RESUMO
Since 1814, when rubella was first described, the origins of the disease and its causative agent, rubella virus (Matonaviridae: Rubivirus), have remained unclear1. Here we describe ruhugu virus and rustrela virus in Africa and Europe, respectively, which are, to our knowledge, the first known relatives of rubella virus. Ruhugu virus, which is the closest relative of rubella virus, was found in apparently healthy cyclops leaf-nosed bats (Hipposideros cyclops) in Uganda. Rustrela virus, which is an outgroup to the clade that comprises rubella and ruhugu viruses, was found in acutely encephalitic placental and marsupial animals at a zoo in Germany and in wild yellow-necked field mice (Apodemus flavicollis) at and near the zoo. Ruhugu and rustrela viruses share an identical genomic architecture with rubella virus2,3. The amino acid sequences of four putative B cell epitopes in the fusion (E1) protein of the rubella, ruhugu and rustrela viruses and two putative T cell epitopes in the capsid protein of the rubella and ruhugu viruses are moderately to highly conserved4-6. Modelling of E1 homotrimers in the post-fusion state predicts that ruhugu and rubella viruses have a similar capacity for fusion with the host-cell membrane5. Together, these findings show that some members of the family Matonaviridae can cross substantial barriers between host species and that rubella virus probably has a zoonotic origin. Our findings raise concerns about future zoonotic transmission of rubella-like viruses, but will facilitate comparative studies and animal models of rubella and congenital rubella syndrome.
Assuntos
Mamíferos/virologia , Filogenia , Vírus da Rubéola/classificação , Vírus da Rubéola/isolamento & purificação , Sequência de Aminoácidos , Animais , Animais de Zoológico/imunologia , Animais de Zoológico/virologia , Membrana Celular/virologia , Quirópteros/virologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Equidae/imunologia , Equidae/virologia , Evolução Molecular , Feminino , Mapeamento Geográfico , Alemanha , Especificidade de Hospedeiro , Humanos , Masculino , Mamíferos/imunologia , Marsupiais/imunologia , Marsupiais/virologia , Fusão de Membrana , Camundongos , Modelos Animais , Modelos Moleculares , Rubéola (Sarampo Alemão)/congênito , Rubéola (Sarampo Alemão)/virologia , Vírus da Rubéola/química , Vírus da Rubéola/imunologia , Alinhamento de Sequência , Uganda , Proteínas do Envelope Viral/químicaRESUMO
Equine infectious anemia (EIA) is a disease caused by a Lentivirus that is currently controlled exclusively by identification of seropositive animals. In most countries, including Brazil, the official diagnostic test for EIA is the agar gel immunodiffusion test (AGID). Although this assay has a high specificity it can produce false negative reactions or equivocal results due to weak precipitation lines, especially in samples from donkeys, mules or newly infected equids. In this pioneering study, it was used overlapping synthetic peptide pools to map and identify a consensus, widely recognised antibody epitope within env encoding the EIAV envelope proteins. A 20-mer soluble peptide encompassing this epitope (pgp45) was then synthesized and tested in an indirect ELISA test. Using a panel of 859 EIA positive and negative equid serum samples, the pgp45 ELISA had 96.1% concordance, 98.6% sensitivity and 95.6% specificity respectively, when compared to AGID. The sensitivity and specificity of the pgp45 ELISA was also >90% when tested in individual equid species including horses (Equus caballus), donkeys (Equus asinus) and mules (Equus caballus x Equus asinus). Moreover, in a horse experimentally infected with the pathogenic Wyoming EIAV strain viral-specific antibodies were detected at 10 days post-infection (dpi) whereas in AGID no specific antibody was detected until 18 days of experimental infection. This peptide can now be used as an antigen in serological tests, especially for rapid screening of large numbers of equids, where it may contribute significantly in the control of EIA, especially at sites with high populations of donkeys and mules.
