1
|
Poulsen CS, Yoshida A, Wellbrant TT, Leifsson PS, Skallerup P, Thamsborg SM, Nejsum P. Migratory pattern of zoonotic Toxocara cati and T. canis in experimentally infected pigs. Eur J Clin Microbiol Infect Dis 2024; 43:587-596. [PMID: 38261158 PMCID: PMC10917876 DOI: 10.1007/s10096-024-04753-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024]
Abstract
BACKGROUND Over a billion people are infected with Toxocara canis or T. cati, the roundworms of dogs and cats. Historically, T. canis has been considered the main species responsible for human toxocarosis, but as serodiagnosis cannot discriminate between the two species, this remains unresolved. We used pigs as a relevant large animal model for human infection to assess the migratory pattern of T. cati and T. canis. METHODS Pigs were inoculated with T. cati or T. canis eggs or PBS (negative controls) and necropsied 14 or 31 days later. Different organs and tissues were examined for parasites and pathological changes. RESULTS Overall, the two parasite species had a similar migration pattern reaching multiple organs and tissues, including the mesenteric lymph nodes, liver, lungs, and diaphragm. We recovered larvae of both species in the brain, suggesting that T. cati also can cause neurological toxocarosis in humans. Both species induced systemic eosinophilia and histopathological changes in the lungs, livers, and mesenteric lymph nodes. CONCLUSION This study emphasises the importance of T. cati as a zoonotic agent and the need to develop diagnostic methods that can differentiate between sources of infection in humans.
Collapse
Affiliation(s)
- Casper Sahl Poulsen
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Ayako Yoshida
- Department of Veterinary Sciences, University of Miyazaki, Miyazaki, Japan
| | | | - Pall Skuli Leifsson
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Stig Milan Thamsborg
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Nejsum
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Aarhus, Denmark.
- Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark.
| |
Collapse
|
2
|
Xu J, Han Q. Prevalence, Infection, and Risk to Human Beings of Toxocara canis in Domestic Food-Producing Animals. Vet Sci 2024; 11:83. [PMID: 38393101 PMCID: PMC10892340 DOI: 10.3390/vetsci11020083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/03/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Toxocariasis is a significant food-borne zoonotic parasitic disease, and a range of birds and mammals are the paratenic hosts of Toxocara canis. The consumption of raw or undercooked meat and viscera of these paratenic hosts frequently leads to T. canis infection and the development of human toxocariasis. In this review, we will perform an analysis of relevant papers published in the National Center for Biotechnology Infrastructure database on the parasitism, migration, and infection of T. canis in chickens, pigeons, quail, pigs, cattle, sheep, and other food-producing animals, so as to make the public aware of the risk factors of human toxocariasis, improve the public's understanding of T. canis infection, and provide evidence for targeted prevention and control measures.
Collapse
Affiliation(s)
- Jingyun Xu
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life and Health Sciences, Hainan University, Haikou 570228, China;
- One Health Institute, Hainan University, Haikou 570228, China
| | - Qian Han
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life and Health Sciences, Hainan University, Haikou 570228, China;
- One Health Institute, Hainan University, Haikou 570228, China
| |
Collapse
|
3
|
Abstract
Human toxocariasis is a neglected tropical disease, which is actually global in distribution and has a significant impact on global public health. The infection can lead to several serious conditions in humans, including allergic, ophthalmic and neurological disorders such as epilepsy. It is caused by the common roundworm species Toxocara canis and Toxocara cati, with humans becoming accidentally infected via the ingestion of eggs or larvae. Toxocara eggs are deposited on the ground when infected dogs, cats and foxes defecate, with the eggs contaminating crops, grazing pastures, and subsequently food animals. However, transmission of Toxocara to humans via food consumption has received relatively little attention in the literature. To establish the risks that contaminated food poses to the public, a renewed research focus is required. This review discusses what is currently known about food-borne Toxocara transmission, highlighting the gaps in our understanding that require further attention, and outlining some potential preventative strategies which could be employed to safeguard consumer health.
Collapse
|
4
|
Sierra MF, Ricoy G, Sosa S, Colavecchia SB, Santillán G, López CM, Mundo SL, Sommerfelt IE. Humoral immune response of pigs infected with Toxocara cati. Exp Parasitol 2020; 218:107997. [PMID: 32946882 DOI: 10.1016/j.exppara.2020.107997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/14/2020] [Accepted: 09/13/2020] [Indexed: 11/16/2022]
Abstract
Toxocara cati is one of the causative agents of human toxocariasis. Serological methods are used for diagnosis in paratenic hosts like humans but the humoral immune response triggered by this parasite is unknown. We characterized the humoral immune response to T. cati excretory-secretory antigens (TES) in pigs as animal model during the acute and chronic stages of infection. ELISA and Western Blot techniques were used to determine antibody response. Pigs were experimentally inoculated with 100,000 infective Toxocara cati eggs. Blood was collected at 7, 14, 21 and 28 days post-inoculation (d.p.i.) to assess the acute stage of infection and 90, 120 and 180 d. p.i. for chronic stage analysis. ELISA showed values higher than the cut-off of specific IgM and IgG at 7 d. p.i. with significant differences at 0 and 7 d. p.i. for IgM and at 14, 21 and 28 d. p.i. for IgG in the acute stage. Higher and stable levels were detected in the chronic stage. Western Blot showed bands from 102 to 38 kDa detected by specific IgM and IgG. More immunogenic bands were identified by specific IgG. In the chronic stage of infection a band near 31 kDa was the only band detected by IgM until 150 d. p.i. Specific IgG recognized bands between 102 and 31 kDa. This study demonstrates how the humoral immune response evolves in the acute and chronic stages of infection and provides evidence on the role of the pig as a paratenic host of T. cati.
