RESUMO
Trichinellosis is a foodborne disease caused by ingestion of raw or undercooked meat containing Trichinella spp. larvae. Consumption of wild boar (Sus scrofa) meat represents an important source of human trichinellosis worldwide. In El Palmar National Park (EPNP), Argentina, invasive alien wild boars are controlled and meat from culled animals is released for public consumption following on-site artificial digestion (AD) testing. Meat trimmings and offal from the control program are often used as food for dogs (Canis familiaris). We evaluated infection and exposure to Trichinella spp. in wild boars from EPNP, as well as exposure to Trichinella spp. and associated risk factors in dogs and human consumers of wild boar meat. Trichinella spp. larvae were detected in muscle samples from 5/49 wild boars by AD (10.2%; 95% confidence interval [CI], 3.8%-23%), with a mean burden of 0.24 larvae per gram (lpg; range, 0.06-0.95 lpg). Anti-Trichinella antibodies were not detected in wild boar serum samples (n=42). In dogs, 12/34 were seropositive to Trichinella spp. (35.29%; 95%, CI, 20.3%-53.5%). Immunoglobulin (Ig) G antibodies were not detected in human serum samples (n=63). Our results reveal the presence, albeit at low prevalence, of Trichinella spp. in wild boars and exposure in dogs fed game offal. These findings suggest that the low prevalence and parasitic load in wild boars, together with the best practices applied by EPNP culling program personnel, contribute to keeping the risk of infection in people low. The dog results highlight that the parasite is circulating in the area, and therefore the risk of infection is not negligible. We recommend the implementation of an animal surveillance strategy in order to monitor the evolution of this zoonosis in the study area.
Assuntos
Doenças do Cão , Nitrofenóis , Doenças dos Suínos , Trichinella , Triquinelose , Suínos , Humanos , Animais , Cães , Triquinelose/epidemiologia , Triquinelose/veterinária , Triquinelose/parasitologia , Argentina/epidemiologia , Parques Recreativos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/parasitologia , Carne/parasitologia , Imunoglobulina G , Sus scrofa , Doenças do Cão/epidemiologia , Compostos de EpóxiRESUMO
VirB proteins from Brucella spp. constitute the type IV secretion system, a key virulence factor mediating the intracellular survival of these bacteria. Here, we assessed whether a Th1-type immune response against VirB proteins may protect mice from Brucella infection and whether this response can be induced in the dog, a natural host for Brucella. Splenocytes from mice immunized with VirB7 or VirB9 responded to their respective antigens with significant and specific production of gamma interferon (IFN-γ), whereas interleukin-4 (IL-4) was not detected. Thirty days after an intraperitoneal challenge with live Brucella abortus, the spleen load of bacteria was almost 1 log lower in mice immunized with VirB proteins than in unvaccinated animals. As colonization reduction seemed to correlate with a Th1-type immune response against VirB proteins, we decided to assess whether such a response could be elicited in the dog. Peripheral blood mononuclear cells (PBMCs) from dogs immunized with VirB proteins (three subcutaneous doses in QuilA adjuvant) produced significantly higher levels of IFN-γ than cells from control animals upon in vitro stimulation with VirB proteins. A skin test to assess specific delayed-type hypersensitivity was positive in 4 out of 5 dogs immunized with either VirB7 or VirB9. As both proteins are predicted to locate in the outer membrane of Brucella organisms, the ability of anti-VirB antibodies to mediate complement-dependent bacteriolysis of B. canis was assessed in vitro. Sera from dogs immunized with either VirB7 or VirB9, but not from those receiving phosphate-buffered saline (PBS), produced significant bacteriolysis. These results suggest that VirB-specific responses that reduce organ colonization by Brucella in mice can be also elicited in dogs.