Assuntos
Antígenos Virais/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Equidae/virologia , Anemia Infecciosa Equina/diagnóstico , Cavalos/virologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/química , Equidae/imunologia , Anemia Infecciosa Equina/imunologia , Reações Falso-Negativas , Cavalos/imunologia , Sensibilidade e Especificidade , Testes Sorológicos/veterinária , Proteínas do Envelope Viral/síntese químicaRESUMO
Significant structural differences in the extracellular domain of toll-like receptor 9 (TLR9) account for species-specific recognition of its ligand CpG-ODN sequences. TLR9 is extensively studied in human, mice and some domestic animals. The recognition ability appears to be utilized differently by various species and breeds, but so far no comprehensive study exists about the equine TLR9 gene. We characterized TLR9 sequences of Marwari and Zanskari breeds of horses and Poitu donkey. We sequenced and identified the protein coding regions of equine TLR9 and compared with other animals and human beings. Furthermore, we also analyzed the amino acid substitutions and their likely implications on functions. The analysis revealed 14% evolutionary divergence between equine and human TLR9, while it was 1% between the Equus caballus and Equus asinus and less than 1% within Equus caballus. In phylogenetic analysis of predicted amino acids, the indigenous equines grouped with thoroughbred Equus caballus, while human, cattle, dog, sheep, mice, and buffalo formed separate clades. Furthermore, we also analyzed the amino acid substitutions and their likely implications on functions by sorting intolerant from tolerant (SIFT) analysis and predicted two substitutions of amino acids (D80N and S822P) in Marwari horses in leucine rich repeat 1 (LRR1) without any functional effects. The substitutions (V214A and Y579C) in LRR 3 and LRR11 in Zanskari horses were predicted to have functional consequences. Out of overall 8 substitutions, three substitutions (I420V, S970R and R1001C) were found in Equus asinus in LRR7, LRR 13, and toll interleukin receptor (TIR) domains, while the substitution G649S is observed in Poitu donkey only. We report for the first time that despite the conserved residues, the striking effect of substitutions, found within the TLR9 genes of different equine breeds/species may have possible implications.
Assuntos
Sequência de Aminoácidos , Equidae/genética , Cavalos/genética , Filogenia , Análise de Sequência de Proteína , Receptor Toll-Like 9/genética , Animais , Equidae/imunologia , Cavalos/crescimento & desenvolvimento , Humanos , Domínios Proteicos , Especificidade da Espécie , Receptor Toll-Like 9/imunologiaRESUMO
Donkeys (Equus asinus) are widely distributed throughout China; they are used for their meat, as food, and certain donkey-derived items are also important for traditional Chinese medicinal purposes. However, only limited information is available on Toxoplasma gondii infection in donkeys in China, especially the eastern region, which is one of the largest production areas. Thus, the present study was conducted to detect specific anti-T. gondii antibodies using a commercially available indirect hemagglutination test (IHA) kit and to evaluate the risk factors that are associated with seroprevalence in the Shandong province of eastern China. A total of 213/1278 (17%) donkeys tested from Shandong province were positive for T. gondii antibodies. Statistical analysis revealed that gender and feeding habits of the animal are associated with T. gondii infection. These results provide information for the prevention and control of toxoplasmosis in donkeys, other animals, and humans in this region and elsewhere.
Assuntos
Equidae/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Anticorpos Antiprotozoários/sangue , China/epidemiologia , Equidae/imunologia , Feminino , Testes de Hemaglutinação/veterinária , Humanos , Masculino , Carne/parasitologia , Fatores de Risco , Estudos Soroepidemiológicos , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/transmissãoRESUMO
Asymptomatic tick-borne infections are a common feature in wild herbivores. In human-dominated habitats, snare injuries to wild herbivores are common and are likely to co-occur with enzootic infections. The influence of injury on pattern, course and outcome of enzootic infection in wild herbivores is unknown. We identified Theileria species infecting zebra and assessed the relationship between host injury-status and parasitaemia, parasite diversity and selection regimes. We also determined host leucocyte differential as this can reveal mechanisms by which injuries influence infections. Theileria infecting zebra was identified using PCR and sequencing of the V4 region of the 18â¯s rRNA gene and confirmed with phylogenetic analyses. The influence of injury status on parasite infection patterns, genetic diversity and selection were assessed using population genetic tools. Parasitaemia estimated from prevalence and leucocyte differential were determined from microscopic examination of Giemsa stained thin blood smears. Phylogenetic and sequence analyses revealed that the zebra population studied was infected with three Theileria equi haplotypes. Parasitaemia was lower among injured compared to non-injured animals and lower during dry than wet season. Mean (±SD) genetic diversity was 0.386 (±0.128) in injured and 0.513 (±0.144) in non-injured zebra (Pâ¯=â¯.549). Neutrality tests indicated that T. equi is under strong purifying selection in injured females (Li & Fu's D*â¯=â¯-2.037) and demographic expansion in all zebra during the wet season (Tajima Dâ¯=â¯-1.904). Injured zebras had a higher median per cent of neutrophils (64% vs 37%) a lower median per cent of basophils (0% vs 1%) and eosinophils (2% vs 4.5%) than non-injured animals, suggesting a heightened immune response and a shift from a Th2 to Th1 T-Cell response favoring the elimination of intracellular parasites in injured animals. This study demonstrates the utility of population genetics in revealing factors influencing parasite diversity and infection patterns.
