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Dwight D Bowman - One of the best experts on this subject based on the ideXlab platform.
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The anatomy of the third-stage larva of Toxocara canis and Toxocara cati.
Advances in parasitology, 2020Co-Authors: Dwight D BowmanAbstract:Abstract This review describes the morphology and ultrastructure of the third-stage larva of Toxocara canis, the larval stage that hatches from the egg and persists in the tissues of various paratenic hosts including infected humans. This larva remains unchanged as it passes from host to host and lives for extended periods in this same body form until it makes its way to the gastro-intestinal tract of its final host. There has been less work on the anatomy and ultrastructure of the larva of Toxocara cati, but overall, it appears very similar to that of T. canis with the only apparent difference being that the larva is a few microns thinner in diameter. The paper describes the anatomy and ultrastructure of the larva and the various major structures of the various body systems including the cuticle, hypodermis, the nervous tissue, oesophagus and the lumen-free intestine, and the large excretory gland cell that fills much of the pseudocoel and which appears to be the source of the components that are recognized immunologically by the infected host. It is suggested that further detailed studies on the larva could provide significant information that would allow a greater understanding of how the larva persists within these hosts and may provide information that would make the larva an excellent link to work on nematode anatomy that would link the work being done with this model system to that of Caenorhabditis elegans and the large amount of historical work already performed on adult ascaridoid nematodes.
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visceral larval migrans of Toxocara canis and Toxocara cati in non canid and non felid hosts
2020Co-Authors: Timothy Wu, Dwight D BowmanAbstract:Abstract Toxocara canis and Toxocara cati are considered the most ubiquitous gastrointestinal helminths in domesticated canids and felids. Ascarid eggs passed in the faeces of canids and felids in a suitable environment may remain infective for years and are capable of infecting not only canids and felids, but a large range of other vertebrate paratenic hosts, including man. Infection with Toxocara species also occurs following the ingestion of paratenic hosts containing infective larvae. As infective larvae are incapable of completing their lifecycle in these hosts, they instead travel to different parts of the body, sometimes inducing inflammatory responses, and in some cases remaining entrapped in the body for years. Migration routes depend on the host species; however, nearly all organs may be affected with varying quantities of larval burdens.
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Efficacy of a milbemycin oxime-praziquantel combination product against adult and immature stages of Toxocara cati in cats and kittens after induced infection
Veterinary Parasitology, 2006Co-Authors: Rudolf Schenker, Dwight D Bowman, Christian Epe, R. Cody, Wolfgang Seewald, G. Strehlau, Pablo JunqueraAbstract:Abstract Two studies were performed to examine the efficacy of milbemycin oxime against fourth-stage larvae or adults of Toxocara cati . In the study to determine efficacy against fourth-stage larvae, 20 domestic shorthair cats were inoculated with 500 embryonated eggs. Four weeks after inoculation, the animals were allocated to two groups, and cats in one group were treated with medicated tablets containing 4 mg milbemycin oxime and 10 mg praziquantel (MILBEMAX ® ) and cats in the other group with placebo tablets. Seven days after treatment the animals were euthanatized and necropsied for worm counting. The number of worms found was significantly ( p = 0.0002) lower in cats treated with medicated tablets than in cats treated with placebo tablets. The reduction in the number of worms was 96.53%. In the study to determine efficacy against mature adult worms, 13 kittens were inoculated with T. cati embryonated eggs. On day 45 after inoculation and after the infection had been confirmed through faecal examinations for 11 out of the 13 animals, the 11 infected animals were allocated to two groups and treated as in the first study. Seven days after treatment, all animals were euthanatized and necropsied for worm counting. The number of worms found was significantly ( p = 0.0043) lower in kittens treated with medicated tablets than in kittens treated with placebo tablets. The reduction in the number of worms was 95.90%. No adverse effects were recorded during either study. It is concluded that the milbemycin oxime–praziquantel tablets that were used are efficacious for the control of T. cati infections in cats.
