RESUMEN
Toxoplasma gondii is a coccidian that infects almost all warm-blooded animals, including birds. Rocas Atoll Biological Reserve, located in the northeast of Brazil, is the only atoll in the South Atlantic, and home to the largest population of seabirds in the western Atlantic. In this study the occurrence of T. gondii antibodies in seabirds from Rocas Atoll were determined. Birds were manually captured, blood samples were taken, and antibodies detected by the modified agglutination test (>5). In total, 267 birds of seven species belonging to three families (Sternidae, Fregatidae and Sulidae) and two orders (Charadriiformes and Suliformes) were sampled. Out of the 267 samples, 20 (7.3%) were seropositive: nine out of 48 brown noddies (Anous stolidus), one out of 26 black noddies (Anous minutus), three out of 20 magnificent frigatebirds (Fregata magnificens), five out of 95 sooty terns (Onychoprion fuscatus) and two out of 20 red-footed boobies (Sula sula). None of the 33 masked boobies (Sula dactylatra) and the 25 brown boobies (Sula leucogaster) were seropositive. The antibody titers were 5 (n=6), 10 (n=4), 20 (n=3), 40 (n=6) and 160 (n=1). Due to the uniqueness of this environment, monitoring the seabirds is suggested to maintaining this Conservation Unit.
Asunto(s)
Anticuerpos Antiprotozoarios , Aves , Toxoplasma , Animales , Brasil , Anticuerpos Antiprotozoarios/sangre , Toxoplasma/inmunología , Aves/parasitología , Toxoplasmosis Animal/diagnóstico , Toxoplasmosis Animal/inmunología , Toxoplasmosis Animal/epidemiología , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/inmunologíaRESUMEN
Environmental challenges are integrated in the inmunoneuroendocrine interplay, impacting the immune system of the challenged individuals, and potentially implying transgenerational effects on their offspring. This study addressed whether dietary supplementation with thymol can modulate the immune response of adult Japanese quail when simultaneously exposed to an inoculum of inactivated Salmonella Enteritidis and a chronic heat stress (CHS). We also evaluated whether the experienced situations by adults can affect the immune response of their undisturbed offspring. In the parental generation, supplemented quail exposed to CHS had a higher inflammatory response and similar values of the heterophil/lymphocyte (H/L) ratio than those that were not supplemented. In their offspring, those chicks whose parents were exposed to CHS showed higher inflammatory response and lower antibody production. Regarding the H/L ratio, chicks whose parents were supplemented showed lower H/L ratio values. Dietary supplementation with thymol partially and positively modulated the inflammatory response and avoided H/L ratio alteration in the parental generation exposed to high environmental temperatures, suggesting these adults were better at dealing with the challenge. The lower H/L ratio values in the offspring suggests that chicks are more capable to deal with potential stressful situations associated with conventional breeding conditions.
Asunto(s)
Alimentación Animal , Enfermedades de las Aves/prevención & control , Coturnix/inmunología , Trastornos de Estrés por Calor/veterinaria , Salmonella enteritidis/inmunología , Timol/administración & dosificación , Animales , Enfermedades de las Aves/sangre , Enfermedades de las Aves/inmunología , Enfermedades de las Aves/microbiología , Coturnix/microbiología , Femenino , Trastornos de Estrés por Calor/sangre , Trastornos de Estrés por Calor/inmunología , Trastornos de Estrés por Calor/prevención & control , Calor/efectos adversos , Recuento de Linfocitos , Linfocitos/inmunología , Masculino , Exposición Materna , Neuroinmunomodulación/efectos de los fármacos , Óvulo/inmunología , Exposición Paterna , Factores SexualesRESUMEN
The prevalence of anti-Toxoplasma gondii antibodies was investigated among 104 ratites: 68 rheas (Rhea americana), 16 emus (Dromaius novaehollandiae), and 20 ostriches (Struthio camelus) in 4 Brazilian states. The prevalence in rheas was 26.5% (18 of 68), and titers were 1:100 (n = 8), 1:200 (n = 1), 1:400 (n = 4), 1:800 (n = 4), and 1:1,600 (n = 1). In emus, the prevalence was 50% (8 of 16), and titers were 1:50 (n = 1) and 1:100 (n = 7). The ostriches were slaughtered for human consumption, and 80% (16 of 20) were seropositive with titers of 1:200 (n = 1), 1:400 (n = 9), and 1:800 (n = 6). Sera were tested with a modified agglutination test, and the results confirmed the distribution of the parasite in ratite species from Brazil. The data obtained in this study show that T. gondii is prevalent among ratites from Brazil, and therefore ratite meat should also be considered a potential source of human infection. This is the first report of T. gondii seroprevalence in emus.
