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Objective: This study aimed to detect Toxocara cati in cats by microscopic and molecular analysis using PCR, sequencing, and phylogenetic analysis. Materials and Methods: Randomly selected 200 cat feces samples were taken from various private veterinarian clinics in Baghdad. To identify eggs of T. cati by the flotation method, DNA from 100 cat feces was extracted, and one pair of ITS2 region-specific primers was used for polymerase chain reaction, followed by sequencing. Results: Toxocara cati infection rate was found to be 23 out of 100 fecal samples using PCR. Ten DNA product sequence data studies showed 98%-100% similarity to the 5.8S ribosomal RNA gene sequences found in the Gene Bank. The study incidence showed that the overall infection rate by microscopic examination was 23%, with no significant difference between stray cats (27%), and domestic cats (19%). After studying the effect of several epidemiological parameters on the infection rate, it was found that the infection rates of stray and domestic cats were higher in kittens under six months of age, at 46.1% and 27%, respectively, whereas rates were lower for the adult than six months was 11.5% of domestic cats and 14.7% of stray cats. The percentage of stray and domestic male cats that were registered was 35.5%, whereas the female cats registered were 20.6% and 17.5%, respectively. Conclusion: Cats are significant clinical reservoirs for zoonotic parasites. In Iraq, Baghdad has a high incidence of T. cati detections. Compared to conventional methods, PCR is thought to be a more sensitive, accurate diagnostic procedure that confirms the species' identity.
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PURPOSE: Toxoplasma gondii (T. gondii) and Toxocara spp. are two types of parasites that can infect humans and various animals, including dogs. Police dogs and their trainers have a vital role in law enforcement, and their health and well-being are crucial for them to effectively carry out their duties. No study has yet been conducted on the prevalence of T. gondii and Toxocara spp. infections among police dogs and their trainers in Iran. The objective of this study was to determine the sero-molecular prevalence of T. gondii and Toxocara spp. infections in police dogs and their trainers in Tehran, the capital of Iran. METHODS: In Tehran province, the anti-narcotics police have nearly 200 well-trained police dogs. Each dog is assigned a dedicated trainer and upon completing missions, is housed separately in a designated area. In the present study, a total of 150 samples were gathered. These included 50 blood samples from randomly selected police dogs, 50 fecal samples from the same dogs, and 50 blood samples from their trainers. The Modified Agglutination Test (MAT) was performed to detect T. gondii antibodies in dog blood samples and the ELISA system was utilized to identify anti-Toxoplasma and anti-Toxocara antibodies in the sera of the dog trainers. A specific segment of the SAG2 and ITS genes were amplified via nested-PCR in order to molecularly detect T. gondii in human blood samples and Toxocara spp. in dog fecal samples. RESULTS: Regarding serological findings, the prevalence of T. gondii in dog and human blood samples was 4% (2/50) and 10% (5/50), respectively. According to reports, the seroprevalence of Toxocara spp. in human blood samples was 6% (3/50). No statistically significant association was found between the prevalence of the examined parasites and variables (age, sex, and breed) in dogs, as well as the age variable in military personnel. Molecular findings showed that out of the 50 dog fecal samples and 50 human blood samples, there was no presence of Toxocara spp. and T. gondii, respectively. CONCLUSION: Understanding the prevalence of parasitic infections helps public health officials assess the risk to human and animal populations. This information can guide the development of prevention and control measures to reduce the spread of these infections. Overall, the prevalence of parasitic infections, particularly T. gondii and Toxocara spp., in police dogs and their trainers remains uncertain and necessitates further in-depth research.
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We aimed to develop an indirect enzyme-linked immunosorbent assay (ELISA) to evaluate the presence of specific IgG against Toxocara canis and Toxocara cati somatic antigens on the serum of patients with toxocariasis. The sensitivity, specificity, positive and negative predictive values for indirect-ELISA were calculated by receiver operating characteristic curve (ROC) analysis and Youden's J using Likelihood ratio. All statistics were analysed and graphs are plotted using GraphPad Prism version 8.4.3 (Graph Pad Software, La Jolla, CA, USA), with 95% confidence interval (CI). The sensitivity, specificity, positive and negative predictive values for T. canis were 100%, 82%, 79% and 100%, respectively. The mentioned variables for T. cati were 97%, 82%, 78% and 98%, respectively. Five immune reactive bands of 38, 40, 72, 100 and 250 kDa were common in both species. Toxocara crude antigens were highly immunogenic in human sera. Immunoreactive bands against T. canis compared to T. cati somatic antigen were about two times more. Unlike Toxocara excretory-secretory antigen, that was homologue in two species, somatic antigens of T. canis and T. cati showed different immunoreactive bands in our western blot.
