RESUMEN
We examined 31 free-ranging coyotes (Canis latrans) from central Georgia, USA, for select parasites and viral agents. Sixteen coyotes had adult heartworms (Dirofilaria immitis). Serum samples from 27 animals revealed antibodies against canine parvovirus (100%), canine distemper virus (48%), canine adenovirus (37%), and Trypanosoma cruzi (7%); none were detected against Leishmania spp. Twenty-two of 24 (92%) coyotes were positive for Toxoplasma gondii. Real-time PCR of feces revealed 32% of coyotes were shedding canine parvovirus, and sequencing revealed type 2b and 2c. Because coyotes could be a spillover host of domestic dog (Canis lupus familiaris) pathogens, studies of the transmission of pathogens between coyotes and domestic dogs are warranted.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/veterinaria , Coyotes , Dirofilariasis/parasitología , Infecciones por Parvoviridae/veterinaria , Animales , Anticuerpos Antivirales/sangre , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/parasitología , Dirofilariasis/epidemiología , Reservorios de Enfermedades/veterinaria , Heces/virología , Femenino , Georgia/epidemiología , Masculino , Infecciones por Parvoviridae/epidemiología , Infecciones por Parvoviridae/virología , Parvovirus Canino/inmunología , Reacción en Cadena de la Polimerasa , Trypanosoma cruzi/inmunologíaRESUMEN
Collection of blood samples from veterinary and wildlife patients is often challenging because the samples have to be collected on farm or in the wild under various environmental conditions. This poses many technical problems associated with venipuncture materials, their safe use and disposal, transportation and processing of collected samples. Dried blood spot (DBS) sample collection techniques offer a simple and practical alternative to traditional blood collection methods to obtain blood samples from animals for parasite antibody evaluation. The DBS collection devices are compact, simple to use, and are particularly useful for large number of samples. Additionally, DBS samples take up less space and they are easier to transport than traditional venipuncture-collected blood samples. Visceral leishmaniasis (VL) is a potentially fatal parasitic disease of dogs and humans and it is frequently diagnosed by antibody tests. Immunochromatographic tests (ICT) for antibodies to Leishmania infantum are commercially available for dogs and they produce qualitative results in minutes. Measurement of canine antibodies to L. infantum with the ICT using traditional venipuncture has been validated previously, but the use of DBS samples has not been evaluated using this method. The purpose of the present study was to determine the ability of DBS samples to detect antibodies to L. infantum in dogs using a commercial ICT assay. One hundred plasma samples from dogs experimentally infected with the LIVT-1 strain of L. infantum were collected by venipuncture and frozen. Individual samples were thawed, and then 80 µl plasma (2 drops) was aliquotted onto the 8-spoked disk pad on individual DBS sample collection devices (HemaSpot™, Spot-On Sciences, Austin, TX), dried, and stored in the dark at room temperature. After one month and six months, respectively, 2 spokes of the 8 spokes of the disk pad of each DBS sample were removed and eluted in 200 µl PBS. The eluate was used to test for antibodies in the ICT and compared to ICT results using thawed plasma (same initial source). Sensitivity and specificity of the ICT using DBS were determined by using ICT results from traditional blood collection samples for comparison. After 1 month, DBS samples showed 100% sensitivity and specificity when compared to ICT results on thawed plasma samples collected by traditional venipuncture. After six months storage at room temperature, DBS samples demonstrated 79% sensitivity and 100% specificity compared to traditional blood collection. Results from this study indicate that dried blood spot collection may be a useful tool for screening dogs for antibodies to L. infantum with the ICT assay.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedades de los Perros/inmunología , Leishmania infantum/inmunología , Leishmaniasis Visceral/veterinaria , Animales , Enfermedades de los Perros/parasitología , Perros , Leishmania infantum/aislamiento & purificación , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/parasitología , Sensibilidad y EspecificidadRESUMEN
Toxocara canis is a zoonotic nematode parasite that can be transmitted to humans by food or water contaminated with T. canis eggs from infected dog feces. High-pressure processing (HPP) is a useful alternative to thermal treatments to eliminate pathogens from foods. Most of the research on HPP has focused on prokaryotes, but little is known about its effects on eukaryotic organisms. We evaluated the ability of HPP to affect embryonation of T. canis eggs to test the hypothesis that HPP treatment can delay development of T. canis eggs. Efficacy of HPP was determined by using an embryonation assay on T. canis eggs from naturally infected puppies. For each treatment, 2500 T. canis eggs in tap water were placed in sealable plastic bags and subjected to 138-400 megapascals (MPa; 1 MPa=10 atm=147 psi) for 60 s in a commercial HPP unit. We found that treatment with 300 or 400 MPa for 60 s killed 100% of eggs using embryonation as the standard. Treatment with 250, 241, and 207 MPa was less effective and killed 80%, 56%, and 8% of eggs, respectively. Results from this study suggest that HPP may be a useful treatment to protect foods from T. canis contamination.