Collapse
Affiliation(s)
- Maria Florencia Sierra
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - Gerardo Ricoy
- Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
| | - Sonia Sosa
- Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
| | - Silvia Beatriz Colavecchia
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Inmunología, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - Graciela Santillán
- Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
| | - Clara Maria López
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - Silvia Leonor Mundo
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Inmunología, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - I E Sommerfelt
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| |
Collapse
|
5
|
Nicoletti A, Gomez-Puerta LA, Arroyo G, Bustos J, Gonzalez AE, Garcia HH, For The Cysticercosis Working Group In Peru. Toxocara Brain Infection in Pigs is Not Associated with Visible Lesions on Brain Magnetic Resonance Imaging. Am J Trop Med Hyg 2020; 103:273-275. [PMID: 32431279 DOI: 10.4269/ajtmh.19-0912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Human exposure to Toxocara spp. is very frequent, and its larvae can cross the blood-brain barrier and invade the central nervous system (CNS), causing neurotoxocariasis. We aimed to establish a neurotoxocariasis animal model in pigs confirmed by necropsy. Also, the presence of larvae in the CNS was assessed using magnetic resonance imagings (MRIs), to establish brain lesions caused by the larvae migration. Ten pigs were infected intraperitoneally with 3,000 Toxocara larvae. Cerebral toxocariasis was evaluated using MRIs at days 7, 14, 21, and 49, and pigs were euthanized after the examination. Brain tissues were examined by microscopy, and five pigs presented Toxocara, most frequently at day 21 after infection. None of the 10 pigs showed alterations on MRIs. Our study confirms that intraperitoneal Toxocara infection produces neurotoxocariasis in pigs. Toxocara larvae passage through the brain does not seem to produce lesions detectable at MRIs.
Collapse
Affiliation(s)
| | - Luis A Gomez-Puerta
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gianfranco Arroyo
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Javier Bustos
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Armando E Gonzalez
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru.,School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Hector H Garcia
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | |
Collapse
|
6
|
Nijsse R, Overgaauw P, Ploeger H, Mughini-Gras L. Sources of environmental contamination with Toxocara spp.: An omnipresent parasite. ADVANCES IN PARASITOLOGY 2020; 109:585-614. [PMID: 32381219 DOI: 10.1016/bs.apar.2020.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Embryonated Toxocara eggs in the environment are considered to be the most important source of human toxocariasis. These eggs, however, are also a source of infection for the definitive and paratenic hosts. Most available literature focuses on Toxocara canis in dogs, or other canids. There are, however, other Toxocara species with their accompanying definitive hosts. Results from studies that modelled patent infections in dogs, cats and foxes show that although dogs are a very important source for environmental contamination with Toxocara eggs, other sources cannot be ignored. For a good understanding of the relative contributions of different definitive hosts to environmental contamination with Toxocara eggs, computational models should be built and fed with data from different fields of expertise as is discussed in this paper.
Collapse
Affiliation(s)
- Rolf Nijsse
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - Paul Overgaauw
- Division of Veterinary Public Health, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Harm Ploeger
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Lapo Mughini-Gras
- Division of Veterinary Public Health, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; National Institute for Public Health and the Environment, Centre for Infectious Disease Control (CIb), Bilthoven, The Netherlands
| |
Collapse
|
7
|
Abstract
SUMMARYToxocara species infect a wide range of companion, domestic and wild animals as definitive and paratenic hosts, via multiple routes of transmission, producing long-lived tissue-inhabiting larvae and resistant eggs that can survive in the external environment. Therefore Toxocara and the disease it causes in humans, toxocariasis, represents an ideal aetiological agent for the development of the one health approach. However, despite increasing awareness of the public health significance of toxocariasis, gaps in our understanding of certain key aspects of the parasite's biology and epidemiology remain. These gaps hinder our ability to integrate research effort within the veterinary, medical and environmental disciplines. This review will highlight key deficits in our understanding of nine dimensions of Toxocara epidemiology and discuss a potential scenario to develop a more integrated, one health approach to improve our understanding of the prevention and control of this complex and cryptic zoonosis.
