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1.
Acta Parasitol ; 64(2): 352-359, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30941666

ABSTRACT

BACKGROUND: In tropical environments, abandoned animals can be an important source for human zoonotic infections, such as human visceral leishmaniasis and other vector-borne diseases. Here, we report the frequency of protozoan and helminth intestinal parasites in stray dogs, which might have an implication for human health in urban Brazilian settings. MATERIAL AND METHODS: We performed necropsies on 93 animals, euthanized due to canine visceral leishmaniasis control program, and examined their intestines looking for the presence of helminths; we determined the parasite load, and the elimination of eggs and cysts of protozoan parasites in fecal samples. Further, we performed serology tests for the detection of specific antibodies against Toxoplasma gondii. RESULTS: Overall, a high prevalence of intestinal parasites with potential for human zoonoses resulted and only 8.6% of examined intestines remained negative. The most prevalent helminths were Ancylostoma caninum and Dipylidium caninum. For nematodes, high worm burdens were detected for A. caninum and Trichuris vulpis. Additionally, we analyzed worm burdens and quantitative stool examinations, but found no significant association between positive serology for Leishmania infection and intestinal parasite burden. Interestingly, serology for T. gondii infection revealed a prevalence of 33.3% and a positive result was significantly associated with a higher A. caninum adult worm recovery (p = 0.0087). CONCLUSION: Our results showed stray dogs living in urban areas are heavily parasitized, which presents a potential risk for humans. Beyond the control of canine visceral leishmaniasis, we propose an improvement of the control program to reduce the risk for other parasitic diseases in dogs and humans.


Subject(s)
Dog Diseases/epidemiology , Dogs/parasitology , Intestinal Diseases, Parasitic/veterinary , Leishmaniasis, Visceral/veterinary , Animals , Animals, Wild/parasitology , Antibodies, Protozoan/blood , Brazil/epidemiology , Dog Diseases/diagnosis , Dog Diseases/parasitology , Feces/parasitology , Female , Humans , Intestinal Diseases, Parasitic/diagnosis , Intestinal Diseases, Parasitic/epidemiology , Intestines/parasitology , Leishmania , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/epidemiology , Male , Parasite Load , Prevalence , Urban Renewal , Zoonoses
2.
Int J Parasitol Parasites Wildl ; 7(3): 432-438, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30479944

ABSTRACT

Recent studies carried out in Brazil have shown that strains from the same Toxoplasma gondii genotype can infect humans, domestic animals (dogs and cats) and animals slaughtered for human consumption (pigs, sheep, goats, and chickens), suggesting a common infection route. However, little is known about the importance of free-living wild birds within this epidemiological context. The objective of this work was to isolate, genotype, and evaluate the virulence for mice of new isolates of T. gondii obtained from free-living wild birds from the state of Minas Gerais, Southeastern Brazil. From August 2016 to June 2017, T. gondii was isolated from the hearts and brains collected from 6 out of 45 free-living wild birds, namely, a roadside hawk (Rupornis magnirostris), a campo flicker (Colaptes campestris), a southern caracara (Caracara plancus) and a tropical screech-owl (Megascops choliba), all rescued in Belo Horizonte. One isolate was obtained from a toco toucan (Ramphastos toco), rescued in Cristiano Otoni, and another was obtained from southern caracara, rescued in Santa Luzia. Five different genotypes were identified by PCR-RFLP. A unique genotype was shared in two different isolates obtained from a southern caracara and a toco toucan. This genotype has never been previously described in any other host or place. Three isolates were classified as of intermediary virulence and three isolates as avirulent for mice. The combined analysis of alleles ROP18/ROP5 (a serine/threonine kinase, and a polymorphic pseudokinase, respectively) was effective in determining the virulence of five of all the isolates with the exception of that from R. magnirostris. Atypical isolates of T. gondii obtained from free-living wild birds rescued in the state of Minas Gerais share the same genotypes of strains that infect humans, domestic animals, and animals slaughtered for human consumption.