Assuntos
Proteínas de Bactérias/imunologia , Sistemas de Secreção Bacterianos , Vacina contra Brucelose/imunologia , Brucella/crescimento & desenvolvimento , Brucella/imunologia , Baço/microbiologia , Células Th1/imunologia , Adjuvantes Imunológicos , Animais , Anticorpos Antibacterianos/imunologia , Carga Bacteriana , Proteínas de Bactérias/administração & dosagem , Bacteriólise , Brucella/patogenicidade , Vacina contra Brucelose/administração & dosagem , Brucella abortus/imunologia , Brucella canis/imunologia , Cães , Hipersensibilidade Tardia , Injeções Subcutâneas , Interferon gama/imunologia , Interleucina-4/imunologia , Leucócitos Mononucleares/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Baço/citologia , Baço/imunologia , VacinaçãoRESUMO
Canine brucellosis is an infectious disease caused by the Gram-negative bacterium Brucella canis. Unlike conventional control programs for other species of the genus Brucella, currently there is no vaccine available against canine brucellosis, and preventive measures are simply diagnosis and isolation of infected dogs. New approaches are therefore needed to develop an effective and safe immunization strategy against this zoonotic pathogen. In this study, BALB/c mice were subcutaneously immunized with the following: (i) the recombinant Brucella Omp31 antigen formulated in different adjuvants (incomplete Freund adjuvant, aluminum hydroxide, Quil A, and Montanide IMS 3012 VGPR), (ii) plasmid pCIOmp31, or (iii) pCIOmp31 plasmid followed by boosting with recombinant Omp31 (rOmp31). The immune response and the protective efficacy against B. canis infection were characterized. The different strategies induced a strong immunoglobulin G (IgG) response. Furthermore, spleen cells from rOmp31-immunized mice produced gamma interferon and interleukin-4 (IL-4) after in vitro stimulation with rOmp31, indicating the induction of a mixed Th1-Th2 response. Recombinant Omp31 administered with different adjuvants as well as the prime-boost strategy conferred protection against B. canis. In conclusion, our results suggest that Omp31 could be a useful candidate for the development of a subcellular vaccine against B. canis infection.
Assuntos
Anticorpos Antibacterianos/sangue , Proteínas da Membrana Bacteriana Externa/imunologia , Vacina contra Brucelose/imunologia , Brucella canis/imunologia , Brucelose/imunologia , Linfócitos T Citotóxicos/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Brucelose/prevenção & controle , Cães , Camundongos , Camundongos Endogâmicos BALB C , VacinaçãoRESUMO
The adhesion of bacterial pathogens to host cells is an event that determines infection, and ultimately invasion and intracellular multiplication. Several evidences have recently shown that this rule is also truth for the intracellular pathogen Brucella. Brucella suis displays the unipolar BmaC and BtaE adhesins, which belong to the monomeric and trimeric autotransporter (TA) families, respectively. It was previously shown that these adhesins are involved in bacterial adhesion to host cells and components of the extracellular matrix (ECM). In this work we describe the role of a new member of the TA family of B. suis (named BtaF) in the adhesive properties of the bacterial surface. BtaF conferred the bacteria that carried it a promiscuous adhesiveness to various ECM components and the ability to attach to an abiotic surface. Furthermore, BtaF was found to participate in bacterial adhesion to epithelial cells and was required for full virulence in mice. Similar to BmaC and BtaE, the BtaF adhesin was expressed in a small subpopulation of bacteria, and in all cases, it was detected at the new pole generated after cell division. Interestingly, BtaF was also implicated in the resistance of B. suis to porcine serum. Our findings emphasize the impact of TAs in the Brucella lifecycle.
Assuntos
Adesinas Bacterianas/metabolismo , Aderência Bacteriana/fisiologia , Brucella suis/fisiologia , Brucella suis/patogenicidade , Adesinas Bacterianas/química , Adesinas Bacterianas/imunologia , Animais , Brucelose/imunologia , Brucelose/metabolismo , Linhagem Celular , Matriz Extracelular/metabolismo , Humanos , Masculino , Camundongos , Família Multigênica , Multimerização Proteica , Transporte Proteico , Suínos , VirulênciaRESUMO
Canine brucellosis represents a major reproductive problem worldwide and it is considered a zoonotic disease. New approaches are therefore urgently needed to develop an effective and safe immunization strategy against Brucella canis. In the present study, BALB/c mice were subcutaneously immunized with the recombinant chimera rBLSOmp31 formulated in different adjuvants. The different strategies induced a vigorous immunoglobulin G (IgG) response, with high titers of IgG1 as well as IgG2. Besides, spleen cells from rBLSOmp31-immunized mice produced gamma interferon and IL-4, suggesting the induction of a mixed Th1-Th2. Vaccination with rBLSOmp31-IFA formulation provided the best protection levels comparable with that given by control vaccines. None of the immunization strategies induced serological interference in diagnosis. Hitherto, this is the first report that a recombinant vaccine confers protection against B. canis in mice.