Collapse
|
8
|
Larval migration of the ascarid nematode Toxocara canis following infection and re-infection in the gerbil Meriones unguiculatus. J Helminthol 2015; 90:569-76. [PMID: 26337823 DOI: 10.1017/s0022149x15000760] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A morphological and immunohistochemical study of larval migration patterns was performed in gerbils that were infected once (primary infected group) or twice (secondary infected group) with 1500 eggs of Toxocara canis. Animals from the primary infected and the re-infected group were killed at different times after infection, and larvae were counted in the intestines, liver, lungs and brain. Fragments of all organs were formalin fixed and paraffin embedded for histology and immunohistochemistry analyses (using polyclonal anti-Toxocara serum raised in rabbits infected with T. canis). In the primary infected group, larvae were more abundant in the intestine at 24 h, in the liver and lungs between 24 and 72 h and in the brain after 96 h; larvae predominated in the brain for up to 60 days after infection. In the re-infected group, an increase in the number of larvae in the liver and a reduction in the number of larvae in the brain was observed up to 60 days after re-infection. Inflammatory reactions were absent or limited. Eosinophils and loose granulomata were observed around the larvae and their antigens in the primary infected group and were more severe. Many eosinophils and typical epithelioid granulomata were observed around larvae in the re-infected group. These results demonstrate that the migration pattern of T. canis larvae in gerbils is similar to that in mice and rats, exhibiting a late neurotropic stage. In the re-infected group, there was histological evidence of an adaptive T-helper 2 (Th-2) response, and larvae were apparently retained within granulomata in the liver, without obvious signs of destruction.
Collapse
|
9
|
Lee JY, Yang MH, Hwang JH, Kang M, Paeng JW, Yune S, Lee BJ, Choi DC. The Prevalence of Toxocariasis and Diagnostic Value of Serologic Tests in Asymptomatic Korean Adults. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2015; 7:467-75. [PMID: 26122506 PMCID: PMC4509659 DOI: 10.4168/aair.2015.7.5.467] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 03/11/2015] [Accepted: 04/01/2015] [Indexed: 12/02/2022]
Abstract
Purpose Toxocariasis is the most common cause of peripheral blood eosinophilia in Korea and produces eosinophilic infiltration in various organs, including the lung. However, the prevalence of toxocariasis in the general population is rarely reported. Methods We investigated the seroprevalence of Toxocara larval antibody among asymptomatic people who attended Samsung Medical Center for a health checkup, including low-dose chest computed tomography (CT) between March 2012 and December 2013. A total of 633 people (400 men and 233 women) were prospectively recruited. Results The Toxocara-seropositive rate was 51.2% using the current cutoff value based on Toxocara enzyme-linked immunosorbent assay (ELISA) (67.0% for men and 24.0% for women). In the multivariate-adjusted model, age (odds ratio [OR], 1.08; 95% confidence intervals [CI], 1.04-1.11), male sex (OR, 3.47; 95% CI, 2.26-5.33), rural residence (OR, 1.55; 95% CI, 1.05-2.30), and history of raw liver intake (OR, 8.52; 95% CI, 3.61-20.11) were significantly associated with Toxocara seropositivity. When subjects were divided into 3 groups using cutoff values base on weak positive and strong positive control optical densities (ODs), the ORs for peripheral blood eosinophilia and serum hyperIgEaemia were 0.31 (95% CI, 0.02-2.89) in the weakpositive group and 36.64 (95% CI, 11.73-111.42) in the strong positive group compared to the seronegative group. Similarly, ORs for the solid nodule with surrounding halo were 2.54 (95% CI, 0.60-10.84) in the weak positive group and 15.08 (95 CI 4.09-55.56) in the strong positive group compared to the seronegative group. Conclusions The study indicated that the Toxocara-seropositive rate obtained by using the current cutoff value based on ELISA was high in the asymptomatic population in Korea. The results of this study suggest that active toxocariasis may be more frequently seen in the Toxocara-strong positive group than in the Toxocara-weak positive group.
Collapse
Affiliation(s)
- Jin Young Lee
- Center for Health Promotion, Samsung Medical Center, Seoul, Korea
| | - Moon Hee Yang
- Center for Health Promotion, Samsung Medical Center, Seoul, Korea
| | - Jung Hae Hwang
- Center for Health Promotion, Samsung Medical Center, Seoul, Korea
| | - Mira Kang
- Center for Health Promotion, Samsung Medical Center, Seoul, Korea
| | - Jae Won Paeng
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Korea
| | - Sehyo Yune
- Division of Allergy, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Byung Jae Lee
- Division of Allergy, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Dong Chull Choi
- Division of Allergy, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
| |
Collapse
|
10
|
Serological examination of fattening pigs reveals associations between Ascaris suum, lung pathogens and technical performance parameters. Vet Parasitol 2015; 210:151-8. [PMID: 25952722 DOI: 10.1016/j.vetpar.2015.04.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 04/15/2015] [Accepted: 04/17/2015] [Indexed: 11/21/2022]
Abstract
Diagnosing the presence of the highly prevalent and economically important pig parasite Ascaris suum on fattening farms has so far been challenging. Currently, only the number of livers affected at slaughter is routinely used to measure parasite exposure. However, recently, a new serological test was developed based on the detection of antibodies to the A. suum haemoglobin molecule. The test showed to be highly sensitive for the detection of exposure to A. suum in fattening pigs. In this study we first compared the performance of A. suum serology versus the percentage of affected livers at slaughter, subsequently we investigated potential associations between A. suum infection levels and exposure to important lung pathogens and finally we identified correlations between serological data and technical performance parameters (TPIs) from 20 Belgian and 20 German pig fattening farms. In both Belgian and German farms, a significant relationship was detected between elevated average Ascaris serology and percentages of affected livers (ρ=0.63 and ρ=0.75, respectively). On the Belgian farms, both Ascaris serology and the percentage of affected livers were negatively correlated with average daily gain (ADG) (ρ=-0.69 and ρ=-0.56, respectively). Using the German dataset, only a borderline negative association was detected between the percentage of affected livers and the ADG (ρ=-0.44, P=0.053). In contrast, only in the German farms, correlations between the percentage of affected lungs at slaughter and elevated presence of A. suum and several other airway pathogens were detected. To conclude, this study indicates that serological screening for A. suum on fattening farms is an attractive new diagnostic tool that can be used to indicate the presence of roundworm infection by measuring infection intensity. Furthermore the results of this study also add weight to the evidence that both roundworm infections as well as herd exposure to airway pathogens have a significant impact on farm productivity and hence, that all these factors should to be taken into account when assessing pig health and farm productivity.