Subject(s)
Antibodies, Helminth , Antigens, Helminth , Enzyme-Linked Immunosorbent Assay , Immunoglobulin G , Sensitivity and Specificity , Toxocara canis , Toxocara , Toxocariasis , Humans , Animals , Antigens, Helminth/immunology , Antigens, Helminth/blood , Toxocariasis/immunology , Toxocariasis/diagnosis , Toxocariasis/blood , Toxocara/immunology , Antibodies, Helminth/blood , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/blood , Toxocara canis/immunology , Adult , Predictive Value of Tests , ROC Curve , Female , MaleABSTRACT
Omalizumab, a humanized anti-IgE monoclonal antibody, is commonly employed in the treatment of antihistamine-refractory chronic spontaneous urticaria (CSU), where it significantly reduces free IgE levels, minimizing histamine release from basophils and mast cells. Despite its efficacy, there are concerns regarding its effect on parasitic defense due to IgE's role in combating parasitic infestations. We present a case of a 28-year-old female agriculturist with a six-month history of CSU who experienced a paradoxical exacerbation of her symptoms following an increase in the omalizumab treatment dose. This deterioration coincided with a serologically confirmed parasitic infection with Echinococcus granulosus and Toxocara canis. Despite normal eosinophil counts and IgE levels, which are typically used to identify parasitic infections, the patient's clinical worsening prompted further investigation that led to the identification of the parasitic infection. Treatment with albendazole and omalizumab discontinuation led to the resolution of her CSU, suggesting that the parasitic infection was contributing to the symptom exacerbation. This case highlights the need for careful screening for parasitic infections before initiating omalizumab in antihistamine-refractory CSU patients from endemic regions, or patients who deteriorate clinically on omalizumab, especially when other indicators such as eosinophil count and IgE levels might not suggest infection. It also underscores the importance of considering a tailored approach to managing CSU that balances effective treatment with the potential for adverse effects related to immunomodulation.
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BACKGROUND: The hygiene hypothesis suggests that early life exposure to helminth infections can reduce hypersensitivity in the immune system. OBJECTIVE: The present study aims to evaluate the effects of Toxocara cati (T. cati) somatic products on allergic airway inflammation. METHODS: Between 2018 and 2020, T. cati adult worms were collected from stray cats in Mashhad, Iran (31 out of 186 cats), and their somatic extract was collected. Thirty BALB/c mice were equally divided into three groups, including the OVA group (sensitized and challenged with ovalbumin), the somatic administered group (received somatic extract along with ovalbumin sensitization), and the PBS group (sensitized and challenged with phosphate buffer saline). Bronchoalveolar lavage (BAL) fluid was collected to assess the number of cells, and lung homogenates were prepared for cytokine analysis. Histopathological analysis of the lungs was performed, and inflammatory cells and mucus were detected. Cytokine levels (IL-4, IL-5, IL-10) were measured using enzyme-linked immunosorbent assay (ELISA), and ovalbumin-specific immunoglobulin E (IgE) levels were determined using a capture ELISA. RESULTS: The somatic group significantly decreased regarding the lung pathological changes, including peribronchiolitis, perivasculitis, and eosinophil influx, compared to the group treated with ovalbumin alone. These changes were accompanied by a decrease in proinflammatory cytokines IL-4 and IL-5 and an increase in the anti-inflammatory cytokine IL-10, indicating a shift toward a more balanced immune response. The number of inflammatory cells in the BAL fluid was also significantly reduced in the somatic group, indicating a decrease in inflammation. CONCLUSION: These preclinical findings suggest that in experimental models, T. cati somatic extract exhibits promising potential as a therapeutic agent for mitigating allergic airway inflammation. Its observed effects on immune response modulation and reduction of inflammatory cell infiltration warrant further investigation in clinical studies to assess its efficacy and safety in human patients.