Asunto(s)
Enfermedades de las Aves/parasitología , Paleognatos/parasitología , Toxoplasma/inmunología , Toxoplasmosis Animal/epidemiología , Toxoplasmosis Animal/inmunología , Pruebas de Aglutinación/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/inmunología , Brasil/epidemiología , Dromaiidae/parasitología , Femenino , Masculino , Carne/normas , Prevalencia , Reiformes/parasitología , Distribución por Sexo , Struthioniformes/parasitologíaRESUMEN
Toxoplasmosis has been reported in many avian species, but little information is available from wild penguin populations. Leptospira can infects domestic and wild animals. Spheniscus magellanicus belong to the order Sphenisciformes, family Spheniscidae, and are colonial birds. These seabirds live in temperate waters along the Atlantic shores of South America, and their total population has been estimated to be 1,300,000 breeding pairs. Magdalena Island (Chile) hosts an important breeding colony but, over recent decades, a marked decline in the number of birds has been seen. The objective of this study was to determine occurrences of antibodies against T. gondii and Leptospira spp. in penguins (Spheniscus magellanicus) on Magdalena Island, from where no previous data on these agents were available. Serum samples were collected from 132 penguins on Magdalena Island. Antibodies against Toxoplasma gondii were detected using the modified agglutination test (Titer ≥20), and anti-Leptospira spp. antibodies were detected using the microscopic agglutination test (Titer ≥100). T. gondii antibodies were detected in 57 (43.18%) of the 132 serum samples, with titers that ranged from 20 to 320. None of the penguins in this study was reactive to anti-Leptospira spp. antibodies. This is the first report of T. gondii seropositivity in free-living Magellanic penguins in Chile.
Asunto(s)
Enfermedades de las Aves/inmunología , Leptospira/inmunología , Leptospirosis/veterinaria , Spheniscidae , Toxoplasma/inmunología , Toxoplasmosis Animal/inmunología , Pruebas de Aglutinación/veterinaria , Animales , Anticuerpos Antibacterianos/sangre , Anticuerpos Antiprotozoarios/sangre , Antígenos Bacterianos/inmunología , Enfermedades de las Aves/microbiología , Enfermedades de las Aves/parasitología , Chile , Islas , Leptospirosis/inmunología , Leptospirosis/microbiología , Spheniscidae/microbiología , Spheniscidae/parasitología , Toxoplasmosis Animal/parasitologíaRESUMEN
The main motivation for this study was to determine the occurrence of Toxoplasma gondii, a cosmopolitan widespread zoonotic parasite distribution that can infect a wide variety of mammals and birds, in Magellanic penguins (Spheniscus magellanicus) in Brazil. In recent decades there has been a significant increase in the number of penguins originating from Argentinian and Chilean Patagonia, where these birds are born, that arrive on the Brazilian coast, where many of them are stranded and rescued. Tissue samples were collected from 330 individuals surveyed from 2012-2015 at the Institute for Marine Animal Research and Rehabilitation (IPRAM) located in Cariacica, state of Espirito Santo, Brazil. Serum were collected from 145 animals surveyed in 2015 for the detection of anti-T. gondii antibodies using the Modified Agglutination Test (MAT ≥20) and 18 birds were positive, with titers of 20 (7 birds), 40 (9 birds) and 80 (2 birds). Mouse bioassay for the isolation of T. gondii was performed using tissues from 54 penguins that were also surveyed in 2015, but no isolates were obtained. DNA from tissue samples of 330 individuals was PCR amplified and sequenced to detect tissue cyst forming coccidians by using pan sarcocystids-directed primers (based on 18S rDNA). These samples were from animals surveyed in 