scholarly journals Toxocara canis- and Toxocara cati-Induced Neurotoxocarosis is Associated with Comprehensive Brain Transcriptomic Alterations

2022 ◽  
Vol 10 (1) ◽  
pp. 177
Author(s):  
Patrick Waindok ◽  
Elisabeth Janecek-Erfurth ◽  
Dimitri L. Lindenwald ◽  
Esther Wilk ◽  
Klaus Schughart ◽  
...  
Keyword(s):  
Cholesterol Biosynthesis ◽  
Clinical Signs ◽  
Paratenic Host ◽  
Toxocara Canis ◽  
Host Responses ◽  
Toxocara Cati ◽  
Transcription Analysis ◽  
Whole Genome Microarray ◽  
The Central Nervous System ◽  
Paratenic Hosts

Toxocara canis and Toxocara cati are globally occurring zoonotic roundworms of dogs and cats. Migration and persistence of Toxocara larvae in the central nervous system of paratenic hosts including humans may cause clinical signs of neurotoxocarosis (NT). As pathomechanisms of NT and host responses against Toxocara larvae are mostly unknown, whole-genome microarray transcription analysis was performed in cerebra and cerebella of experimentally infected C57Bl/6J mice as paratenic host model at days 14, 28, 70, 98, and 120 post-infection. Neuroinvasion of T. cati evoked 220 cerebral and 215 cerebellar differentially transcribed genes (DTGs), but no particular PANTHER (Protein ANalysis THrough Evolutionary Relationships) pathway was affected. In T. canis-infected mice, 1039 cerebral and 2073 cerebellar DTGs were identified. Statistically significant dysregulations occurred in various pathways, including cholesterol biosynthesis, apoptosis signaling, and the Slit/Robo mediated axon guidance as well as different pathways associated with the immune and defense response. Observed dysregulations of the cholesterol biosynthesis, as well as the Alzheimer disease-amyloid secretase pathway in conjunction with previous histopathological neurodegenerative findings, may promote the discussion of T. canis as a causative agent for dementia and/or Alzheimer’s disease. Furthermore, results contribute to a deeper understanding of the largely unknown pathogenesis and host-parasite interactions during NT, and may provide the basis for prospective investigations evaluating pathogenic mechanisms or designing novel diagnostic and therapeutic approaches.

The occurrence of Toxocara species in naturally infected broiler chickens revealed by molecular approaches

2016 ◽  
Vol 91 (5) ◽  
pp. 633-636 ◽  
Author(s):  
M. Zibaei ◽  
S.M. Sadjjadi ◽  
S. Maraghi
Keyword(s):  
Skeletal Muscles ◽  
Broiler Chickens ◽  
Diagnostic Technique ◽  
Dna Amplification ◽  
Paratenic Host ◽  
Toxocara Canis ◽  
Toxocara Cati ◽  
Molecular Approaches ◽  
Wide Range ◽  
Paratenic Hosts

AbstractConsuming raw and undercooked meat is known to enhance the risk of human toxocariasis because Toxocara species have a wide range of paratenic hosts, including chickens. The aim of this study was to identify species of Toxocara in naturally infected broiler chickens using molecular approaches. A polymerase chain reaction (PCR) method was used for the differentiation of Toxocara canis and Toxocara cati larvae recovered from tissues and organs, and identified by microscopic observations. Thirty-three 35- to 47-day-old broiler chickens were used for examination of Toxocara larvae. The duodenum, liver, lungs, heart, kidneys, skeletal muscles and brain of each chicken were examined using the pepsin method, and DNA from each tissue was extracted as the template for PCR assay. The findings revealed that 5 of 33 (15.2%) broiler chickens were infected with Toxocara larvae. Larvae were recovered from the liver (n = 19), duodenum (n = 8), skeletal muscles (n = 8) and brain (n = 2) of broiler chickens naturally infected with Toxocara spp. The results showed that the frequencies of the species in the chickens were T. canis larvae (n = 5, 83.3%) and T. cati larvae (n = 1, 16.7%). Our data from the present study demonstrated the importance of broiler chickens as a paratenic host for the parasite's life cycle in the environment. The implementation of DNA amplification as a routine diagnostic technique is a specific and alternative method for identification of Toxocara larvae, and allowed the observation of specific species under field conditions within the locations where broiler chickens are typically raised and exposed to Toxocara spp. eggs or larvae.