Assuntos
Equidae/parasitologia , Variação Genética , Theileria/genética , Theileriose/complicações , Theileriose/parasitologia , Ferimentos e Lesões/complicações , Animais , Biomarcadores , Diferenciação Celular , Equidae/imunologia , Feminino , Geografia , Haplótipos , Imunoglobulina E/imunologia , Quênia , Contagem de Leucócitos , Masculino , Filogenia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Theileria/imunologia , Theileriose/imunologiaRESUMO
The legendary therapeutics properties of donkey milk have recently been supported by many clinical trials who have clearly demonstrated that, even if with adequate lipid integration, it may represent a valid natural substitute of cow milk for feeding allergic children. During the last decade many investigations by MS-based methods have been performed in order to obtain a better knowledge of donkey milk proteins. The knowledge about the primary structure of donkey milk proteins now may provide the basis for a more accurate comprehension of its potential benefits for human nutrition. In this aspect, experimental data today available clearly demonstrate that donkey milk proteins (especially casein components) are more closely related with the human homologues rather than cow counterparts. Moreover, the low allergenic properties of donkey milk with respect to cow one seem to be related to the low total protein content, the low ratio of caseins to whey fraction, and finally to the presence in almost all bovine IgE-binding linear epitopes of multiple amino acid differences with respect to the corresponding regions of donkey milk counterparts.
Assuntos
Alimentação com Mamadeira , Equidae/imunologia , Hipersensibilidade a Leite/prevenção & controle , Proteínas do Leite/imunologia , Animais , Epitopos , Manipulação de Alimentos/métodos , Temperatura Alta , Humanos , Lactente , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Espectrometria de Massas , Hipersensibilidade a Leite/imunologia , Estado Nutricional , Valor Nutritivo , Proteômica/métodosRESUMO
West Nile fever (WNF) is a viral disease of wild birds transmitted by mosquitoes. Humans and equids can also be affected and suffer from meningoencephalitis. In Algeria, since the 1994 epidemic, no data on WNV circulation was available until 2012. In September 2012, a fatal human case of WNV neuro-invasive infection occurred in Jijel province. This study describes the first seroprevalence study of West Nile virus (WNV) antibodies conducted in the equine population in Algeria. During 2014, serum samples were collected from 293 equids (222 donkeys and 71 horses) asymptomatic and unvaccinated for WNV in three localities in Northeastern wetlands of Algeria. Antibodies against WNV were found in 51 samples (seroprevalence 17.4%) of sampled equids, distributed as follows: 19 (seroprevalence 26.8%) horses and 32 (seroprevalence 14.4%) donkeys. Moreover 7 horses coming from Blida, in the center of Algeria, were tested before and after an 8-months stay in North-East Algeria. We observe a seroconversion in 2 horses, showing WNV circulation in 2014 in this specific region of Algeria.
Assuntos
Anticorpos Antivirais/sangue , Equidae , Doenças dos Cavalos/imunologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/isolamento & purificação , Argélia/epidemiologia , Animais , Animais Selvagens/imunologia , Animais Selvagens/virologia , Doenças Assintomáticas/epidemiologia , Culicidae/virologia , Ensaio de Imunoadsorção Enzimática/veterinária , Equidae/imunologia , Cavalos/imunologia , Humanos , Soroconversão , Estudos Soroepidemiológicos , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/imunologia , Febre do Nilo Ocidental/virologia , Áreas AlagadasRESUMO
Brazilian spotted fever (BSF) is a fatal zoonosis because of the difficulties in its early diagnosis and treatment. Occurrences of BSF in the northeast of the state of Paraná prompted investigation of areas at risk of this rickettsiosis in the municipalities of Japira, Jaboti, Pinhalão and Tomazina. To determine the areas at risk, 592 serum samples from dogs and 230 from equids were analyzed by means of the indirect immunofluorescence assay (IFA) for Rickettsia rickettsii and R. parkeri . In addition, risk probability maps were drawn up using the kriging indicator technique. Among the samples tested, 5.3% (43/822) indicated presence of antibodies reactive to at least one of the two Rickettsia species tested: 7.8% of the equids (18/230) and 4.2% of the dogs (25/592) were positive. Geostatistical analysis showed that the average seropositivity rate was 5 to 6%. Although the average seropositivity rates observed among these dogs and equids were lower than those reported from endemic areas of Brazil, the biotic components (etiological agent, vector and reservoirs) and environmental aspects of BSF epidemiology were present in these municipalities.