Collapse
|
11
|
Sommerfelt IE, Duchene A, Daprato B, Lopez CM, Cardillo N, Franco AJ. Experimental infection with Toxocara cati in pigs: migratory pattern and pathological response in early phase. Rev Inst Med Trop Sao Paulo 2014; 56:347-52. [PMID: 25076437 PMCID: PMC4131822 DOI: 10.1590/s0036-46652014000400013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/21/2013] [Indexed: 11/22/2022] Open
Abstract
Experimental inoculations of approximately 100,000 infective
Toxocara cati larval eggs were done in twelve pigs. The
T. cati eggs used for inoculation were collected from cat's
feces. Another group of three pigs served as an uninfected control. Groups of
infected pigs were euthanized at seven, 14, 21, and 28 days post-inoculation (dpi).
Tissue samples were taken for digestion and histopathology changes in early phase.
The number of larvae recovered from the lungs peaked at seven and 14 dpi and were
also present at 21, and 28 dpi. Larvae of T. cati were present in
the lymph nodes of the small and large intestine at seven, 14, and 28 dpi and at
seven, 14, 21, and 28 dpi respectively. In other studied tissues, no larvae or less
than one larva per gram was detected. The pathological response observed in the liver
and lungs at seven and 14 dpi, showed white spots on the liver surface and areas of
consolidation were observed in the lungs. The lungs showed an inflammatory reaction
with larvae in center at 28 dpi. In the liver we observed periportal and perilobular
hepatitis. The lymph nodes of the intestines displayed eosinophil lymphadenitis with
reactive centers containing parasitic forms in some of them. The granulomatous
reaction was not observed in any tissues. The role of the other examined tissues had
less significance. The relevance of this parasite as an etiological agent that leads
to disease in paratenic hosts is evident.
Collapse
Affiliation(s)
- Irma Estela Sommerfelt
- Cátedra de Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Adriana Duchene
- Cátedra de Patología Clínica, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Betina Daprato
- Cátedra de Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Clara María Lopez
- Cátedra de Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Natalia Cardillo
- Cátedra de Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Aníbal Juan Franco
- Cátedra de Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
12
|
Rahbar A, Alborzi A, Seifi Abad Shapoori M. An alternative method for producing Toxocara canis second stage larvae from a paratenic host (pigeon) for mRNA extraction purpose. J Parasit Dis 2013; 39:186-9. [PMID: 26063997 DOI: 10.1007/s12639-013-0310-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 05/05/2013] [Indexed: 11/29/2022] Open
Abstract
Toxocara canis is a prevalent zoonotic parasite which can cause serious disease in puppies and humans. Excretory-secretory and coating antigens of the second stage larvae (L2) are the best targets for performing immunodiagnostic and also immunoprophylactic tests. Various hatching methods have been described to bring out L2 from the resistant infective egg shell; but these methods are difficult to do and have had different results when performed by different practitioners. In this study, second stage larvae were obtained from the viscera of pigeons (a paratenic host) which were infected with infective eggs. Infective Toxocara canis eggs were given to ten pigeons and live larvae were recovered from their excised livers and lungs by using the Baermann's apparatus in the next days. Two in vitro methods for larvae hatching were also performed including a so-called physiological hatching method according to Ponce-Macotela et al. (J Parasitol 175:382-385, 2010), and a mechanical hatching method according to Alcântara-Neves and Santos (J Exp Parasitol 119:349-351, 2008) and their results were compared with the in-vivo method. Results show that averagely 36.2 % of fed larvae recovered from livers and 0.15 % from lungs. Average larvae recovery in the first day after infection (24.2 %) was significantly lower than subsequent days (39 %). Maximum larvae recovered in day 3 (55 %). In-vitro methods we carried out did not have acceptable results and only a few larvae did hatch using these methods.
