Resumo A ocorrência de ectoparasitas em nutria selvagem é pouco compreendido. Cinquenta e cinco nutria selvagem capturadas (Myocastor coypus) de sua região indígena foram examinados para os ectoparasitas após até captura a partir de dezembro de 2013 a dezembro de 2014. As capturas ocorreram no estado de Buenos Aires, a área mais densamente povoada do país por nutria, caraterizada como uma pastagem temperada, que se tornou área principal para a agricultura sustentável. Uma espécie de piolhos de mastigação (Pitrufquenia coypus, Marelli, 1932), uma pulga (Nosopsyllus fasciatus, Bosc, 1800) e um carrapato (Rhipicephalus sanguineus, Latreille, 1806) foram recolhidos. Catorze por cento dos animais foram infestadas pelo P.coypus, um parasita obrigatório do nutria, sendo o ectoparasita mais prevalente. A ocorrência de N. fasciatus e R. sanguineus continua controversa, pois podem ou não ser algumas espécies hospedeiras acidentais. Para nosso conhecimento, este é o primeiro estudo abrangente e sistemático de ectoparasitas em nutria selvagem do hemisfério sul, a região indígena desta espécie.

Abstract The occurrence of ectoparasites in wild nutria is poorly understood. Fifty-five livetrapped wild nutria (Myocastor coypus) from its indigenous region were examined for ectoparasites after capture from December 2013 to December 2014. The captures came from the Buenos Aires Province, by far the area of the country most densely populated by nutria, characterized as a temperate grassland, which are prime areas for sustained agriculture. Only one species of chewing lice (Pitrufquenia coypus, Marelli, 1932), one flea (Nosopsyllus fasciatus, Bosc, 1800) and one tick (Rhipicephalus sanguineus, Latreille, 1806) were collected. Fourteen percent of the animals were infested and P.coypus, an obligate parasite of the nutria, which was the most prevalent ectoparasite. N. fasciatus and R. sanguineus occurrence remains controversial as they may or may not be some accidental host species. To our knowledge, this is the first comprehensive and systematic survey of ectoparasites in wild nutria from the southern hemisphere, the indigenous region of this species.

O objetivo do presente estudo foi descrever um caso de isolamento de espécie patogênica de Leptospira interrogans em amostra de urina de um humano morador da zona rural do Município de Cruz Alta, Estado do Rio Grande do Sul. De cada amostra de urina, uma alíquota foi semeada nos meios Fletcher e Ellinghausen - McCullough - Johnson - Harris (EMJH). As amostras, nas quais houve crescimento de espiroquetas, foram encaminhadas para o Laboratório de Leptospirose do Instituto de Patobiologia do Instituto Nacional de Tecnologia Agropecuária, Buenos Aires, Argentina e foram tipificadas pela técnica Multiple Locus of Variable Number Tandem Repeat (MLVA). De um residente do sexo masculino da área rural do município de Cruz Alta, foi isolada Leptospira interrogans sorovariedade Copenhageni cepa Fiocruz L1-130, uma descoberta muito importante e que serve como um alerta por caracterizar uma situação de risco de epidemia de leptospirose por uma cepa patogênica. Os profissionais de saúde precisam ser mais comprometidos com a atenção primária à saúde no Brasil e rotineiramente aplicar ações de medicina preventiva nas comunidades rurais, a fim de obter sucesso no controle da leptospirose e de outras importantes zoonoses

The aim of this study was to describe the isolation of a pathogenic strain of Leptospira interrogans from the urine sample of a male human living in the rural area of the County of Cruz Alta, Rio Grande do Sul. An aliquot of each urine sample was sown in a Fletcher and Ellinghausen - McCullough - Johnson - Harris (EMJH) media. Samples in which there was growth of spirochetes were sent to the Leptospirosis Laboratory of the Institute of Pathobiology in the National Institute of Agricultural Technology, Buenos Aires, Argentina and were typified by the Multiple Locus of Variable Number Tandem Repeat technique (MLVA). Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 was isolated, and this is a very important finding that serves as a warning to characterize risk situation of leptospirosis epidemic by a pathogenic strain. Health professionals need to be more committed to the primary health care in Brazil and routinely apply actions of preventive medicine in rural communities in order to get success in the control of leptospirosis and other important zoonoses