3.
Vet Parasitol ; 247: 19-25, 2017 Nov 30.
Article in English | MEDLINE | ID: mdl-29080759

ABSTRACT

Recent studies indicate that proteins GRA15, ROP5, ROP16, ROP17, and ROP18 of Toxoplasma gondii are involved in the process of interaction, cellular invasion, and immune response of the host. Among these proteins, alleles of the polymorphic ROP18 and ROP5 seem to be directly associated with T. gondii virulence in mice. The purpose of this work was to isolate and genotype T. gondii from pig, goat, and sheep slaughtered for human consumption in the state of Piauí, Northeastern Brazil and relate the variability of genes that express virulence proteins of the parasite to virulence in mice. T. gondii was isolated from 16 pigs and 9 goats. The parasite was not isolated from sheep samples. Eleven different genotypes were identified using PCR-RFLP. A unique genotype not yet described in any other host and or anywhere else was common to three pig isolates. Eighteen isolates (72%) were characterized as avirulent, four (16%) as intermediate virulence and three (12%) as virulent to mice. The combined analysis of ROP18 and ROP5 in the isolates studied in Piauí, showed four different allele associations: 4/3 (virulent strains), 3/3, 3/1, and 2/3 (avirulent strains). The association 2/3 was not previously described in the literature. Our results indicated that GRA15, ROP16, and ROP17 alleles were not associated with T. gondii virulence in mice. Pigs and goats raised and slaughtered for human consumption in the state of Piauí are infected with isolates of T. gondii presenting different genotypes. We concluded that the virulence protein ROP18, analyzed alone or in combination with ROP5, was effective in determining virulence for mice for the new isolates of T. gondii.


Subject(s)
Goat Diseases/parasitology , Protein Serine-Threonine Kinases/metabolism , Swine Diseases/parasitology , Toxoplasma/genetics , Toxoplasmosis, Animal/parasitology , Virulence Factors/metabolism , Alleles , Animals , Biomarkers , Female , Genotype , Genotyping Techniques/veterinary , Goats , Mice , Mice, Inbred BALB C , Phylogeny , Protein Serine-Threonine Kinases/genetics , Protozoan Proteins/genetics , Protozoan Proteins/metabolism , Sequence Analysis, DNA/veterinary , Swine , Toxoplasma/isolation & purification , Toxoplasma/metabolism , Toxoplasma/pathogenicity , Virulence , Virulence Factors/genetics
4.
J Parasitol ; 102(1): 157-60, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26418172

ABSTRACT

Genotyping of Toxoplasma gondii is traditionally performed using DNA obtained from tachyzoites after isolation by bioassay in mice. In this study, genotyping of T. gondii was performed by multiplex nested polymerase chain reaction restriction fragment length polymorphism (Mn-PCR-RFLP) in DNA obtained from the lungs of experimentally infected mice, the hearts of naturally infected free-range chickens, and human blood samples of newborns with congenital toxoplasmosis. The efficiency of Mn-PCR varied according to the marker. We obtained complete genotypes of all of the mice lung samples. In chickens, total or partial genotyping was performed on all of the 15 samples. Two complete genotypes were obtained, including one identified for the first time, and another previously described in different hosts including dogs, cats, and humans. In blood from infants, partial genotypes were obtained in 8 of the 12 samples. Mouse bioassay is the most efficient method to obtain DNA from T. gondii , but direct tissue genotyping enhances the likelihood of obtaining molecular information on T. gondii and is an effective tool as a complement to isolation in mice. In this study, we genotyped Toxoplasma gondii directly from human (blood samples of newborns with congenital toxoplasmosis) and free-range chickens (hearts) by Mn-PCR-RFLP. We present partial and complete genotypes and provide technical and scientific information about T. gondii genotyping methods.


Subject(s)
Genotype , Genotyping Techniques/methods , Toxoplasma/classification , Toxoplasmosis, Animal/parasitology , Toxoplasmosis, Congenital/parasitology , Amniotic Fluid/chemistry , Animals , Biological Assay , Brazil , Cats , Chickens , DNA, Protozoan/blood , DNA, Protozoan/cerebrospinal fluid , Dogs , Genetic Markers , Humans , Infant, Newborn , Mice , Toxoplasma/genetics
5.
Res Vet Sci ; 94(3): 587-9, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23395253

ABSTRACT

Genotyping of Toxoplasma gondii in different regions of Brazil has shown high diversity and high frequency of virulent genotypes among Brazilian animals. The aim of the study was to characterize samples of T. gondii isolates obtained from naturally infected sheep, goats, pigs and free-range chickens slaughtered for human consumption in Rio Grande do Norte, Northeast Brazil. Nineteen T. gondii samples (isolated from 1 goat, 5 pigs and 13 free-range chickens) were genotyped. Six different genotypes were identified, including two novel genotypes. The archetype genotypes, i.e., types I, II and III, were not found. In mice, seventeen isolates (89.5%) were classified as virulent, and only two (10.5%) were classified as avirulent. This study displays the genotypic variability of the parasite in Northeast Brazil.


