Toxocara canis is a widespread parasite of canids with a wide range of paratenic hosts, but also one of the overlooked agents causing nervous system infections of humans. Previous experimental infections of mice demonstrated the impact of high infection doses of larvae on neurobehavioral disorders and pathological changes. In contrast to previous studies, we aimed to investigate the long-term (up to 100 weeks) impact of low- to high-dose infection in mice. We focused on their physical condition, motor skills, and the accompanying pathologies in the brain. Three groups of BALB/c mice were infected with 10, 100, and 1000 T. canis larvae/mouse and specific anti-T. canis excretory-secretory antigens immunoglobulin G antibody response, general condition, and motor skills were tested in defined intervals within 100 weeks after infection. The number of larvae in selected organs was assessed and the pathological changes in the brain were studied histologically. As a result, subtle to severe impairments in general condition and motor skills were detected, with generally earlier onsets occurring the higher the infection dose was. The specific immunoglobulin G antibody levels corresponding to the infection dose were detected in all infected groups. Necrosis, cellular infiltrations, and foamy cells developed in moderate- and high-infection dose mice, in contrast with hemorrhages detected in all groups. This study demonstrated the long-term negative impact of T. canis infection on the paratenic host, particularly at moderate and high infectious doses. Although pathological changes in the brain were observed even in low-infection dose mice, their physical and motor condition was comparable to the control group.
- MeSH
- Immunoglobulin G * blood MeSH
- Larva MeSH
- Disease Models, Animal MeSH
- Brain * parasitology pathology MeSH
- Mice, Inbred BALB C * MeSH
- Mice MeSH
- Antibodies, Helminth * blood MeSH
- Toxocara canis * immunology MeSH
- Toxocariasis * parasitology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Toxocara canis, a gastrointestinal parasite of canids, is also highly prevalent in many paratenic hosts, such as mice and humans. As with many other helminths, the infection is associated with immunomodulatory effects, which could affect other inflammatory conditions including autoimmune and allergic diseases. Here, we investigated the effect of T. canis infection on the course of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Mice infected with 2 doses of 100 T. canis L3 larvae 5 weeks prior to EAE induction (the Tc+EAE group) showed higher EAE clinical scores and greater weight loss compared to the non-infected group with induced EAE (the EAE group). Elevated concentrations of all measured serum cytokines (IL-1α, IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ and TNF-α) were observed in the Tc+EAE group compared to the EAE group. In the CNS, the similar number of regulatory T cells (Tregs; CD4+FoxP3+Helios+) but their decreased proportion from total CD4+ cells was found in the Tc+EAE group compared to the EAE group. This could indicate that the group Tc+EAE harboured significantly more CD4+ T cells of non-Treg phenotype within the affected CNS. Altogether, our results demonstrate that infection of mice with T. canis worsens the course of subsequently induced EAE. Further studies are, therefore, urgently needed to reveal the underlying pathological mechanisms and to investigate possible risks for the human population, in which exposure to T. canis is frequent.
- MeSH
- CD4-Positive T-Lymphocytes pathology MeSH
- Cytokines MeSH
- Encephalomyelitis, Autoimmune, Experimental * pathology MeSH
- Humans MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Multiple Sclerosis * pathology MeSH
- Toxocara canis * MeSH
- Toxocariasis * complications MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The nematodes Toxocara canis (Werner, 1782) and Toxocara cati (Schrank, 1788) have been associated with worse human cognitive function in children and middle-aged adults. In this study, we sought to determine the association between Toxocara seropositivity and serointensity determined by detection of IgG antibodies against the Toxocara antigen recombinant Tc-CTL-1 and cognitive function in older adults, including approximately 1,350 observations from the 2013-2014 National Health and Nutrition Examination Survey. Mean fluorescence intensity was used to quantify IgG antibodies against the Toxocara recombinant Tc-CTL-1 antigen, and respondents were considered positive at values greater than 23.1. In adjusted models from sample sizes ranging from 1,274 to 1,288 depending on the individual cognitive task, we found that Toxocara seropositivity was associated with worse performance on the animal-fluency task (b = -1.245, 95% CI: -2.392 to -0.099, P< 0.05) and the digit-symbol coding task (b = -5.159, 95% CI: -8.337 to -1.980, P< 0.001). Toxocara serointensity assessed using log-transformed mean fluorescence intensity as a continuous variable was associated with worse performance on the digit-symbol coding task (b = -1.880, 95% CI: -2.976 to -0.783, P < 0.001). There were no significant associations with tasks assessing memory. Further, age modified the association between Toxocara and cognitive function, although sex, educational attainment, and income did not. These findings suggest that Toxocara might be associated with deficits in executive function and processing speed in older U.S. adults, although additional research is required to better describe cognitive function in older adults who are seropositive for Toxocara spp.