Assuntos
Anticorpos Antibacterianos/sangue , Doenças do Cão/epidemiologia , Equidae/sangue , Infecções por Rickettsia/veterinária , Rickettsia/imunologia , Febre Maculosa das Montanhas Rochosas/veterinária , Animais , Brasil/epidemiologia , Doenças do Cão/diagnóstico , Cães , Equidae/imunologia , Probabilidade , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/epidemiologia , Rickettsia rickettsii/imunologia , Febre Maculosa das Montanhas Rochosas/diagnóstico , Febre Maculosa das Montanhas Rochosas/epidemiologiaRESUMO
Abstract Brazilian spotted fever (BSF) is a fatal zoonosis because of the difficulties in its early diagnosis and treatment. Occurrences of BSF in the northeast of the state of Paraná prompted investigation of areas at risk of this rickettsiosis in the municipalities of Japira, Jaboti, Pinhalão and Tomazina. To determine the areas at risk, 592 serum samples from dogs and 230 from equids were analyzed by means of the indirect immunofluorescence assay (IFA) for Rickettsia rickettsii and R. parkeri . In addition, risk probability maps were drawn up using the kriging indicator technique. Among the samples tested, 5.3% (43/822) indicated presence of antibodies reactive to at least one of the two Rickettsia species tested: 7.8% of the equids (18/230) and 4.2% of the dogs (25/592) were positive. Geostatistical analysis showed that the average seropositivity rate was 5 to 6%. Although the average seropositivity rates observed among these dogs and equids were lower than those reported from endemic areas of Brazil, the biotic components (etiological agent, vector and reservoirs) and environmental aspects of BSF epidemiology were present in these municipalities.
Resumo A febre maculosa brasileira (FMB) é uma zoonose fatal devido às dificuldades para diagnosticá-la e tratá-la precocemente. A ocorrência de casos de FMB no Estado do Paraná suscitou a investigação de áreas de risco desta rickettsiose nos municípios de Japira, Jaboti, Pinhalão e Tomazina, na mesorregião norte pioneiro do Paraná. Para determinar as áreas de risco foram analisadas amostras de soro de 592 cães e 230 equídeos submetidos à reação de imunofluorescência indireta para Rickettsia rickettsii e R. parkeri. Além disto, foram construídos mapas de probabilidade de risco pela técnica de krigagem indicatriz. Das amostras testadas 5,3% (43/822) continham anticorpos para pelo menos uma das duas rickettsias testadas. Os equídeos apresentaram uma positividade de 7,8% (18/230) e os cães de 4,2% (25/592). A análise geoestatística mostrou que a soropositividade média é de 5 a 6%. Embora as soropositividade médias de cães e equídeos constatadas tenham sido menores do que as relatadas em áreas endêmicas do território brasileiro, os componentes bióticos (agente etiológico, vetor e reservatórios) e ambientais da epidemiologia da FMB se fazem presentes nos municípios referidos.
Assuntos
Animais , Cães , Rickettsia/imunologia , Infecções por Rickettsia/veterinária , Febre Maculosa das Montanhas Rochosas/veterinária , Equidae/sangue , Anticorpos Antibacterianos/sangue , Rickettsia rickettsii/imunologia , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/epidemiologia , Brasil/epidemiologia , Febre Maculosa das Montanhas Rochosas/diagnóstico , Febre Maculosa das Montanhas Rochosas/epidemiologia , Probabilidade , Equidae/imunologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologiaRESUMO
Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (IFAT) with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys) of the samples tested by IFAT (cut-off ≥50) and 21% (69 donkeys) by the direct agglutination test (SAT ≥50). The SAT and IFAT results for S. neurona showed a poor concordance (value of Kappa=0.051). This is the first report of Neospora spp. antibodies in Brazilian donkeys and the first detection of antibodies against S. neurona in this animal species.