Subject(s)
Toxoplasma/genetics , Toxoplasmosis, Animal/epidemiology , Animals , Brazil/epidemiology , Chickens/parasitology , Enzyme-Linked Immunosorbent Assay/veterinary , Genotype , Goat Diseases/epidemiology , Goat Diseases/parasitology , Goats/parasitology , Mice/parasitology , Poultry Diseases/epidemiology , Poultry Diseases/parasitology , Sheep/parasitology , Sheep Diseases/epidemiology , Sheep Diseases/parasitology , Swine/parasitology , Swine Diseases/epidemiology , Swine Diseases/parasitology , Toxoplasmosis, Animal/parasitology
6.
Parasitol Int ; 62(2): 181-8, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23269201

ABSTRACT

Conversion of Toxoplasma gondii tachyzoites to the bradyzoite stage and tissue cyst formation in the life cycle of the parasite have crucial roles in the establishment of chronic toxoplasmosis. In this work we investigated the in vitro cystogenesis and behavior of the EGS strain, isolated from human amniotic fluid. We observed that tachyzoites of the EGS strain converted to intracellular cysts spontaneously in LLC-MK2 epithelial cells, HSFS fibroblasts and C6 glial cell lineage. The peak of conversion occurred in the LLC-MK2 cells after 4days of infection, when 72.3±15.9 of the infected cells contained DBA positive cysts. Using specific markers against bradyzoite, tachyzoite and cyst wall components, we confirmed stage conversion and distinguished immature from mature cysts. It was also observed that the deposition of cyst wall components occurred before the total conversion of parasites. Transmission electron microscopy confirmed the fully conversion of parasites presenting the typical characteristics of bradyzoites as the posterior position of the nucleus and the presence of amylopectin granules. A thick cyst wall was also detected. Besides, the scanning microscopy revealed that the intracyst matrix tubules were shorter than those from the parasitophorous vacuole intravacuolar network and were immersed in a granular electron dense material. The EGS strain spontaneously forms high burden of cysts in cell culture without artificial stress conditions, and constitutes a useful tool to study this stage of the T. gondii life cycle.


Subject(s)
Life Cycle Stages , Toxoplasma/growth & development , Toxoplasmosis/parasitology , Amniotic Fluid/parasitology , Animals , Brazil , Cells, Cultured , Humans , Microscopy, Electron, Transmission , Toxoplasma/isolation & purification , Toxoplasma/ultrastructure
7.
Parasite ; 19(3): 249-57, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22910667

ABSTRACT

The aim of this study was to verify the effect of immunosuppression by cyclophosphamide (Cy) on susceptibility of BALB/c mice subjected to challenge with recombinant strains of Toxoplasma gondii. Animals were prime infected with the D8 (recombinant I/III) or the ME49 (type II) non-virulent strains, weekly immunosuppressed with Cy and challenged with the CH3 or EGS virulent strains (I/III). Parasites recovered from surviving mice were submitted to PCR-RFLP analysis to confirm co-infection. Prime-infection with the D8 strain conferred more protection against challenge with the CH3 and EGS strains when compared with ME49 prime infection. Cy treatment caused significant leukopenia in the infected mice, what probably favors reinfection after challenge. Reinfection was associated with increased levels of IgA. Otherwise, Cy-treated mice presented significantly lower IgA levels after challenge, suggesting involvement of this immunoglobulin on protection against reinfection. In conclusion, BALB/c mice susceptibility to reinfection by T. gondii is related to genetic differences among the strains used for primary and challenge infections. Alteration of the host's immune integrity by Cy probably compromises the protection previously established by primary infection.