Assuntos
Vacina contra Brucelose/administração & dosagem , Vacina contra Brucelose/imunologia , Brucella canis/imunologia , Brucelose/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antibacterianos/sangue , Brucelose/imunologia , Modelos Animais de Doenças , Feminino , Imunoglobulina G/sangue , Injeções Subcutâneas , Interferon gama/metabolismo , Interleucina-4/metabolismo , Leucócitos Mononucleares/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Baço/imunologiaRESUMO
Brucella ovis is the etiologic agent of ovine brucellosis. The control measures for this disease are periodical diagnosis by serological tests and/or bacteriological culture and culling of positive animals. Vaccination with Brucella melitensis Rev 1 is recommended when prevalence is high. This attenuated strain vaccine gives protection against B. ovis but it has important disadvantages associated with the development of antibodies interfering with serodiagnosis, virulence for humans and the prohibition of its use in countries considered free of B. melitensis. Consequently, there is a need for new safe and effective brucellosis vaccines to be developed. We have previously reported that the polymeric subcellular vaccine BLSOmp31 confers protection against experimental challenge with B. ovis when rams are immunized three times. In the present work we evaluated and characterized, along 56 weeks after the first immunization of adult rams, the evolution of the immune response elicited by BLSOmp31 using a short immunization schedule.
Assuntos
Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Brucelose/veterinária , Doenças dos Ovinos/prevenção & controle , Animais , Anticorpos Antibacterianos/sangue , Brucella ovis , Brucelose/prevenção & controle , Esquemas de Imunização , Interferon gama , Masculino , Proteínas Recombinantes/imunologia , OvinosRESUMO
Ovine brucellosis by Brucella ovis is a highly prevalent disease in Argentina. This study aimed to evaluate the pathogenicity of B. ovis and the serological response in ewes during late pregnancy and in their offspring. Six adult ewes were distributed in two groupsG1 (pregnant females, n = 4) and G2 (nonpregnant females, n = 2). Three pregnant ewes at 15 days prepartum and one nonpregnant eve were inoculated with B. ovis. Sera of sheep and their offspring were analyzed by different serological tests. Samples of cervicovaginal mucus, placenta and milk were studied by bacteriology. A Brucella genus-specific PCR assay was carried out in placenta and milk samples. Placenta samples were hystopathologically processed. g1 females gave birth to live lambs, but one died hours postpartum. Serological techniques employed detected antibodies in serum of inoculated pregnant animal 5 days postchallenge. sera of female controls G1 and G2 remained negative throughout the study. Cervicovaginal mucus of infected ewes in G1 and G2 yielded negative results to bacteriology, but B. ovis was isolated from milk. The PCR assay was positive for the placenta and milk from inoculated pregnant ewes. Histopathology revealed necrotic suppurative placentitis in one placenta. However, although results demonstrated that B. ovis can invade the placenta and mammary gland, this bacterium did not cause abortion when it was inoculated intravenously at 15 days prepartum. B. ovis infection induced an early humoral response in pregnant ewes, but their lambs remained seronegative, indicating that there was no transfer of antibodies in infancy. Placenta colonization and milk excretion of B. ovis involves a potential source of infection for lambs, which could play a role as latent carriers of infection.
Assuntos
Brucella ovis/patogenicidade , Brucelose/veterinária , Complicações Infecciosas na Gravidez/veterinária , Doenças dos Ovinos/microbiologia , Aborto Animal , Animais , Animais Recém-Nascidos/imunologia , Anticorpos Antibacterianos/sangue , Brucella ovis/imunologia , Brucelose/complicações , Brucelose/imunologia , Brucelose/microbiologia , Brucelose/transmissão , Muco do Colo Uterino/microbiologia , DNA Bacteriano/análise , Feminino , Transmissão Vertical de Doenças Infecciosas/veterinária , Glândulas Mamárias Animais/microbiologia , Leite/microbiologia , Placenta/microbiologia , Placenta/patologia , Doenças Placentárias/imunologia , Doenças Placentárias/microbiologia , Doenças Placentárias/veterinária , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologia , Ovinos/imunologia , Ovinos/microbiologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/transmissãoRESUMO
La brucelosis ovina por Brucella ovis es una enfermedad de prevalencia alta en Argentina. Para evaluar la patogenicidad de B. ovis y la respuesta serológica durante el último mes de gestación, 6 ovejas se distribuyeron en dos grupos: G1, ovejas preñadas, n = 4 y G2, ovejas no preñadas, n = 2. Tres ovejas del G1 (15 días preparto) y una del G2 fueron inoculadas con B. ovis. Se analizaron muestras de suero mediante diferentes pruebas serológicas. Se realizó aislamiento y PCR a partir de mucus cérvico-vaginal (mcv), placenta y leche. En las muestras de placenta se realizó histopatología. Las hembras del G1 parieron corderos vivos; se detectaron anticuerpos en las ovejas desafiadas del G1 a partir de los 5 días posinoculación. El mcv de las ovejas desafiadas resultó negativo al aislamiento en ambos grupos. Las muestras de leche del G1 fueron positivas por cultivo y PCR a B. ovis. La técnica de PCR resultó positiva en las placentas de las ovejas desafiadas del G1. La histopatología reveló una placentitis necrótica supurativa en una de las ovejas desafiadas. El desafío con B. ovis preparto resultó en la invasión de la placenta y de la glándula mamaria, con la consecuente excreción de la bacteria por leche. La infección con B. ovis indujo una respuesta humoral temprana en las ovejas. La colonización de la placenta por B. ovis y la excreción de la bacteria por la leche sugieren un potencial riesgo de infección activa para los corderos y la posibilidad de que estos se comporten como portadores latentes de la infección.