Role of cats in human toxocarosis

2020 ◽  
Vol 11 (9) ◽  
pp. 400-408
Author(s):  
Pablo David Jimenez Castro ◽  
Sarah GH Sapp
Keyword(s):  
Definitive Host ◽  
Human Disease ◽  
Clinical Signs ◽  
Toxocara Canis ◽  
Infection Risk ◽  
Domestic Cats ◽  
Toxocara Cati ◽  
Related Disease ◽  
Paratenic Hosts

Toxocara cati, the feline ascarid, is ubiquitous in domestic cats globally and is increasingly recognised as an important zoonotic species. In the definitive host, infections with the adult ascarid usually do not present any clinical signs; if clinical signs do appear, it is usually in kittens infected with T. cati, especially by the trans-mammary route. Diseases may include cachexia, a pot-bellied appearance, respiratory disorders, diarrhoea, vomiting, among other signs, and these may present as early as 3 weeks of age. However, infections with Toxocara spp. larvae in paratenic hosts (including humans and many other animals), can result in serious complications from the migration of larvae. Historically, there has been an assumption that Toxocara canis was the most likely cause of Toxocara spp.-related disease; while it is probably true that T. canis is responsible for the majority of infections, it is important that those caused by T. cati are accurately identified so that the contribution of this parasite to human disease can be established and then handled appropriately. Overall, the detection of infections in cats and the control of parasite stages in the environment are essential to minimise the infection risk to other animals or humans.

Behavioural changes and muscle strength inRattus norvegicusexperimentally infected withToxocara catiandT. canis

2014 ◽  
Vol 89 (4) ◽  
pp. 465-470 ◽  
Author(s):  
S.V. Santos ◽  
J.V.L. Moura ◽  
S.A.Z. Lescano ◽  
J.M. Castro ◽  
M.C.S.A. Ribeiro ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Paratenic Host ◽  
Toxocara Canis ◽  
Female Rats ◽  
Toxocara Cati ◽  
Behavioural Changes ◽  
Laboratory Rats ◽  
Nematode Parasites ◽  
Male And Female Rats ◽  
Paratenic Hosts

AbstractToxocara canisandToxocara catiare nematode parasites in dogs and cats, respectively, transmitted by ingestion of embryonated eggs, transmammary and transplacental (T. canis) routes and paratenic host predation. Many parasites use mechanisms that change the behaviour of their hosts to ensure continued transmission. Several researchers have demonstrated behavioural changes in mouse models as paratenic hosts forT. canis. However, there have been no studies on behavioural changes in laboratory rats (Rattus norvegicus)experimentally infected withT. cati. This study investigated behavioural changes and muscle strength in male and female rats experimentally infected withT. catiorT. canisin acute and chronic phases of infection. Regardless of sex, rats infected withT. catishowed a greater decrease in muscle strength 42 days post infection compared to rats infected withT. canis. However, behavioural changes were only observed in female rats infected withT. canis.