Asunto(s)
Enfermedades de los Perros/parasitología , Contaminación de Alimentos/prevención & control , Óvulo/fisiología , Toxocara canis/fisiología , Toxocariasis/parasitología , Animales , Perros , Heces/parasitología , Manipulación de Alimentos/métodos , Humanos , Presión Hidrostática , Toxocara canis/embriologíaRESUMEN
Trypanosoma cruzi is a zoonotic parasite of humans and other mammalian hosts with distribution throughout the Americas. Domestic and wild canine species are reservoirs for human T. cruzi infections. The present study examined the prevalence of antibodies to T. cruzi in wild canids from the United States. Sera from 13 red foxes (Vulpes vulpes) and 263 coyotes (Canis latrans), originating in Pennsylvania and Tennessee, were assayed for antibodies to T. cruzi with immunochromatographic tests. Antibodies to T. cruzi were found in 2 of 276 (0.72%) of all wild canids tested. Both T. cruzi-positive wild canids were coyotes and represented 2 of 21 (9.52%) wild canids assayed from Tennessee. Antibodies to T. cruzi were not detected in red fox. Anti-T. cruzi antibodies were not found in any wild canids from Pennsylvania. These results suggest that coyotes are exposed to T. cruzi in Tennessee but not in Pennsylvania.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/veterinaria , Coyotes/parasitología , Zorros/parasitología , Trypanosoma cruzi/inmunología , Animales , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/inmunología , Coyotes/sangre , Zorros/sangre , Pennsylvania/epidemiología , Estudios Seroepidemiológicos , Tennessee/epidemiologíaRESUMEN
Visceral leishmaniasis (VL) is a zoonosis with worldwide distribution. Infections with the Leishmania donovani complex, including Leishmania infantum, cause the VL. Domestic dogs are the most important reservoir host for human VL, and wild canids are also susceptible. In the United States, infections with L. infantum are common in the foxhound dog breed. Little information is available regarding L. infantum in wild canids in the Unites States. Sera from 11 foxes and 256 coyotes originating in Pennsylvania and Tennessee (USA) were tested for antibodies to visceralizing Leishmania spp. with rapid immunochromatographic dipstick assays, which utilize recombinant antigen K39. Anti-Leishmania spp. antibodies were found in 5 of 267 (1.9%) of wild canids from Pennsylvania, including four coyotes and one red fox. These results suggest that wild canids are exposed to Leishmania spp. at a low level in the United States.