Subject(s)
Cyclophosphamide/therapeutic use , Immunocompromised Host , Immunosuppressive Agents/therapeutic use , Toxoplasma/drug effects , Toxoplasmosis, Animal/immunology , Animals , Antibodies, Protozoan/blood , Brain/parasitology , Chickens , Cyclophosphamide/pharmacology , DNA, Protozoan/chemistry , Disease Models, Animal , Dogs , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulins/blood , Immunosuppressive Agents/pharmacology , Leukocyte Count , Mice , Mice, Inbred BALB C , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Toxoplasma/genetics , Toxoplasma/immunology , Toxoplasmosis, Animal/drug therapy , Toxoplasmosis, Congenital/parasitology
8.
Vet Parasitol ; 160(3-4): 225-9, 2009 Mar 23.
Article in English | MEDLINE | ID: mdl-19091475

ABSTRACT

The objective of this work was to carry out a study on caprine toxoplasmosis in the state of Minas Gerais, Brazil. To determine the prevalence of toxoplasmosis in goats in Minas Gerais, 767 sera from goats were tested by ELISA (enzyme-linked immunosorbent assay) and IFAT (indirect fluorescence antibody test). The prevalence of antibodies to Toxoplasma gondii was 43.0% and 46.0% by ELISA and IFAT, respectively. It was observed that 26.8% of the goats show low-avidity IgG to T. gondii. These results suggest the presence of animals in recent phase of toxoplasmosis in Minas Gerais. The risk factors for toxoplasmosis in goats were: age over 36 months (OR=1.21; IC 95% 1.02-1.44), use of pen (OR=1.83; IC 95%1.01-3.31) and pure breed animals (OR=2.49; IC 95% 1.11-5.59).


Subject(s)
Antibodies, Protozoan/blood , Goat Diseases/epidemiology , Toxoplasma/immunology , Toxoplasmosis, Animal/epidemiology , Age Factors , Animals , Brazil/epidemiology , Breeding , Confidence Intervals , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Fluorescent Antibody Technique, Indirect/methods , Fluorescent Antibody Technique, Indirect/veterinary , Goats , Immunoglobulin G/blood , Male , Odds Ratio , Risk Factors , Seroepidemiologic Studies
9.
Arq. bras. med. vet. zootec ; 60(1): 36-41, fev. 2008. tab
Article in English | LILACS | ID: lil-483255

ABSTRACT

In order to identify possible risk factors for T. gondii infection in goat herds in Ceará, Brazil, 2362 serum samples were tested by ELISA. The serological prevalence was 25.1 percent. The risk factors identified for Toxoplasma gondii infection in goat herds were age, number of cats, use of wooden feeding troughs and absence of feeding troughs. Goats older than 37 months had 2.01 (CI 95 percent; 1.55 - 2.61) higher risk of infection than younger animals. Greater risk of infection was observed in farms with more than 10 cats (OR = 1.73; CI 95 percent; 1.01 - 3.33). The use of wooden feeding troughs represented a high probability of infection (OR = 7.81; CI 95 percent; 1.66 - 36.67). The lack of feeding troughs also represented a high probability of infection (OR = 5.50; CI 95 percent; 1.24 - 24.39).


Com o objetivo de se identificarem os fatores de risco associados à presença de infecção por toxoplasmose em rebanhos caprinos no estado do Ceará, Brasil, soros sanguíneos de 2362 caprinos foram testados por meio de ELISA. A prevalência estimada pelo ELISA foi 25,1 por cento. Os fatores de risco identificados nas propriedades foram: idade dos animais, número de gatos, comedouro manufaturado de madeira e ausência de comedouro. Em caprinos com mais de 37 meses de idade o risco de estarem infectados pelo T. gondii foi 2,01 vezes maior (IC 95 por cento; 1,55 - 2,61) que em animais mais jovens. Maior risco de infecção foi observado em fazendas com mais de 10 gatos (OR = 1,73; IC 95 por cento 1,01 - 3,33). Quando a propriedade utilizava comedouros de madeira, o risco de estarem infectados foi também maior (OR = 7.81; IC 95 por cento; 1.66 - 36.67). Animais oriundos de propriedades sem comedouro também apresentaram alto risco de infecção (OR = 5.50; IC 95 por cento; 1,24 - 24,39).