2015 and from frozen stocked tissues from animals surveyed in the years 2012 and 2013. The positives were PCR amplified and sequenced with genus Sarcocystis-specific primers (based on internal transcribed spacer 1, RNA polymerase beta subunit coding gene, and cytochrome B coding gene) and with Sarcocystis falcatula/Sarcocystis neurona- specific primers (based on surface antigens SAG2, SAG3 and SAG4). Sixteen (3.0%) of pectoral muscle samples were positive by all the seven molecular markers and all the samples were identical to each other. Organisms close related to Sarcocystis falcatula were confirmed in all cases. This is the first report on molecular detection of infection by S. falcatula-related organisms and the first report of seropositivity for T. gondii in free-living Magellanic penguins in Brazil. Felids and didephid opossums are definitive hosts of T. gondii and S. falcatula, respectively. Where the penguins acquire the infective forms of the parasites shed by the terrestrial mammals remains to be elucidated.
Asunto(s)
Enfermedades de las Aves/epidemiología , Coccidios , Coccidiosis/veterinaria , Spheniscidae/parasitología , Animales , Antígenos de Protozoos/sangre , Enfermedades de las Aves/sangre , Enfermedades de las Aves/inmunología , Brasil , Coccidios/inmunología , Coccidiosis/sangre , Coccidiosis/epidemiología , Coccidiosis/inmunología , Músculo Esquelético/inmunología , Músculo Esquelético/parasitología , Filogenia , Spheniscidae/sangre , Spheniscidae/genética , Spheniscidae/inmunologíaRESUMEN
Global urban development continues to accelerate and have diverse effects on wildlife. Although most studies of anthropogenic impacts on animals have focused on indirect effects (e.g., environmental modifications like habitat change or pollution), there may also be direct effects of physical human presence and actions on wildlife stress, behavior, and persistence in cities. Most studies on how humans physically interact with wildlife have focused on the active, daytime phase of diurnal animals, rarely considering effects of our night-time activities. We hypothesized that, if night-time human presence is a stressor for wildlife that are not commonly exposed to humans, night-disturbed rural animals would show stronger physiological signs of elevated stress than would urban individuals. Specifically, we experimentally investigated the effects of human presence at night (HPAN) on disease, body mass, and mass-specific metabolic rates in urban- and rural-caught house finches (Haemorhous mexicanus) in captivity. Our HPAN treatment consisted of a human entering the housing room of the birds and briefly jostling the home cages of each finch as the person walked around the room for a 3-min period on five randomly selected nights per week. Compared with a control (night-undisturbed) group, we found that HPAN greatly increased the odds finches were awake for ca. 33 min post-disturbance, but that chronic treatment did not alter body mass, parasitic infection by coccidian endoparasites, or mass-specific basal metabolic rates. Additionally, finches caught from urban and rural sites did not differ in their response to the treatment. Overall, our results are consistent with those showing that brief but regular human disturbances can have acute negative effects on wildlife, but carry few if any long-term metabolic or disease-related costs in fast-lived birds. However, these findings contrast with the broad, chronic physiological effects of other anthropogenic changes, such as artificial light at night, and highlight the differential impacts that various human activities (which differ in sensory stimulus type, perceived threat, duration and intensity, etc.) can have on wildlife health and behavior.