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efficacy of selamectin against experimentally induced and naturally acquired infections of Toxocara cati and ancylostoma tubaeforme in cats
Veterinary Parasitology, 2000Co-Authors: Tom L Mctier, J A Wren, D J Shanks, G Pengo, T G Rowan, Clark D Smothers, John W Mccall, Dwight D Bowman, Antoinette D JerniganAbstract:Abstract The efficacy of selamectin against experimentally induced and naturally acquired infections of adult ascarids (Toxocara cati) and adult hookworms (Ancylostoma tubaeforme) was evaluated in five controlled studies in cats. Two studies evaluated the efficacy of selamectin against both ascarid (natural or induced) and hookworm (induced) infections; two studies evaluated the efficacy of selamectin against single natural infections of T. cati or A. tubaeforme; and the fifth study evaluated the efficacy of selamectin against induced infections of A. tubaeforme. Cats received selamectin topically in unit doses designed to deliver a minimum of 6 mg kg−1. Treatments were applied to the skin on each animal’s back at the base of the neck in front of the scapulae. For experimentally induced infections, cats were inoculated orally with approximately 500 embryonated eggs of T. cati 56 days prior to treatment and/or approximately 150–250 larvae (L3) of A. tubaeforme 30 or 42 days prior to treatment. For both induced and naturally acquired infections, cats were allocated randomly to treatments (6–12 cats per treatment) on the basis of fecal egg counts to receive either selamectin or a vehicle containing the inert formulation ingredients. In all studies, adult worm counts were performed at necropsy 14 days after the last treatment administration. Against T. cati, a single application of selamectin provided a 100% reduction in the geometric mean number of adult worms for both experimentally induced and naturally acquired infections. Against A. tubaeforme, a single administration of selamectin provided a 99.4% reduction in the geometric mean number of adult worms in cats with natural infections, and an 84.7–99.7% reduction in adult worms in cats with induced infections. Two doses of selamectin administered at monthly intervals provided a 91.9% reduction in the geometric mean number of adult A. tubaeforme worms in cats with experimentally induced infections. The geometric mean numbers of adult worms (T. cati and A. tubaeforme) from selamectin-treated cats were significantly (P≤0.0018) lower than for vehicle-treated cats in all studies. Thus, a single topical unit dosage providing a minimum dosage of 6 mg kg−1 selamectin was highly effective in the treatment of naturally acquired and experimentally induced infections of T. cati and A. tubaeforme in cats.
Kensuke Taira - One of the best experts on this subject based on the ideXlab platform.
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Detection of larvae of Toxocara cati and T. tanuki from the muscles of free-ranging layer farm chickens
Parasitology Research, 2021Co-Authors: Natsuki Okada, Hong-kean Ooi, Kensuke TairaAbstract:Although raw or undercooked livestock meat or viscera has been suggested to be a source of human toxocariasis, there have been few reports on the prevalence of Toxocara larvae in the tissue of livestock animals. To investigate the presence of Toxocara larvae in chickens, we examined 50 culled chickens from a commercial layer farm. The liver, breast meat, and thigh meat were separated individually and artificially digested to examine for the presence of larvae. Nematode larvae were detected in 2 out of 50 chickens. One larva was detected from the breast meat, and it was molecularly identified as Toxocara tanuki . The other from the thigh meat of another chicken was molecularly identified as Toxocara cati . The present study demonstrated for the first time that T. tanuki larvae do infect chickens in the natural environment. The fact that Toxocara spp. larvae were found in muscles of farm chickens suggests that consumption of raw or undercooked chicken meat may present a risk for human toxocariasis.
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Toxocara cati larval migration to mouse fetuses through transplacental infection.
