Comparative genomics of pathogenic Leptospira interrogans serovar Canicola isolated from swine and human in Brazil

Leptospira interrogans serovar Canicola is one of the most important pathogenic serovars for the maintenance of urban leptospirosis. Even though it is considered highly adapted to dogs, serovar Canicola infection has already been described in other animals and even a few human cases. Here, we present the genomic characterisation of two Brazilian L. interrogans serovar Canicola strains isolated from slaughtered sows (L0-3 and L0-4) and their comparison with human strain Fiocruz LV133. It was observed that the porcine serovar Canicola strains present the genetic machinery to cause human infection and, therefore, represent a higher risk to public health. Both human and porcine serovar Canicola isolates also presented sequences with high identity to the Chinese serovar Canicola published plasmids pGui1 and pGui2. The plasmids identification in the Brazilian and Chinese serovar Canicola strains suggest that extra-chromosomal elements are one more feature of this serovar that was previously unnoticed.

Genotipos de cepas de Leptospira spp. aisladas de perros en Buenos Aires, Argentina / Genotypes of Leptospira spp. strains isolated from dogs in Buenos Aires, Argentina

La leptospirosis es una enfermedad infecciosa de amplia distribución global; endémica en Argentina. El objetivo de este estudio fue obtener los perfiles genéticos de las cepas de Leptospira spp. aisladas de casos clínicos de perros provenientes de la provincia de Buenos Aires, empleando el análisis de repeticiones en tándem de número variable en múltiples locus [multiple-locus variable-number tandem repeats analysis (MLVA)]. Fueron genotipificadas por MLVA ocho cepas aisladas de perros. Se obtuvo un perfil idéntico al de Leptospira interrogans serovar Canicola Hond Utrecht IV en las cepas denominadas Dogy y Mayo. Las cepas denominadas Bel, Sarmiento, La Plata 4581 y La Plata 5478 mostraron un perfil idéntico al genotipo de L. interrogans serovar Portlandvere MY 1039. La cepa denominada Avellaneda presentó un perfil idéntico al genotipo L. interrogans serovar Icterohaemorrhagiae RGA, y la cepa denominada SB mostró un perfil idéntico al genotipo de L. interrogans serovar Pomona Baires y similar al serovar Pomona Pomona. Sería de gran utilidad incluir un mayor número de cepas provenientes de distintas poblaciones caninas de diversas provincias de Argentina a fin de conocer los perfiles de las cepas circulantes en el país. La información así obtenida contribuirá al control de la leptospirosis en la población canina

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

Genotypes of pathogenic Leptospira spp isolated from rodents in Argentina

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.

A importância de Leptospira interrogans sorovariedades Icterohaemorrhagiae e Canicola na zona litorânea e nos campos sulinos do Rio Grande do Sul / The importance of Leptospira interrogans serovars Icterohaemorrhagiae and Canicola in coastal zone and in southern fields of Rio Grande do Sul, Brazil

This study aimed to describe the occurrence of Leptospira interrogans serovars Icterohaemorrhagiae and Canicola, in coastal zone and in southern grasslands of Rio Grande do Sul, Brazil. In each one of the four analyzed farms blood samples were collected from free-living wild animals, domestic animals and humans to perform serological testing for leptospirosis. The presence of antibodies was verified by microscopic agglutination test (MAT). The criterion adopted to consider a serum as agglutination reactant was at least 50% of leptospira for a microscopic field of 100x. From 17 blood samples collected at Chuí, five (29.41%) were positive, three (60.00%) for serovar Icterohaemorrhagiae and two (40.00%) for Canicola. From 21 samples collected in the County of Santana da Boa Vista, six (28.57%) were positive, four (66.67%) for serovar Canicola and two (33.33%) for serovar Icterohaemorrhagiae. From 32 samples collected at Alegrete, 10 (31.25%) were positive, seven (70.00%) for serovar Icterohaemorrhagiae and three (30.00%) foro serovar Canicola. From 17 blood samples collected in Cruz Alta, three (17.64%) were positive, two (66.67%) for serovar Icterohaemorrhagiae and one (33.33%) for Canicola. It is necessary to improve sanitary practices on farms in the state of Rio Grande do Sul, in order to achieve success in leptospirosis control programs.