Leptospirosis is an infectious disease of wide global distribution, which is endemic in Argentina. The objective of this study was to obtain the genetic profiles of Leptospira spp. strains isolated from clinical cases of dogs in the province of Buenos Aires by the multiple-locus variable-number tandem repeat analysis (MLVA). Eight isolated canine strains were genotyped by MLVA, obtaining the identical profile of Leptospira interrogans serovar Canicola Hond Utrecht IV in the strains named Dogy and Mayo. The strains named Bel, Sarmiento, La Plata 4581 and La Plata 5478 were identical to the profile of the genotype of L. interrogans serovar Portlandvere MY 1039.The strain named Avellaneda was identical to the genotype profile of L. interrogans serovar Icterohaemorrhagiae RGA and the strain named SB had the same profile as the L. interrogans serovar Pomona Baires genotype and was similar to the profile of serovar Pomona Pomona genotype. It would be useful to include a larger number of isolates from different dog populations in various provinces of Argentina and to characterize the genetic profiles of the strains circulating in the country. The information obtained will be useful for the control of leptospirosis in the dog population.

Leptospirosis is the most widespread zoonosis in the world and significant efforts have been made to determine and classify pathogenic Leptospira strains. This zoonosis is maintained in nature through chronic renal infections of carrier animals, with rodents and other small mammals serving as the most important reservoirs. Additionally, domestic animals, such as livestock and dogs, are significant sources of human infection. In this study, a multiple-locus variable-number tandem repeat analysis (MLVA) was applied to genotype 22 pathogenic Leptospira strains isolated from urban and periurban rodent populations from different regions of Argentina. Three MLVA profiles were identified in strains belonging to the species Leptospira interrogans (serovars Icterohaemorrhagiae and Canicola); one profile was observed in serovar Icterohaemorrhagiae and two MLVA profiles were observed in isolates of serovars Canicola and Portlandvere. All strains belonging to Leptospira borgpetersenii serovar Castellonis exhibited the same MLVA profile. Four different genotypes were isolated from urban populations of rodents, including both mice and rats and two different genotypes were isolated from periurban populations.

Brucella abortus is the causative agent of bovine brucellosis, a worldwide zoonosis. Up to date, eight biovars of B. abortus have been described. In Argentina, biovar 1 is the most frequently isolated. However, biovar 2, which is more pathogenic than biovar 1, is also found. Molecular methods for subtyping isolates are necessary for allowing epidemiological surveillance and control of eradication programs. Due to the genetic homogeneity of the genus Brucella, the development of molecular typing tools has been difficult. The publication of microorganism genomes facilitates the design of this approach. The aim of this work was to employ a Multiple Locus VNTR Analysis (MLVA) scheme for strains from Argentina isolated in our laboratory. From the 56 isolates analyzed, 47 different genotypic profiles were obtained. All the strains typed as biovar 2 showed the same profile. This scheme allowed assigning each isolate to the biovar it belongs to. All the genotypes were related using the goeBURST analysis and biovar 2 was proposed as founder.