Collapse
Affiliation(s)
- Amir Rahbar
- Shahid Chamran University, Ahwaz, Khuzestan Islamic Republic of Iran
| | - Alireza Alborzi
- Shahid Chamran University, Ahwaz, Khuzestan Islamic Republic of Iran
| | | |
Collapse
|
13
|
|
14
|
Alba-Hurtado F, Muñoz-Guzmán MA, Valdivia-Anda G, Tórtora JL, Ortega-Pierres MG. Toxocara canis: larval migration dynamics, detection of antibody reactivity to larval excretory-secretory antigens and clinical findings during experimental infection of gerbils (Meriones unguiculatus). Exp Parasitol 2009; 122:1-5. [PMID: 19545524 DOI: 10.1016/j.exppara.2009.01.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 01/07/2009] [Accepted: 01/14/2009] [Indexed: 12/01/2022]
Abstract
In this study, Mongolian gerbils were used to analyse features of Toxocara infection that included larval migration, humoral immune responses to Toxocara canis excretory-secretory antigens (TES) and aspects of host physiology. At day 10 post-infection (p.i.) most larvae were in the intestine and the lungs while later the total number of larvae was higher in the carcass tissue; the number of larvae per gram of tissue was lower elsewhere other than in the brain. Infected animals showed several neurological abnormalities, an early increase in leukocyte and neutrophil levels, two peaks of peripheral eosinophilia (5 and 40 d.p.i.) and high antibody levels against TES in the circulation and in the vitreous humor. A sequential recognition of eight T.canis larval antigens with MW from 24 to 200 kDa was detected by Western blot. The results obtained in this study further support the use of gerbils as an experimental model for systemic, ocular and cerebral toxocariasis.
Collapse
Affiliation(s)
- F Alba-Hurtado
- Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, 54714 Cuautitlán, Mexico.
| | | | | | | | | |
Collapse
|
15
|
Cardillo N, Rosa A, Ribicich M, López C, Sommerfelt I. Experimental infection with Toxocara cati in BALB/c mice, migratory behaviour and pathological changes. Zoonoses Public Health 2008; 56:198-205. [PMID: 18990197 DOI: 10.1111/j.1863-2378.2008.01182.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Experimental inoculations of 1000 Toxocara cati larval eggs were carried out in 18 BALB/c mice. The T. cati eggs used for inoculation were collected from the faeces of naturally infected cats. Euthanasia was performed on two mice on days 1, 2, 3, 4, 5, 6, 14, 21 and 28 post-inoculation (p.i.). Tissue samples were taken for digestion and histopathology. Larvae were recovered from all infected mice and the average of all larvae recovered was 28.3% (95%; CI: 14.1-42.4). Maximum number was obtained from liver on days 1 and 2 p.i.; from the lung on day 2 p.i. and from the brain on day 28 p.i. In muscle, the recovery was high as from day 3 p.i., with the maximum obtained on day 28 p.i. Superficial foci of congestion and haemorrhage were macroscopically observed in the lungs between days 2 and 5 p.i. and in the brain between days 3 and 6 p.i. Microscopic lesions were observed in the liver between days 2 and 14 p.i., with periportal and subcapsule inflammatory infiltrates. In the lungs, haemorrhages and inflammatory infiltrates can be observed in the alveolar parenchyma, close to bronchioles and large blood vessels. In the brain, congestive areas without inflammatory reactions were seen. In muscle, the presence of inflammatory infiltrates and degenerated muscle can be observed surrounding a parasite larva. These same lesions were observed in myocardium and pericardium. The kidneys were congested with inflammatory infiltrates. The inflammatory cells present in all the tissues studied were lymphocytes, neutrophils and a few eosinophils. Formation of granulomas or signs of larva encapsulation were not observed. The migratory pattern of T. cati larvae in BALB/c mice and its tendency to become concentrated in the muscle reinforce the importance of the mouse as a paratenic host for the parasite's cycle in the environment.
Collapse
Affiliation(s)
- N Cardillo
- Cátedra de Parasitología y Enfermedades Parasitarias, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | | | | | | | | |
Collapse
|
16
|
Jex AR, Waeschenbach A, Littlewood DTJ, Hu M, Gasser RB. The mitochondrial genome of Toxocara canis. PLoS Negl Trop Dis 2008; 2:e273. [PMID: 18682828 PMCID: PMC2483351 DOI: 10.1371/journal.pntd.0000273] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 07/10/2008] [Indexed: 11/25/2022] Open
Abstract
Toxocara canis (Ascaridida: Nematoda), which parasitizes (at the adult stage) the small intestine of canids, can be transmitted to a range of other mammals, including humans, and can cause the disease toxocariasis. Despite its significance as a pathogen, the genetics, epidemiology and biology of this parasite remain poorly understood. In addition, the zoonotic potential of related species of Toxocara, such as T. cati and T. malaysiensis, is not well known. Mitochondrial DNA is known to provide genetic markers for investigations in these areas, but complete mitochondrial genomic data have been lacking for T. canis and its congeners. In the present study, the mitochondrial genome of T. canis was amplified by long-range polymerase chain reaction (long PCR) and sequenced using a primer-walking strategy. This circular mitochondrial genome was 14162 bp and contained 12 protein-coding, 22 transfer RNA, and 2 ribosomal RNA genes consistent for secementean nematodes, including Ascaris suum and Anisakis simplex (Ascaridida). The mitochondrial genome of T. canis provides genetic markers for studies into the systematics, population genetics and epidemiology of this zoonotic parasite and its congeners. Such markers can now be used in prospecting for cryptic species and for exploring host specificity and zoonotic potential, thus underpinning the prevention and control of toxocariasis in humans and other hosts.