O presente estudo teve como objetivo descrever a ocorrência de Leptospira interrogans sorovariedades Icterohaemorrhagiae e Canicola, na zona litorânea e nos campos sulinos do Estado do Rio Grande do Sul. Em cada uma das quatro propriedades foram realizadas colheitas de sangue de animais selvagens de vida livre, de animais domésticos e de seres humanos para realização de sorologia para leptospirose. A presença de anticorpos foi verificada pela técnica de Soroaglutinação Microscópica (SAM). O critério adotado para considerar um soro como reagente foi aglutinação de pelo menos 50% das leptospiras no campo microscópico no aumento de 100x. Das 17 amostras de sangue colhidas na propriedade pertencente ao Município de Chuí, cinco (29,41%) foram positivas, três (60,00%) à sorovariedade Icterohaemorrhagiae e duas (40,00%) à Canicola. Das 21 amostras colhidas em Santana da Boa Vista, seis (28,57%) foram positivas, quatro (66,67%) à Canicola e duas (33,33%) à Icterohaemorrhagiae. Das 32 amostras colhidas em Alegrete, 10 (31,25%) foram positivas, sete (70,00%) à Icterohaemorrhagiae e três (30,00%) à Canicola. Das 17 amostras colhidas em Cruz Alta, três (17,64%) foram positivas, duas (66,67%) à Icterohaemorrhagiae e uma (33,33%) à Canicola. É necessário melhorias nas práticas sanitárias em propriedades rurais do Estado do Rio Grande do Sul, a fim de se obter sucesso em programas locais de controle da leptospirose.

Prozone effects in microscopic agglutination tests for leptospirosis in the sera of mice infected with the pathogenic Leptospira interrogans serovar Canicola

Mice experimentally infected with a pathogenic strain of Leptospira interrogans serovar Canicola produced false negative results (prozone effect) in a microscopic agglutination test (MAT). This prozone effect occurred in several serum samples collected at different post-infection times, but it was more prominent in samples collected from seven-42 days post-infection and for 1:50 and 1:100 sample dilutions. This phenomenon was correlated with increased antibody titres in the early post-infection phase. While prozone effects are often observed in serological agglutination assays for the diagnosis of animal brucellosis and human syphilis, they are not widely reported in leptospirosis MATs.

Anticorpos revelados pelo teste de inibição do crescimento de leptospiras in vitro (TICL) contra os sorovares Canicola, Icterohaemorrhagiae e Copenhageni em cães adultos revacinados anualmente com vacina comercial contendo bacterinas dos sorovares Canicola, Icterohaemorrhagiae, Grippotyphosa e Pomona / Antibody revealed by growth inhibition test the of leptospires in vitro (GIT) against serovars Canicola, Icterohaemorrhagiae and Copenhageni in adult dogs revaccinated annually with commercial vaccine containing serovars Canicola, Icterohaemorrhagiae, Grippotyphosa and Pomona bacterins

Na atualidade, o sorovar Copenhageni é o representante do sorogrupo Icterohaemorrhagiae, mantido por roedores sinantrópicos, que tem prevalecido nos cães e seres humanos das grandes metrópoles brasileiras. A despeito de alguns autores sugerirem a existência de proteção cruzada entre sorovares incluídos em um mesmo sorogrupo esta condição ainda não foi suficientemente esclarecida para os sorovares Icterohaemorrhagiae e Copenhageni. No presente trabalho cães adultos com dois a seis anos de idade primo-vacinados com três doses intervaladas de 30 dias a partir dos 60 dias de idade e revacinados anualmente com vacina anti-leptospirose polivalente contendo os sorovares Canicola, Icterohaemorrhagiae, Grippotyphosa e Pomona foram revacinados com a mesma vacina e aos 30 dias da revacinação foram submetidos aos testes de soroaglutinação microscópica (SAM) e de inibição do crescimento de leptospiras in vitro (TICL), para avaliação comparativa dos níveis de anticorpos produzidos para os sorovares Canicola, Icterohaemorrhagiae e Copenhageni. Os resultados obtidos indicaram que a imunidade conferida pela vacina para o sorovar Icterohaemorrhagiae é mais duradoura que a observada para o sorovar Canicola, já que títulos de anticorpos neutralizantes >1,0 log10 foram observados antes do reforço vacinal não havendo substancial aumento após a revacinação. Quanto ao sorovar Canicola, a revacinação resultou em considerável aumento do título de anticorpos neutralizantes quando comparado ao momento anterior a revacinação (p=0,001). A análise dos valores encontrados após a revacinação demonstrou claramente que cães revacinados com bacterina produzida com o sorovar Icterohaermorrhagiae não apresentam aumento do título de anticorpos inibidores do crescimento contra o sorovar Copenhageni, em nível suficiente para inibir o crescimento de leptospiras. Apesar disso, os títulos de anticorpos inibidores de crescimento anti-Copenhageni encontrados antes e após a revacinação demonstraram que, pelo menos certo grau de proteção contra a infecção por esse sorovar pode ser esperado para os cães vacinados com bacterinas do sorovar Icterohaemorrhagiae, não sendo, no entanto, uma proteção cruzada completa.