Asunto(s)
Peso Corporal , Resistencia a la Enfermedad , Ecosistema , Metabolismo Energético , Pinzones/fisiología , Animales , Enfermedades de las Aves/inmunología , Ciudades , Pinzones/inmunología , Actividades Humanas , UrbanizaciónRESUMEN
Hosts counteract infections using two distinct defence strategies, resistance (reduction in pathogen fitness) and tolerance (limitation of infection damage). These strategies have been minimally investigated in multi-host systems, where they may vary across host species, entailing consequences both for hosts (virulence) and parasites (transmission). Comprehending the interplay among resistance, tolerance, virulence and parasite success is highly relevant for our understanding of the ecology and evolution of infectious and parasitic diseases. Our work investigated the interaction between an insect parasite and its most common bird host species, focusing on two relevant questions: (i) are defence strategies different between main and alternative hosts and, (ii) what are the consequences (virulence and parasite success) of different defence strategies? We conducted a matched field experiment and longitudinal studies at the host and the parasite levels under natural conditions, using a system comprising Philornis torquans flies and three bird hosts - the main host and two of the most frequently used alternative hosts. We found that main and alternative hosts have contrasting defence strategies, which gave rise in turn to contrasting virulence and parasite success. In the main bird host, minor loss of fitness, no detectable immune response, and high parasite success suggest a strategy of high tolerance and negligible resistance. Alternative hosts, on the contrary, resisted by mounting inflammatory responses, although with very different efficiency, which resulted in highly dissimilar parasite success and virulence. These results show clearly distinct defence strategies between main and alternative hosts in a natural multi-host system. They also highlight the importance of defence strategies in determining virulence and infection dynamics, and hint that defence efficiency is a crucial intervening element in these processes.
Asunto(s)
Enfermedades de las Aves/parasitología , Muscidae/fisiología , Miasis/veterinaria , Animales , Argentina , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/inmunología , Aves , Susceptibilidad a Enfermedades , Bosques , Especificidad del Huésped , Miasis/epidemiología , Miasis/inmunología , Miasis/parasitologíaRESUMEN
During a medical entomology course in Boa Vista, Roraima, colonies of Triatoma maculata closely associated with pigeon nests were observed in concrete air-conditioner box located on the external plastered and cemented walls of a modern brick-built apartment block. In only one eight-hole ceramic brick, located inside one air-conditioner box, 127 specimens of T. maculata were collected. T. maculata is a recognised vector of Trypanosoma cruzi in the surrounding area and its domiciliation increases the risk of Chagas disease transmission.
Asunto(s)
Enfermedad de Chagas/transmisión , Insectos Vectores/fisiología , Triatoma/parasitología , Trypanosoma cruzi/fisiología , Distribución Animal , Animales , Enfermedades de las Aves/inmunología , Brasil , Columbidae/parasitología , Vivienda , Humanos , Población UrbanaRESUMEN
Glucocorticoid stress hormones are important for energy mobilization as well as regulation of the immune system, and thus these hormones are particularly likely to both influence and respond to pathogen infection in vertebrates. In this study, we examined how the glucocorticoid stress response in house finches (Haemorhous mexicanus) interacts with experimental infection of the naturally-occurring bacterial pathogen, Mycoplasma gallisepticum (MG). We also investigated whether infection-induced concentrations of corticosterone (CORT), the primary glucocorticoid in birds, were associated with the expression of sickness behavior, the lethargy typically observed in vertebrates early in infection. We found that experimental infection with MG resulted in significantly higher CORT levels on day 5 post-infection, but this effect appeared to be limited to female house finches only. Regardless of sex, infected individuals with greater disease severity had the highest CORT concentrations on day 5 post-infection. House finches exposed to MG exhibited behavioral changes, with infected birds having significantly lower activity levels than sham-inoculated individuals. However, CORT concentrations and the extent of sickness behaviors exhibited among infected birds were not associated. Finally, pre-infection CORT concentrations were associated with reduced inflammation and pathogen load in inoculated males, but not females. Our results suggest that the house finch glucocorticoid stress response may both influence and respond to MG infection in sex-specific ways, but because we had a relatively low sample size of males, future work should confirm these patterns. Finally, manipulative experiments should be performed to test whether the glucocorticoid stress response acts as a brake on the inflammatory response associated with MG infection in house finches.