Subject(s)
Cytokines , Mice, Inbred BALB C , Toxocara , Animals , Mice , Toxocara/immunology , Toxocara/drug effects , Cytokines/metabolism , Cytokines/immunology , Immunoglobulin E/immunology , Immunoglobulin E/blood , Ovalbumin/immunology , Lung/immunology , Lung/pathology , Lung/parasitology , Lung/drug effects , Bronchoalveolar Lavage Fluid/immunology , Asthma/immunology , Asthma/drug therapy , Disease Models, Animal , Cats , Female , Toxocariasis/drug therapy , Toxocariasis/immunology , Toxocariasis/parasitologyABSTRACT
BACKGROUND: Human toxocariasis is a neglected parasitic disease characterised by the syndromes visceral, cerebral, and ocular larva migrans. This disease is caused by the migrating larvae of Toxocara roundworms from dogs and cats, affecting 1.4 billion people globally. Via extracellular vesicles (EVs), microRNAs have been demonstrated to play roles in host-parasite interactions and proposed as circulating biomarkers for the diagnosis and follow-up of parasitic diseases. METHODS: Small RNA-seq was conducted to identify miRNAs in the infective larvae of T. canis and plasma EV-containing preparations of infected BALB/c mice. Differential expression analysis and target prediction were performed to indicate miRNAs involved in host-parasite interactions and miRNAs associated with visceral and/or cerebral larva migrans in the infected mice. Quantitative real-time polymerase chain reaction (PCR) was used to amplify circulating miRNAs from the infected mice. RESULTS: This study reports host and parasite miRNAs in the plasma of BALB/c mice with visceral and cerebral larva migrans and demonstrates the alterations of these miRNAs during the migration of larvae from the livers through the lungs and to the brains of infected mice. After filtering unspecific changes in an irrelevant control, T. canis-derived miRNAs and T. canis infection-induced differential miRNAs are predicted to modulate genes consistently involved in mitogen-activated protein kinase (MAPK) signalling and pathways regulating axon guidance and pluripotency of stem in the infected mice with visceral and cerebral larva migrans. For these plasma circulating miRNAs predicted to be involved in host-parasite crosstalk, two murine miRNAs (miR-26b-5p and miR-122-5p) are experimentally verified to be responsive to larva migrans and represent circulating biomarker candidates for visceral and cerebral toxocariasis in BALB/c mice. CONCLUSIONS: Our findings provide novel insights into the crosstalk of T. canis and the mammalian host via plasma circulating miRNAs, and prime agents and indicators for visceral and cerebral larva migrans. A deep understanding of these aspects will underpin the diagnosis and control of toxocariasis in humans and animals.
Subject(s)
Circulating MicroRNA , Mice, Inbred BALB C , Toxocara canis , Toxocariasis , Animals , Toxocara canis/genetics , Toxocara canis/physiology , Mice , Toxocariasis/parasitology , Toxocariasis/blood , Circulating MicroRNA/blood , Circulating MicroRNA/genetics , Host-Parasite Interactions , Larva Migrans, Visceral/parasitology , Larva Migrans, Visceral/blood , Female , Larva Migrans/parasitology , Larva Migrans/blood , Larva/genetics , Dogs , MicroRNAs/blood , MicroRNAs/genetics , Biomarkers/blood , Brain/parasitologyABSTRACT
Toxocariasis is a parasitic zoonotic infection caused by Toxocara spp., ascarid nematodes of companion animals (dogs and cats) affecting people in both high-income and low/middle-income countries. Toxocariasis can manifest as several distinct syndromes. The most frequent, often termed common toxocariasis, is a self-limiting and mild febrile illness. Ocular and visceral larva migrans are severe disease manifestations affecting the eye and other internal organs, respectively, but their reported occurrence is rare. The vast majority of symptomatic cases are thought due to common toxocariasis, which has also been associated with cognitive impairment in children. Few studies to date have sought to quantity the health burden of toxocariasis in humans. In this study we provide a preliminary estimation using the Disability-Adjusted Life Year (DALY) approach. We estimate a total of 23,084 DALYs are lost annually in 28 selected countries due to common toxocariasis. Extrapolating based on a global average seroprevalence rate of 19%, we estimate 91,714 DALYs per year are lost across all countries due to toxocariasis, of which 40,912 are attributable to less severe forms, i.e. common toxocariasis, and 50,731 to cognitive impairment in children. Clinically diagnosed and reported ocular and visceral larva migrans represent a small proportion of estimated total health burden. We also found a positive correlation at national level between prevalence in cats or dogs and seroprevalence in humans, but no correlation between estimated soil contamination and seroprevalence in humans. Finally, we estimate the potential economic impact of toxocariasis in selected countries at 2.5 billion USD per annum, from costs of medical treatment and lost income. These preliminary estimates should serve as a call to action for further research and evidence-based measures to tackle toxocariasis.