Assuntos
Anticorpos Antiprotozoários/sangue , Coccidiose/veterinária , Equidae/imunologia , Neospora/imunologia , Sarcocystis/imunologia , Sarcocistose/veterinária , Animais , Brasil/epidemiologia , Coccidiose/epidemiologia , Coccidiose/imunologia , Hiperbilirrubinemia Neonatal/veterinária , Prevalência , Sarcocistose/epidemiologia , Sarcocistose/imunologia , Estudos SoroepidemiológicosRESUMO
Abstract Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (IFAT) with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys) of the samples tested by IFAT (cut-off ≥50) and 21% (69 donkeys) by the direct agglutination test (SAT ≥50). The SAT and IFAT results for S. neurona showed a poor concordance (value of Kappa=0.051). This is the first report ofNeospora spp. antibodies in Brazilian donkeys and the first detection of antibodies against S. neurona in this animal species.
Resumo Sarcocystis neurona e Neospora hughesi são protozoários coccídios que infectam equídeos e são responsáveis por doenças neurológicas nessas espécies. Neste estudo, a soroprevalência de infecção porS. neurona e Neospora spp. foi determinada em amostras de 333 soros de jumentos da Região Nordeste do Brasil. Anticorpos contra Neospora spp. foram detectados em 2% (7 jumentos) dos 333 animais examinados pela reação de imunofluorescência indireta (RIFI), com ponto de corte de 40. Anticorpos contra S. neurona foram detectados em 3% (10 jumentos) das amostras pela RIFI (ponto de corte de 50) e em 21% (69 jumentos) pela técnica de aglutinação direta (SAT - ponto de corte de 50). SAT e RIFI, para diagnóstico de S. neurona, apresentaram uma baixa concordância (Kappa = 0,051). Essa é a primeira observação de anticorpos anti-N. caninum em jumentos brasileiros e a primeira detecção de anticorpos contra S. neurona nessa espécie.
Assuntos
Animais , Anticorpos Antiprotozoários/sangue , Sarcocystis/imunologia , Sarcocistose/veterinária , Coccidiose/veterinária , Neospora/imunologia , Equidae/imunologia , Brasil/epidemiologia , Estudos Soroepidemiológicos , Prevalência , Sarcocistose/imunologia , Sarcocistose/epidemiologia , Coccidiose/imunologia , Coccidiose/epidemiologia , Hiperbilirrubinemia Neonatal/veterináriaRESUMO
Equine herpesvirus type 1 (EHV-1) causes respiratory disorders and abortion in equids while EHV-1 regularly causes equine herpesvirus myeloencephalopathy (EHM), a stroke-like syndrome following endothelial cell infection in horses. Both EHV-1 and EHV-9 infections of non-definitive hosts often result in neuronal infection and high case fatality rates. Hence, EHV-1 and EHV-9 are somewhat unusual herpesviruses and lack strict host specificity, and the true extent of their host ranges have remained unclear. In order to determine the seroprevalence of EHV-1 and EHV-9, a sensitive and specific peptide-based ELISA was developed and applied to 428 sera from captive and wild animals representing 30 species in 12 families and five orders. Members of the Equidae, Rhinocerotidae and Bovidae were serologically positive for EHV-1 and EHV-9. The prevalence of EHV-1 in the sampled wild zebra populations was significantly higher than in zoos suggesting captivity may reduce exposure to EHV-1. Furthermore, the seroprevalence for EHV-1 was significantly higher than for EHV-9 in zebras. In contrast, EHV-9 antibody prevalence was high in captive and wild African rhinoceros species suggesting that they may serve as a reservoir or natural host for EHV-9. Thus, EHV-1 and EHV-9 have a broad host range favoring African herbivores and may have acquired novel natural hosts in ecosystems where wild equids are common and are in close contact with other perissodactyls.