Role of cats in human toxocarosis

2021 ◽  
Vol 26 (1) ◽  
pp. 1-8
Author(s):  
Pablo David Jimenez Castro ◽  
Sarah GH Sapp
Keyword(s):  
Definitive Host ◽  
Human Disease ◽  
Clinical Signs ◽  
Toxocara Canis ◽  
Infection Risk ◽  
Domestic Cats ◽  
Toxocara Cati ◽  
Related Disease ◽  
Paratenic Hosts

Toxocara cati, the feline ascarid, is ubiquitous in domestic cats globally and is increasingly recognised as an important zoonotic species. In the definitive host, infections with the adult ascarid usually do not present any clinical signs; if clinical signs do appear, it is usually in kittens infected with T. cati, especially by the transmammary route. Diseases may include cachexia, a pot-bellied appearance, respiratory disorders, diarrhoea, vomiting, among other signs, and these may present as early as 3 weeks of age. However, infections with Toxocara spp. larvae in paratenic hosts (including humans and many other animals), can result in serious complications from the migration of larvae. Historically, there has been an assumption that Toxocara canis was the most likely cause of Toxocara spp.-related disease; while it is probably true that T. canis is responsible for the majority of infections, it is important that those caused by T. cati are accurately identified so that the contribution of this parasite to human disease can be established and then handled appropriately. Overall, the detection of infections in cats and the control of parasite stages in the environment are essential to minimise the infection risk to other animals or humans.

Distribution of Toxocara infection in the environment and in definitive and paratenic hosts in Estonia

2006 ◽  
Vol 54 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Heli Talvik ◽  
Epp Moks ◽  
Erika Mägi ◽  
T. Järvis ◽  
Illa Miller
Keyword(s):  
Rattus Norvegicus ◽  
Risk Group ◽  
Toxocara Canis ◽  
Toxocara Cati ◽  
Low Level ◽  
Larval Infection ◽  
Small Intestines ◽  
Paratenic Hosts ◽  
The Town ◽  
Home Territory

The aim of the study was to elucidate the distribution and possible transmission routes of Toxocara spp. infection in Estonia. Out of 454 faecal and sand samples collected from park lawns and sandpits in the town of Tartu, 19 were Toxocara positive (4.2%). Out of the 45 sandpit samples 17.8% were Toxocara positive. Cat faeces was found in 21 sandpit samples. Parasitological necropsies were performed on 41 euthanised stray dogs and 27 cats in the Tallinn Dog Home. Additionally, 13 wild free-roaming brown rats (Rattus norvegicus) were captured from the Tallinn Dog Home territory, necropsied and studied for the presence of Toxocara larvae. Toxocara canis adults were found in 14.6% of the dogs and Toxocara cati (syn. mystax) adults in the small intestines of 48.2% of the cats examined. Larval infection was detected in the kidney and liver in 5 dogs (12.2%). Our study demonstrated only low-level larval Toxocara infections in adult dogs. Toxocara larvae were not found in cats and brown rats. According to the results of this study, cats more often carry Toxocara infection than dogs. Under our conditions, stray and free-roaming cats are the main contaminators of the environment with Toxocara eggs. Children playing in sandpits are the main risk group for larval toxocarosis.

scholarly journals A murine model for cerebral toxocariasis: characterization of host susceptibility and behaviour

Parasitology ◽  
2006 ◽  
Vol 132 (6) ◽  
pp. 791-801 ◽  
Author(s):  
C. M. HAMILTON ◽  
P. STAFFORD ◽  
E. PINELLI ◽  
C. V. HOLLAND
Keyword(s):  
Inbred Mice ◽  
Water Source ◽  
Toxocara Canis ◽  
Host Susceptibility ◽  
Larval Distribution ◽  
The Central Nervous System ◽  
Brain Involvement ◽  
Cerebral Infection ◽  
Paratenic Hosts ◽  
The Impact

Toxocara canis, the parasitic roundworm of dogs, can infect a number of paratenic hosts, such as mice and humans, due to the widespread dissemination of its ova in the environment. In these paratenic hosts, larvae have been shown to exhibit a predilection for the central nervous system, resulting in an increasing number of parasites migrating to the brain as infection progresses. In an initial experiment, we investigated the differential brain involvement ofT. canisin 7 strains of inbred mice, and chose 2 strains, susceptible (BALB/c) and resistant (NIH) to cerebral infection. In a second experiment, both strains were investigated in terms of course of migration, larval accumulation, and behavioural response toT. canisinfection. Results revealed that infected BALB/c mice took significantly longer to drink from a water source (following a period of deprivation), compared with control mice, indicating some degree of memory impairment. Cerebral larval recoveries from both strains of mice demonstrated variation between the two experiments, suggesting that larval burdens may not be a reliable indicator of susceptibility or resistance toT. canisinfection. The percentage of total recovered larvae in each organ may be a better representation of larval distribution. Our model system may provide insights into the impact of chronic geohelminth infection on cognitive development.

