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A series of laboratory experiments were conducted to study the fate and transport of Toxoplasma gondii oocysts in soils as a function of soil physicochemical properties and soil water chemistry properties. Soil columns were homogeneously packed with loamy sand soils (Lewiston and Greenson series) and sandy loam soils (Sparta and Gilford series), and subject to hydrologic conditions characterized by the absence and presence of an anionic surfactant—Aerosol 22 in the artificial rainfall. Quantitative polymerase chain reaction (qPCR) was utilized for the detection and enumeration of oocysts in soil leachates to evaluate their breakthrough and in soil matrices to examine their spatial distribution. Differences in the rate and extent of transport of oocysts were observed as a function of physical and chemical parameters tested. The breakthrough of oocysts was observed for all the soils irrespective of the presence of surfactant. However, in the absence of surfactant, the predominant fate of oocysts in soils subject to simulated rainfall was their retention in the soil profile. The presence of surfactant induced a change in the fate of oocysts in these soils exposed to rainfall simulation as the predominant fate of oocysts was found to be in the soil leachates. [ABSTRACT FROM AUTHOR]

Toxoplasmosis, caused by the obligate intracellular protozoan Toxoplasma gondii, is a worldwide parasitic zoonosis. A cross‐sectional study was carried out to determine the exposure to T. gondii in equids in Europe. Serum samples from 1399 equids (1085 horses, 238 donkeys, and 76 mules/hinnies) bred in four European countries (Italy, Spain, United Kingdom [UK], and Ireland) were collected during the period of 2013–2021. The overall seroprevalence of T. gondii was 18.9% (95% Confidence Interval [CI]: 16.9–21.0) by using the modified agglutination test (MAT) at a cut‐off of 1:25. Seropositivity by country was 27.1% in Italy, 16.6% in Spain, 12.0% in UK and 7.0% in Ireland. Anti‐T. gondii antibodies were detected in 12.8% of the horses, 43.7% of the donkeys, and in 28.9% of the mules/hinnies. A Generalized Estimating Equation (GEE) analysis was carried out to study the associations between seropositivity and explanatory variables related to individuals, herds, and management measures on these herds, selected based on the bivariate analysis. The risk for being seropositive for T. gondii was 5.3 and 2.7 times higher in donkeys and mules/hinnies than in horses, respectively. In addition, significantly higher seropositivity was observed in horses from herds that used disinfectants less than once a week (13.9%; p = 0.038, odds ratio [OR] = 1.6; 95% CI: 1.03–2.62) compared with those from herds that performed weekly disinfection of the facilities (9.4%). This is the first large‐scale seroepidemiological study on T. gondii comprising horses, donkeys, and mules/hinnies in Europe and the first report of T. gondii exposure in horses from Ireland and UK. We found a widespread distribution of T. gondii among equid populations in different European countries. The seroprevalence found in these species, especially in donkeys and mules/hinnies, highlights the potential risk of human infection through the consumption of their raw/undercooked milk or meat. [ABSTRACT FROM AUTHOR]