Currently, the serovar Copenhageni is the representative of serogroup Icterohaemorrhagiae maintained in synanthropic rodents found most frequently in dogs and humans in metropolitan areas of Brazil. Despite some authors have suggested the existence of cross-protection between serovars included in the same serogroup, this condition has not yet been sufficiently clarified for serovars Icterohaemorrhagiae and Copenhageni. In the present work, 2 to 6-year-old dogs, vaccinated at 60, 90 and 120 days of age and thereafter, revaccinated annually with commercial vaccine containing Canicola, Icterohaemorrhagiae, Grippotyphosa and Pomona bacterins were evaluated as to the immune status against leptospirosis before and 30 days after revaccination. Mycroscopic agglutination test (MAT) and in vitro growth inhibition test (GIT) were performed to search for agglutinating anti-Leptospira antibodies and neutralizing anti-Leptospira antibodies, respectively for serovars Canicola and Icterohaemorrhagiae, and additionally, for serovar Copenhageni, not included in the vaccine. The results showed that the immunity conferred by the vaccine to serovar Icterohaemorrhagiae is more lasting than that observed for serovar Canicola, since neutralizing antibody titers >1.0 log10 were observed before the booster vaccination with no substantial increase after revaccination. As for the serovar Canicola, revaccination resulted in a considerable increase in neutralizing antibody titer when compared to the one observed previously to the revaccination (p=0.001). The analysis of the data obtained by GIT allowed us to conclude that dogs given vaccine containing Icterohaemorrhagiae bacterin did not produce neutralizing antibodies against serovar Copenhageni enough to inhibit leptopiral growth at the same level as occurred for the homologous serovar. Despite this, the GIT titer found for serovar Copenhageni before and after revaccination showed that at least, some level of protection could be expected for dogs vaccinated with serovar Icterohaemorrhagiae bacterin, not a complete cross protection.

Detection of reactive canines to Leptospira in Campeche City, Mexico / Detection of reactive canines to Leptospira in Campeche City, Mexico.

Leptospira reactivity in stray and household dogs in Campeche as well as associated risk factors to the seropositivity in household dogs have been herein determined. The survey included 323 dogs, 142 of which were stray dogs and 181 household dogs. Nine Leptospira interrogans serovars were tested by the microagglutination test. Reactivity was 21.3

corresponded to household dogs and 26.7

), and Leptospira Icterohaemorrhagiae (16.12

) were the most common serovars reacting against the serum of household animals, while Leptospira Canicola (15.78

), and Leptospira Pomona (7.89

) were those reacting in stray dogs. Results showed that all dogs have been in contact with different Leptospira serovars and outdoor exposure is the main infection risk factor.

Diagnosis of canine leptospirosis using an immunomagnetic separation-PCR method

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.

Brote de leptospirosis asociado a la natación en una fuente de agua subterránea en una zona costera, Lima - Perú / An outbreak of leptospirosis associated with swimming in a spring of underground water in a coastal area, Lima - Peru

Objetivos. Determinar la magnitud de un brote y los factores asociados a la presencia de leptospirosis en la localidadde residencia de un menor de edad que presentó un cuadro de síndrome ictérico hemorrágico. Materiales y métodos.Fueron entrevistados y examinados niños y adolescentes de la zona de residencia del caso índice que frecuentaban unafuente común de infección entre los meses de enero y febrero del 2004. Se realizaron exámenes de ELISA IgM, MAT, PCR y cultivo para el diagnóstico de leptospirosis. Resultados. Fueron incluidos 77 sujetos entre 2 a 18 años de edad, siendo confirmados 21 casos (27,3 por ciento). Los signos y síntomas de los casos confirmados fueron fiebre, cefalea, mialgias, dolor abdominal, náusea, vómitos e hiporexia. Tres de ellos presentaron ictericia, hemorragia y falla renal. El análisis bivariado mostró que aquellos que estuvieron en contacto con la fuente de infección de agua clara (cristalina) tuvieron un OR=3,26(IC95 por ciento 1,22 a 8,72) y el contacto con perros en la fuente de agua un OR de 5,63 (IC95 por ciento 1,40 a 22,63). Conclusiones. Se confirmó un brote de leptospirosis dentro de un contexto epidemiológico nuevo relacionados a una fuente común de agua subterránea y asociada al contacto con perros dentro de esta fuente. Esta investigación permitirá ampliar el conocimiento acerca de esta patología, así como considerar la leptospirosis como causa de enfermedad febril aguda.