Asunto(s)
Coyotes , Zorros , Leishmania/inmunología , Leishmaniasis/veterinaria , Animales , Leishmaniasis/epidemiología , Leishmaniasis/parasitología , Pennsylvania/epidemiología , Tennessee/epidemiologíaRESUMEN
Leishmaniasis is an insect-transmitted parasitic disease with a worldwide distribution. Leishmania spp. infections cause a broad spectrum of clinical signs, ranging from skin lesions to fatal visceral disease. Dogs are a major reservoir host for visceral leishmaniasis in humans. While the disease is endemic in the Middle East and North Africa, little is known concerning canine Leishmania spp. infections in Egypt. Accordingly, blood samples were collected from 50 stray dogs in Giza, Egypt. Canine sera were tested for antibodies to visceralizing Leishmania spp. by commercial immunochromatographic strip assays based on recombinant antigen K39. Antibodies to Leishmania spp. were found in 5 of 50 (10%) of dogs tested from Egypt. Results from this study indicate that stray dogs are exposed to visceralizing Leishmania species in Egypt.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedades de los Perros/epidemiología , Leishmania/inmunología , Leishmaniasis/veterinaria , Animales , Cromatografía de Afinidad/veterinaria , Enfermedades de los Perros/parasitología , Perros , Egipto/epidemiología , Femenino , Leishmaniasis/epidemiología , Masculino , Estudios SeroepidemiológicosRESUMEN
Trypanosoma cruzi was demonstrated in blood smears and heart tissue from a 5-year old, female, English Cocker Spaniel that had never been outside of the state of Virginia, USA. Plasma from the dog was positive in a commercially available immunochromatographic dipstick assay for T. cruzi and negative in an immunochromatographic dipstick assay for visceral Leishmania spp. The plasma from the dog had an indirect immunofluorescent antibody titer of 1:800 against epimastigotes of T. cruzi while the titer was 1:50 against promastigotes of L. infantum. The parasite was isolated from the blood in vitro from the dog (TcVT-1 isolate) and used to experimentally infect female C3H and ICR mice. The parasite was nonpathogenic for experimentally inoculated mice. DNA was isolated from parasites grown in vitro and used to determine that the genotype of T. cruzi present in the dog was genotype TcIV. This genotype is common in raccoons, Procyon lotor, in North America and suggests that raccoons may serve as reservoirs for canine infection.
Asunto(s)
Enfermedad de Chagas/veterinaria , Enfermedades de los Perros/parasitología , Trypanosoma cruzi/aislamiento & purificación , Animales , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/parasitología , ADN Protozoario/genética , Enfermedades de los Perros/epidemiología , Perros , Femenino , Genotipo , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos ICR , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/genética , Trypanosoma cruzi/patogenicidad , Virginia/epidemiologíaRESUMEN
Feline intestinal trichomoniasis caused by Tritrichomonas foetus is associated with large bowel diarrhea in cats from many parts of the world. It has long been recognized as an economically important sexually transmitted disease that causes early abortion in cattle. Isolates of T. foetus from cattle are infectious for the large intestine of cats and isolates of T. foetus from cats are infectious for the reproductive system of cattle. The parasite is maintained by fecal-oral transmission in cats. The present study was conducted to examine the survival of a feline isolate of T. foetus, AUTf-12, under various conditions that are relevant to fecal-oral transmission in cats. Trophozoites were grown in TYM medium and then exposed to water, cat urine, dry cat food, canned cat food, clumping cat litter, or filter paper for various lengths of time and then re-cultured in TYM medium. Trophozoites survived exposure to distilled or tap water for 30 but not 60 min, while they survived for at least 180 min in urine. Trophozoites survived for 30 min on dry cat food but survived for 120-180 min in canned cat food. No survival of trophozoites was observed on cat litter but trophozoites survived for 15 min when placed on filter paper. Our results indicate that T. foetus can survive and be potentially infectious in water, urine, dry cat food and canned cat food.