Asunto(s)
Enfermedades de las Aves/inmunología , Corticosterona/metabolismo , Infecciones por Mycoplasma/etiología , Mycoplasma gallisepticum/metabolismo , Animales , Femenino , Pinzones , MasculinoRESUMEN
Raising ostriches became an important economic activity after their products became commodities. The health of farm animals is of paramount importance, so assessing basic immunological responses is necessary to better understand health problems. We developed a method to obtain ostrich thrombocytes and macrophages. The thrombocytes died by apoptosis after 48 h in culture, and the macrophages expanded in size and increased the number of acidic compartments. Macrophages were activated by chicken interferon-γ, producing high levels of nitric oxide. Toxoplasma gondii was able to infect these macrophages, and activation controlled parasitic reproduction. T. gondii, however, persisted in these cells, and infection reduced the production of nitric oxide. These results are important for the future assessment of the basic cellular and immunobiology of ostriches and demonstrate T. gondii suppression of nitric oxide production.
Asunto(s)
Enfermedades de las Aves/inmunología , Plaquetas/metabolismo , Técnicas de Cultivo de Célula/veterinaria , Activación de Macrófagos , Macrófagos/metabolismo , Struthioniformes , Toxoplasmosis Animal/inmunología , Animales , Enfermedades de las Aves/parasitología , Plaquetas/citología , Plaquetas/ultraestructura , Escherichia coli/fisiología , Femenino , Inmunidad Celular , Interferón gamma/farmacología , Lipopolisacáridos/farmacología , Macrófagos/citología , Macrófagos/ultraestructura , Microscopía Electrónica de Rastreo , Toxoplasma/fisiología , Toxoplasmosis Animal/parasitologíaRESUMEN
We evaluated the prevalence of WNV and SLEV neutralizing antibodies in captive and free-ranging raptors from Argentina by plaque-reduction neutralization test. Eighty plasma samples from 12 species were analyzed. Only one captive adult Crowned Eagle (Harpyhaliaetus coronatus) was WNV seropositive (prevalence: 1.25%; antibody titer of 1:80). Two captive Crowned Eagles were SLEV seropositive (prevalence: 2.50%; antibody titers: 1:80 and 1:40).These findings expand the geographic distribution of WNV and SLEV and confirm their activity in central and northeastern Argentina. West Nile virus activity in Argentina may represent a potential threat to Crowned Eagles and other endangered raptors in this country.
Asunto(s)
Anticuerpos Antivirales/sangre , Enfermedades de las Aves/epidemiología , Virus de la Encefalitis de San Luis/inmunología , Rapaces , Virus del Nilo Occidental/inmunología , Animales , Argentina , Enfermedades de las Aves/inmunología , PrevalenciaRESUMEN
Infection with parasites and pathogens is costly for hosts, causing loss of nutritional resources, reproductive potential, tissue integrity and even life. In response, animals have evolved behavioural and immunological strategies to avoid infection by pathogens and infestation by parasites. Scientists generally study these strategies in isolation from each other; however, since these defences entail costs, host individuals should benefit from balancing investment in these strategies, and understanding of infectious disease dynamics would benefit from studying the relationship between them. Here, we show that Carpodacus mexicanus (house finches) avoid sick individuals. Moreover, we show that individuals investing less in behavioural defences invest more in immune defences. Such variation has important implications for the dynamics of pathogen spread through populations, and ultimately the course of epidemics. A deeper understanding of individual- and population-level disease defence strategies will improve our ability to understand, model and predict the outcomes of pathogen spread in wildlife.