Background: Toxoplasma gondii is a widespread zoonotic protozoan parasite capable of infecting all warm‐blooded animals. Although the genotypes of T. gondii in pigs have been reported worldwide, there is no information on the genotypes and diversity of T. gondii in pigs in Grenada, West Indies. Objectives: The aims of the present study were to isolate, genotype and determine the diversity of T. gondii genotypes in pigs. Methods: We carried out a modified agglutination test (MAT) on blood from 149 pig hearts collected from a local meat market. Myocardial tissue homogenate from pigs that tested positive for T. gondii was homogenized and inoculated into mice for isolation of the parasite. We collected mouse tissues and extracted DNA for genotyping based on 11 polymerase chain reaction‐restriction fragment length polymorphism markers (SAG1, SAG2, alt. SAG2, SAG 3, BTUB, GRA6, L358, PK1, C22‐8, C 29‐2 and Apico). Results: Out of the 149 pig hearts, 31 (20.8%) tested positive for T. gondii on MAT. Bioassays in mice yielded 12 isolates designated TgpgGr1 to TgpgGr12. Molecular characterisation of T. gondii revealed four genotypes as follows: ToxoDB #2‐clonal type III (seven isolates); ToxoDB #7 (three isolates); ToxoDB #13 (one isolate); ToxoDB #30 (1 isolate). Overall, ToxoDB #2 was the most common (58%). Toxo database (DB) # 13, which causes interstitial pneumonia in affected mice, has also been reported. Conclusion: The genetic diversity of T. gondii in pigs in Grenada is lower than that in other surrounding Caribbean areas. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is a parasitic zoonosis caused by Toxoplasma gondii which infects warm‐blooded species worldwide. Humans can be infected through ingestion of tissue cysts from raw or undercooked meat, including game meat. A nationwide large‐scale cross‐sectional study was conducted to assess exposure to T. gondii in seven wild ruminant species in Spain. A total of 2,040 serum samples from 77 sampling sites randomly distributed in the five bioregions (BRs) covering mainland Spain were tested for antibodies against T. gondii using the modified agglutination test. The overall seroprevalence was 22.0% (449/2,040). Seroprevalence by species in decreasing order was as follows: 39.6% (141/356) in roe deer (Capreolus capreolus), 37.1% (138/372) in fallow deer (Dama dama), 16.6% (92/553) in red deer (Cervus elaphus), 14.0% (26/186) in Southern chamois (Rupicapra pyrenaica), 11.5% (24/209) in mouflon (Ovis aries musimon), 7.8% (27/346) in Iberian wild goat (Capra pyrenaica) and 5.6% (1/18) in Barbary sheep (Ammotragus lervia). Seropositivity was detected in 74.0% (57/77) of the sampling sites. Results indicate widespread but not homogeneous exposure to T. gondii in wild ruminant populations in Spain during the last two decades and highlight differences related to animal species and spatial distribution of these species in this country; this implies potential consequences of T. gondii for animal health, conservation and public health. [ABSTRACT FROM AUTHOR]

The possibility of Toxoplasma gondii transmitted from game meat to humans is of public health concern. Here we determined seroprevalence and risk factors associated with T. gondii in large game ungulates that cohabit in Sierras de Cazorla, Segura and Las Villas Natural Park (SCSV‐NP) (Southern Spain), a natural park with high human–animal interaction. Antibodies against T. gondii in 328 wild ungulates were assayed by the modified agglutination test (MAT ≥ 1:25). Antibodies were found in 39 (11.9%, 95% CI: 8.4–15.4) wild ungulates, with seroprevalence levels of 20.8% in wild boars (Sus scrofa) (5/24), 19.0% in fallow deer (Dama dama) (12/63), 13.9% in Iberian ibex (Capra pyrenaica hispanica) (14/101), 7.9% in red deer (Cervus elaphus) (6/76), and 3.1% in mouflons (Ovis aries musimon) (2/64). Significantly higher seroprevalence was observed in fallow deer and wild boars compared to mouflons. Animals living close to urban areas (<2 km) had 4.6‐times higher risk compared to those living at >5 km of urban areas. The results indicate high circulation of T. gondii in wild ungulates in SCSV‐NP, which is of animal and public health concern. The increased seroprevalence of T. gondii detected in wildlife ungulates living close to urban areas may increase human infection in those areas if meat from infected animals is consumed raw or undercooked. [ABSTRACT FROM AUTHOR]