Objectives. Identify the frequency and risk factors of leptospirosis outbreak in the locality of residence of an index casewith icterohemorrhagic syndrome. Material and methods. Were interviewed and examined children and teenagers fromresidence area of index case who frequented a common source of infection between January and February, 2004. Allof them were screened for leptospirosis using IgM-ELISA and microscopic agglutination test (MAT), PCR and culture.Results. Were enrolled 77 subjects between 2 to 18 years old, only 21 (27.3 per cent) were confirmed cases. The signs and symptoms of the confirmed cases were fever, headache, myalgia, abdominal pain, nausea, vomiting and anorexia. Three of them presented with jaundice, bleeding and renal failure. The presence of contact with the source of infection of underground water (OR=3.26, 95 per centIC 1.22 to 8.72), and the contact with dogs in the water source of infection (OR = 5.63, 95 per cent IC = 1.40 to 22.63) were identified as significant factors associated with leptospirosis. Conclusions. It wasconfirmed an outbreak of leptospirosis in a new epidemiological context related to a common source of underground water and associated by contact with dogs in the same source. This data will allow to expand the knowledge about this disease as well as to consider leptospirosis as an important cause of acute febrile disease.

Isolation of leptospira Serovars Canicola and Copenhageni from cattle urine in the state of Paraná, Brazil / Isolamento de leptospiras dos Sorovares Canicola e Copenhageni em amostras de urina de bovinos no estado do Paraná, Brasil

In 2001, 698 urine samples were randomly collected from cattle at a slaughterhouse in the State of Paraná, Brazil. Direct examination using dark field microscopy was carried out immediately after collection. Five putative positive samples were cultured in modified EMJH medium, yielding two positive cultures (LO-14 and LO-10). Typing with monoclonal antibodies revealed that the two isolates were similar to Canicola (LO-14) and Copenhageni (LO-10). Microscopic agglutination test results show that Hardjo is the most common serovar in cattle in Brazil. Rats and dogs are the common maintenance hosts of serovars Copenhageni and Canicola. The excretion of highly pathogenic serovars such as Copenhageni and Canicola by cattle can represent an increasing risk for severe leptospirosis is large populations, mainly living in rural areas.

No ano de 2001, 698 amostras de urina foram colhidas aleatoriamente, durante o abate em um frigorífico do Estado do Paraná, Brasil. O exame direto em microscópio de campo escuro foi realizado imediatamente após a colheita. As cinco amostras de urina positivas neste exame foram semeadas em meio EMJH modificado, sendo possível o crescimento de leptospiras em duas (LO-14 e LO-10). As estirpes isoladas foram tipificadas, por painel de anticorpos monoclonais, como mais similares ao perfil das amostras de referência dos sorovares Canicola (LO-14) e Copenhageni (LO-10). No Brasil, inquéritos sorológicos utilizando a prova de soroaglutinação microscópica mostram o predomínio de reações para o sorovar Hardjo em bovinos. Roedores e cães são os reservatórios mais comuns dos sorovares Copenhageni e Canicola, respectivamente. A eliminação dos sorovares Canicola e Copenhageni pela espécie bovina pode resultar em um aumento na ocorrência de casos graves de leptospirose humana, principalmente na população rural.

Detection of leptospires in clinically healthy piglets born from sows experimentally infected with Leptospira interrogans serovar Canicola

Leptospirosis is an important zoonosis that causes reproductive disorders in swine. The isolation of leptospires from aborted fetuses, stillbirths and weak piglets was obtained in several occasions, however, the bacteria was never isolated from apparently healthy piglets born from apparently healthy infected dams. Six sows of the Landrace breed with a known date of service and pregnancy confirmed by ultrasonography were infected intravenously with 5ml of Leptospira interrogans serovar Canicola inoculum between 76 and 90 days of gestation, and one week after farrowing, at least one piglet per sow was euthanized and samples of liver, kidneys, lungs, heart, spleen and gastric content were taken and examined by PCR. Reproductive disorders or any clinical sign of infection were not observed in the inoculated sows. The piglets born from these animals presented no clinical signs or macroscopic lesions that could be attributed to leptospirosis. All inoculated sows presented anti-leptospires antibodies by microscopic serum-agglutination test (MAT) in the postinoculation serum samples and leptospires were not found in the urine as well as were not detected by PCR applied in this material, however, PCR accomplished in kidneys and liver from a euthanized sow presented positive results. Of the total of 12 euthanized piglets, 10 (83.3 percent) presented positive results by PCR in at least one of the kidney, liver, heart, spleen, lung and gastric content samples. The present study reports the vertical transmission of the infection and the detection of leptospires in clinically healthy piglets born from experimentally infected sows, which is important of the epidemiological point of view as the maintenance of clinically healthy infected animals may allow the persistence of the bacteria in the herd, exposing other animals to the risk of infection.