Veterinary parasitology, 2021Co-Authors: Natsuki Okada, Hong-kean Ooi, Kensuke TairaAbstract:Abstract To examine the Toxocara cati larval migration in mouse fetuses through vertical transmission, 7 pregnant mice were orally inoculated with 5000 embryonated eggs at day 4 and again with the same dose at day 9 of gestation (total 10,000 eggs / mouse). Seven non-pregnant mice of the same age were also inoculated likewise. All mice were necropsied 12 days after the first inoculation with eggs. The carcass, viscera, uterus, placenta and fetuses were individually removed and digested with pepsin for larval counts. Larvae were recovered from all pregnant and non-pregnant mice. The majority of the larvae were recovered from the carcass, and some from the viscera, uterus, placenta and fetuses. There were no differences between the pregnant and non-pregnant mice for the number of larvae in the carcass, viscera and uterus. Of a total of 103 fetuses from the 7 pregnant mice, larvae were recovered from 74 fetuses (71.8 %). The mean number of larvae recovered per infected fetus was 2.6 (n = 103), and the maximum number of larvae recovered in a fetus was 9. This study showed that most mouse fetuses were infected with T. cati larvae through intrauterine transmission, although the number of larvae was low. Since no significant difference in the number of larvae recovered from the pregnant and non-pregnant mice was observed, it is suggested that pregnancy does not directly affect the vertical transmission of T. cati larvae.
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Effect of low temperatures on the infectivity of Toxocara cati larvae parasitized in mouse tissues
Helminthologia, 2013Co-Authors: Kensuke Taira, Natsuki Okada, V. Šnábel, Yasuhide SaitohAbstract:The infectivity of Toxocara cati larvae in mouse tissues, following storage at 4 °C and −25 °C, was measured using a bioassay in mice. Tissues of donor mice infected with 30-day-old T. cati larvae were stored at 4 °C for 7 and 14 days, and at −25 °C for 24 hours, then tissue larvae were inoculated into recipient mice (n = 6/group). After 15 days, larval burden in recipient mice was assessed by digestion. In the control group, a mean of 42.0 % of the inoculated larvae were established in mice. Storage of tissues at 4 °C for 7 and 14 days did not affect larval infectivity; means of 43.5 % and 37.4 % of inoculated larvae, respectively, were established in mice. Larvae exposed to −25 °C for 24 hours did not establish in mice, except for one larva recovered from a single mouse. These results may support the potential of tissue larvae in livestock animals as a causative agent of human toxocarosis.
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High infectivity of Toxocara cati larvae from muscles of experimentally infected rats.
Veterinary Parasitology, 2013Co-Authors: Kensuke Taira, Tomonori Yanagida, Naoko Akazawa, Yasuhide SaitohAbstract:Abstract The organ distribution of Toxocara cati larvae in albino rats Rattus norvegicus (n = 6/group) experimentally inoculated with 1000 embryonated eggs was examined 1, 2, 3, 7, 30, 90, and 180 days post inoculation (dpi), and the infectivity of recovered larvae was evaluated by bioassay in mice. The intestines, liver, lungs, muscles (carcass) and other organs (heart, brain, spleen, kidneys and genital organs) were digested for larval recovery. Larvae were recovered from all rats, with the mean number of recovered larvae ranging from 13.3 at 1 dpi to 135.6 at 90 dpi. Most of the larvae recovered were detected in the intestines (56.3%) and liver (43.8%) at 1 dpi; liver (21.6%) and lungs (69.6%) at 2 dpi; muscles (45.9%) and lungs (36.9%) at 3 dpi. Subsequently, most of larvae were recovered from muscles at 7 dpi (92.5%), 30 dpi (97.8%), 90 dpi (99.4%) and 180 dpi (99.1%). In the mouse bioassay, 43.8% of 90-day-old larvae and 43.0% of 180-day-old larvae recovered from rats established in mice. The present study demonstrated that T. cati larvae persist predominantly in rat muscles and nearly half of them retain infective for at least half a year. The results indicate that R. norvegicus may be a suitable paratenic host of T. cati under natural conditions.