Brucella abortus es el agente causal de la brucelosis bovina, enfermedad zoonótica que se encuentra ampliamente distribuida en el mundo. Actualmente existen ocho biovariedades de B. abortus. En Argentina se encuentra con mayor frecuencia la biovariedad 1, pero también se suele aislar la biovariedad 2, que es más patogénica que la anterior. Resulta necesario contar con métodos de tipificación que tengan la resolución suficiente para permitir el seguimiento epidemiológico de los brotes de brucelosis y de los programas de control de la enfermedad. Debido a la gran homogeneidad genética que existe entre las distintas especies del género Brucella, ha sido dificultoso el desarrollo de herramientas moleculares para realizar el análisis epidemiológico de los aislamientos. La publicación del genoma de varias especies de Brucella facilitó el diseño de estas herramientas. El objetivo del presente trabajo fue emplear un esquema de análisis multilocus de VNTR en aislamientos de Argentina obtenidos en nuestro laboratorio. De los 56 aislamientos analizados se obtuvieron 47 perfiles genotípicos diferentes. El empleo de este esquema permitió asignarles a dichos aislamientos la biovariedad correspondiente. A través del análisis goeBURST se pudo relacionar a todos los genotipos entre sí, y además, proponer al genotipo de la biovariedad 2 como fundador.

Leptospirosis is a zoonosis of ubiquitous distribution caused by spirochetes. Leptospires exist either as saprophytic water-associated organisms or as animal pathogens that can survive in water. Previous works have demonstrated that both saprophytic and pathogenic leptospires are able to produce functional biofilms, which consist of a community of bacteria embedded in an extracellular matrix attached to a surface. This structure is believed to provide protection from environmental aggressiveness. In the present study, we analyzed the capacity of biofilm formation both of a a recent field isolate of Leptospira interrogans serovar Pomona obtained from an aborted swine fetus and of the saprophytic Leptospira biflexa serovar Patoc. We used light microscopy, immunofluorescence, and scanning electron microscopic examinations on glass and polystyrene plate models to evaluate the process in vitro. The ability to form bacterial aggregations in vivo was tested using pregnant guinea pigs infected with both strains. We obtained biofilms both on glass and plastic surfaces. Scanning electron microscopic analysis showed differences in the biofilm structure formed by both strains. L. interrogans serovar Pomona cell aggregations were observed in placental tissues by light microscopy. Biofilms and cell aggregations are consistent with the life of saprophytic strains in water and could help pathogenic strains to colonize the host and lead to abortion in pregnant animals.

La leptospirosis es una zoonosis de amplia distribución causada por el género Leptospira. Las leptospiras existen de manera saprófita asociadas a ambientes acuáticos o como patógenos animales que también pueden sobrevivir en el agua. Trabajos previos demostraron que tanto las leptospiras saprófitas como las patógenas tienen la capacidad de formar biofilms, que consisten en una comunidad de bacterias embebidas en una matriz extracelular adherida a una superficie. Esta estructura tendría la función de proveer protección contra el medioambiente. En este estudio, analizamos la capacidad de formar biofilm en un aislamiento obtenido recientemente de un feto porcino abortado, caracterizado como Leptospira interrogans serovar Pomona, y en la bacteria saprófita Leptospira biflexa serovar Patoc. Se estudió la formación de biofilm en distintas superficies (vidrio y poliestireno), las que se evaluaron por microscopía óptica, inmunofluorescencia y microscopía electrónica de barrido. La capacidad de formar agregaciones bacterianas in vivo se evaluó utilizando un modelo de cobayas preñadas infectadas con ambas cepas. Se obtuvieron biofilms tanto en las superficies plásticas como de vidrio. La microscopía de barrido mostró diferencias en la estructura del biofilm formado entre ambas cepas. Se observaron agregaciones celulares en vasos placentarios de los animales infectados con L. interrogans serovar Pomona. Los biofilms y las agregaciones celulares son compatibles con la vida saprofítica en el agua y podrían favorecer a los microorganismos patógenos en la colonización del hospedador, lo que podría llevar al aborto en los animales preñados.