Subject(s)
Animals , Enzyme-Linked Immunosorbent Assay , Goats , Risk Factors , Toxoplasma/isolation & purification , Toxoplasmosis, Animal/epidemiology
10.
Micron ; 38(7): 729-33, 2007.
Article in English | MEDLINE | ID: mdl-17596951

ABSTRACT

Ocular toxoplasmosis is present in 20% of infected immunocompetent individuals. Toxoplasmosis is the most common cause of posterior uveitis in immunocompetent subjects and congenital toxoplasmosis transmission was the first parasite to be linked to human lesions in the eye. An experimental model for congenital ocular toxoplasmosis was developed in C57BL/6 mice with the purpose to evaluate Toxoplasma induced ocular pathology during fetal life. Toxoplasma gondii, ME-49 strain, was used to infect pregnant females. Histological analysis of pre-natal fetal eyes from infected female mice, did not show parasite infestation, however, alterations were observed in the outer nuclear layer (ONL) and in the inner nuclear layers (INL) of the retina. Edema was also observed, characterized by the increase of interstitial spaces forming lacunae between the ONL and INL cells and a net of vessels associated with an intense inflammatory infiltrate. These histological observations suggest that ocular lesions are not delayed manifestations of toxoplasmosis. The eye was affected in the initial phase of disease, and these alterations were of similar nature as those observed in mice at later stages of infection.


Subject(s)
Embryo, Mammalian/pathology , Toxoplasmosis, Ocular/congenital , Toxoplasmosis, Ocular/pathology , Animals , Disease Models, Animal , Female , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Pregnancy , Retina/pathology
11.
Parasite ; 13(2): 143-9, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16800123

ABSTRACT

In an attempt to isolate and characterize Toxoplasma gondii from the State of Minas Gerais, Brazil, musculature samples from 72 pigs, 25 dogs, 28 free-range chickens and 50 chickens produced in industrialized farms were collected. Antibodies to T. gondii have not been detected in pigs, but were found in nine (40.9 %) out of 22 dogs, and in 15 (53.6 %) of 28 free range chickens. T. gondii was not isolated from pigs and industrialized chickens, but from eight dogs and 11 free range chickens. In order to determine T. gondii virulence, female BALB/c mice were inoculated with 10(3), 10(2), 10(1) and 10(0) tachyzoites of the 19 isolates. The strains RH (virulent) and ME49 (non-virulent) were used as references. Isolates were divided into three groups according to the virulence phenotype: five isolates were classified into virulent in mice, one into non-virulent and 13 into intermediate virulent. Nested-PCR of T. gondii SAG2 locus amplified DNA from 21 out of 22 DNA samples directly extracted from heart of free range chickens. These samples were genotyped through a PCR-RFLP assay. Seventeen (80.9 %) were classified into type I; one (4.8 %) into type III and three (14.3 %) into type I or II.


Subject(s)
Chickens/parasitology , Dog Diseases/parasitology , Poultry Diseases/parasitology , Swine Diseases/parasitology , Toxoplasma , Toxoplasmosis, Animal/parasitology , Animals , Antibodies, Protozoan/blood , Biological Assay , Brazil/epidemiology , DNA, Protozoan/analysis , Dog Diseases/epidemiology , Dogs , Female , Genotype , Male , Mice , Mice, Inbred BALB C , Muscle, Skeletal/parasitology , Polymerase Chain Reaction/veterinary , Polymorphism, Restriction Fragment Length , Poultry Diseases/epidemiology , Prevalence , Swine , Swine Diseases/epidemiology , Toxoplasma/genetics , Toxoplasma/immunology , Toxoplasma/isolation & purification , Toxoplasma/pathogenicity , Toxoplasmosis, Animal/epidemiology , Virulence
12.
Parasite ; 12(2): 171-7, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15991831

ABSTRACT

The efficacy of atovaquone and sulfadiazine was examined alone or in combination for the treatment of mice infected with six Brazilian Toxoplasma gondii strains previously genotyped using the PCR-RFLP assays of the SAG2 gene, in addition to RH strain. Swiss mice were infected intraperitoneally with 10(2) tachyzoites from each strain of T. gondii and treated with 6.25, 12.5, 25 and 50 mg/Kg/day of atovaquone or 40, 80, 160 and 320 mg/Kg/day of sulfadiazine. In a second experiment, mice were treated with the association of previously determined doses of each drug. Treatment started 48 hours post-infection, and lasted 10 days. The susceptibility of T. gondii to atovaquone and to sulfadiazine was different according to the parasite strain. It was observed strains that are susceptible to atovaquone, and strains that are resistant to it. Type I strains were more susceptible to the activity of sulfadiazine and more resistant to atovaquone. Yet type III strains were susceptible to atovaquone and to sulfadiazine. Association of atovaquone and sulfadiazine presented a synergic effect in the treatment of mice infected with RH type I strain and an additive effect in the treatment of mice infected with one type I strain and with two type III strains.