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tolerance to low temperatures of Toxocara cati larvae in chicken muscle tissue
Veterinary Parasitology, 2012Co-Authors: Kensuke Taira, Yasuhide Saitoh, Natsuki Okada, Hiromu Sugiyama, C M O KapelAbstract:Abstract Infectivity of Toxocara cati larvae in muscle tissue of chickens after storage at 4 °C and −25 °C was assessed in a mouse bioassay to provide information on the risk of meat-borne toxocarosis. Muscle tissue samples of 30-day old T. cati infections were stored at 4 °C for 14 and 28 days and at −25 °C for 12, 24 and 48 h, whereafter, larvae were released by digestion. For each experimental group, the released larvae were inoculated in six mice. After 15 days, mice were euthanized and larval burden was assessed by digestion. In the control group (no storage of the infected chicken meat), 47.9% of the inoculated larvae established in mice, whereas storage of meat at 4 °C for 14 days or 28 days reduced the recovery to 24.1% or 3.3%, respectively. Muscle larvae exposed to −25 °C for 12, 24 or 48 h did not establish in the mice. The observation that larvae retain infective after refrigeration at exposure in 4 °C for 28 days, emphasize the zoonotic potential of poultry meat as a causative agent of human toxocarosis.
C. Epe - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the efficacy of emodepside plus praziquantel topical solution against ascarid infections (Toxocara cati or Toxascaris leonina) in cats
Parasitology Research, 2005Co-Authors: C. R. Reinemeyer, S. D. Charles, J. Buch, T. Settje, G. Altreuther, L. Cruthers, J. W. Mccall, D. R. Young, C. EpeAbstract:Eleven controlled studies were conducted in the United States and Europe to evaluate the efficacy of a topical solution of emodepside (3 mg/kg)+praziquantel (12 mg/kg) (Profender^®, Bayer AG, Leverkusen, Germany) against infection with various stages of the ascarid nematodes Toxocara cati and Toxascaris leonina . Infections were induced by administration of larvated ascarid eggs, and stage–specific efficacy was evaluated by treating cats at scheduled intervals post–inoculation. All studies featured random allocation to treatment groups, placebo–treated control animals and assessment of outcome measures by masked personnel. The product (emodepside+praziquantel topical solution) was 100% effective against mature adults and immature adult T. cati . In addition, it was 96.8% effective against third stage larvae and at least 99.4% effective against fourth stage larvae of T. cati , respectively. Efficacy against mature, immature adult and L4 stages of T. leonina exceeded 93.4%, but regulatory “adequacy of infection” criteria were not met in sorne studies. No adverse reactions to treatment were noted in cats treated with the emodepside+praziquantel topical solution.
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Vertical transmission of Toxocara cati Schrank 1788 (Anisakidae) in the cat
Parasitology Research, 2004Co-Authors: N. Coati, T. Schnieder, C. EpeAbstract:In eight cats and their offspring the mode of transmission of Toxocara cati following natural and experimental infection was investigated in three experiments. In experiments 1 and 2 the kittens of four cats with a chronic natural infection and of four cats with an acute experimental infection, respectively, were examined. In experiment 3 two queens of experiment 2 were mated again to examine whether in the adult cat “dormant” larvae exist in the tissue, that can be reactivated during pregnancy or lactation to infect the offspring. Additionally, the muscle tissue and organs of two adult cats, one with chronic one with acute infection, were examined for hypobiotic larvae. Pre-natal infections with T. cati did not occur in experiments 1 or 2. In none of the kittens that were examined directly after birth were larvae found. In the offspring of experiment 1 one single larva of T. cati was found 28 days post-partum. Whereas in the kittens of experiment 2 up to 333 larvae were found in one animal. Lactogenic transmission of larvae occurs after acute infection of the queen during late pregnancy but not during chronic natural infection. There is no evidence for the existence of arrested somatic larvae in the adult cat as an important host-finding strategy in the life cycle of T. cati . Following milk-borne infections, the majority of larvae seem to undergo direct development in the intestine without tracheal migration. Only a small number of larvae was found in other organs.