Asunto(s)
Alimentación Animal/parasitología , Enfermedades de los Gatos/parasitología , Infecciones Protozoarias en Animales/parasitología , Tritrichomonas foetus/clasificación , Tritrichomonas foetus/fisiología , Animales , Enfermedades de los Gatos/orina , Gatos , Masculino , Tritrichomonas foetus/aislamiento & purificación , Trofozoítos/fisiologíaRESUMEN
High hydrostatic pressure processing (HPP) is an effective non-thermal treatment used to inactivate pathogens from a variety of food and food products. It has been extensively examined using prokaryotic organisms and protozoan's but has had limited study on metazoans. Treatment using HPP has been shown to be effective in inactivating nematode larvae in food and preventing embryonation of Ascaris suum eggs. We conducted experiments using eggs of the canine whipworm Trichuris vulpis collected from naturally infected dogs and A. suum eggs from naturally infected pigs. We observed a delay in development of eggs of T. vulpis in a preliminary experiment and conducted 2 experiments to test the hypothesis that appropriate HPP levels can induce a delay in embryonation of nematode eggs. In experiment 1, nonembryonated T. vulpis eggs in tap water were packaged in sealable bags and exposed to 138-600 megapascals (MPa; 1 MPa=10 atm=147 psi) for 60s in a commercial HPP unit. In a second experiment, nonembryonated eggs of A. suum were exposed to 138-600 MPa and treated for 60s in the same commercial HPP unit. Embyronation of T. vulpis eggs was delayed by 4 and 5 days for eggs treated with 207 and 241 MPa but eventually eggs developed and the numbers of embryonated eggs was similar to controls on day 55. Embryonation of T. vulpis eggs treated with 345 or 350 MPa was delayed by 9 days and never reached more than 5% of eggs embryonated. On day 55 post treatment, 95% of control nontreated T. vulpis eggs were embryonated, 100-65% of eggs treated with 138-276 MPa were embryonated, a maximum of 5% of eggs treated with 345-350 MPa were embryonated, and 0% of eggs treated with ≥ 400 MPa were embryonated. T. vulpis eggs treated with ≥ 400 MPa did not undergo cell division. Embryrnation of A. suum eggs was delayed by 4, 10, and 16 days for eggs treated with 207, 241, and 250MPa, respectively, compared to nontreated control eggs. A. suum eggs treated with 207 MPa eventually embryonated to similar % embryonation values as controls and 138 MPa treated eggs but eggs treated with 241 or 250 MPa were always <5% embryonated. A. suum eggs treated with ≥ 300 MPa did not undergo cell division. On the final day of examination at day 56 after treatment, the % of embryonated eggs was 92% nontreated controls, 94% treated with 138 MPa, 84% treated with 207 MPa, 2% treated with 241 or 250 MPa, and 0% treated with 276, 200, 345, 400, or 414 MPa, respectively.
Asunto(s)
Ascaris suum/fisiología , Óvulo/fisiología , Trichuris/fisiología , Animales , Ascaris suum/embriología , Manipulación de Alimentos/métodos , Presión Hidrostática , Trichuris/embriologíaRESUMEN
Besnoitia darlingi and Besnoitia neotomofelis are cyst-forming tissue apicomplexan parasites that use domestic cats (Felis domesticus) as definitive hosts and opossums (Didelphis virginiana ) and Southern Plains woodrats (Neotoma micropus) as intermediate hosts, respectively. Nothing is known about the prevalence of B. darlingi or B. neotomofelis in cats from the United States. Besnoitia darlingi infections have been reported in naturally infected opossums from many states in the United States, and B. neotomofelis infections have been reported from Southern Plains woodrats from Texas, but naturally infected cats have not been identified. The present study examined the IgG antibody response of cats to experimental infection (B. darlingi n â=â 1 cat; B. neotomofelis n â=â 3 cats). Samples from these cats were used to develop an indirect immunofluorescent antibody test (IFAT), which was then used to examine seroprevalence of IgG antibodies to tachyzoites of B. darlingi and B. neotomofelis in a population of domestic cats from Virginia (N â=â 232 cats) and Pennsylvania (N â=â 209). The serum from cats inoculated with B. darlingi or B. neotomofelis cross-reacted with each other's tachyzoites. The titers to heterologous tachyzoites were 1 to 3 dilutions lower than to homologous tachyzoites. Sera from B. darlingi- or B. neotomofelis-infected cats did not react with tachyzoites of Toxoplasma gondii or Neospora caninum or merozoites of Sarcocystis neurona using the IFAT. Antibodies to B. darlingi were found in 14% and 2% of cats from Virginia and Pennsylvania, respectively. Antibodies to B. neotomofelis were found in 5% and 4% of cats from Virginia and Pennsylvania, respectively. Nine cats from Virginia and 1 cat from Pennsylvania were positive for both.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedades de los Gatos/epidemiología , Coccidiosis/veterinaria , Sarcocystidae/inmunología , Animales , Anticuerpos Antiprotozoarios/biosíntesis , Enfermedades de los Gatos/parasitología , Gatos , Línea Celular , Chlorocebus aethiops , Coccidiosis/epidemiología , Reacciones Cruzadas , Técnica del Anticuerpo Fluorescente/veterinaria , Humanos , Ratones , Pennsylvania/epidemiología , Estudios Seroepidemiológicos , Organismos Libres de Patógenos Específicos , Virginia/epidemiologíaRESUMEN