Abstract: Felis catus, the domestic cat, is the definitive host for parasites that may result in adverse health outcomes in humans. Prevalence data of zoonotic parasites in feral cats, which are free‐roaming domestic cats that are born and live in the wild, are limited. The objective of this study was to assess seroprevalence of Toxoplasma gondii antibodies and copro‐prevalence of potentially zoonotic parasites in feral cats and to evaluate risk factors for seropositivity and faecal excretion of parasites. In this cross‐sectional survey, 275 feral cats at Trap‐Neuter‐Release clinics in Central Virginia were tested for parasites via faecal flotation, direct immunofluorescence assay (faeces) and modified agglutination testing (serum). Toxoplasma gondii seroprevalence was 22.35% (95% CI: 17.47–27.86). Faecal prevalence of T. gondii‐like oocysts was 1.04% (95% CI: 0.13–3.71), Toxocara cati 58.85% (95% CI: 51.54–65.89), Ancylostoma spp. 18.75% (95% CI: 13.49–25.00), Giardia duodenalis 5.73% (95% CI: 2.89–10.02) and Cryptosporidium spp. 3.33% (95% CI: 1.37–7.24). Female cats were more likely than males to excrete faecal Ancylostoma spp. eggs (OR 2.88; 95% CI 1.34–6.17). Adults were more likely than immature cats to be seropositive (OR 2.10; 95% CI: 1.11–3.97) and to excrete faecal Ancylostoma spp. eggs (OR 2.57; 95% CI: 1.10–5.99). However, immature cats were more likely than adults to excrete T. cati eggs (OR 6.79; 95% CI: 3.31–13.90) and to excrete one or more potentially zoonotic species (OR 4.67; 95% CI: 2.28–9.55) in faeces. Results of this study have implications for human and animal health and highlight the importance of collaboration between public health, medical and veterinary communities in preventive efforts. [ABSTRACT FROM AUTHOR]

Little is known of the epidemiology of toxoplasmosis in Minnesota. Here, we evaluated Toxoplasma gondii infection in 50 wild bobcats ( Lynx rufus) and 75 other animals on/near 10 cattle farms. Antibodies to T. gondii were assayed in serum samples or tissue fluids by the modified agglutination test (MAT, cut-off 1:25). Twenty nine of 50 bobcats and 15 of 41 wildlife trapped on the vicinity of 10 farms and nine of 16 adult domestic cats ( Felis catus) and six of 14 domestic dogs resident on farms were seropositive. Toxoplasma gondii oocysts were not found in feces of any felid. Tissues of all seropositive wild animals trapped on the farm were bioassayed in mice and viable T. gondii was isolated from two badgers ( Taxidea taxus), two raccoons ( Procyon lotor), one coyote ( Canis latrans), and one opossum ( Didelphis virginiana). All six T. gondii isolates were further propagated in cell culture. Multi-locus PCR-RFLP genotyping using 10 markers (SAG1, SAG2 (5′-3′SAG2, and alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico), and DNA from cell culture derived tachyzoites revealed three genotypes; #5 ToxoDataBase (1 coyote, 1 raccoon), #1 (1 badger, 1 raccoon, 1 opossum), and #2 (1 badger). This is the first report of T. gondii prevalence in domestic cats and in bobcats from Minnesota, and the first isolation of viable T. gondii from badger. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is a protozoan parasite that is responsible for approximately 24% of deaths attributed to foodborne pathogens in the United States. It is thought that a substantial portion of human T. gondii infections is acquired through the consumption of meats. The dose-response relationship for human exposures to T. gondii-infected meat is unknown because no human data are available. The goal of this study was to develop and validate dose-response models based on animal studies, and to compute scaling factors so that animalderived models can predict T. gondii infection in humans. Relevant studies in literature were collected and appropriate studies were selected based on animal species, stage, genotype of T. gondii, and route of infection. Data were pooled and fitted to four sigmoidal-shaped mathematical models, and model parameters were estimated using maximum likelihood estimation. Data from a mouse study were selected to develop the dose-response relationship. Exponential and beta-Poisson models, which predicted similar responses, were selected as reasonable dose-response models based on their simplicity, biological plausibility, and goodness fit. A confidence interval of the parameter was determined by constructing 10,000 bootstrap samples. Scaling factors were computed by matching the predicted infection cases with the epidemiological data. Mouse-derived models were validated against data for the dose-infection relationship in rats. A human dose-response model was developed as P (d) = 1-exp (-0.0015 × 0.005 × d) or P (d) = 1-(1 + d × 0.003 / 582.414)-1.479. Both models predict the human response after consuming T. gondii-infected meats, and provide an enhanced risk characterization in a quantitative microbial risk assessment model for this pathogen. [ABSTRACT FROM AUTHOR]