scholarly journals Toxocara canis, Toxocara cati and Toxascaris leonina in wild and domestic carnivores

2012 ◽  
Vol 49 (1) ◽  
pp. 3-10 ◽  
Author(s):  
A. Okulewicz ◽  
A. Perec-Matysiak ◽  
K. Buńkowska ◽  
J. Hildebrand
Keyword(s):  
Paratenic Host ◽  
Toxocara Canis ◽  
Life Cycles ◽  
Molecular Techniques ◽  
Toxocara Cati ◽  
Wild Canids ◽  
Alternative Approaches ◽  
Domestic Carnivores ◽  
Toxascaris Leonina

AbstractAscarididae nematodes of genera Toxocara and Toxascaris are of significant epizootic relevance among predatory mammals from families Canidae and Felidae. Localization of these nematodes in the definitive hosts, their morphology, as well as the measurements of eggs and adult worms are similar. Recently, molecular techniques have provided alternative approaches for the identification of ascarid species. A common feature of the life cycles of these generally monoxenous nematodes is the significant participation of small rodents. In case of Toxocara spp., the rodent plays the role of paratenic host but optional intermediate host for T. leonina. Several studies indicate co-occurence of both T. canis and T. leonina in domestic and wild canids as well as T. cati and T. leonina in felids. Although the infections of humans with T. canis and T. cati are common worldwide, larvae of T. leonina has the potential to cause human disease as emerging zoonosis.

Molecular characterization of Toxocara spp. eggs isolated from public parks and playgrounds in Shiraz, Iran

2018 ◽  
Vol 93 (3) ◽  
pp. 306-312 ◽  
Author(s):  
M. Choobineh ◽  
F. Mikaeili ◽  
S.M. Sadjjadi ◽  
S. Ebrahimi ◽  
S. Iranmanesh
Keyword(s):  
Toxocara Canis ◽  
Human Infection ◽  
Soil Samples ◽  
Its Rdna ◽  
Public Parks ◽  
Toxocara Cati ◽  
Nested Polymerase Chain Reaction ◽  
Pcr Rflp ◽  
Zinc Sulphate Solution ◽  
Paratenic Hosts

AbstractHuman toxocariasis, a worldwide parasitic disease, is caused by the larval stage of intestinal nematodes of dogs and cats, namely Toxocara canis and Toxocara cati. Human infection occurs by the accidental ingestion of embryonated eggs present in the soil, vegetables or on other contaminated surfaces, as well as via consumption of uncooked paratenic hosts, such as bird meat and giblets. The objective of this study was to evaluate the contamination of soil in public parks and playgrounds in Shiraz using microscopy and molecular methods. A total of 150 soil samples were collected from public parks and playgrounds in various areas of Shiraz, southern Iran. The samples were treated with saturated zinc sulphate solution, and Toxocara spp. eggs were detected by microscopic observation followed by nested polymerase chain reaction (PCR). To differentiate T. canis and T. cati eggs from each other, PCR restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS)-rDNA region by SalI endonuclease enzyme was used. PCR-sequencing was performed to confirm the results of the PCR-RFLP method. Based on the flotation results of the 150 soil samples, six (4%) were found to be positive for Toxocara spp. eggs, whereas nested-PCR showed 24 samples to be positive (16%). Based on the PCR-RFLP method and the sequence of the ITS-rDNA region, a total of 23 out of 24 isolates were confirmed as T. cati and one out of 24 as T. canis. The results showed a higher number of soil samples to be positive for Toxocara by the molecular method than microscopy, and higher T. cati infection in soil samples, which could have an important role in human infection with toxocariasis in this region.

scholarly journals The Role of Nile Tilapia (Oreochromis niloticus) in the Life Cycle of Toxocara spp.