Dogs are reservoir hosts for Trypanosoma cruzi , the causative agent of American trypanosomiasis. A rapid immunochromatographic dipstick test (ICT) is available commercially for canine serological testing. The ICT was developed with the use of sera from South American dogs, but it is not routinely used in the United States. We evaluated the utility of the ICT in detecting anti-T. cruzi antibodies in dogs from the United States. Dogs (N â=â 64) were experimentally infected with United States' isolates of T. cruzi from an opossum (Didelphis virginiana), an armadillo (Dasypus novemcinctus), and a domestic dog (Canis familiaris), and were tested after experimental infection. Sera from uninfected United States dogs (n â=â 79; hemaculture negative) were used as negative controls. In a blind study, sera were tested by the ICT and compared to the indirect immunofluorescent antibody test with the use of Brazil-strain epimastigotes as antigen. The sensitivity of the ICT was 91% and the specificity was 98% in dogs experimentally infected with United States isolates. Our study indicates that the ICT could be a useful screening tool for serological surveillance of canine T. cruzi exposure in the United States.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Armadillos/parasitología , Enfermedad de Chagas/veterinaria , Enfermedades de los Perros/diagnóstico , Zarigüeyas/parasitología , Trypanosoma cruzi/inmunología , Animales , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/inmunología , Cromatografía/métodos , Reacciones Cruzadas , Reservorios de Enfermedades , Enfermedades de los Perros/inmunología , Enfermedades de los Perros/parasitología , Perros , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Sensibilidad y EspecificidadRESUMEN
American trypanosomiasis and leishmaniasis are caused by related hemoflagellate parasites, Trypanosoma cruzi and Leishmania spp., which share several common host species. Both zoonotic protozoans are endemic in the United States. Canines, including domestic and wild canids, are reservoir hosts for human infections with T. cruzi and Leishmania spp. The present study examined the seroprevalence of T. cruzi and Leishmania spp. in wild canids from North Carolina and Virginia. Wild canine species tested in this work included 49 gray foxes (Urocyon cinereoargenteus) and 5 red foxes (Vulpes vulpes). Overall, sera samples from 54 foxes (North Carolina â=â 43; Virginia â=â 11) were tested by immunochromatographic strip assays (ICT). Antibodies to T. cruzi were found in 4 (9%) gray foxes from North Carolina and 2 (18%) gray foxes from Virginia. Antibodies to Leishmania spp. were detected in 1 (2%) gray fox from North Carolina. Our results indicate that wild canids are exposed more frequently to T. cruzi in North Carolina than Leishmania spp. and only T. cruzi in Virginia.
Asunto(s)
Enfermedad de Chagas/veterinaria , Zorros/parasitología , Leishmania/inmunología , Leishmaniasis/veterinaria , Trypanosoma cruzi/inmunología , Animales , Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/transmisión , Cromatografía/métodos , Cromatografía/veterinaria , Reservorios de Enfermedades/parasitología , Humanos , Leishmaniasis/epidemiología , Leishmaniasis/transmisión , North Carolina/epidemiología , Estudios Seroepidemiológicos , Virginia/epidemiología , ZoonosisRESUMEN
Pouco se sabe sobre a importância da capivara, Hydrochoerus hydrochaeris, como reservatórios de parasitas de zoonóticas ou
importância veterinária. Sera de 63 capivaras, de 6 municípios do Estado de Sa ~ o Paulo, Brasil, foram examinados para detecção de anticorpos
Trypanosoma cruzi, Leishmania infantum, Encephalitozoon cuniculi, Sarcocystis neurona e Neospora caninum utilizando uma indireta
teste de imunofluorescência. Cinco (8%) dos 63 capivaras tinham anticorpos para T. cruzi epimastigotas. Nenhuma das amostras de
capivara reagiram positivamente com promastigotas L. infantum ou com esporos de E. cuniculi. Dois (3%) das amostras de soro foram positivas
para anticorpos para S. neurona merozoítos, e 2 (3%) das amostras de soro foram positivas para anticorpos para N. caninum taquizoítos. A
amostra de soro a partir de 1 capivara foi positivo para anticorpos contra ambos T. cruzi e N. caninum. Nenhum dos restantes 62 amostras reagiram
com mais de um parasita.