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BACKGROUND: Infections may contribute to Alzheimer's disease (AD) risk. Limited evidence suggests Toxocara spp. infection/exposure could influence AD development. METHODS: We investigated Toxocara seropositivity and AD in Iranian adults using a matched case-control study. Our sample included 90 AD cases and 91 healthy older adults. Anti-Toxocara immunoglobulin G (IgG) antibodies were assessed via enzyme-linked immunosorbent assay. We computed the odds ratios (ORs) and 95% confidence intervals (CIs) through univariable and multivariable analyses, adjusting for potential confounders. RESULTS: There were 33/90 (36.67% [95% CI 26.75 to 47.48]) anti-Toxocara IgG seropositive individuals identified among the AD cases and 21/91 (23.07% [95% CI 14.89 to 33.09]) among the healthy controls. In univariable analysis, a significant association was identified between anti-Toxocara IgG seropositivity and AD (OR 1.93 [95% CI 1.01 to 3.69], p<0.001). Moreover, the association remained significant (OR 2.18 [95% CI 1.05 to 4.49], p<0.001) in multivariable analysis after adjustment for covariates. There was no association between anti-Toxocara IgG seropositivity and the severity of AD (OR 0.75 [95% CI 0.21 to 2.61], p=0.47). CONCLUSIONS: Our findings indicated that Toxocara exposure/infection could be a potential risk factor for development of AD. To better understand a real causality between Toxocara exposure/infection and AD and related dementias, follow-up designed and adequately powered studies are needed.
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The aim of the study was to determine the species composition of the intestinal parasite fauna of foxes from the Pomerania region, with a particular emphasis on helminth species considered dangerous to humans, and to determine their prevalence and intensity of infection. In total, 165 digestive systems from foxes inhabiting the Pomeranian region were examined. The prevalence of intestinal parasites among the studied foxes was 61.8%. Our findings confirm that foxes in Pomerania carry various parasites, some of which pose a direct threat to human health. As such, constant monitoring of their infestation is essential. Particular attention should be paid to parasite species with potential for transmission to humans, such as Echinococcus multilocularis, Alaria alata and Toxocara canis, whose respective prevalence was found to be 10.9%, 17.6% and 28.5%.
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We investigated organ specific Toxocara canis larval migration in mice infected with T. canis larvae. We observed the worm burden and systemic immune responses. Three groups of BALB/c mice (n=5 each) were orally administered 1,000 T. canis 2nd stage larvae to induce larva migrans. Mice were sacrificed at 1, 3, and 5 weeks post-infection. Liver, lung, brain, and eye tissues were collected. Tissue from 2 mice per group was digested for larval count, while the remaining 3 mice underwent histological analysis. Blood hematology and serology were evaluated and compared to that in a control uninfected group (n=5) to assess the immune response. Cytokine levels in bronchoalveolar lavage (BAL) fluid were also analyzed. We found that, 1 week post-infection, the mean parasite load in the liver (72±7.1), brain (31±4.2), lungs (20±5.7), and eyes (2±0) peaked and stayed constant until the 3 weeks. By 5-week post-infection, the worm burden in the liver and lungs significantly decreased to 10±4.2 and 9±5.7, respectively, while they remained relatively stable in the brain and eyes (18±4.2 and 1±0, respectively). Interestingly, ocular larvae resided in all retinal layers, without notable inflammation in outer retina. Mice infected with T. canis exhibited elevated levels of neutrophils, monocytes, eosinophils, and immunoglobulin E. At 5 weeks post-infection, interleukin (IL)-5 and IL-13 levels were elevated in BAL fluid. Whereas IL-4, IL-10, IL-17, and interferon-γ levels in BAL fluid were similar to that in controls. Our findings demonstrate that a small portion of T. canis larvae migrate to the eyes and brain within the first week of infection. Minimal tissue inflammation was observed, probably due to increase of anti-inflammatory cytokines. This study contributes to our understanding of the histological and immunological responses to T. canis infection in mice, which may have implications to further understand human toxocariasis.