Ovine brucellosis by Brucella ovis is a highly prevalent disease in Argentina. This study aimed to evaluate the pathogenicity of B. ovis and the serological response in ewes during late pregnancy and in their offspring. Six adult ewes were distributed in two groupsGI (pregnant females, n = 4) and G2 (nonpregnant females, n = 2). Three pregnant ewes at 15 days prepartum and one nonpregnant eve were inoculated with B. ovis. Sera of sheep and their offspring were analyzed by different serological tests. Samples of cervicovaginal mucus, placenta and milk were studied by bacteriology. A Brucella genus-specific PCR assay was carried out in placenta and milk samples. Placenta samples were hystopathologically processed. G1 females gave birth to live lambs, but one died hours postpartum. Serological techniques employed detected antibodies in serum of inoculated pregnant animal 5 days postchallenge. Sera of female controls G1 and G2 remained negative throughout the study. Cervicovaginal mucus of infected ewes in G1 and G2 yielded negative results to bacteriology, but B. ovis was isolated from milk. The PCR assay was positive for the placenta and milk from inoculated pregnant ewes. Histopathology revealed necrotic suppurative placentitis in one placenta. However, although results demonstrated that B. ovis can invade the placenta and mammary gland, this bacterium did not cause abortion when it was inoculated intravenously at 15 days prepartum. B. ovis infection induced an early humoral response in pregnant ewes, but their lambs remained seronegative, indicating that there was no transfer of antibodies in infancy. Placenta colonization and milk excretion of B. ovis involves a potential source of infection for lambs, which could play a role as latent carriers of infection.
Assuntos
Animais , Feminino , Gravidez , Brucella ovis/patogenicidade , Brucelose/veterinária , Complicações Infecciosas na Gravidez/veterinária , Doenças dos Ovinos/microbiologia , Aborto Animal , Animais Recém-Nascidos/imunologia , Anticorpos Antibacterianos/sangue , Brucella ovis/imunologia , Brucelose/complicações , Brucelose/imunologia , Brucelose/microbiologia , Brucelose/transmissão , Muco do Colo Uterino/microbiologia , DNA Bacteriano/análise , Transmissão Vertical de Doenças Infecciosas/veterinária , Glândulas Mamárias Animais/microbiologia , Leite/microbiologia , Reação em Cadeia da Polimerase , Doenças Placentárias/imunologia , Doenças Placentárias/microbiologia , Doenças Placentárias/veterinária , Placenta/microbiologia , Placenta/patologia , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/transmissão , Ovinos/imunologia , Ovinos/microbiologiaRESUMO
La brucelosis ovina por Brucella ovis es una enfermedad de prevalencia alta en Argentina. Para evaluar la patogenicidad de B. ovis y la respuesta serológica durante el último mes de gestación, 6 ovejas se distribuyeron en dos grupos: G1, ovejas preñadas, n = 4 y G2, ovejas no preñadas, n = 2. Tres ovejas del G1 (15 días preparto) y una del G2 fueron inoculadas con B. ovis. Se analizaron muestras de suero mediante diferentes pruebas serológicas. Se realizó aislamiento y PCR a partir de mucus cérvico-vaginal (mcv), placenta y leche. En las muestras de placenta se realizó histopatología. Las hembras del G1 parieron corderos vivos; se detectaron anticuerpos en las ovejas desafiadas del G1 a partir de los 5 días posinoculación. El mcv de las ovejas desafiadas resultó negativo al aislamiento en ambos grupos. Las muestras de leche del G1 fueron positivas por cultivo y PCR a B. ovis. La técnica de PCR resultó positiva en las placentas de las ovejas desafiadas del G1. La histopatología reveló una placentitis necrótica supurativa en una de las ovejas desafiadas. El desafío con B. ovis preparto resultó en la invasión de la placenta y de la glándula mamaria, con la consecuente excreción de la bacteria por leche. La infección con B. ovis indujo una respuesta humoral temprana en las ovejas. La colonización de la placenta por B. ovis y la excreción de la bacteria por la leche sugieren un potencial riesgo de infección activa para los corderos y la posibilidad de que estos se comporten como portadores latentes de la infección.(AU)