OuvirLer foneticamente
Asunto(s)
Humanos , Trypanosoma , Trypanosoma cruzi , Anticuerpos , Leishmania , Leishmania donovaniRESUMEN
Little is known about the importance of capybara, Hydrochoerus hydrochaeris, as reservoirs for parasites of zoonotic or veterinary importance. Sera from 63 capybaras, from 6 counties in the state of São Paulo, Brazil, were examined for antibodies to Trypanosoma cruzi, Leishmania infantum, Encephalitozoon cuniculi, Sarcocystis neurona, and Neospora caninum using an indirect immunofluorescent antibody test. Five (8%) of the 63 capybaras had antibodies to T. cruzi epimastigotes. None of the samples from capybara reacted positively with L. infantum promastigotes or with spores of E. cuniculi . Two (3%) of the serum samples were positive for antibodies to S. neurona merozoites, and 2 (3%) of the serum samples were positive for antibodies to N. caninum tachyzoites. A serum sample from 1 capybara was positive for antibodies to both T. cruzi and N. caninum. None of the remaining 62 samples reacted with more than 1 parasite.
Asunto(s)
Enfermedad de Chagas/veterinaria , Coccidiosis/veterinaria , Encefalitozoonosis/veterinaria , Leishmaniasis Visceral/veterinaria , Enfermedades de los Roedores/epidemiología , Sarcocistosis/veterinaria , Animales , Anticuerpos Antifúngicos/sangre , Anticuerpos Antiprotozoarios/sangre , Brasil/epidemiología , Línea Celular , Enfermedad de Chagas/epidemiología , Chlorocebus aethiops , Coccidiosis/epidemiología , Reservorios de Enfermedades , Encephalitozoon cuniculi/inmunología , Encefalitozoonosis/epidemiología , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Leishmania infantum/inmunología , Leishmaniasis Visceral/epidemiología , Masculino , Neospora/inmunología , Roedores , Sarcocystis/inmunología , Sarcocistosis/epidemiología , Estudios Seroepidemiológicos , Trypanosoma cruzi/inmunologíaRESUMEN
Canine leishmaniasis and American trypanosomiasis (AT) are caused by related hemoflagellated parasites, Leishmania spp. and Trypanosoma cruzi, which share several common host species. Dogs are reservoirs for human infections by both pathogens. We determined the prevalence of antibodies to Leishmania spp. and T. cruzi in dogs from Grenada, West Indies. We examined 70 dog sera using the qualitative immunochromatographic dipstick tests (ICTs) based on recombinant antigens specific for visceral leishmaniasis and AT. Antibodies to visceral Leishmania were not detected in Grenadian dogs by ICT. Using the canine dipsticks for AT, antibodies to T. cruzi were determined in 3 (4.3%) of the 70 dogs. Results from this study indicate that dogs in Grenada are exposed in low levels to T. cruzi , but not to visceral Leishmania spp. at all.