Subject(s)
Coccidiostats/therapeutic use , Naphthoquinones/therapeutic use , Sulfadiazine/therapeutic use , Toxoplasma/drug effects , Toxoplasmosis, Animal/drug therapy , Animals , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Atovaquone , Coccidiostats/pharmacology , Dose-Response Relationship, Drug , Drug Combinations , Drug Synergism , Female , Genotype , Mice , Naphthoquinones/pharmacology , Random Allocation , Sulfadiazine/pharmacology , Toxoplasma/genetics , Toxoplasma/growth & development , Treatment Outcome
13.
Parassitologia ; 45(2): 61-70, 2003 Jun.
Article in English | MEDLINE | ID: mdl-15266998

ABSTRACT

The diversity among coccidian parasites of the genus Besnoitia is incompletely known. Of the eight currently described members of the genus, only B. jellisoni is known to parasitize a rodent host. Here, we propose a new name, Besnoitia akodoni, for the species initially isolated form the rodent Akodon montensis in Brazil. The tissue cysts of B. akodoni were up to 442 microm in diameter and bradyzoites were 8.4 x 1.4 microm in size. The bradyzoites contained enigmatic bodies, micronemes and rhoptries. Tachyzoites were 5.8 x 1.5 microm in size and they could be grown in vitro in bovine monocytes and African Green monkey cells where they divided by endodyogeny. Besnoitia akodoni was infective to laboratory-raised mice (Mus musculus) and gerbils (Meriones unguiculatus) but not to cats (Felis catus). Comparison of the conserved sequences of the small subunit rDNA clearly established the close relationship of B. akodoni with other members of the genus. However, sequences of the more variable first internal transcribed spacer portion of the ribosomal DNA repeat support its differentiation from the other species of the genus.


Subject(s)
Coccidiosis/veterinary , Muridae/parasitology , Sarcocystidae/isolation & purification , Animals , Brazil , Cats/parasitology , Coccidiosis/parasitology , Feces/parasitology , Gerbillinae/parasitology , Mice , Muscle, Skeletal/parasitology , Raptors/parasitology , Sarcocystidae/genetics , Sarcocystidae/growth & development , Sarcocystidae/ultrastructure , Sequence Alignment , Species Specificity
14.
Parasite ; 9(3): 261-9, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12375370

ABSTRACT

The effect of 14 natural and synthetic naphthoquinones in the replication of Toxoplasma gondii was evaluated. In vitro studies were accomplished in cultures of 2C4 fibroblasts infected with RH-strain. Enzyme-linked immunosorbent assay was used to quantify parasite growth. For the studies in vivo, mice were infected with tachyzoites of the RH strain or cysts of the T. gondii EGS strain. In vitro, seven naphthoquinones demonstrated significant inhibition of intracellular T. gondii growth at concentrations of 1 and 5 micrograms/ml. Only three compounds were significantly protective when tested in animals: 2-hydroxy-3'-(3'-pentenyl)-1,4-naphthoquinone (PHNQ4), 2-hydroxy-3-(1'-vinylphenyl)-1,4-naphthoquinone (PHNQ5), and 2-hydroxy-3-(1'-propen-3'-phenyl)-1,4-naphthoquinone (PHNQ6). In animals infected with the EGS strain and treated with PHNQ4 (50 mg/kg/day orally), a 7-day prolongation of the time to death was observed. Treatment with 100 mg/kg/day orally or 50 mg/kg/day i.p. of PHNQ5 resulted in a 5-day and 16-day prolongation of the time to death, respectively. Treatment with 50 mg/kg/day orally or 50 mg/kg/day i.p. of PHNQ6 resulted in a 4-day prolongation of the time to death or up to 30 days after treatment, respectively. Our results suggest that the naphthoquinones may be important therapeutic agents for the treatment of toxoplasmosis.


Subject(s)
Antiprotozoal Agents/pharmacology , Naphthoquinones/pharmacology , Toxoplasma/drug effects , Toxoplasmosis, Animal/drug therapy , Animals , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/therapeutic use , Disease Models, Animal , Dose-Response Relationship, Drug , Enzyme-Linked Immunosorbent Assay , Female , Fibroblasts/drug effects , Fibroblasts/parasitology , Humans , Mice , Naphthoquinones/chemical synthesis , Naphthoquinones/therapeutic use , Toxoplasma/growth & development
15.
Vet Parasitol ; 106(1): 83-7, 2002 May 30.
Article in English | MEDLINE | ID: mdl-11992714

ABSTRACT

Seven cross-bred dogs were inoculated with Angiostrongylus vasorum and serum samples were analyzed using the enzyme-linked immunosorbent assay (ELISA) and Western blot (WB). ELISA detected specific antibodies anti-A. vasorum, from 14 to 28 days after inoculation (DAI) and persisted throughout the experiment. Using WB, the main antigens detected had molecular weight of approximately 115, 102, 86, 76, 69, 56, 41, 32, 28, 20-22 and 10kDa.