Collapse
Affiliation(s)
- Aaron R. Jex
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia
| | | | | | - Min Hu
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia
| | - Robin B. Gasser
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia
| |
Collapse
|
17
|
Larval migration of Toxocara canis in piglets and transfer of larvae from infected porcine tissue to mice. J Helminthol 2008; 82:245-9. [PMID: 18416883 DOI: 10.1017/s0022149x08974344] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Visceral larva migrans (VLM), caused by Toxocara canis larvae in humans, animals and birds, is now well documented throughout the world. Seven piglets were infected orally with 5 x 104 embryonated eggs and the migration and distribution of T. canis larvae in the tissues were evaluated. After artificial gastric juice digestion, larval yields at necropsy from different organs and muscles on days 1, 3, 7, 15 and 30 post-infection (DPI) revealed 3.05, 0.97, 0.21, 0.13, 0.05, 0.14% recovery from liver, lungs, heart, kidneys, skeletal muscles and brain tissues respectively, with a total of 2486 (4.97%) recovery from all tissues together. The highest number of larvae 1527 (3.05%) was recovered from the liver throughout the period (1-30 DPI), indicating a special affinity of larvae for the liver. Subsequently five mice were each infected orally with 5 g of infected pig liver and, after necropsy on 10 DPI, 20 +/- 3.62, 17 +/- 5.10, 3 +/- 1.26, 12 +/- 3.92 and 30 +/- 5.69 larvae were recovered from liver, lungs, heart, brain and muscles, respectively. Thus, primarily, the migratory potential and adaptation of T. canis larvae in porcine tissue was examined and, subsequently, their establishment in the second paratenic host, the mouse, has been successful. No influence of host sex on the migratory potential of T. canis larvae was observed. The related pathology caused by migratory larvae and its zoonotic significance through the consumption of raw or undercooked pork has been emphasized.
Collapse
|
18
|
Lloyd S. Seroprevalence of Toxocara canis in sheep in Wales. Vet Parasitol 2006; 137:269-72. [PMID: 16500027 DOI: 10.1016/j.vetpar.2006.01.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 01/13/2006] [Accepted: 01/17/2006] [Indexed: 11/27/2022]
Abstract
Antibody levels to Toxocara canis L2 excretory/secretory antigens were examined by ELISA in 400 serum samples from sheep in Powys and Gwent, Wales. A positive OD value was set at the mean +/-3S.D. of 45 control samples. Seroprevalence increased with age. Seven percent and 13% of 6-month-old sheep showed positive OD values as did 16% of 10-month-old, 27% and 31% of 15-month-old and 47% of cull ewes. Analysis of variance showed a significant increase in ELISA OD values among the seropositive sheep with increasing age of sheep.
Collapse
Affiliation(s)
- Sheelagh Lloyd
- Department of Veterinary Medicine, University of Cambridge, Madingley Rd., Cambridge, UK.
| |
Collapse
|
19
|
Pecinali NR, Gomes RN, Amendoeira FC, Bastos ACMP, Martins MJQA, Pegado CS, Bastos OMP, Bozza PT, Castro-Faria-Neto HC. Influence of murine Toxocara canis infection on plasma and bronchoalveolar lavage fluid eosinophil numbers and its correlation with cytokine levels. Vet Parasitol 2005; 134:121-30. [PMID: 16168564 DOI: 10.1016/j.vetpar.2005.06.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2005] [Indexed: 10/25/2022]
Abstract
Toxocara canis is a nematode of the Ascaridae family that normally parasites the small intestine of canid species. Humans are accidentally infected upon ingestion of embryonated eggs, and can manifest several clinical alterations such as fever, hepatomegaly, splenomegaly, respiratory symptoms, muscle pain and anorexia. In the present work, we investigated the kinetics of tissue distribution of L2 larva in lungs, liver, kidney, brain, skeletal muscle and myocardium. Also, we analyzed the blood and bronchoalveolar lavage fluid (BAL) for levels of IL-6, IFN-gamma, eotaxin and Regulated on Activation Normal T Cell Expressed and Secreted (RANTES) in experimental murine T. canis infection. We observed liver, lung and kidney lesions correlated to larva migration as early as the first day of infection. After the seventh post-infection day, larva could also be detected in brain, skeletal muscle and heart, as an indicator of biphasic migration pattern. Increased inflammatory activity was detected in BAL and plasma of infected animals, as was an intense eosinophil migration associated with an increase in the levels of all the cytokines studied. In conclusion, our results establish a tight correlation between tissue lesions caused by larva migration and increased plasma levels of pro-inflammatory and eosinophil chemotactic cytokines. Thus, murine T. canis infection may prove to be useful in understanding the role of cytokines in infection.