Assuntos
Animais Selvagens/virologia , Animais de Zoológico/virologia , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/imunologia , Doenças dos Cavalos/epidemiologia , Animais , Anticorpos Antivirais/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Equidae/imunologia , Equidae/virologia , Infecções por Herpesviridae/virologia , Doenças dos Cavalos/virologia , Cavalos/virologia , Peptídeos/imunologia , PrevalênciaRESUMO
Sex hormones, reproductive status, and pathogen load all affect stress. Together with stress, these factors can modulate the immune system and affect disease incidence. Thus, it is important to concurrently measure these factors, along with their seasonal fluctuations, to better understand their complex interactions. Using steroid hormone metabolites from fecal samples, we examined seasonal correlations among zebra and springbok stress, reproduction, gastrointestinal (GI) parasite infections, and anthrax infection signatures in zebra and springbok in Etosha National Park (ENP), Namibia, and found strong seasonal effects. Infection intensities of all three GI macroparasites examined (strongyle helminths, Strongyloides helminths, and Eimeria coccidia) were highest in the wet season, concurrent with the timing of anthrax outbreaks. Parasites also declined with increased acquired immune responses. We found hormonal evidence that both mares and ewes are overwhelmingly seasonal breeders in ENP, and that reproductive hormones are correlated with immunosuppression and higher susceptibility to GI parasite infections. Stress hormones largely peak in the dry season, particularly in zebra, when parasite infection intensities are lowest, and are most strongly correlated with host mid-gestation rather than with parasite infection intensity. Given the evidence that GI parasites can cause host pathology, immunomodulation, and immunosuppression, their persistence in ENP hosts without inducing chronic stress responses supports the hypothesis that hosts are tolerant of their parasites. Such tolerance would help to explain the ubiquity of these organisms in ENP herbivores, even in the face of their potential immunomodulatory trade-offs with anti-anthrax immunity.
Assuntos
Animais Selvagens/parasitologia , Antraz/diagnóstico , Fezes/parasitologia , Hormônios/metabolismo , Animais , Antílopes/imunologia , Antílopes/parasitologia , Antraz/imunologia , Antraz/veterinária , Eimeria/imunologia , Eimeria/isolamento & purificação , Equidae/imunologia , Equidae/parasitologia , Helmintos/imunologia , Helmintos/isolamento & purificação , Hormônios/imunologia , Hormônios/isolamento & purificação , Interações Hospedeiro-Parasita/imunologia , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/veterinária , Namíbia , Estações do AnoRESUMO
Pathogen evasion of the host immune system is a key force driving extreme polymorphism in genes of the major histocompatibility complex (MHC). Although this gene family is well characterized in structure and function, there is still much debate surrounding the mechanisms by which MHC diversity is selectively maintained. Many studies have investigated relationships between MHC variation and specific pathogens, and have found mixed support for and against the hypotheses of heterozygote advantage, frequency-dependent or fluctuating selection. Few, however, have focused on the selective effects of multiple parasite types on host immunogenetic patterns. Here, we examined relationships between variation in the equine MHC gene, ELA-DRA, and both gastrointestinal (GI) and ectoparasitism in plains zebras (Equus quagga). Specific alleles present at opposing population frequencies had antagonistic effects, with rare alleles associated with increased GI parasitism and common alleles with increased tick burdens. These results support a frequency-dependent mechanism, but are also consistent with fluctuating selection. Maladaptive GI parasite 'susceptibility alleles' were reduced in frequency, suggesting that these parasites may play a greater selective role at this locus. Heterozygote advantage, in terms of allele mutational divergence, also predicted decreased GI parasite burden in genotypes with a common allele. We conclude that an immunogenetic trade-off affects resistance/susceptibility to parasites in this system. Because GI and ectoparasites do not directly interact within hosts, our results uniquely show that antagonistic parasite interactions can be indirectly modulated through the host immune system. This study highlights the importance of investigating the role of multiple parasites in shaping patterns of host immunogenetic variation.