Subject(s)
Angiostrongylus/immunology , Dog Diseases/immunology , Dog Diseases/parasitology , Strongylida Infections/veterinary , Angiostrongylus/growth & development , Animals , Antibodies, Helminth/blood , Antigens, Helminth/blood , Blotting, Western/veterinary , Dogs , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Random Allocation , Strongylida Infections/blood , Strongylida Infections/immunology , Strongylida Infections/parasitology
16.
Mem. Inst. Oswaldo Cruz ; 95(1): 121-6, Jan.-Feb. 2000. tab, ilus
Article in English | LILACS | ID: lil-251324

ABSTRACT

In a study of congenital transmission during acute infection of Toxoplasma gondii, 23 pregnant Balb/c mice were inoculated orally with two cysts each of the P strain. Eight mice were inoculated 6-11 days after becoming pregnant (Group 1). Eight mice inoculated on the 10th-15th day of pregnancy (Group 2) were treated with 100 mg/kg/day of minocycline 48 h after inoculation. Seven mice inoculated on the 10th-15th day of pregnancy were not treated and served as a control (Group 3). Congenital transmission was evaluated through direct examination of the brains of the pups or by bioassay and serologic tests. Congenital transmission was observed in 20 (60.6 per cent) of the 33 pups of Group 1, in one (3.6 per cent) of the 28 pups of Group 2, and in 13 (54.2 per cent) of the 24 pups of Group 3. Forty-nine Balb/c mice were examined in the study of congenital transmission of T. gondii during chronic infection. The females showed reproductive problems during this phase of infection. It was observed accentuated hypertrophy of the endometrium and myometrium. Only two of the females gave birth. Our results demonstrate that Balb/c mice with acute toxoplasmosis can be used as a model for studies of congenital T. gondii infection. Our observations indicate the potential of this model for testing new chemotherapeutic agents against congenital toxoplasmosis.


Subject(s)
Animals , Female , Pregnancy , Mice , Minocycline/therapeutic use , Pregnancy Complications , Tetracyclines/therapeutic use , Toxoplasmosis, Congenital/drug therapy , Uterus/pathology , Blotting, Western , Chronic Disease , Endometrium/pathology , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique, Indirect , Hypertrophy , Mice, Inbred BALB C , Myometrium/pathology , Toxoplasmosis, Congenital/immunology , Toxoplasmosis, Congenital/prevention & control
17.
Arq. bras. med. vet. zootec ; 46(4): 369-79, ago. 1994. ilus, tab
Article in Portuguese | LILACS | ID: lil-240221

ABSTRACT

Acompanhou-se a evoluçäo da infecçäo por Strongyloides papillosus em 14 caprinos sem raça definida, de três a seis meses de idade, inoculados com 3.000 larvas infectantes por kg de peso vivo. Os resultados mostraram que a suscetibilidade ao parasita näo está relacionada com a idade do animal, mas que o período de eliminaçäo de ovos de S. papillosus foi mais longo nos animais mais jovens. A necrópsia foram observadas alteraçöes histopatológicas que caracterizam enterite catarral aguda com pronunciada exulceraçäo simples da mucosa. A pesquisa de anticorpos da classe IgC, pelo ELISA, mostrou que esses anticorpos foram detectados a partir do 20§ dia após a inoculaçäo (DAI) até o 200§ DAI, quando os animais foram necropsiados. Os níveis máximos de anticorpos (título variando entre 1:5.120 a 1:40.960) foram observados entre o 30§ e o 130§ DAI


Subject(s)
Animals , Goats , Strongyloides , Enzyme-Linked Immunosorbent Assay/veterinary
18.
Arq. bras. med. vet. zootec ; 45(4): 361-8, ago. 1993. tab
Article in Portuguese | LILACS | ID: lil-240138