Ovine brucellosis by Brucella ovis is a highly prevalent disease in Argentina. This study aimed to evaluate the pathogenicity of B. ovis and the serological response in ewes during late pregnancy and in their offspring. Six adult ewes were distributed in two groupsGI (pregnant females, n = 4) and G2 (nonpregnant females, n = 2). Three pregnant ewes at 15 days prepartum and one nonpregnant eve were inoculated with B. ovis. Sera of sheep and their offspring were analyzed by different serological tests. Samples of cervicovaginal mucus, placenta and milk were studied by bacteriology. A Brucella genus-specific PCR assay was carried out in placenta and milk samples. Placenta samples were hystopathologically processed. G1 females gave birth to live lambs, but one died hours postpartum. Serological techniques employed detected antibodies in serum of inoculated pregnant animal 5 days postchallenge. Sera of female controls G1 and G2 remained negative throughout the study. Cervicovaginal mucus of infected ewes in G1 and G2 yielded negative results to bacteriology, but B. ovis was isolated from milk. The PCR assay was positive for the placenta and milk from inoculated pregnant ewes. Histopathology revealed necrotic suppurative placentitis in one placenta. However, although results demonstrated that B. ovis can invade the placenta and mammary gland, this bacterium did not cause abortion when it was inoculated intravenously at 15 days prepartum. B. ovis infection induced an early humoral response in pregnant ewes, but their lambs remained seronegative, indicating that there was no transfer of antibodies in infancy. Placenta colonization and milk excretion of B. ovis involves a potential source of infection for lambs, which could play a role as latent carriers of infection.(AU)
Assuntos
Animais , Feminino , Gravidez , Brucella ovis/patogenicidade , Brucelose/veterinária , Complicações Infecciosas na Gravidez/veterinária , Doenças dos Ovinos/microbiologia , Aborto Animal , Animais Recém-Nascidos/imunologia , Anticorpos Antibacterianos/sangue , Brucella ovis/imunologia , Brucelose/complicações , Brucelose/imunologia , Brucelose/microbiologia , Brucelose/transmissão , Muco do Colo Uterino/microbiologia , DNA Bacteriano/análise , Transmissão Vertical de Doenças Infecciosas/veterinária , Glândulas Mamárias Animais/microbiologia , Leite/microbiologia , Placenta/microbiologia , Placenta/patologia , Doenças Placentárias/imunologia , Doenças Placentárias/microbiologia , Doenças Placentárias/veterinária , Reação em Cadeia da Polimerase , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologia , Ovinos/imunologia , Ovinos/microbiologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/transmissãoRESUMO
Brucella is responsible for brucellosis, one of the most common zoonoses worldwide that causes important economic losses in several countries. Increasing evidence indicates that adhesion of Brucella spp. to host cells is an important step to establish infection. We have previously shown that the BmaC unipolar monomeric autotransporter mediates the binding of Brucella suis to host cells through cell-associated fibronectin. Our genome analysis shows that the B. suis genome encodes several additional potential adhesins. In this work, we characterized a predicted trimeric autotransporter that we named BtaE. By expressing btaE in a nonadherent Escherichia coli strain and by phenotypic characterization of a B. suis ΔbtaE mutant, we showed that BtaE is involved in the binding of B. suis to hyaluronic acid. The B. suis ΔbtaE mutant exhibited a reduction in the adhesion to HeLa and A549 epithelial cells compared with the wild-type strain, and it was outcompeted by the wild-type strain in the binding to HeLa cells. The knockout btaE mutant showed an attenuated phenotype in the mouse model, indicating that BtaE is required for full virulence. BtaE was immunodetected on the bacterial surface at one cell pole. Using old and new pole markers, we observed that both the BmaC and BtaE adhesins are consistently associated with the new cell pole, suggesting that, in Brucella, the new pole is functionally differentiated for adhesion. This is consistent with the inherent polarization of this bacterium, and its role in the invasion process.