Assuntos
Equidae , Enteropatias Parasitárias/veterinária , Infecções por Strongylida/veterinária , Infestações por Carrapato/veterinária , Animais , Equidae/genética , Equidae/imunologia , Equidae/parasitologia , Feminino , Frequência do Gene , Heterozigoto , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/parasitologia , Complexo Principal de Histocompatibilidade/genética , Complexo Principal de Histocompatibilidade/imunologia , Masculino , Namíbia/epidemiologia , Estações do Ano , Estrongilídios/isolamento & purificação , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/imunologia , Infecções por Strongylida/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/imunologia , Infestações por Carrapato/parasitologia , Carrapatos/fisiologiaRESUMO
A neosporose tem grande importância em bovinos, e sua patogênese neste hospedeiro, em termos gerais, está esclarecida, porém, em equídeos é pobremente conhecida. Na Colômbia ainda não foram reportados anticorpos Anti-Neospora spp. em equídeos, sendo assim objetivou-se no presente estudo avaliar a ocorrência do parasito em jumentos (Equus asinus) de fazendas que apresentavam risco da doença nestes animais. Foram utilizados 56 animais no estado de Sucre (Colômbia), escolhidos aleatoriamente dentro das fazendas selecionadas. Utilizou-se um peptídeo recombinante originado de Neospora caninum (NcGRA1) para o diagnóstico por Dot-ELISA, e o soro foi diluído em 1:200. Este estudo reporta, pela primeira vez no estado de Sucre e na Colômbia, a presença de anticorpos anti-Neospora spp. na espécie Equus asinus, com uma ocorrência de 19,7% (11/56) dos animais amostrados...
The neosporosis has great importance in cattle, and its pathogenesis in this host has been generally clarified, however, in horses, neosporosis is poorly known, and in Colombia anti-Neospora spp antibodies have not been reported. Therefore, the main objective in the present study was to evaluate the occurrence of this parasite in donkeys (Equus asinus) from farms that presented a risk of disease in these animals, as well as no health plan for them. Were used 56 animals randomly chosen inside selected farms in the state of Sucre (Colombia). A recombinant peptide originated from Neospora caninum (NcGRA1) was used for the diagnosis with Dot-ELISA and serum was diluted 1:200. This study is the first to report the presence of anti-Neospora spp. in donkeys (Equus asinus) in the state of Sucre, and in Colombia. The occurrence was in 19.7% of the animals sampled (11/56)...
Assuntos
Animais , Anticorpos/isolamento & purificação , Equidae/imunologia , Neospora/isolamento & purificação , Medidas de Ocorrência de DoençasRESUMO
Few studies have examined host-pathogen interactions in wildlife from an immunological perspective, particularly in the context of seasonal and longitudinal dynamics. In addition, though most ecological immunology studies employ serological antibody assays, endpoint titre determination is usually based on subjective criteria and needs to be made more objective. Despite the fact that anthrax is an ancient and emerging zoonotic infectious disease found world-wide, its natural ecology is not well understood. In particular, little is known about the adaptive immune responses of wild herbivore hosts against Bacillus anthracis. Working in the natural anthrax system of Etosha National Park, Namibia, we collected 154 serum samples from plains zebra (Equus quagga), 21 from springbok (Antidorcas marsupialis) and 45 from African elephants (Loxodonta africana) over 2-3 years, resampling individuals when possible for seasonal and longitudinal comparisons. We used enzyme-linked immunosorbent assays to measure anti-anthrax antibody titres and developed three increasingly conservative models to determine endpoint titres with more rigourous, objective mensuration. Between 52 and 87% of zebra, 0-15% of springbok and 3-52% of elephants had measurable anti-anthrax antibody titres, depending on the model used. While the ability of elephants and springbok to mount anti-anthrax adaptive immune responses is still equivocal, our results indicate that zebra in ENP often survive sublethal anthrax infections, encounter most B. anthracis in the wet season and can partially booster their immunity to B. anthracis. Thus, rather than being solely a lethal disease, anthrax often occurs as a sublethal infection in some susceptible hosts. Though we found that adaptive immunity to anthrax wanes rapidly, subsequent and frequent sublethal B. anthracis infections cause maturation of anti-anthrax immunity. By triggering host immune responses, these common sublethal infections may act as immunomodulators and affect population dynamics through indirect immunological and co-infection effects. In addition, with our three endpoint titre models, we introduce more mensuration rigour into serological antibody assays, even under the often-restrictive conditions that come with adapting laboratory immunology methods to wild systems. With these methods, we identified significantly more zebras responding immunologically to anthrax than have previous studies using less comprehensive titre analyses.