Mohammad Zibaei - One of the best experts on this subject based on the ideXlab platform.
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Modified method to enhanced recovery of Toxocara cati larvae for the purposes of diagnostic and therapeutic.
Experimental parasitology, 2016Co-Authors: Mohammad Zibaei, Soji UgaAbstract:Abstract Human toxocariasis, extraintestinal-migration of Toxocara species, is a worldwide helminthic zoonosis in many places of the undeveloped countries. Toxocara cati is one of the common helminths in cats and it is a potentially preventable disease. Its diagnosis and treatment depend on the demonstration of specific excretory-secretory Toxocara antibodies from Toxocara larvae by immunological assays. This study provides a simple manual technique which can be performed in any laboratory for recovering a large number of Toxocara cati larvae from the thick-shelled eggs. The devices that are required contain a manual homogenizer and a filter membrane of 40 μm mesh; the rest of materials and solutions is standard laboratory ware. In the modified method the larval yields were 2.7 times higher (3000 larval/ml) and the time spent in performing the modified method was shorter (75 min). Further benefits over already techniques are the easy and repeatable, inexpensive and convenient materials, simplicity to perform and require less time for recovery of Toxocara cati larvae for subsequent cultivation and harvest of the larval excretory-secretory antigens for diagnostic or treatment purposes.
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Toxocara cati larvae in the eye of a child: a case report.
Asian Pacific journal of tropical biomedicine, 2014Co-Authors: Mohammad Zibaei, Seyed Mahmoud Sadjjadi, Seyed Hamidreza Jahadi-hosseiniAbstract:Toxocariasis is a consequence of human infection by Toxocara larvae. There are symptomatic (visceral, ocular) and asymptomatic course of toxocariasis. The ocular form is very rare. We present a 6-year-old patient who developed an ocular form of toxocariasis caused by Toxocara cati. He demonstrated lesions in the peripheral retina of the right eye. White granuloma was present in the superior peripheral retina. A positive immunological assay for toxocariasis essentially completed the outcomes. On the basis of clinical manifestations and conducted examinations, a diagnosis of ocular form of toxocariasis was established. Albendazole and corticosteroids were applied in treatment. Current results clearly highlight the usefulness of excretory-secretory antigens derived from larvae of Toxocara cati for the fine diagnosis ocular larva migrans caused by Toxocara larvae.
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A Comparative Histopathology, Serology and Molecular Study, on Experimental Ocular Toxocariasis by Toxocara cati in Mongolian Gerbils and Wistar Rats
BioMed research international, 2013Co-Authors: Mohammad Zibaei, Seyed Mahmoud Sadjjadi, Soji Uga, A. Oryan, Mehdi Karamian, Seyed Hamidreza Jahadi-hosseiniAbstract:The aim of this study was to compare the performance of three in-house diagnostic tests, that is, histopathology, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR), for the diagnosis after experimental infection with Toxocara cati. Twenty Mongolian gerbils and Wistar rats were divided into ten groups (/group). Toxocara cati infections were established in Mongolian gerbils and Wistar rats by administering doses of 240 and 2500 embryonated Toxocara cati eggs by gavage, respectively. Tissue sections were stained with Haematoxylin and Eosin and observed under the light microscope. Sera and vitreous fluid collected from separate infected groups were tested against Toxocara cati antigens, for 92 days postinfection. Genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) blocks, and aqueous fluids belong to the animals. The histopathology test gave negative results among the groups of animals examined between 5 and 92 days postinfection. The ELISA results showed that anti-Toxocara antibodies have risen between 7 and 61 days postinfection in sera and vitreous fluid in the animals infected, respectively. Analysis of PCR products revealed positive band (660 bp) in the orbital tissue infected Mongolian gerbils at 5 days postinfection. Of the three evaluated methods, the PCR could be recommended for scientific and laboratory diagnoses of toxocariasis in experimentally infected animals.