Asunto(s)
Enfermedad de Chagas/veterinaria , Enfermedades de los Perros/epidemiología , Leishmaniasis Cutánea/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/epidemiología , Reservorios de Enfermedades , Enfermedades de los Perros/parasitología , Perros , Grenada/epidemiología , Leishmania/inmunología , Leishmaniasis Cutánea/epidemiología , Estudios Seroepidemiológicos , Pruebas Serológicas/métodos , Pruebas Serológicas/veterinaria , Trypanosoma cruzi/inmunologíaRESUMEN
We searched the National Cancer Institute (NCI) compound library for structures related to the antitumor quinoline NSC3852 (5-nitroso-8-quinolinol) and used a computer algorithm to predict the antiprotozoan activity for each of 13 structures. Half of these compounds inhibited Toxoplasma gondii tachyzoite propagation in human fibroblasts at < or =1 microM. The active compounds comprise a series of low-molecular-weight quinolines bearing nitrogen substituents in the ring-5 position. NSC3852 (EC(50) 80 nM) and NSC74949 (EC(50) 646 nM) were the most potent. NSC3852 also inhibited Plasmodium falciparum growth in human red blood cells (EC(50) 1.3 microM). To investigate the mechanism for NSC3852's anti-T. gondii activity, we used chemiluminescence assays to detect reactive oxygen species (ROS) formation in freshly isolated tachyzoites and in infected host cells; the absence of ROS generation by NSC3852 in these assays indicated NSC3852 does not redox cycle in T. gondii. Inhibitors of enzyme sources of free radicals such as superoxide anion, nitric oxide (NO), and their reaction product peroxynitrite did not interfere with the anti-T. gondii activity of NSC3852. However, inhibition of T. gondii tachyzoite propagation by NSC3852 involved redox reactions because tachyzoites were protected from NSC3852 by inclusion of the cell permeant superoxide dismutase mimetic, MnTMPyP, or N-acetylcysteine in the culture medium. We conclude that the Prediction of Activity Spectra for Substances (PASS) computer program is useful in finding new compounds that inhibit T. gondii tachyzoites in vitro and that NSC3852 is a potent T. gondii inhibitor that acts by indirect generation of oxidative stress in T. gondii.
Asunto(s)
Antiprotozoarios/farmacología , Hidroxiquinolinas/farmacología , Compuestos Nitrosos/farmacología , Plasmodium falciparum/efectos de los fármacos , Toxoplasma/efectos de los fármacos , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Antioxidantes/farmacología , Antiprotozoarios/química , Benzotiazoles , Línea Celular , Células Cultivadas , Diaminas , Eritrocitos/parasitología , Fibroblastos/parasitología , Colorantes Fluorescentes , Humanos , Hidroxiquinolinas/antagonistas & inhibidores , Óxido Nítrico/metabolismo , Compuestos Nitrosos/antagonistas & inhibidores , Compuestos Orgánicos , Pruebas de Sensibilidad Parasitaria , Plasmodium falciparum/crecimiento & desarrollo , Quinolinas/química , Quinolinas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Toxoplasma/crecimiento & desarrolloRESUMEN
Cases of visceral leishmaniasis, one of the most neglected tropical diseases, are increasing globally. Dogs are considered an important reservoir host for visceral leishmaniasis in people. The first cases of human visceral leishmaniasis in Vietnam have recently been reported. Blood samples were collected from 41 dogs in rural Vietnam. Sera were examined for antibodies to visceralizing Leishmania spp. by canine immunochromatographic strip assays based on recombinant K39 antigen. Antibodies to Leishmania spp. were not detected in any of the dogs tested. Results from this study suggest that rural dogs are not likely to be involved in the emergence of human visceral leishmaniasis in Vietnam.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Reservorios de Enfermedades , Enfermedades de los Perros/epidemiología , Leishmania/inmunología , Leishmaniasis Visceral/veterinaria , Animales , Reservorios de Enfermedades/parasitología , Enfermedades de los Perros/inmunología , Perros , Femenino , Humanos , Técnicas Inmunológicas/veterinaria , Leishmaniasis Visceral/epidemiología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/parasitología , Masculino , Salud Rural , Vietnam/epidemiologíaRESUMEN
There are 3 strains of Encephalitozoon cuniculi that occur in mammals. Strain III is associated with clinical disease in dogs, although some can be asymptomatic carriers and excrete spores in their urine. Several cases of human E. cuniculi infection caused by strain III have been observed in immunocompromised patients, indicating that E. cuniculi should be considered a zoonotic agent. Encephalitozoon cuniculi can cause fatal disease in maternally-infected or young dogs. Clinical signs in these animals included blindness, encephalitis, retarded growth rate, and nephritis. Encephalitozoon cuniculi has also been associated with primary renal failure in adult dogs. The present study used the direct agglutination test (DAT, cut-off 1:50) and the indirect fluorescent antibody test (IFAT, cut-off 1:10) to examine the prevalence of antibodies to E. cuniculi in dogs from Brazil and Colombia. Using the DAG, 31 (27.4%) of 113 dogs from Brazil and 47 (18.5%) of 254 dogs from Colombia were seropositive. Nine (14.3%) of 63 dogs from Brazil and 18 (35.3%) of the 51 dogs from Colombia were seropositive by indirect immunofluorescent antibody test. These results indicate that dogs from Brazil and Colombia are exposed to E. cuniculi.