Assuntos
Antílopes/imunologia , Antílopes/microbiologia , Antraz/imunologia , Antraz/veterinária , Elefantes/imunologia , Elefantes/microbiologia , Equidae/imunologia , Equidae/microbiologia , Interações Hospedeiro-Patógeno , Estações do Ano , Imunidade Adaptativa , Animais , Anticorpos Antibacterianos/sangue , Namíbia/epidemiologiaRESUMO
To evaluate the effect of seminal plasma in endometrial inflammation in donkeys, samples from fresh pure, fresh diluted and frozen-thawed semen of three different jackasses were co-incubated in water bath at 37°C with uterine Jennie's secretions collected 6h after artificial insemination with frozen-thawed donkey semen. Individual sperm movement parameters using the computerised sperm analysis system (CASA) and sperm-polymorphonuclear neutrophils (sperm-PMN) attachment observed in Diff-Quick stained smears were evaluated at 0, 1, 2, 3 and 4h of co-incubation. Controls consisted of incubating diluted or frozen-thawed sperm in the absence of uterine secretions. For data analyses, a repeated measures ANOVA was performed with incubation time as intra-subject factor and with treatment and donkey as inter-subject factor, followed by a post-hoc Bonferroni's test. Greater values (P<0.05) of sperm-PMN percentages and a loss of progressive motility were observed in frozen-thawed semen compared with pure and diluted fresh semen samples throughout the incubation time. In addition, the presence of seminal plasma in fresh and diluted semen samples reduced the inflammatory response of polymorphonuclear neutrophils produced after insemination by suppressing the sperm-PMN attachment in vitro. Motility sperm parameters analysed by CASA were also less affected than those in frozen-thawed semen samples. In conclusion, seminal plasma in jennies appears to have a modulation on the endometrial response after artificial insemination with frozen-thawed donkey semen. As a result, spermatozoa with the greater motility characteristics are selected.
Assuntos
Endométrio/imunologia , Equidae/imunologia , Inseminação Artificial/veterinária , Neutrófilos/imunologia , Sêmen/imunologia , Espermatozoides/imunologia , Animais , Endométrio/citologia , Feminino , Citometria de Fluxo/veterinária , Técnicas In Vitro , Masculino , Análise do Sêmen/veterináriaRESUMO
Strangles is an extremely contagious and sometimes deadly disease of the Equidae. The development of an effective vaccine should constitute an important asset to eradicate this worldwide infectious disease. In this work, we address the development of a mucosal vaccine by using a Supercritical Enhanced Atomization (SEA) spray-drying technique. Aqueous solutions containing the Streptococcus equi extracts and chitosan were converted into nanospheres with no use of organic solvents. The immune response in a mouse model showed that the nanospheres induced a well-balanced Th1 and Th2 response characterized by a unitary ratio between the concentrations of IgG2a and IgG1, together with IgA production. This strategy revealed to be an effective alternative for immunization against S. equi, and therefore, it may constitute a feasible option for production of a strangles vaccine.
Assuntos
Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/administração & dosagem , Vacinas Estreptocócicas/imunologia , Streptococcus equi/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Quitosana/química , Equidae/imunologia , Feminino , Doenças dos Cavalos/prevenção & controle , Cavalos/imunologia , Imunoglobulina G/imunologia , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Nanosferas/química , Soluções/química , Vacinas Estreptocócicas/química , Células Th1/imunologia , Células Th2/imunologia , Vacinação/métodos , Água/químicaRESUMO
Wildlife, free-ranging and captive, poses and causes serious population problems not unlike those encountered with human overpopulation. Traditional lethal control programs, however, are not always legal, wise, safe, or publicly acceptable; thus, alternative approaches are necessary. Immunocontraception of free-ranging wildlife has reached the management level, with success across a large variety of species. Thus far, the immunocontraceptive research and management applications emphasis have been centered on porcine zona pellucida and gonadotropin-releasing hormone vaccines. Contraceptive success has been achieved in more than 85 different wildlife species, at the level of both the individual animal and the population. At the population management level with free-ranging species, the primary focus has been on wild horses, urban deer, bison, and African elephants. The challenges in the development and application of vaccine-based wildlife contraceptives are diverse and include differences in efficacy across species, safety of vaccines during pregnancy, the development of novel delivery systems for wild and wary free-ranging animals, and the constraints of certain non-contraceptive effects, such as effects on behavior. Beyond the constraints imposed by the public and a host of regulatory concerns, there exists a real limitation for funding of well-designed programs that apply this type of fertility control.