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Experimental Toxocara cati Infection in Gerbils and Rats
The Korean journal of parasitology, 2010Co-Authors: Mohammad Zibaei, Seyed Mahmoud Sadjjadi, Soji UgaAbstract:Mongolian gerbils and Wistar rats were inoculated orally with 240 and 2,500 Toxocara cati embryonated eggs, respectively, to evaluate the larval recovery in different tissues and organs, such as the liver, lungs, heart, kidney, and skeletal muscles after 5, 30, 49, 70, and 92 days post-infection (PI). Larval recovery rates were 1.7-30.0% in Mongolian gerbils on days 5-92 PI and 0.2-3.8% in rats on the same days. These results indicate that Mongolian gerbils and Wistar rats are suitable experimental paratenic hosts for the study of neurological toxocariasis as well as visceral toxocariasis.
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production of monoclonal antibody against Toxocara cati second stage larvae and its application for the detection of circulating antigens
Hybridoma, 2010Co-Authors: Mohammad Zibaei, Seyed Mahmoud Sadjjadi, Satoko Ishiyama, Bahador Sarkari, Soji UgaAbstract:Toxocariasis is an important zoonotic disease caused by the second-stage larvae of Toxocara species. Human toxocariasis is usually diagnosed by serological methods. We prepared monoclonal antibody specific for Toxocara cati (T. cati) and performed the following experiments using this antibody to increase the sensitivity of our capture ELISA for antigen detection. The isotype of monoclonal antibody was IgG3. Using this monoclonal antibody, a capture ELISA was developed. The produced monoclonal antibody reacted well with excretory-secretory (ES) antigen of T. cati with protein nature but not with other T. cati related antigens. A monoclonal antibody was raised against ES antigen of T. cati larval stage. No cross-reaction was found with antigens of Ascaris suum, Dirofilaria immitis, Trichostrongylus orientalis, encysted larvae of Trichinella spiralis, and metacercariae of Centrocestus armatus. The system had enough sensitivity to detect 5 ng/mL of circulating antigens in the serum. The results indicate that ...
Irma Sommerfelt - One of the best experts on this subject based on the ideXlab platform.
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Humoral immune response of pigs infected with Toxocara cati.
Experimental parasitology, 2020Co-Authors: Maria Florencia Sierra, Gerardo Ricoy, Sonia Sosa, Silvia Beatriz Colavecchia, Graciela Santillán, Clara Maria López, Silvia Leonor Mundo, Irma SommerfeltAbstract: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.
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A Toxocara cati eggs concentration method from cats' faeces, for experimental and diagnostic purposes.
Experimental parasitology, 2014Co-Authors: Natalia Marina Cardillo, Irma Sommerfelt, A Rosa, Mariano Emmanuel Ercole, Mariana Ines Pasqualetti, Fernando Adrián Fariña, Matías Gastón Pérez, Miriam Mabel RibicichAbstract:Abstract Toxocariosis is a zoonotic parasite infection worldwide distributed, now considered a neglected disease associated to poverty. For experimental infection in animals and to develop the diagnosis in humans it is necessary to obtain large number of Toxocara spp. larval eggs. Toxocara cati eggs recovered percentage from faeces of infected cats was determined employing a novel egg concentration method. The McMaster egg counting technique and the concentration method were applied on 20 positive cats’ sample faeces obtained from naturally infected cats. The mean percentage of eggs recovered by the concentration method was 24.37% higher than the count obtained by McMaster egg counting technique. The main advantage of this method is that it can be obtained a small final volume with a high number of recovered eggs and a good quality inoculum for experimental and diagnostic purposes.