Asunto(s)
Anticuerpos Antifúngicos/sangre , Enfermedades de los Perros/epidemiología , Encephalitozoon cuniculi/inmunología , Encefalitozoonosis/veterinaria , Pruebas de Aglutinación/veterinaria , Animales , Brasil/epidemiología , Línea Celular , Colombia/epidemiología , Enfermedades de los Perros/microbiología , Perros , Encefalitozoonosis/epidemiología , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Humanos , Estudios Seroepidemiológicos , Salud Urbana , Zoonosis/microbiología , Zoonosis/transmisiónRESUMEN
Old World cutaneous leishmaniasis is caused by infection with Leishmania major and Leishmania tropica. Pentamidine and related dications exhibit broad spectrum antiprotozoal activity. Based on the previously reported efficacy of these compounds against related organisms, 18 structural analogs of pentamidine were evaluated for in vitro antileishmanial activity, using pentamidine as the standard reference drug for comparison. Furan analogs and reversed amidine compounds were examined for activity against L. major and L. tropica promastigotes. The most active compounds against both Leishmania species were in the reversed amidine series. DB745 and DB746 exhibited the highest activity against L. major and DB745 was the most active compound against L. tropica. Both of these compounds exhibited 50% inhibitory concentrations (IC50) below 1 nM for L. major. Ten reversed amidines were also tested for their ability to inhibit growth in an axenic amastigote model. Nine of 10 reversed amidine analogs were active at concentrations below 1 nM. These results justify further study of dicationic compounds as potential new agents for treating cutaneous leishmaniasis.
Asunto(s)
Amidinas/farmacología , Antiprotozoarios/farmacología , Furanos/farmacología , Leishmania major/efectos de los fármacos , Leishmania tropica/efectos de los fármacos , Amidinas/química , Amidinas/toxicidad , Animales , Antiprotozoarios/toxicidad , Células Cultivadas , Furanos/química , Furanos/toxicidad , Humanos , Concentración 50 Inhibidora , Leishmania major/crecimiento & desarrollo , Leishmania tropica/crecimiento & desarrollo , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/parasitología , Masculino , Mioblastos/efectos de los fármacos , Pruebas de Sensibilidad Parasitaria , Pentamidina/farmacología , RatasRESUMEN
Wild canids are reservoir hosts for Leishmania infantum and Trypanosoma cruzi. The present study examined the prevalence of antibodies to these zoonotic parasites in a population of wild canids from a nonagricultural setting in South Carolina. Sera from 26 gray foxes (Urocyon cinereoargenteus) and 2 coyotes (Canis latrans) were examined for antibodies to L. infantum and T. cruzi using the indirect immunofluorescent antibody test and commercially available parasite-specific immunochromatigraphic strip assays. Antibodies to L. infantum were not detected by either assay in gray foxes or coyotes. Two (8%) of 26 gray foxes were positive in both the T. cruzi immunofluorescent antibody and strip assays. Antibodies to T. cruzi were not detected in coyotes. Results from this study indicate that wild canids are exposed to T. cruzi, but not L. infantum. in this geographic region.