An improved method to obtain antigen-excreting Toxocara canis larvae

Alcântara-Neves, Neuza Maria; Santos, Alana Batista dos; Mendonça, Lívia Ribeiro; Figueiredo, Camila A.; Pontes-de-Carvalho, Lain Carlos

doi:10.1016/j.exppara.2008.03.006

Cited by 34 publications

(21 citation statements)

References 10 publications

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“…Excretory/secretory products of T. canis larvae (TcESLA) were obtained as described previously [30] with appropriate modifications [31]. Briefly, puppies from parasite-infected bitches were treated with piperazine (100 mg/kg) and mineral oil.…”

Section: Methodsmentioning

confidence: 99%

Toxocara Seropositivity, Atopy and Wheezing in Children Living in Poor Neighbourhoods in Urban Latin American

et al. 2012

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Background Toxocara canis and T. cati are parasites of dogs and cats, respectively, that infect humans and cause human toxocariasis. Infection may cause asthma-like symptoms but is often asymptomatic and is associated with a marked eosinophilia. Previous epidemiological studies indicate that T. canis infection may be associated with the development of atopy and asthma.ObjectivesTo investigate possible associations between Toxocara spp. seropositivity and atopy and childhood wheezing in a population of children living in non-affluent areas of a large Latin American city.MethodsThe study was conducted in the city of Salvador, Brazil. Data on wheezing symptoms were collected by questionnaire, and atopy was measured by the presence of aeroallergen-specific IgE (sIgE). Skin prick test (SPT), total IgE and peripheral eosinophilia were measured. Toxocara seropositivity was determined by the presence of anti-Toxocara IgG antibodies, and intestinal helminth infections were determined by stool microscopy.FindingsChildren aged 4 to 11 years were studied, of whom 47% were seropositive for anti-Toxocara IgG; eosinophilia >4% occurred in 74.2% and >10% in 25.4%; 59.6% had elevated levels of total IgE; 36.8% had sIgE≥0.70 kU/L and 30.4% had SPT for at least one aeroallergen; 22.4% had current wheezing symptoms. Anti-Toxocara IgG was positively associated with elevated eosinophils counts, total IgE and the presence of specific IgE to aeroallergens but was inversely associated with skin prick test reactivity.ConclusionThe prevalence of Toxocara seropositivity was high in the studied population of children living in conditions of poverty in urban Brazil. Toxocara infection, although associated with total IgE, sIgE and eosinophilia, may prevent the development of skin hypersensitivity to aeroallergens, possibly through increased polyclonal IgE and the induction of a modified Th2 immune reaction.

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Section: Methodsmentioning

confidence: 99%

Toxocara Seropositivity, Atopy and Wheezing in Children Living in Poor Neighbourhoods in Urban Latin American

et al. 2012

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“…The eggs were released from the uterus by applying gentle pressure with forceps. Later the eggs were transferred to 4 % formalin in normal saline and incubated at a temperature of 26°C for 35 days to induce embryonation (Alcantara-Neves et al 2008). The embryonated egg suspension was washed and treated with 4 % sodium hypochlorite solution for 2 h to induce decortication.…”

Section: Methodsmentioning

confidence: 99%

In vitro production of Toxocara canis excretory-secretory (TES) antigen

et al. 2014

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Toxocara canis is a widespread gastrointestinal nematode parasite of dogs and cause Toxocara larva migrans, an important zoonotic disease in humans on ingestion of infective eggs. Toxocarosis is one of the few human parasitic diseases whose serodiagnosis uses a standardized antigen, T. canis excretory secretory antigen (TES). The present study describes collection of T. canis adult worm, collection and embryonation of T. canis eggs, hatching and separation of T. canis larvae, in vitro maintenance of T. canis second stage larvae for production of TES, concentration of culture fluid TES and yield of TES in correlation with various methods cited in literature.

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“…This was incubated at 28-30°C for 30 days to allow for embryonation of the larvae. 12 Larvae were hatched and processed according to methods by Alcantara-Neves and others 13 and Mohamad and others 14 In brief, the formaldehyde was removed by washing five times with sterile PBS. An equal volume of 7-14% sodium hydrochloride (Sigma-Aldrich, St. Louis, MO) was added, and the solution was placed on a shaker at room temperature for 15 minutes until the eggs lost their external layer.…”

Section: Methodsmentioning

confidence: 99%

Production of Toxocara cati TES-120 Recombinant Antigen and Comparison with its T. canis Homolog for Serodiagnosis of Toxocariasis

Zahabiun

Sadjjadi

Yunus

et al. 2015

The American Journal of Tropical Medicine and Hygiene

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Abstract. Toxocariasis is a cosmopolitan zoonotic disease caused by the infective larvae of Toxocara canis and T. cati. Diagnosis in humans is usually based on clinical symptoms and serology. Immunoglobulin G (IgG)-enzyme-linked immunosorbent assay kits using T. canis excretory-secretory (TES) larval antigens are commonly used for serodiagnosis. Differences in the antigens of the two Toxocara species may influence the diagnostic sensitivity of the test. In this study, T. cati recombinant TES-120 (rTES-120) was cloned, expressed, and compared with its T. canis homolog in an IgG4-western blot. The diagnostic sensitivity and specificity of T. cati rTES-120 were 70% (33/47) and 100% (39/39), respectively. T. canis rTES-120 showed 57.4% sensitivity and 94.4% specificity. When the results of assays using rTES-120 of both species were considered, the diagnostic sensitivity was 76%. This study shows that using antigens from both Toxocara species may improve the serodiagnosis of toxocariasis.

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An improved method to obtain antigen-excreting Toxocara canis larvae

Cited by 34 publications

References 10 publications

Toxocara Seropositivity, Atopy and Wheezing in Children Living in Poor Neighbourhoods in Urban Latin American

Toxocara Seropositivity, Atopy and Wheezing in Children Living in Poor Neighbourhoods in Urban Latin American

In vitro production of Toxocara canis excretory-secretory (TES) antigen

Production of Toxocara cati TES-120 Recombinant Antigen and Comparison with its T. canis Homolog for Serodiagnosis of Toxocariasis

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