Subject(s)
Brain , Cytokines , Larva , Liver , Lung , Mice, Inbred BALB C , Toxocara canis , Toxocariasis , Animals , Toxocara canis/immunology , Toxocariasis/immunology , Toxocariasis/pathology , Toxocariasis/parasitology , Larva/immunology , Mice , Cytokines/metabolism , Lung/parasitology , Lung/immunology , Lung/pathology , Liver/parasitology , Liver/pathology , Liver/immunology , Brain/parasitology , Brain/immunology , Brain/pathology , Bronchoalveolar Lavage Fluid/immunology , Bronchoalveolar Lavage Fluid/parasitology , Female , Parasite Load , Eye/parasitology , Eye/immunology , Eye/pathology , Disease Models, AnimalABSTRACT
BACKGROUND: Toxocara canis is considered one of the most neglected parasitic zoonoses and threatens the health of millions of people worldwide with a predilection for pediatric and adolescent populations in impoverished communities. Exploring the invasion and developmental mechanisms associated with T. canis infection in its definitive canine hosts will help to better control zoonotic toxocariasis. METHODS: Proteomic changes in samples from the upper lobe of the left lung of Beagle puppies were systematically analyzed by quantitative proteomic technology of data-independent acquisition (DIA) at 96 h post-infection (hpi) with T. canis. Proteins with P-values < 0.05 and fold change > 1.5 or < 0.67 were considered proteins with differential abundance (PDAs). RESULTS: A total of 28 downregulated PDAs and 407 upregulated PDAs were identified at 96 hpi, including RhoC, TM4SFs and LPCAT1, which could be associated with the maintenance and repair of lung homeostasis. GO annotation and KEGG pathway enrichment analyses of all identified proteins and PDAs revealed that many lung proteins have correlation to signal transduction, lipid metabolism and immune system. CONCLUSIONS: The present study revealed lung proteomic alterations in Beagle dogs at the lung migration stage of T. canis infection and identified many PDAs of Beagle dog lung, which may play important roles in the pathogenesis of toxocariasis, warranting further experimental validation.
Subject(s)
Dog Diseases , Lung , Proteomics , Toxocara canis , Toxocariasis , Animals , Dogs , Toxocariasis/parasitology , Lung/parasitology , Dog Diseases/parasitology , ProteomeABSTRACT
Domestic dogs and cats can serve as a source of environmental contamination with Toxocara spp. and Blastocystis spp., and this represents a neglected public and veterinary health problem. We assessed the microscopic and molecular prevalence of these species in a locality in Algeria and identified the associated risk factors. The faeces of 225 dogs and 78 cats were collected in Mitidja between March and July 2022. The samples were analysed by coproscopy and by polymerase chain reaction (PCR) targeting the Internal Transcribed Spacer 2 (ITS2) and Small Subunit Ribosomal (SSU-RNA) of T. canis and Blastocystis spp. respectively. The overall microscopic prevalence of Toxocara spp. in dogs and cats was 9.78 ± 1.98% and 12.82 ± 7.42%, respectively. The rate of Blastocystis spp. was 15.11 ± 2.39% and 15.38 ± 4.08% in dogs and cats, respectively while the molecular prevalence of T. canis in dogs was 4.89 ± 1.44% and in cats 1.28 ± 1.27%; the prevalence of Blastocystis spp. was 41.78 ± 3.29% and 34.62 ± 5.39% in dogs and cats, respectively. Phylogenetic and phylogeographic analyses identified the presence of the H1 subtype of T. canis in dogs, and the ST1 subtype of Blastocystis in dogs and cats. Dogs with clinical signs were more likely to be infected with T. canis (OR 6.039, P < 0.05) than healthy dogs. This study demonstrates that dogs and cats are carriers of Toxocara spp. and Blastocystis spp. and are therefore a source of environmental contamination. Veterinarians and human health professionals should work together to implement control strategies as part of a "One Health" approach to improving animal health and reducing the risk of transmission to humans.