A Leptospirose é uma importante zoonose que causa transtornos reprodutivos em suínos. O isolamento de leptospiras de fetos abortados, natimortos e leitões fracos foi obtido em várias ocasiões, porém, a bactéria nunca foi isolada de leitões aparentemente saudáveis nascidos de matrizes com infecção subclínica. Seis matrizes da raça Landrace com data de serviço conhecida e gravidez confirmada por ultrasonografia foram infectadas entre 76 e 90 dias de gestação por via intravenosa com 5 ml de inóculo de Leptospira interrogans sorovar Canicola, e uma semana após o parto, pelo menos um leitão por matriz foi eutanaziado e foram colhidas amostras de fígado, rins, pulmões, coração, baço e conteúdo gástrico para exame por PCR. Transtornos reprodutivos ou qualquer sinal clínico de infecção não foram observados nas matrizes inoculadas. Os leitões nascidos destes animais não apresentaram sinais clínicos ou lesões macroscópicas que poderiam ser atribuídos à leptospirose. Todas as matrizes inoculadas apresentaram anticorpos anti-leptospiras no teste de soroaglutinação microscópica (MAT) nas amostras de soros colhidas após a inoculação, e não foram encontradas leptospiras na urina como também não foram detectadas pela PCR aplicada neste material, porém, a PCR realizada em rins e fígado de uma matriz eutanaziada apresentou resultado positivo. Dos 12 leitões eutanaziados, 10 (83,3 por cento) apresentaram resultados positivos na PCR em pelo menos uma das amostras de rim, fígado, coração, baço, pulmão e conteúdo gástrico. O presente estudo relata a transmissão vertical da infecção e a detecção de leptospiras em leitões clinicamente saudáveis nascidos de matrizes infectadas experimentalmente, o que é importante do ponto de vista epidemiológico, pois a manutenção de animais com infecção subclínica pode permitir a persistência da bactéria no rebanho, expondo outros animais ao risco de infecção.

Inmunogenicidad y capacidad protectora en hamsters de vacunas antileptospirósicas monovalentes de células enteras del serogrupo Ballum / Immunogenicity and protective capacity of leptospiral whole-cell monovalent serogroup Ballum vaccines in hamsters

El serogrupo Ballum de Leptospira constituye en la actualidad la primera causa de leptospirosis humana en Cuba. Vacunas de células enteras químicamente inactivadas fueron formuladas a partir de dos cepas clínicas de Leptospira interrogans serogrupo Ballum empleando como adyuvante hidróxido de aluminio. Los niveles de aglutininas inducidos en hamsters por una u otra preparación vacunal fueron estimados mediante aglutinación microscópica y la actividad IgG específica fue cuantificada mediante ELISA. La capacidad de protección homóloga y heteróloga contra la infección letal y subletal se determinó mediante el desafío con 100 y 10 000 DL50 de cinco cepas virulentas pertenecientes a los serogrupos Ballum, Canicola, Icterohaemorrhagiae y Pomona. Las evaluaciones realizadas demostraron que ambas vacunas fueron inmunogénicas e indujeron una completa protección homóloga en el modelo animal empleado. La protección cruzada frente a serogrupos heterólogos solo fue significativa en una de las preparaciones monovalentes frente al desafío con 100 DL50 de Canicola. Como resultado de este estudio se pudo comprobar la alta inmunogenicidad y capacidad protectora en hamsters de vacunas monovalentes de células enteras formuladas a partir de dos cepas candidatas vacunales del serogrupo de Leptospira de mayor circulación en humanos en Cuba no incluido en la vacuna actualmente disponible.