Collapse
Affiliation(s)
- Ney Roner Pecinali
- Laboratório de Imunofarmacologia, Departamento de Fisiologia e Farmacodinâmica e Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Sommerfelt IE, Rosa A, Duchene A, Degregorio O, López C, Pisanú A, De Torres R. Toxocara canis in experimentally infected pigs: migratory pattern and tissue lesions. Vet Parasitol 2004; 125:323-34. [PMID: 15482888 DOI: 10.1016/j.vetpar.2004.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Accepted: 07/14/2004] [Indexed: 10/26/2022]
Abstract
Fifteen Yorkshire female pigs were inoculated with 100,000 infective T. canis eggs. Three animals were used as uninfected controls. Groups of three infected pigs were euthanized by accepted methods on days 7, 14, 21, 28 and 126 p.i., respectively. Larvae were recovered from all animals included in each group slaughtered on days 7 and 14 p.i.; on day 21 p.i. from two pigs, on day 28 p.i. from one, and no larvae were found on day 126 p.i. Differences in the mean number of larvae per gram in lymph nodes, liver and lungs between slaughter days, were significant for livers on day 7 p.i. and for lungs on day 14 p.i. (P < 0.10). The decrease over time was significant in all the organs that previously had larvae. Larvae were not found in the other organs and tissues analysed. Macroscopical lesions were found in the liver, lungs and lymph nodes on days 7, 14, 21, and 28 p.i. The entire surface of the liver was covered with small white spots on day 7 p.i., on days 14 and 21 p.i. the spots were distinctly nodular and, in some places, individual lesions were confluent. Lesions had apparently started to heal on days 28 and 126 p.i. appearance was normal. Lymph nodes were enlarged and oedematous during the first 4 weeks and the lungs had small areas of consolidation visible all over the surface, but by day 126 p.i., no visible lesions could be seen. Microscopical lesions were observed in the liver on day 7 p.i., with a largely periportal hepatitis. Numerous eosinophils and lymphocytes were present. The typical granulomatous reaction was observed on days 14 and 21 p.i. with a central necrotic core and a narrow region of fibroblastic tissue. By day 28 p.i. lesions had almost disappeared and the number of eosinophils was fewer. There were fewer leukocytes and the fibrous tissue had disappeared from the liver on day 126 p.i. For the first 3 weeks, pictures of the lymph nodes and the lungs were characterised by the formation of a granuloma. In the center of the granuloma larvae were observed. The majority of the lesions had healed by day 126 p.i.
Collapse
Affiliation(s)
- I E Sommerfelt
- Departamento de Medicina Preventiva y Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Av. Chorroarín 280, 1427 Buenos Aires, Argentina.
| | | | | | | | | | | | | |
Collapse
|
21
|
Obwaller A, Duchêne M, Walochnik J, Wiedermann G, Auer H, Aspöck H. Association of autoantibodies against small nuclear ribonucleoproteins (snRNPs) with symptomatic Toxocara canis infestation. Parasite Immunol 2004; 26:327-33. [PMID: 15679629 DOI: 10.1111/j.0141-9838.2004.00716.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several studies have demonstrated the occurrence of autoantibodies in the course of infestations with helminth parasites and a number of target proteins have been identified. Sera from patients suffering from toxocarosis, a disease caused by the parasitic roundworm Toxocara canis, and from healthy individuals were tested for autoantibodies by immunofluorescence and immunoblot assays using HEp-2 cells as antigen. A considerable proportion of the sera from patients with toxocarosis-associated symptoms were autoantibody-positive, with a speckled staining pattern in the immunofluorescence test (62%) and with anti-snRNP reactivity in the immunoblot assay (98%). In contrast, significantly fewer sera from asymptomatic individuals scored positive in these assays (18% in the immunofluorescence test, P < 0.005; 24% in the immunoblot, P < 0.005). Although the causative link between Toxocara infestation and the occurrence of autoantibodies is still unclear, our results show that increased amounts of autoantibodies are associated with clinical symptoms of inflammation. Thus a serum test for autoantibodies in toxocarosis patients might be a valuable gatekeeper assay for the decision for or against anti-inflammatory treatment.
Collapse
Affiliation(s)
- Andreas Obwaller
- Department of Medical Parasitology, Clinical Institute of Hygiene and Medical Microbiology, Medical University of Vienna, Austria
| | | | | | | | | | | |
Collapse
|
22
|
Taira K, Saeed I, Permin A, Kapel CMO. Zoonotic risk of Toxocara canis infection through consumption of pig or poultry viscera. Vet Parasitol 2004; 121:115-24. [PMID: 15110409 DOI: 10.1016/j.vetpar.2004.01.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Revised: 12/30/2003] [Accepted: 01/12/2004] [Indexed: 12/01/2022]
Abstract
The potential zoonotic risk of Toxocara canis infections from consumption of swine or poultry viscera containing larvae was assessed using a pig model. Two groups of six pigs were fed either fresh swine viscera (group FS) or poultry viscera (FP) containing around 3500 Toxocara larvae. Another two groups of six pigs were fed swine viscera (PS) or poultry viscera (PP) preserved at 4 degrees C for 1 week. All pigs were necropsied 14 days after the exposure. Liver white spots were counted and T. canis specific IgG antibodies were measured by ELISA. Larval burdens were assessed in the mesenteric lymph nodes, liver, lungs, brain, tongue, and eyes. All recipient pigs exhibited several white spots on the liver surface and detectable antibody levels. Larvae were recovered predominantly from the lungs, but also from the mesenteric lymph nodes and the liver, a few larvae were found in the brain and tongue of the pigs. Two larvae were found in the eyes of two pigs in group FS. Mean percentages of total larval recoveries in groups FS, FP, PS, and PP were 75.3, 63.6, 42.6, and 18.8%, respectively. Significantly higher numbers of larvae were recovered from pigs given swine viscera than pigs given poultry viscera. The preservation at 4 degrees C for 1 week caused a significant reduction in the larval infectivity overall, nevertheless, the recoveries remained substantial. The fact that larvae migrating in swine or poultry organs and tissues have high infectivity in pigs even after preservation at 4 degrees C for 1 week, suggests that human infection with T. canis might easily occur following consumption of raw or undercooked dishes, either fresh or refrigerated, prepared from swine or poultry organs and tissues harbouring T. canis larvae.