- MeSH
- Immunoglobulin G MeSH
- Cognition MeSH
- Toxocara MeSH
- Toxocariasis * complications diagnosis epidemiology MeSH
- Nutrition Surveys MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Larval toxocarosis is a zoonosis caused by larvae of Toxocara canis and T. cati, a gastrointestinal nematode of canids and felids, respectively. Diagnosis is usually performed by ELISA IgG using Toxocara excretory-secretory products as an antigen. Due to laboriousness of isolation of the products and subsequent process of standardization of antigenic compounds, routine use of this method is limited and can produce inaccurate diagnostical results. The purpose of this study was to discover new specific antigenic proteins that could be used in routine serological methods of larval toxocarosis. MATERIALS AND METHODS: Toxocara excretory-secretory products were collected and separated by SDS-PAGE. Proteins from the gel were electro-transferred to a membrane and incubated with mouse sera. Antigenic proteins were analyzed using the liquid chromatography-tandem mass spectrometry approach. Selected proteins were prepared in recombinant form and tested with mice and human sera by ELISA and Western blot. RESULTS: A total of four recombinant protein antigens were prepared (rTc-TES-26, rTc-ASA, rTc-PDP, and rTc-ASP). They were analyzed by ELISA and Western blot using mice and human sera. For all sera, three of the four recombinant antigens correlated with Toxocara excretory-secretory products in ELISA analysis. By Western blot, the infection was confirmed in all experimentally infected mice and two out of seven human patients. CONCLUSION: Combination of the presented methods and analyses represents a possible method of effective identification of Toxocara protein antigens for the purpose of routine serodiagnosis.
Human toxocariasis is a helminthozoonosis caused by the migration of Toxocara species larvae through an organism. The infection in humans is transmitted either by direct ingestion of the eggs of the parasite, or by consuming undercooked meat infested with Toxocara larvae. This parasitosis can be found worldwide, but there are significant differences in seroprevalence in different areas, depending mainly on hot climate conditions and on low social status. However, the literature estimates of seroprevalence are inconsistent. Infected patients commonly present a range of symptoms, e.g., abdominal pain, decreased appetite, restlessness, fever, and coughing. This manuscript presents a case report of a polytraumatic patient who underwent a two-phase spinal procedure for a thoracolumbar fracture. After the second procedure, which was a vertebral body replacement via thoracotomy, the patient developed a pathologic pleural effusion. A microscopic cytology examination of this effusion revealed the presence of Toxocara species larvae. Although the patient presented no specific clinical symptoms, and the serological exams (Enzyme-linked immunosorbent assay (ELISA), Western blot) were negative, the microscopic evaluation enabled a timely diagnosis. The patient was successfully treated with albendazole, with no permanent sequelae of the infection.