O presente estudo objetivou comparar o desempenho de três testes para o sorodiagnóstico da Brucella abortus em búfalos (Bubalus bubalis). Soros de 696 fêmeas bubalinas adultas foram submetidos aos testes: teste imunoenzimático indireto (ELISA-I), teste imunoenzimático competitivo (ELISA-C), teste de polarização fluorescente (TPF), 2-mercaptoetanol (2-ME) e teste de fixação do complemento (FC). Foi empregada, como gold standard, a combinação de dois testes, FC e 2-ME. A curva ROC foi construída para os três testes: ELISA-I, ELISA-C e PF e, com base nos resultados desta análise, foi calculado o índice de concordância Kappa para cada teste. As melhores combinações de sensibilidade (Sr) e especificidade (Er) e os melhores resultados de Kappa foram alcançados pelo ELISA-C (96,9%, 99,1% e 0,932, respectivamente), seguido pelo PF (92,2%, 97,6%, e 0,836, respectivamente). Concluiu-se que os resultados dos estudos com os testes ELISA-C e PF em bovinos podem ser inferidos para búfalos com razoável segurança e que ambos demonstraram ser testes confirmatórios promissores para a espécie estudada.

The objective of the present study was to compare the performance of three serological tests for diagnosis of Brucella abortus infections in buffaloes (Bubalus bubalis). Serum samples collected from 696 adult females were submitted to the competitive enzyme-linked immunosorbent assay (ELISA-C), (I-ELISA), fluorescence polarization test (FPA), 2-mercaptoethanol test (2-ME) and complement fixation test (CFT). The gold standard was the combination of CFT and 2-ME, considering as positive the reactors in both CFT and 2-ME, and as negative those non-reactors. ROC analyses were done for C-ELISA, I-ELISA and FPA and the Kappa agreement index were also calculated. The best combinations of relative sensitivity (SEr) and relative specificity (SPr) and Kappa were given by C-ELISA (96.9%, 99.1%, and 0.932, respectively) and FPA (92.2%, 97.6 and 0.836, respectively). The C-ELISA and FPA were the most promising confirmatory tests for the serological diagnosis of brucellosis in buffaloes, and for these tests, cut-off values for buffaloes may be the same as those used for bovines.

Diagnosis of leptospirosis by PCR is hampered due to the presence of substances on biological fluids. Here, we report an immunomagnetic separation step prior to PCR which improved the detection of Leptospira spp. in blood and urine samples from dogs. It resulted in a significant improvement on sensitivity for diagnosis of canine leptospirosis.

Esta investigação teve por objetivo validar o teste de polarização fluorescente (TPF) para o diagnóstico sorológico da brucelose bovina, determinando a sensibilidade (SE) e a especificidade relativas (SP) e verificando a reprodutibilidade do teste em quatro laboratórios no Brasil. Foram selecionadas 1.389 amostras de soro sanguíneo, as quais foram inicialmente submetidas aos testes do antígeno acidificado tamponado (AAT) e mercaptoetanol (2-ME). As mesmas amostras foram submetidas à reação de fixação de complemento (RFC) e ao TPF. Para a avaliação do TPF, foi adotada a combinação dos resultados do AAT, da RFC e do 2-ME, utilizados como população de referência (padrão-ouro). Para a determinação do ponto de corte do TPF que proporciona a melhor combinação de sensibilidade e especificidade, foi usada a análise TG-ROC. A concordância entre os resultados dos quatro laboratórios foi determinada com base no indicador kappa e no coeficiente de correlação de Pearson. Os pontos de corte do TPF situaram-se entre 85,2 e 93,6 mP, conforme o laboratório. A sensibilidade variou de 91,7 a 97,3%, e a especificidade situou-se na faixa de 82,6 a 98,3%. Na comparação entre os resultados do TPF dos quatro laboratórios, o indicador kappa ficou entre 0,69 e 0,95, o que indica, na maioria das situações, reprodutibilidade excelente, e o coeficiente de correlação variou entre 0,76 e 0,99. Os resultados indicaram que o TPF apresentou bom desempenho, na maioria das situações, com sensibilidade e especificidade elevadas. Em comparação com os testes convencionais, o TPF apresenta as vantagens de ser de execução mais rápida e mais fácil e não estar sujeito à ocorrência de prozona, como a RFC e o 2-ME, nem de atividade anticomplementar, como a RFC.