Asunto(s)
Enfermedades de las Aves/inmunología , Pinzones/fisiología , Inmunidad Innata , Conducta Social , Proteínas de Fase Aguda/análisis , Animales , Anticuerpos Antibacterianos/sangre , Enfermedades de las Aves/sangre , Enfermedades de las Aves/microbiología , Enfermedades de las Aves/fisiopatología , Distribución de Chi-Cuadrado , Pinzones/inmunología , Pinzones/microbiología , Adyuvante de Freund/farmacología , Inyecciones Intradérmicas/veterinaria , Masculino , Estadísticas no Paramétricas , Factores de Tiempo , Grabación en VideoRESUMEN
In the austral summer of 2011, in the rural area of Villarrica county, southern Chile (39 degrees 16'S, 72 degrees 19'W), seven black-faced ibis juveniles (approximately 4 mo old) were observed in the field with weakness; they were unable to follow the group and struggling to take flight. Three of these birds were euthanatized, and complete necropsies were performed. Gross examination showed severe infestation with Colpocephalum trispinum and Ardeicola melanopis lice, moderate emaciation, pale musculature, bursal atrophy, and severe hemorrhagic enteritis due to a heavy proventricular and intestinal infection with Porrocaecum heteropterum nematodes. Fungal pneumonia and severe lymphoid depletion on thymus, spleen, and bursa were diagnosed by microscopic examination. Bursal lesions included apoptosis and necrosis of lymphoid cells, and several cystic follicles. The presence of severe lymphoid depletion associated with fungal pneumonia and severe external and internal parasite infections suggest the presence of an immunosuppressive syndrome in these birds that caused the death of several black-faced ibis juveniles in southern Chile during the summer of 2011.
Asunto(s)
Enfermedades de las Aves/inmunología , Huésped Inmunocomprometido , Animales , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/patología , Aves , Chile/epidemiología , Enfermedades Parasitarias en Animales/inmunología , Enfermedades Parasitarias en Animales/patología , Aspergilosis Pulmonar/microbiología , Aspergilosis Pulmonar/patología , Aspergilosis Pulmonar/veterinariaRESUMEN
Mycoplasma gallisepticum (MG) has become a common cause of conjunctivitis in free-living house finches (Carpodacus mexicanus) since its emergence in the early 1990s. To date, temporal and spatial genotypic variation in MG has been documented, but phenotypic variation in pathogenicity and immunogenicity has not been examined. House finches were inoculated with MG isolates Virginia (VA)1994, California (CA)2006, or North Carolina (NC)2006, which were cultured from free-living house finches with conjunctivitis in 1994, 2006, and 2006, respectively. Infection with NC2006 resulted in the most severe eye lesions, highest pathogen loads, and highest levels of pathogen-specific lachrymal and serum antibodies. Infection with CA2006 caused the least severe eye lesions, lowest pathogen load, and lowest levels of antibodies. A small number of birds in each group developed protracted, severe disease in spite of robust antibody responses, suggesting that immunopathology may contribute to the lesions. Immunoblot analyses indicated that isolates are antigenically similar; thus, there may be partial cross-protection if a house finch encounters two or more strains of MG throughout the course of its lifetime. This study provides evidence that MG strains or strain variants circulating in house finch populations vary in their ability to cause disease, induce antibody responses, and persist in the host.
Asunto(s)
Enfermedades de las Aves/inmunología , Enfermedades de las Aves/microbiología , Conjuntivitis Bacteriana/veterinaria , Pinzones/microbiología , Infecciones por Mycoplasma/veterinaria , Mycoplasma gallisepticum/inmunología , Mycoplasma gallisepticum/patogenicidad , Animales , Anticuerpos Antibacterianos/análisis , Anticuerpos Antibacterianos/sangre , Carga Bacteriana , Enfermedades de las Aves/patología , Conjuntivitis Bacteriana/inmunología , Conjuntivitis Bacteriana/microbiología , Conjuntivitis Bacteriana/patología , Genotipo , Infecciones por Mycoplasma/inmunología , Infecciones por Mycoplasma/microbiología , Infecciones por Mycoplasma/patología , Factores de TiempoRESUMEN
Neospora caninum is a protozoan parasite that presents worldwide distribution and is mainly implicated as responsible for bovine abortion. Although the presence of birds in cattle-raising properties is positively correlated to higher infection rates, very little has been described about the role of these animals in the parasite's life cycle. In that sense, this work aimed to investigate the serological and histological positivity of different avian species sampled in its natural habitat or in captivity. No serological positivity was observed in the 294 tested serum samples. On the other hand, Apicomplexa-like cysts found in muscular tissues of two Psittaciformes were immunostained with N. caninum antisera. These findings indicate that N. caninum may infect a wider range of hosts than described to date, and that further studies should be performed in order to determine the presence of the infection in different avian species.