- MeSH
- Enzyme-Linked Immunosorbent Assay MeSH
- Humans MeSH
- Parasites * MeSH
- Seroepidemiologic Studies MeSH
- Social Status MeSH
- Toxocara MeSH
- Toxocariasis * diagnosis drug therapy MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Case Reports MeSH
Cats are important hosts for different zoonotic parasites that can be hazardous to human health. To date, few studies have attempted to identify the factors affecting parasitic infections in shelter animals. This study aims to analyse the presence of endoparasites in shelter cats in Tartu, Estonia, and identify factors affecting endoparasite prevalence and intensity. The risk factors considered were age, location (urban vs rural cats) and time spent in shelter. In total, 290 faecal samples were collected from cats at an animal shelter in 2015-2016 and investigated for endoparasites using the concentration flotation technique. In total, 138 shelter cats (47.6%) were infected with endoparasites and their overall prevalence was: Toxocara cati (36.6%), Cystoisospora spp. (12.4%), Taeniidae gen. sp. (4.1%), Toxoplasma gondii/Hammondia hammondi (3.4%), Eucoleus aerophilus (2.1%), Cryptosporidium spp. (2.1%), Ancylostoma sp. (0.7%) and Giardia sp. (0.7%). Coinfections occurred in 38 cats (13.1%) most frequently of T. cati and Cystoisospora spp. (4.5%), Cystoisospora spp. and T. gondii/H. hammondi (2.1%). Where species identification of cestode and nematode samples was not possible according to morphology, genetic analysis of the mitochondrial cox1 gene was carried out. DNA was successfully analysed for 6 out of 13 samples that required genetic identification, revealing Ancylostoma tubaeforme in one nematode sample and Hydatigera taeniaeformis in five cestode samples. Cats from rural areas had significantly higher endoparasite prevalence than cats from urban areas. Helminth prevalence decreased to some extent due to anthelmintic treatment in cats available for adoption (held ≥15 days in the shelter), whereas the prevalence of infection with protists increased significantly in these animals. It is important to note that the analysis revealed lower infection intensity for quarantine cats (held 1-14 days in the shelter) compared with cats available for adoption. The relatively high prevalence of endoparasites (including zoonotic) in shelter cats ready for adoption suggests that current anthelminthic procedures require improvements.
- MeSH
- Ancylostoma isolation & purification MeSH
- Cestoda isolation & purification MeSH
- Helminths MeSH
- Coccidia isolation & purification MeSH
- Cryptosporidium isolation & purification MeSH
- Feces parasitology MeSH
- Genes, Helminth MeSH
- Giardia isolation & purification MeSH
- Giardiasis MeSH
- Nematoda isolation & purification MeSH
- Cats parasitology MeSH
- Parasites * classification isolation & purification pathogenicity MeSH
- Prevalence MeSH
- Electron Transport Complex IV genetics MeSH
- Risk Factors MeSH
- Toxocara isolation & purification MeSH
- Toxoplasma isolation & purification MeSH
- Age Factors MeSH
- Zoonoses parasitology MeSH
- Animals MeSH
- Check Tag
- Cats parasitology MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Estonia MeSH
BACKGROUND: Larval toxocarosis (LT), a zoonotic disease transmitted by dogs, cats, and other carnivores, is caused by roundworms of the genus Toxocara. Humans become infected by ingesting embryonated eggs of this parasite. In this study, we present data on the seroprevalence of LT in the Czech Republic collected by the National Reference Laboratory for Tissue Helminthoses in 2012-2016. METHODS: Using enzyme-linked immunosorbent assay, a total of 4428 adults and children with or without clinical symptoms were examined for the presence of IgG antibodies against Toxocara canis excretory-secretory antigens. RESULTS: Of all the persons examined, specific Toxocara antibodies were detected in 160 (3.6%) individuals. There were, however, significant differences between various regions, with seropositivity rates ranging from 1.4 to 7.5%. CONCLUSION: In comparison to studies from 1998 and 2004, our results suggest a decrease in overall Toxocara seroprevalence in the Czech population, whereby the rates are similar to or even lower than rates in some other Central European countries.
- MeSH
- Child MeSH
- Adult MeSH
- Enzyme-Linked Immunosorbent Assay MeSH
- Immunoglobulin G blood MeSH
- Infant MeSH
- Larva MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Infant, Newborn MeSH
- Child, Preschool MeSH
- Antibodies, Helminth blood MeSH
- Aged MeSH
- Seroepidemiologic Studies MeSH
- Toxocara isolation & purification MeSH
- Toxocariasis blood epidemiology MeSH
- Zoonoses epidemiology parasitology MeSH
- Animals MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Infant MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Infant, Newborn MeSH
- Child, Preschool MeSH
- Aged MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