The purpose of this research was the interlaboratorial validation of the polarization fluorescence assay (PFA) for the serodiagnosis of bovine brucellosis, verifying the relative sensitivity, the relative specificity and the reproducibility of the test in four Brazilian laboratories. Serum samples from 1,389 bovines were selected and submitted to the rose Bengal (RBT) and 2-mercaptoethanol tests in one of the laboratories. The same samples were tested by the complement fixation (CFT) test and by the PFA in the four laboratories participating of the research. The reference population (golden standard) used to evaluate the PFA was the combination of the results of RBT, CFT and 2-ME. TG-ROC analysis was used to obtain the cut-off that provided the best combination of sensitivity and specificity. The agreement between laboratories was obtained by the kappa statistic and Pearson correlation coefficient (r). The PFA cut-off values were from 85.2 to 93.6. The sensitivity of the PFA assay varied from 91.7% to 97.3%, and the specificity values varied from 82.6% to 98.3%. When comparing PFA results from the four laboratories, the kappa values was between 0.69 and 0.95, which indicates, in most situations, excellent reproducibility, and the correlation coefficient varied from 0.76 to 0.99. The results showed that the PFA had a good performance, with high sensitivity and specificity. Compared to the conventional tests, the PFA has the advantages of being easy and quick to perform, and it is not prone to the occurrence of prozone, as the CFT or the 2-ME, nor to the occurrence of anti-complementary effect, as the CFT.

Brucellosis is produced by several species of Brucella. Brucella abortus causes abortion and reproductive loss in bovine cattle. In the epidemiology of brucellosis, aborted fetus and their fetal fluids are the main source of infection and dissemination. Although the biological cycle and the disease consequences to domestic cattle have been widely studied, it is not the case with wild fauna. The objective of this study was to determine the serologic prevalence to brucellosis in the grey fox of the pampas (Pseudalopex gymnocercus). To that purpose, 41 foxes were sampled in the centre-east area of La Pampa province (Argentina). Blood samples for serologic studies were collected. A test of agglutination in microplate (SAP), another SAP with the addition of 2-mercapto-etanol (2-ME) and a test of polarization of the fluorescence (FPA) were used for the diagnosis of antibodies against Brucella abortus. For this, 17.1%, 14.7% and 11.8% was the prevalence found by FPA, SAP and SAP with 2-ME. More studies will be necessary to know the role of foxes in disease transmission and maintenance as well as the consequence of the diseases in foxes.

Brucella abortus (Br abortus) es una de las principales causas de abortos y pérdidas reproductivas en el ganado bovino. Los fetos abortados y sus fluidos fetales son la mayor fuente de infección. Es así como la enfermedad puede llegar a animales silvestres cuando ingieren esos tejidos. El objetivo de este trabajo fue determinar la prevalencia serológica de brucelosis en el zorro gris pampeano (Pseudalopex gymnocercus). Se tomaron muestras de sangre de 41 zorros de la región centro-este de la provincia de La Pampa, Argentina. Para determinar la presencia de anticuerpos específicos contra Br abortus se utilizaron las Pruebas de Polarización de la Fluorescencia (FPA), Seroaglutinación en Microplaca (SAP) y Seroaglutinación en Microplaca con 2-mercaptoetanol (2-ME). Sobre un total de 41 sueros procesados por FPA, en 7 (17,1%) se detectaron anticuerpos contra Br abortus. Sólo 34 sueros fueron analizados por las pruebas de SAP y 2-ME, encontrando 5 (14,7%) y 4 (11,8%) muestras positivas, respectivamente. Los resultados permiten inferir que el zorro gris pampeano es susceptible a infectarse con Br. abortus a una tasa de incidencia importante. Es necesario realizar futuros estudios para establecer el rol del zorro en la transmisión de la enfermedad y sus consecuencias en esta especie.