Asunto(s)
Animales Salvajes , Enfermedades de las Aves/parasitología , Coccidiosis/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/inmunología , Aves , Brasil/epidemiología , Coccidiosis/epidemiología , Coccidiosis/inmunología , Coccidiosis/parasitología , MascotasRESUMEN
Toxoplasma gondii affects mainly warm-blooded animals, including birds. Even though previous experimental data indicate that raptors are resistant to clinical infection, there is no information regarding the susceptibility of Brazilian birds of prey to T. gondii. The present study aimed to observe how the crested caracara, a common raptor in Brazil, interacts with T. gondii using an experimental model. Seven crested caracaras, seronegative for T. gondii, were separated into infected (n=5) and control groups (n=2). Birds from the infected group were fed T. gondii-infected Calomys callosus, a rodent present in Brazilian savanna and described as highly susceptible to infection by the parasite, for three consecutive days, while control animals were fed non-infected rodents. All infected birds produced T. gondii-specific IgG antibodies that were firstly detected at day 7 post-infection, with peak production detected between 15 and 30dpi. No significant alterations in clinical and hematological parameters were observed throughout the experimental period, and parasites were sparsely found in muscular tissues after the birds were euthanized. In conclusion, our results demonstrated that crested caracaras are resistant to oral infection with T. gondii, suggesting that the host-parasite relationship between both species has reached a remarkable equilibrium.
Asunto(s)
Enfermedades de las Aves/parasitología , Toxoplasma/inmunología , Toxoplasmosis Animal/parasitología , Animales , Anticuerpos Antiprotozoarios/sangre , Bioensayo , Enfermedades de las Aves/inmunología , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Ratones , Rapaces , Toxoplasmosis Animal/inmunologíaRESUMEN
The rock pigeon (Columba livia) may serve as a reservoir for several pathogenic agents that can be transmitted to poultry, wildlife, domesticated pets, and/or humans via excreta, secretions, or dust from feathers. In addition, ingestion of infected pigeons by wild and domestic animals can also transmit these pathogenic agents. The health status of 126 free-living pigeons in an urban area was evaluated by microbiologic culture for Salmonella and serologic testing for the presence of antibodies for Toxoplasma gondii and for Newcastle disease virus (NDV) from 120 and 109 pigeons, respectively. After drawing blood, the birds were euthanized, and fragments of the liver, spleen, lungs, and gonads, and feces were cultured for Salmonella spp. Salmonella spp. was isolated from 10 birds (7.94%), of which 8 were Salmonella typhimurium, one was Salmonella enterica subsp. enterica serotype 4,12 and one was Salmonella enterica subsp. enterica serotype 4,12,i. Six of 109 pigeons (5.50%) were positive for NDV antibodies when using the hemagglutination inhibition test. Toxoplasma gondii antibodies were detected by immunofluorescence in one of 120 sera tested (0.83%). The results indicate that feral rock pigeons were exposed to NDV and T. gondii, although the exposure was low. In addition, these birds had Salmonella spp. and could disseminate this pathogen in the environment.