Subject(s)
Blastocystis Infections , Blastocystis , Cat Diseases , Dog Diseases , Feces , Toxocara , Toxocariasis , Animals , Dogs , Cats , Algeria/epidemiology , Dog Diseases/epidemiology , Dog Diseases/parasitology , Cat Diseases/parasitology , Cat Diseases/epidemiology , Toxocariasis/epidemiology , Toxocariasis/parasitology , Prevalence , Risk Factors , Blastocystis Infections/epidemiology , Blastocystis Infections/veterinary , Blastocystis Infections/parasitology , Toxocara/genetics , Toxocara/isolation & purification , Toxocara/classification , Feces/parasitology , Blastocystis/genetics , Blastocystis/classification , Blastocystis/isolation & purification , Male , Female , Polymerase Chain Reaction , Microscopy , PhylogenyABSTRACT
Human toxocariasis (HT) is a widespread zoonotic infection globally, notably prevalent in tropical areas. Enhancing our understanding of toxocariasis can lead to increased attention towards the socioeconomic impact and control of this neglected zoonosis. We conducted a comprehensive review of all available articles and official documents on toxocariasis in Iran to identify research gaps and critical needs for its control. This review highlights that despite numerous studies exploring various aspects of toxocariasis in definitive and paratenic hosts, as well as humans and environmental contamination, significant data deficiencies and gaps persist across different regions in the country. These gaps involve investigating the worm burden and reinfection rates in definitive hosts, developing more sensitive methods to detect and differentiate of Toxocara species, and understanding the behavior of definitive host animals. Additionally, identifying potential paratenic hosts for HT and exploring the organ-specific affinity and survival duration of Toxocara larvae within these hosts are essential areas for exploration. It's also imperative to comprehend the sylvatic and domestic cycles of the parasite in paratenic hosts. Furthermore, assessing egg density in the environment, exploring potential new sources such as water, and identifying regions with optimal climatic conditions for the survival and development of Toxocara eggs are crucial for the formulation of effective prevention and control strategies. Identifying at-risk groups, developing early diagnosis techniques, employing imaging methods, and identifying long-term complications in humans are also crucial. Community health organizations should prioritize health education for the public and professionals. Furthermore, accurately estimating definitive host populations, monitoring and preventing their movements in public places, implementing regular deworming practices for pets and stray hosts, and recognizing the infection's significance as a health priority are critical. This comprehensive understanding advocates for a holistic "one health" approach to control of HT.
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Background: Toxocara canis is one of the most important causes of animal toxocariasis with global distribution. We aimed to find out the seroprevalence of toxocariasis in dogs in a rural area in Fars Province, south of Iran. Methods: Dogs blood samples were collected from 60 dogs in three rural areas in the Sar Mashhad region, Fars Province. Dog sera were evaluated for anti-Toxocara antibodies by an indirect ELISA method. The association between the seropositivity and age, gender, and the sampling location were statistically evaluated. Results: Serological assay detected anti-Toxocara antibodies in sera of 32 out of 60 dogs, corresponding to a seroprevalence of 53.3%. The rate of seropositivity was higher in the male dogs. The rate of seropositivity was higher in old dogs. This rate increased with increasing age, however, the association between age and Toxocara seropositivity was not statistically significant. Conclusion: The high prevalence of Toxocara infection in dogs in the current study area confirms that infected dogs are an important source of Toxocara infection for their owners and people who are in close contact with these animals, especially children.
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Introduction: Worldwide, breast cancer is the most important cancer in incidence and prevalence in women. Different risk factors interact to increase the probability of developing it. Biological agents such as helminth parasites, particularly their excretory/secretory antigens, may play a significant role in tumor development. Helminths and their antigens have been recognized as inducers or promoters of cancer due to their ability to regulate the host's immune response. Previously in our laboratory, we demonstrated that chronic infection by Toxocara canis increases the size of mammary tumors, affecting the systemic response to the parasite. However, the parasite does not invade the tumor, and we decided to study if the excretion/secretion of antigens from Toxocara canis (EST) can affect the progression of mammary tumors or the pathophysiology of cancer which is metastasis. Thus, this study aimed to determine whether excretion/secretion T. canis antigens, injected directly into the tumor, affect tumor growth and metastasis. Methods: We evaluated these parameters through the monitoring of the intra-tumoral immune response. Results: Mice injected intratumorally with EST did not show changes in the size and weight of the tumors; although the tumors showed an increased microvasculature, they did develop increased micro and macro-metastasis in the lung. The analysis of the immune tumor microenvironment revealed that EST antigens did not modulate the proportion of immune cells in the tumor, spleen, or peripheral lymph nodes. Macroscopic and microscopic analyses of the lungs showed increased metastasis in the EST-treated animals compared to controls, accompanied by an increase in VEGF systemic levels. Discussion: Thus, these findings showed that intra-tumoral injection of T. canis EST antigens promote lung metastasis through modulation of the tumor immune microenvironment.