Cattle ( Bos taurus) are intermediate hosts for three named species of Sarcocystis, S. cruzi, S. hirsuta, and S. hominis. Recently, a fourth species was identified and named S. sinensis. However, S. sinensis originally named a species of Sarcocystis in water buffalo ( Bubalus bubalis) in China. Based on unverifiable evidence, it was suggested that the same parasite infects cattle. In addition, S. sinensis was recently declared as nomen nudum because its naming violated the rules of International Code of Zoological Nomenclature. Thus, the fourth species using cattle as an intermediate host does not have a valid name. Here, we propose a new name, Sarcocystis rommeli for the S. sinensis-like parasite from cattle in Argentina, and differentiate it ultrastructurally from S. hominis sarcocysts from experimentally infected cattle. Sarcocystis rommeli sarcocysts were microscopic with a 5-μm-thick wall with slender villar protrusions (Vp); the Vp were up to 5 μm long, up to 0.5 μm wide, and of uneven thickness, often bent at an angle. The ground substance layer (Gs) was up to 0.8 μm thick and smooth. Vesicular structures were seen at the base of the Vp. The bradyzoites were 10-12 μm long. Sarcocystis hominis sarcocysts had Vp that were often upright, up to 7.5 μm long, and up to 1.8 μm wide; the Gs was up to 2 μm thick and without vesicles. Its sarcocyst wall was up to 5.6 μm thick, the vp were bent at an angle, up to 5.8 μm long, the Gs was up to 2 μm thick, but without vesicles seen in S. rommeli. Beef containing sarcocysts of S. rommeli was not orally infectious for two human volunteers and a red fox ( Vulpes vulpes). The Sarcocystis described here is molecularly different from S. cruzi, S. hirsuta, and S. hominis based on 18S rRNA and cox1 gene sequences. [ABSTRACT FROM AUTHOR]

There are several reports of Sarcocystis sarcocysts in muscles of dogs, but these species have not been named. Additionally, there are two reports of Sarcocystis neurona in dogs. Here, we propose two new names, Sarcocystis caninum, and Sarcocystis svanai for sarcocysts associated with clinical muscular sarcocystosis in four domestic dogs ( Canis familiaris), one each from Montana and Colorado in the USA, and two from British Columbia, Canada. Only the sarcocyst stage was identified. Most of the sarcocysts identified were S. caninum. Sarcocysts were studied using light microscopy, transmission electron microscopy (TEM), and polymerase chain reaction. Based on collective results two new species, S. caninum and S. svanai were designated . Sarcocystis caninum and S. svanai were structurally distinct. Sarcocystis caninum sarcocysts were up to 1.2 mm long and up to 75 μm wide. By light microscopy, the sarcocyst wall was relatively thin and smooth. By TEM, the sarcocyst wall was 'type 9', 1-2 μm thick, and contained villar protrusions that lacked microtubules. Bradyzoites in sections were 7-9 μm long. Sarcocysts of S. svanai were few and were identified by TEM. Sarcocystis svanai sarcocysts were 'type 1', thin walled (< 0.5 μm), and the wall lacked villar protrusions but had tiny blebs that did not invaginate. DNA was extracted either from infected frozen muscle biopsies or formalin-fixed paraffin-embedded sections. Dogs were either singly infected with S. caninum or multiply co-infected with S. caninum and S. svanai (the result of a mixed infection) based on multilocus DNA sequencing and morphology. BLASTn analysis established that the sarcocysts identified in these dogs were similar to, but not identical to Sarcocystis canis or Sarcocystis arctosi, parasites found to infect polar bears ( Ursus maritimus) or brown bears ( Ursus arctosi), respectively. However, the S. caninum sequence showed 100% identify over the 18S rRNA region sequenced to that of S. arctica, a parasite known to infect Arctic foxes ( Vulpes lagopus). [ABSTRACT FROM AUTHOR]