Asunto(s)
Anticuerpos/sangre , Enfermedades de las Aves/inmunología , Columbidae , Enfermedad de Newcastle/epidemiología , Salmonelosis Animal/epidemiología , Toxoplasmosis Animal/epidemiología , Animales , Enfermedades de las Aves/sangre , Enfermedades de las Aves/epidemiología , Brasil/epidemiología , Enfermedad de Newcastle/inmunología , Enfermedad de Newcastle/virología , Virus de la Enfermedad de Newcastle/inmunología , Salmonella/inmunología , Salmonelosis Animal/inmunología , Salmonelosis Animal/virología , Toxoplasma/inmunología , Toxoplasmosis Animal/inmunologíaRESUMEN
The IgA antibody response plays a vital role in mucosal immunity because it functions to neutralize pathogens at the mucosal surface and thus impedes attachment to underlying tissues. Although the importance of IgA in the mucosal immunity of galliform birds has been established, studies examining IgA-based immunity in passerine birds are lacking, perhaps due in part to the absence of reagents that can detect passerine IgA. A 469 base pair region of the house finch (Carpodacus mexicanus) IgA heavy chain was PCR-amplified from spleen cDNA and sequenced. The predicted amino acid sequence was found to share 55% and 46% identity with the IgA heavy chain of mallard (Anas platyrhynchos) and chicken (Gallus gallus), respectively. The heavy chain fragment was produced using a bacterial expression system and purified. Rabbit anti-sera were generated against the recombinant protein. The anti-sera reacted with a single house finch serum protein ( approximately 50-55kDa) in Western blot. The anti-sera were used to identify plasma cells in the Harderian gland and conjunctiva of house finches with conjunctivitis associated with Mycoplasma gallisepticum infection. The anti-sera were also utilized in an ELISA to detect M. gallisepticum-specific IgA antibodies in lachrymal samples of infected finches.
Asunto(s)
Anticuerpos Antiidiotipos/biosíntesis , Anticuerpos Antibacterianos/análisis , Pinzones/inmunología , Inmunoglobulina A Secretora/inmunología , Mycoplasma gallisepticum/inmunología , Secuencia de Aminoácidos , Animales , Especificidad de Anticuerpos , Secuencia de Bases , Enfermedades de las Aves/inmunología , Enfermedades de las Aves/microbiología , Pollos , Cartilla de ADN/genética , ADN Complementario/genética , Patos , Ensayo de Inmunoadsorción Enzimática , Pinzones/genética , Glándula de Harder/inmunología , Glándula de Harder/microbiología , Inmunidad Mucosa , Inmunoglobulina A Secretora/análisis , Inmunoglobulina A Secretora/genética , Inmunohistoquímica , Indicadores y Reactivos , Datos de Secuencia Molecular , Infecciones por Mycoplasma/inmunología , Infecciones por Mycoplasma/microbiología , Infecciones por Mycoplasma/veterinaria , Conejos , Homología de Secuencia de AminoácidoRESUMEN
Neospora caninum infections in chickens have been recently described by epidemiological and experimental approaches, and these birds may be considered natural intermediate hosts of the parasite. It has been postulated that other bird species might perform this role in wildlife as well. To better understand the sylvatic life cycle of N. caninum, further studies are required. In that sense, this work aimed to observe infection kinetics in pigeons experimentally infected with N. caninum. Experimental infections were conducted in parallel with a related protozoan, Toxoplasma gondii, which has been already described as able to infect pigeons in nature. Our results demonstrated that N. caninum disseminated through various tissues of this host and induced parasite-specific IgG seroconversion. Infection parameters were similar to that observed in the T. gondii infected group, although N. caninum-infected pigeons presented lower IgG titers during acute phase. The results herein described demonstrate that pigeons are a suitable model for N. caninum infection, considering that these data are in agreement with those observed in chickens experimentally infected with this parasite. As pigeons may be revealed as important reservoirs for N. caninum infection in nature, future studies are necessary to determine the real prevalence of this parasite in this and other birds in wildlife.
Asunto(s)
Enfermedades de las Aves/parasitología , Coccidiosis/veterinaria , Neospora , Animales , Enfermedades de las Aves/inmunología , Coccidiosis/inmunología , Coccidiosis/parasitología , Columbidae , Inmunoglobulina G/inmunologíaRESUMEN
Passive transfer of maternal antibodies against West Nile virus (WNV) was studied in a captive population of Chilean (Phoenicopterus chilensis) and Caribbean flamingos (Phoenicopterus ruber ruber). Transfer of WNV antibodies from hens to chicks was documented and measured by plaque-reduction neutralization test. Hen titers were significantly correlated to chick titers. Mean half-life of maternal WNV antibodies was 13.4 days in chicks for which half-life was measurable.