Subject(s)
Breast Neoplasms , Parasites , Toxocara canis , Toxocariasis , Humans , Female , Animals , Mice , Antigens, Helminth , Injections, Intralesional , Lung , Tumor MicroenvironmentABSTRACT
Introduction: Toxocariasis is an infection caused in canines, felines, humans, and other vertebrates by species of the genus Toxocara, such as T. canis and T. cati. The embryonated eggs of these parasites are the primary means of acquiring the infection for both definitive hosts, dogs and cats, respectively, and for intermediates, such as humans and other vertebrates. When deposited on park soils, environmental contamination becomes a risk to environmental, human, and animal health. Objective: To determine the global prevalence of Toxocara cati in cats (Felis catus). Methods: A systematic review of the literature was carried out in six databases (Scopus, PubMed, ScienceDirect, SciELO and Google Scholar) to evaluate the global prevalence of Toxocara cati in cats, defined by coproparasitological, histological, and molecular techniques. A meta-analysis was performed using a random effects model to calculate pooled prevalence and 95% confidence intervals (95% CI). A two-tailed 5% alpha level was used for hypothesis testing. Results: Two hundred and eighty-nine studies were included. The global pooled prevalence of Toxocara cati in cats using coproparasitological methods was 17.0% (95.0% CI: 16.2-17.8%). In the subgroup analysis according to country, Nepal had the highest prevalence of T. cati infection (94.4%; 95% CI 89.7-99.2%). The pooled prevalence of T. cati infection by PCR in four studies was 4.9% (95.0% CI: 1.9-7.9%). Conclusions: This systematic review underscores the need for preventive action against toxocariasis due to its widespread prevalence. The interplay between animal and human health should be emphasised, necessitating measures like deworming cats, hygiene practices, and public education to mitigate risks. Safeguarding feline health can also reduce human transmission, benefiting both species.
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Toxocara is a genus of nematodes, which infects a variety of hosts, principally dogs and cats, with potential zoonotic risks to humans. Toxocara spp. larvae are capable of migrating throughout the host tissues, eliciting eosinophilic and granulomatous reactions, while surviving for extended periods of time, unchanged, in the host. It is postulated that larvae are capable of altering the host's immune response through the release of excretory-secretory products, containing both proteins and extracellular vesicles (EVs). The study of EVs has increased exponentially in recent years, largely due to their potential use as a diagnostic tool, and in molecular therapy. To this end, there have been multiple isolation methods described for the study of EVs. Here, we use nanoparticle tracking to compare the yield, size distribution, and % labelling of EV samples acquired through various reported methods, from larval cultures of Toxocara canis and T. cati containing Toxocara excretory-secretory products (TES). The methods tested include ultracentrifugation, polymer precipitation, magnetic immunoprecipitation, size exclusion chromatography, and ultrafiltration. Based on these findings, ultrafiltration produces the best results in terms of yield, expected particle size, and % labelling of sample. Transmission electron microscopy confirmed the presence of EVs with characteristic cup-shaped morphology. These findings can serve as a guide for those investigating EVs, particularly those released from multicellular organisms, such as helminths, for which few comparative analyses have been performed.