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EXPERIMENTAL INFECTION WITH Toxocara cati IN PIGS: MIGRATORY PATTERN AND PATHOLOGICAL RESPONSE IN EARLY PHASE
Revista do Instituto de Medicina Tropical de Sao Paulo, 2014Co-Authors: Irma Sommerfelt, Clara Maria López, Natalia Marina Cardillo, Betina Daprato, Adriana Duchene, A. FrancoAbstract:Se realizo la infeccion experimental de doce cerdos con aproximadamente 100.000 huevos infectivos de Toxocara cati. Los huevos de T. cati utilizados en la inoculacion fueron recolectados de heces felinas. Otro grupo de tres cerdos no infectados se utilizo como control. Grupos de cerdos infectados se eutanaciaron a los 7,14,21 y 28 dias posinoculacion (pi). Se tomaron muestras de tejidos para digestion y evaluacion de cambios histopatologicos en la etapa temprana de la infeccion. El numero de larvas recuperadas de los pulmones se incremento en los dias 7 y 14 pi, recuperandose tambien los dias 21 y 28 pi. Se encontraron larvas de T. cati en los linfonodulos del intestino delgado y grueso los dias 7,14 y 28 pi y los dias 7,14,21 y 28 pi respectivamente. En los restantes tejidos estudiados o no se recuperaron larvas o los valores fueron menores a una larva por gramo de tejido. La respuesta patologica observada en el higado y los pulmones a los 7 y 14 dias posinoculacion, mostro en la superficie del higado manchas blancas y en los pulmones areas de consolidacion. Los pulmones presentaron una reaccion inflamatoria con presencia de larva en el centro en el dia 28 pi. En el higado se observo una hepatitis periportal y perilobular. Los linfonodulos del intestino presentaron una linfoadenitis eosinofilica con un centro reactivo conteniendo formas parasitarias en algunos de ello. En ninguno de los tejidos se observo la tipica reaccion granulomatosa. El rol de los restantes tejidos examinados fue de menor significancia. Queda evidenciada la importancia de este parasito como un agente etiologico que desarrolla la enfermedad en hospederos paratenicos.
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persistencia de la contaminacion ambiental por huevos de Toxocara cati en un espacio publico argentina
Una Salud, 2011Co-Authors: Betina Daprato, Natalia Marina Cardillo, Martin Kunic, Yanina Berra, Irma SommerfeltAbstract:Toxocara cati es el parasito gastrointestinal mas frecuente en el felino. Los adultos producen huevos que son eliminados con la materia fecal al ambiente, en el cual evolucionan hasta el estadio infestante. En las urbes existen poblaciones felinas que habitan espacios publicos que les ofrecen albergue y proteccion, lo cual conlleva situaciones de riesgo de transmision de zoonosis prevalentes para otros hospedadores. El objetivo del presente trabajo fue estudiar la persistencia de la contaminacion ambiental por huevos de T. cati a lo largo de un ano, en un sitio publico de la Ciudad Autonoma de Buenos Aires, donde se observo la presencia de una poblacion felina estable. Se realizo un muestreo mensual de materia fecal recogida del ambiente desde agosto del 2009 a julio del 2010. Las muestras fueron analizadas por la tecnica de Benbrook y se constato la viabilidad de las larvas por microscopia optica. El promedio de muestras positivas fue de 48,47 (95% IC = 41,79 - 55,16) y no presento diferencias estadisticamente significativas en funcion de los meses del ano (F = 6,13; p = 0,1480), aunque se observo una mayor proporcion de muestras positivas en los meses mas calidos. En las areas urbanas es necesario educar a la poblacion humana sobre el riesgo de transmision de zoonosis por parte de los felinos. Las organizaciones de salud deben actuar en esta direccion para prevenir la transmision y controlar las poblaciones felinas.
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experimental infection with Toxocara cati in balb c mice migratory behaviour and pathological changes
Zoonoses and Public Health, 2009Co-Authors: Natalia Marina Cardillo, A Rosa, M. Ribicich, Clara M. López, Irma SommerfeltAbstract:Summary 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.