Collapse
Affiliation(s)
- K Taira
- Danish Centre for Experimental Parasitology, Department of Veterinary Microbiology, The Royal Veterinary and Agricultural University, Dyrlaegevej 100, DK-1870 Frederiksberg C, Denmark.
| | | | | | | |
Collapse
|
23
|
Akao N, Tomoda M, Hayashi E, Suzuki R, Shimizu-Suganuma M, Shichinohe K, Fujita K. Cerebellar ataxia due to Toxocara infection in Mongolian gerbils, Meriones unguiculatus. Vet Parasitol 2003; 113:229-37. [PMID: 12719137 DOI: 10.1016/s0304-4017(03)00079-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We assessed the usefulness of gerbils as an experimental model for neurologic toxocarosis. Mongolian gerbils, Meriones unguiculatus, infected with Toxocara canis or Toxocara cati (1000 eggs/gerbil) showed progressive neurologic disorders from 50 days after infection in T. canis-infected gerbils or from 120 days after infection in T. cati-infected gerbils. The incidence of the onset was 6 of the 13 gerbils (49%) in the T. canis-gerbils and 5 of the 7 gerbils (71%) in the T. cati-gerbils. Histopathologically, the cerebellum was the most affected in both groups. We observed loss of Purkinje cells, glial nerve fibers, and nerve sheaths. We also found foci consisting of aggregated macrophages scattered in the white matter of the cerebellum. The affected gerbils showed ataxia and ultimately died of cachexia. Our findings suggest that irreversible neurologic toxocarosis in gerbils can be induced by infection with either T. canis or T. cati.
Collapse
Affiliation(s)
- Nobuaki Akao
- Section of Environmental Parasitology, Graduate School of Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8519, Japan.
| | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
A new scheme of clarifying clinical forms of toxocariasis is proposed to include: (i) systemic forms: classical VLM and incomplete VLM; (ii) compartmentalized forms: ocular and neurological toxocariasis; (iii) covert toxocariasis; and (iv) asymptomatic toxocariasis. The following markers are helpful in defining clinical forms namely, patient characteristics and history, clinical symptoms and signs, positive serology, eosinophilia and increased levels of IgE. Amongst the available drugs albendazole is the most commonly used, although other benzimidazole compounds have a similar efficacy. The recommended dose of albendazole is 15 mg kg(-1) body weight daily for 5 days and in some cases with VLM syndrome the treatment needs to be repeated. An evaluation of treatment efficacy can be made by observing a rise in eosinophilia within a week followed by any improvement in clinical symptoms and signs, lower eosinophilia and serological tests taken over a period of at least 4 weeks. In addition to clinical rationales for the specific treatment of VLM and OLM, preventive treatment needs to be considered bearing in mind the increasing risk of larvae localizing in the brain during the course of an infection. To reduce migration of Toxocara larvae a single course of albendazole is suggested in cases where eosinophilia and serology are at least moderately positive.
Collapse
Affiliation(s)
- Z Pawlowski
- University of Medical Sciences, Poznań, Poland.
| |
Collapse
|
25
|
Sommerfelt IE, Santillán G, Lopez C, Ribicich M, Franco AJ. Immunological and hematological response in experimental Toxocara canis-infected pigs. Vet Parasitol 2001; 96:127-34. [PMID: 11230919 DOI: 10.1016/s0304-4017(00)00423-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The relationship between the immunological and hematological response to infection was studied in pigs inoculated experimentally with Toxocara canis. Two groups of four pigs were infected with doses of 1000 and 2000 infective eggs, respectively. Two uninfected animals were used as negative controls. Blood samples were collected from each pig once a week. Serological examination by ELISA to determine antibody levels against T. canis L2/L3 excretory-secretory (ES) antigens showed values higher than the positive cut-off point (1:32) for both the infected groups. These values increased from day 7 p.i. and remained high during the experimental period until day 56. Significant differences were recorded for the two inoculating doses (p</=0.01) from day 14 to 42 p.i. Western blots run on day 7 p.i. with serum from the 2000 eggs group showed two polypeptide bands of 70 and 55kDa. These same bands were observed for both infected groups from day 15 p.i. until the end of the experiment. Eosinophil counts were significantly higher (p</=0.05) for both inoculated groups between weeks 2 and 7 p.i. as compared with the control group. No significant changes were observed for other blood parameters. The pig is a useful animal model since T. canis induces an early immunological response and ELISA can detect the presence of these antibodies against T. canis L(2)/L(3) ES antigens in animals inoculated with low doses of Toxocara eggs.
Collapse
Affiliation(s)
- I E Sommerfelt
- Departamento de Medicina Preventiva y Salud Pública, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Av. Chorroarín 280, 1427, Buenos Aires, Argentina.
| | | | | | | | | |
Collapse
|