enzyme analysis (RFLP) of the surface antigen 2 (SAG2) gene confirmed 26 isolates (92.8%) as type II and 2 (7.1%) as type III. <b>Conclusion:</b> Type II and III are the most common <i>T. gondii</i> genotypes in Egyptian small ruminants with additional importance for public health in Egypt. Further studies are needed on the role of milk in the transmission of toxoplasmosis.

Seroprevalence and isolation of Toxoplasma gondii in sheep intended for human consumption in Paraíba, northeastern Brazil

Toxoplasma gondii is a zoonotic parasite capable of infecting almost all warm-blooded animals. Currently, studies assessing the viability of cysts present in sheep meat are still scarce, especially in the northeastern region of Brazil. Therefore, the aim of this study was to evaluate the seroprevalence of anti-Toxoplasma gondii antibodies, isolate the parasite from tissue samples, and determine factors associated with infection of sheep intended for human consumption in the state of Paraíba, northeastern Brazil. Serum samples from 205 sheep slaughtered in Paraíba were tested using the indirect fluorescence antibody test (IFAT ≥ 64) for the presence of anti-T. gondii antibodies. Among the animals sampled, 30.7% (63/205) were seropositive, with antibody titers ranging from 1:64 to 1:16384. Sixty-one bioassays were performed in mice, and an isolation rate of 47.5% (29/61) was obtained. The infection was lethal to at least one infected mouse in 24.1% (7/29) of the bioassays. The mean length of survival of infected mice was 36.4 days. Females (OR = 3.183; CI = [1.452-6.976]), extensive breeding system (OR = 2.612; CI = [1.120-6.094]), and purebred animals (OR = 2.157; CI = [1.009-4.612]) were considered to be factors associated with infection. These results revealed that the prevalence of anti-T. gondii antibodies and the percentage of viable cysts recovered from sheep destined for human consumption in Paraíba, northeastern Brazil, were high.

Ocular Disease in Mice Inoculated with Pork Heart Samples Infected with Toxoplasma gondii

PURPOSE

We analyzed the frequency, viability, and genetic characteristics of T. gondii in pork heart samples.Methods: Thirty-five fresh pork samples were purchased in a slaughterhouse in Erechim city. The DNA was extracted and qPCR was performed. T. gondii genotyping was performed using PCR-RFLP analysis. Positive samples were digested and inoculated in mice for viability analysis.Results: Our results showed that T. gondii DNA was detected in 25.7% of the pork heart samples and genotyping revealed one new atypical strain. The viability analyses demonstrated that 40% of mice presented clinical signs of T. gondii infection. qPCR was positive in the lung, liver, and brain of mice that presented clinical signs of T. gondii infection. Also, the histopathology analysis showed retinal disorganization, retinal detachment, inflammatory cell infiltration, and fibrosis in the eyes analyzed.Conclusion: Our findings have shown that pork eat from southern Brazil may contain live T. gondii that could be associated with toxoplasmosis.

Economic and public health importance of Toxoplasma gondii infections in sheep: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, control, and genetic diversity of T. gondii in sheep in the past decade. There is debate and uncertainty concerning repeat congenital infection as evidenced by finding T. gondii DNA in progeny of chronically infected sheep. However, there is no concrete evidence that T. gondii is the cause of repeated abortions in sheep. Recent data concerning pathogenesis of abortion in acutely infected sheep are reviewed. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates or tissues of infected sheep revealed low genetic diversity in sheep in Europe, Africa, Asia and North America but high diversity in South America. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Detection and genotypes of Toxoplasma gondii DNA in feces of domestic cats in Colombia

The high prevalence of Toxoplasma gondii in the human population in Colombia has been linked to the existence of a high density of urban stray cats, exposing the whole population to a high density of oocysts. The goal of this study was to determine the DNA prevalence of T. gondii by conventional PCR and to phylogenetically analyze ROP18 sequences from positive samples in domestic cat (Felis catus) fecal samples in the city of Armenia, Quindío. Fecal samples from 140 cats were collected from 10 districts around the city. Samples were concentrated using Ritchie’s method and analyzed through optical microscopy. Concentrates were used for DNA extraction followed by nested PCR amplification for T. gondii gene B1. PCR for ROP18 was performed on all B1 positive samples; the ROP18 sequences obtained were related to the Archetype I Brazilian and Chinese strains. No oocysts were detected by optical microscopy; however, 17.8% (25/140) B1 and 24% (6/25) ROP18 PCR-positive samples were detected. Phylogenetic analyses showed that isolates clustered into a single group. We assessed whether associations existed between T. gondii positive fecal samples and survey variables such as cat healthcare and socioeconomic characteristics of owners, but no statistically significant associations were found. The presence of T. gondii in cat feces is an important factor contributing to the high prevalence in the human population of this city.

Congenital Transmission of Toxoplasma gondii After Experimental Reinfection With Brazilian Typical Strains in Chronically Infected Sheep

Toxoplasma gondii is a cause of congenital diseases, miscarriages and stillbirths in production animals. In Brazil, non-archetypal genotypes of the parasite may be related to severe disease. Experimental infection with T. gondii was studied in sheep to analyse congenital transmission-related parameters in reinfections with different Brazilian parasite strains. Thirteen T. gondii-seronegative sheep were orally infected with 2 × 10³oocysts for the primary infection: G1 (4 animals) were inoculated with TgCatBr71 strain (Type BrI genotype) and G2 andG3 (5 and 4 animals, respectively) withTgCatBr60 strain (Type BrIII genotype). After chronification of infection, the animals were impregnated. A second infection was performed after 60 days of gestation. TheG1 andG3 animals were inoculated withTgCatBr60BrIII and the G2 animals withTgCatBr71 BrI oocysts. The effects of reinfection were compared with a control group (5 animals) through physical examination, ultrasound imaging and serology. Ovine experimental infections were evaluated using mouse bioassays, molecular analysis, serological tests, histopathology, and immunohistochemistry. No abortions occurred; a seropositive lamb and a mummified fetus from G2-BrIIIxBrI were produced. The vertical transmission rate detected in lambs from chronically infected sheep was 31.6% (6/19). It is demonstrated that reinfection and subsequent congenital transmission occured in one sheep with a primary Brl infection challenged with BrIII genotype of T. gondii. In a twin pregnancy from G2-BrIIIxBrI, congenital transmission from a latent infection was detected in both lambs. Congenital transmission could not be tracked in three lambs. Overall, previous T. gondii infection may fail to protect against congenital transmission from a reinfection and primary infection induced insufficient protection against vertical transmission which must be taken into account in decision-making for the use of seropositive animals as breeders. Similar trials with larger groups and contemplating host cellular immune response studies should be conducted to evaluate the actual impact of T. gondii reinfection involving different strains in sheep.

Hepatitis in slaughterhouse workers

Slaughterhouse workers (SHW) are at increased risk of hepatitis which can occur due to different organisms and should be investigated for viral, bacterial, and parasitic organisms. Slaughter house personnel including butchers are at a higher risk of infections from cuts and blood-letting, with the possible risk of the transmission of blood-borne pathogens to their colleagues. The objective of this review is to evaluate the common etiologies of hepatitis in SHW which will assist in the assessment of these patients presenting with transaminitis. Types of Microorganisms causing hepatitis with their reservoirs, routes of transmission, laboratory diagnosis, clinical features, treatment options and preventive strategies are included in this review. Proper investigation and awareness is of utmost importance as it causes significant financial constraints derived from workers health cost and from livestock production losses when the disease is confirmed. The work up is essential because infected workers might be a source of infections to other colleagues, family and the consumers.