2021 ◽  
Vol 8 ◽  
Author(s):  
Everton André de Oliveira ◽  
Yslla Fernanda Fitz Balo Merigueti ◽  
Isabella Braghin Ferreira ◽  
Isabele Santos Garcia ◽  
Alini Soriano Pereira ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Paratenic Host ◽  
Toxocara Canis ◽  
Control Group ◽  
Water Tank ◽  
Paratenic Hosts ◽  
Eggs And Larvae ◽  
Tank Water

The present study aimed to experimentally assess Nile tilapia as potential paratenic host of Toxocara spp. A total of 15 Nile tilapia (Oreochromis niloticus) were fed with 300 embryonated Toxocara canis eggs by oral gavage, while five others of the control group received distilled water. The fish were individually analyzed at 16, 24, 48, 72, and 240 h after inoculation. Water contamination was assessed, and tissue migration by liver, gastrointestinal tract (GIT), eyes, and central nervous system. A murine model was used as the paratenic host for egg infectivity assessment. Eggs and larvae were found in plastic tank water and fish GIT, ranging from 23 to 86% per fish. Eggs and larvae were recovered from the tank water (76.3%) and fish GIT (23.7%). The counting of eggs and larvae observed was negatively correlated with number of eggs and larvae in the water tank (rho = −0.698, p = 0.003). Shedding of embryonated eggs was first detected at 16 and up to 240 h, with significant egg and larvae yield decrease on water-shedding (p = 0.001) and in the GIT (p = 0.007). Although no T. canis larva was recovered in fish tissues, egg infectivity after fish GIT transit was experimentally confirmed by mice assessment. In conclusion, despite shedding viable embryonated eggs through the gastrointestinal tract, tilapias may not play a role as a suitable paratenic hosts for Toxocara spp., posing low risk of zoonotic transmission by fish meat consumption.

Role of small mammals in the epidemiology of toxocariasis

Parasitology ◽  
1995 ◽  
Vol 110 (2) ◽  
pp. 187-193 ◽  
Author(s):  
P. Dubinský ◽  
K. Havasiová-Reiterová ◽  
B. Peťko ◽  
I. Hovorka ◽  
O. Tomašovičová
Keyword(s):  
Small Mammals ◽  
Toxocara Canis ◽  
Human Populations ◽  
Toxocara Cati ◽  
Healthy Human ◽  
Urban Rural ◽  
Paratenic Hosts ◽  
Rural Locality ◽  
Micromys Minutus

SUMMARYStudies were conducted on the role of small mammals in maintaining toxocariasis foci in urban, rural and montane biotopes. The lowest relative density of small mammals was recorded in the urban locality and the highest in the rural and montane localities. Anti-Toxocaraantibodies were most frequently detected in synanthropic and hemisynanthropic speciesMus musculus, Apodemus agrariusandMicromys minutus– 32·0, 30·4 and 25·0%, respectively. The highest seropositivity was found in small mammals from the urban and rural localities – 22·2 and 21·6%, respectively.Toxocara caniswas most prevalent in urban stray dogs (75·0%) and least prevalent in foxes from the montane locality (7·0%). The prevalence ofToxocara catiin cats at the urban, rural and montane localities was 66·2, 65·2 and 76·9%, respectively. In clinically healthy human populations, the highest seroprevalence was detected in the rural locality (14·0%). Children of the same area were 3 times more seropositive (12·9%) than those from the urban and montane localities (4·3 and 4·0%). Our studies suggest an important role for small mammals as paratenic hosts – reservoirs ofToxocaralarvae – in maintaining toxocariasis foci. In this respect toxocariasis may be classified as an anthropopurgic focal zoonosis.

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