Toxoplasma gondii infects virtually all warm-blooded hosts worldwide. Recently, attention has been focused on the genetic diversity of the parasite to explain its pathogenicity in different hosts. It has been hypothesized that interaction between feral and domestic cycles of T. gondii may increase unusual genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals, and wildlife. In the present study, we tested black bear ( Ursus americanus), bobcat ( Lynx rufus), and feral cat ( Felis catus) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 32 (84.2%) of 38 bears, both bobcats, and 2 of 3 feral cats tested by the modified agglutination test (cut off titer 1:25). Hearts from seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 3 of 32 bears, 2 of 2 bobcats, and 2 of 3 feral cats. DNA isolated from culture-derived tachyzoites of these isolates was characterized using multilocus PCR- RFLP markers. Three genotypes were revealed, including Toxo DB PCR- RFLP genotype #1 or #3 (Type II, 1 isolate), #5 (Type 12, 3 isolates), and #216 (3 isolates), adding to the evidence of genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of 3 T. gondii isolates (all #216, 1 from bear, and 2 from feral cat) was determined in outbred Swiss Webster mice; all three were virulent causing 100% mortality. Results indicated that highly mouse pathogenic strains of T. gondii are circulating in wildlife, and these strains may pose risk to infect human through consuming of game meat. [ABSTRACT FROM AUTHOR]

ABSTRACT Hammondia hammondi and Toxoplasma gondii are feline coccidians that are morphologically, antigenically, and phylogenitically related. Both parasites multiply asexually and sexually in feline intestinal enterocytes, but H. hammondi remains confined to enterocytes whereas T. gondii also parasitizes extra-intestinal tissues of the cat. Here, we studied multiplication of H. hammondi in feline intestine and compared with T. gondii cycle. Five parasite-free cats were inoculated orally with tissue cysts and free bradyzoites from skeletal muscles of gamma interferon gene knockout mice and killed at 1, 3, 4, 6, and 7 d later. At 1 and 3 d post inoculation ( DPI), numerous individual intracellular bradyzoites were detected in histological sections of small intestine. At 4 DPI only schizonts were found and they were located in enterocyte cytoplasm above the host cell nucleus. At 6 and 7 DPI both schizonts and gamonts were seen and they were located in enterocytes. Ultrastucturally, schizogonic and gametogonic development of H. hammondi was similar to T. gondii. However, in H. hammondi merozoites rhoptries were longer, and coiled and contained more micronemes than in T. gondii. Ultrastructural development is illustrated in detail. [ABSTRACT FROM AUTHOR]

In this paper the history of Toxoplasma gondii and toxoplasmosis is reviewed. This protozoan parasite was first discovered in 1908 and named a year later. Its medical importance remained unknown until 1939 when T. gondii was identified in tissues of a congenitally infected infant, and veterinary importance became known when it was found to cause abortion storms in sheep in 1957. The discovery of a T. gondii specific antibody test, Sabin–Feldman dye test in 1948 led to the recognition that T. gondii is a common parasite of warm-blooded hosts with a worldwide distribution. Its life cycle was not discovered until 1970 when it was found that felids are its definitive host and an environmentally resistant stage (oocyst) is excreted in feces of infected cats. The recent discovery of its common infection in certain marine wildlife (sea otters) indicates contamination of our seas with T. gondii oocysts washed from land. Hygeine remains the best preventive measure because currently there is no vaccine to prevent toxoplasmosis in humans. [ABSTRACT FROM AUTHOR]

Little is known of Toxoplasma gondii isolates circulating in wildlife. The mouflon ( Ovis ammon) is very popular game animal, hunted for its trophy horns. Here, we report the isolation and genetic characterization of T. gondii from two mouflons from Hawaii, USA. Both sheep had antibodies titers of 1:800 or higher. Viable T. gondii were isolated and nested PCR- RFLP genotyping revealed two genotypes, a clonal Type III (designated TgMouflon US1), and a new genotype (designated TgMouflon US2, and Toxo DB PCR- RFLP genotypes #249). This is the first report of T. gondii infection, isolation and genetic characterization in mouflons from the USA. [ABSTRACT FROM AUTHOR]

The article presents a case study of a duodenal brush preparation in a 10-year-old spayed female Italian Greyhound dog. It states that the dog was presented with history of anorexia and weight loss to the Iowa State University College of Veterinary Medicine. It states that biopsies and gastric and duodenal brush preparations were obtained for histologic and cytologic evaluation.