Subject(s)
Chromatography, Gel , Exosomes , Extracellular Vesicles , Microscopy, Electron, Transmission , Toxocara canis , Toxocara , Ultracentrifugation , Animals , Toxocara/isolation & purification , Toxocara/metabolism , Toxocara/chemistry , Toxocara canis/chemistry , Exosomes/chemistry , Exosomes/ultrastructure , Exosomes/metabolism , Extracellular Vesicles/chemistry , Extracellular Vesicles/ultrastructure , Extracellular Vesicles/metabolism , Dogs , Larva , Immunoprecipitation , Toxocariasis/parasitology , Cats , Nanoparticles/chemistry , Particle Size , Helminth Proteins/analysis , Helminth Proteins/metabolism , Helminth Proteins/chemistry , Helminth Proteins/isolation & purificationABSTRACT
Toxocara canis is a parasitic zoonose that is distributed worldwide and is one of the two pathogens causing toxocariasis. After infection, it causes serious public health and safety problems, which pose significant veterinary and medical challenges. To better understand the regulatory effects of T. canis infection on the host immune cells, murine macrophages (RAW264.7) were incubated with recombinant T. canis C-type lectin 4 (rTc-CTL-4) protein in vitro. The quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to analyze the nucleotide-binding oligomerization domain-containing protein 1/2 (NOD1/2), receptor-interacting protein 2 (RIP2), nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), and mitogen-activated protein kinase (MAPK) on mRNA level and protein expression level in macrophages. Our results indicated that 10 µg/mL rTc-CTL-4 protein could modulate the expression of NOD1, NOD2, and RIP2 at both the transcriptional and translational levels. The protein translation levels of NF-κB, P-p65, p38, and P-p38 in macrophages were also modulated by rTc-CTL-4 protein. Macrophages were co-incubated with rTc-CTL-4 protein after siRNA silencing of NOD1, NOD2, and RIP2. The expression levels of NF-κB, P-p65, p38, and P-p38 were significantly changed compared with the negative control groups (Neg. Ctrl.). Taken together, rTc-CTL-4 protein seemed to act on NOD1/2-RIP2-NF-κB and MAPK signaling pathways in macrophages and might activate MAPK and NF-κB signaling pathways by regulating NOD1, NOD2, and RIP2. The insights from the above studies could contribute to our understanding of immune recognition and regulatory mechanisms of T. canis infection in the host animals.
Subject(s)
NF-kappa B , Toxocara canis , Animals , Mice , NF-kappa B/genetics , Mitogen-Activated Protein Kinases/genetics , Mitogen-Activated Protein Kinases/metabolism , Toxocara canis/metabolism , Signal Transduction/physiology , MacrophagesABSTRACT
Neutrophils, a crucial element of the host defense system, develop extracellular traps against helminth parasites. Neutrophils accumulate around the larvae of Toxocara canis (T. canis) in the tissues of the organism. This study aimed to determine the reaction in canine neutrophils after incubation with infective stage T. canis larvae (L3) in vitro. Most L3 were still active and moved between the extracellular traps (NETs) after 60-min incubation. NETs were not disintegrated by L3 movement. The L3 was only immobilized by NETs, entrapped larvae were still motile between the traps at the 24â¯h incubation. NETs were observed not only to accumulate around the mouth, excretory pole or anus but also the entire body of live L3. The extracellular DNA amount released from the canine neutrophils after being induced with phorbol 12-myristate 13-acetate was not affected by T. canis excretory/secretory products obtained from 250 L3. To the Authors'knowledge, the extracellular trap structures was firstly observed in canine neutrophils against T. canis L3 in vitro. NETs decorated with myeloperoxidase, neutrophil elastase and histone (H3) were observed under fluorescence microscope. There were not significant differences in the amount of extracellular DNA (P > 0.05), but the morphological structure of NETs was different in the live and head-inactivated T. canis larvae.
Subject(s)
Extracellular Traps , Larva , Neutrophils , Toxocara canis , Animals , Dogs , Toxocara canis/physiology , Neutrophils/immunology , Larva/physiology , Larva/immunology , Dog Diseases/parasitology , Dog Diseases/immunology , Toxocariasis/parasitology , Toxocariasis/immunologyABSTRACT
BACKGROUND: The study aims to compare neurological soft signs and executive functions between Toxocara-seropositive and seronegative groups in children with attention-deficit/hyperactivity disorder. METHODS: The study included 60 boys with ADHD, aged 7-12. After blood samples were taken, the Stroop Color Word Test and Judgment of Line Orientation test (JLOT) were implemented to measure executive functions. Neurological soft signs were evaluated with Physical and Neurological Examination for Subtle Signs (PANESS). RESULTS: Serological tests were positive for Toxocara antibodies in 20 cases. There was no significant difference between Toxocara seropositive and seronegative regarding age, socioeconomic status, developmental stages, and ADHD severity. However, Toxocara-seropositive children had higher Stroop time and Stroop interference scores and lower JLOT scores than Toxocara-seronegative children. Furthermore, Toxocara-seropositive children exhibited more neurological soft signs, such as gait and station abnormalities, dysrhythmia, and a longer total time in timed movements compared to Toxocara-seronegative children. CONCLUSION: Our study indicates a link between Toxocara-seropositivity and impaired neurological soft signs and executive functions in ADHD. Further research is needed to understand ADHD mechanisms, develop practical treatments considering immunological factors, and thoroughly evaluate how Toxocara seropositivity affects executive functions and motor skills in children with ADHD.