ABSTRACT

Toxoplasma gondii foi demonstrado em órgäos de 10 entre 12 caprinos inoculados pela via subcutânea com 10 elevado à sétima potência taquizoítos de uma cepa de virulência moderada do T. gondii (C4). O parasito näo foi demonstrado em órgäos de duas cabras näo gestantes que já apresentavam anticorpos anti-T. gondii antes do inóculo, mas foi evidenciado em uma cabra gestante que apresentava estes anticorpos previamente. Os órgäos mais frequentemente parasitados foram cérebro, coraçäo, músculo esquelético e diafragma. Um animal sacrificado no 60§ dia após a inoculaçäo (DAI) apresentou 91 por cento dos órgäos positivos, enquanto outro sacrificado no 561§ DAI, apresentou 17 por cento dos órgäos positivos. A presença do parasita em órgäos de caprinos com 505 a 561 dias de infecçäo indica a importância da carcaça destes animais na transmissäo da toxoplasmose devido ao costume comum de consumo desta carne no Brasil e em outras partes do mundo


Subject(s)
Animals , Goats/parasitology , Toxoplasma
19.
Arq. bras. med. vet. zootec ; 45(2): 173-82, abr. 1993. ilus, tab
Article in English | LILACS | ID: lil-240048

ABSTRACT

Foi avaliada a reaçäo imunoenzimática dot-ELISA, no imunodiagnóstico da toxoplasmose caprina, considerando a reaçäo de Imunofluorescência Indireta (RIFI) como reaçäo de referência. Para a avaliaçäo da dot-ELISA discos de nitrocelulose foram sensibilizados com 0,1 microgramas de proteína/ml de uma soluçäo antigênica obtida através da sonicaçäo de taquizoitas de Toxoplasma gondii. Esta concentraçäo antigênica foi considerada ótima na discriminaçäo de soros reagentes e näo reagentes. Foram testadas 169 amostras de soro, destas 115 (68 por cento) foram reagentes a antígenos de T. gondii, com títulos de anticorpos variando entre 1/16 e 1/16:384, quando testadas através da reaçäo de Imunofluorescência Indireta (RIFI); na dot-ELISA, 119 (70 por cento) foram positivas, com título variando entre 1/16 e 1/65.536. A comparaçäo entre as técnicas mostra os seguintes índices: co-positividade (sensibilidade) 0,89, co-negatividade (especificidade) 0,98, e Youden (concordância) 0,93, quando foi utilizado o título de 1/16 como discriminatório de reaçöes positivas e negativas. Utilizando como discriminatório o título de 1/64, os índices calculados foram co-positividade 0,97, co-negatividade 0,96 e Youden 0,93. Os resultados mostram a possibilidade da utilizaçäo da dot-ELISA no imunodiagnóstico da toxoplasmose caprina. A introduçäo desta reaçäo no imunodiagnóstico da toxoplasmose seria de grande importância, principalmente em estudos soro-epidemiológicos, já que a técnica pode ser realizada sob condiçöes de campo, pois nenhum equipamento especial é requerido para a sua execuçäo


Subject(s)
Animals , Goat Diseases/diagnosis , Enzyme-Linked Immunosorbent Assay/veterinary , Goats , Toxoplasmosis, Animal/diagnosis
20.
Arq. bras. med. vet. zootec ; 44(6): 501-12, dez. 1992. ilus, tab
Article in Portuguese | LILACS | ID: lil-240168

ABSTRACT

Onze cabras gestantes sem raça definida foram inoculadas pela via subcutânea com 10 elevado à sétima potência taquizoítos de uma cepa de virulência moderada do Toxoplasma gondii (CA). Duas cabras gestantes foram usadas como controle näo inoculados. Foi observado transmissäo congênita do T. gondii em sete das oito cabras inoculadas entre o 52§ e o 67§ dia de gestaçäo (cinco abortos e dois partos normais com filhotes debilitados). Três cabras inoculadas entre o 100§ e o 133§ dia de gestaçäo pariram crias aparentemente normais, apesar da ocorrência de transmissäo congênita em um dos animais. Foi possível ainda evidenciar a transmissäo congênita do parasita em uma entre quatro cabras avaliadas em duas gestaçöes sucessivas. As cabras controle pariram crias aparentemente normais, não infectadas pelo T. gondii


Subject(s)
Animals , Female , Pregnancy , Goat Diseases/diagnosis , Goats , Toxoplasmosis/transmission
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