Leptospira serogroup Ballum is at present the first cause of human leptospirosis in Cuba. Killed whole-cell vaccines were formulated with two clinical isolates of Leptospira interrogans serogroup Ballum using aluminum hydroxide as adjuvant. Agglutinins levels induced by each vaccine in hamsters were estimated by microscopic agglutination test and specific IgG activities were quantified by a whole cell-based enzyme-linked immunosorbent assay. Homologous and cross protective capacity against lethal and sublethal infection were determined in vaccinated animals by challenge with 100 and 10 000 LD50 of five virulent strains belonging to serogroups Ballum, Canicola, Icterohaemorrhagiae and Pomona. Both monovalent serogroup Ballum vaccines were immunogenic and induced complete homologous protection in the animal model. Cross-protection was only significant in one of the two vaccines against challenge with 100 LD50 of serogroup Canicola. The results of this study demonstrate the high immunogenicity and protective capacity in hamsters of whole-cell monovalent vaccines formulated with two vaccine candidate strains belonging to the most prevalent serogroup of Leptospira in Cuba.

Empleo de la diafiltración en el lavado de cultivos de Leptospira interrogans canicola canicola para la producción de la vacuna vax-SPIRAL / Use of diafiltration in the lavage of cultures of Leptospira interrogans canicola canicola for the production of vaccine vax-SPIRAL

Se propuso sustituir la tecnología actual de la operación de lavado por un sistema de microfiltración tangencial en las etapas de lavado del cultivo de Leptospira interrogans canicola canicola. Se demostró que es aplicable este sistema porque no hubo afectación celular y se obtuvieron altos niveles de eliminación de contaminantes

Escalado de la fermentación de Leptospira interrogans canicola canicola para la producción de la vacuna vax-SPIRAL / Scale-up of the fermentation of Leptospira interrogans canicola canicola for the production of vax-SPIRAL vaccine

Se establecieron las condiciones de operación para la producción de la vacuna vax-SPIRAL en la escala de 100 L. Se concluyó que debe efectuarse con un flujo de aire de 10 L/min (0,1 vvm) y sin agitación mecánica

Evidencia de exposición a Leptospira / Exposure to Leptospira in stray dogs in the city of Cali

En Cali, y en Colombia en general, se desconoce la epidemiología de la leptospirosis en ambientes urbanos. Además, el papel del perro en el ciclo de transmisión en dichos ambientes no es claro. Para explorar esta situación, realizamos un estudio serológico en Cali a 197 sueros de perros callejeros durante el 2001 y el 2003, utilizando la prueba de microaglutinación (MAT). En la prueba se incluyeron 7 serovares: Icterohaemorrhagiae, Canicola, Gryppotyphosa, Hardjo cepa Hardjobovis, Pomona, Hardjo cepa Hardjoprajitno y Bratislava aportados por el Instituto Colombiano Agropecuario (ICA) de Tuluá. La prueba se interpretó como positiva por la presencia de una aglutinación ³50 por ciento de las leptospiras, con uno o más serovares, en una dilución del suero ³1:100. Encontramos evidencia de infección en el 41,1 por ciento de los perros con, al menos, uno de los serovares. La mayor reactividad fue a Icterohaemorrhagiae con 55,6 por ciento del total de los seropositivos. Se presentaron 48,1 por ciento de coaglutinaciones. No se registraron reacciones contra los serovares Pomona, Hardjo cepa Hardjoprajitno y Bratislava. Estos hallazgos sugieren que el perro callejero es un posible reservorio de leptospira en Cali y resaltan la necesidad de estudiar la epidemiología de la enfermedad en esta ciudad

Brote de leptospirosis humana luego de una inundación en Reconquista (Santa Fe), 1998 / Outbreak of human leptospirosis after a flood in Reconquista, Santa Fe, 1998

Since April of 1998 a high number of leptospirosis cases were detected, coming from the area of Reconquista Central Hospital in Santa Fe province. Since January of that year a notable increase in rainfall and river levels was observed causing inundation. As screening test, macroscopic agglutination (MAT) using 10 serotypes of L. interrogans. Among the 122 patients studied 71 were TR positive and 52 were also ELISA positive, leptospirosis diagnosis being confirmed in 40 of them. Five infecting serogroups were identified: Icterohaemorrhagiae (7/40), Ballum (5/40), Sejroe (3/40), Pomona (3/40) and Canicola (2/40). In the remaining cases (20/40), co-agglutinins were found at the same titer against two or more serotypes of leptospires. Infection prevalence was higher in men and productive age (21 to 40 years). The clinical symptoms more frequently observed were headache, fever and myalgias. All cases occurred after the rains and in the period when the area was flooded. Their clinical presentation, time distribution, geographical localization and high frequency of contact with the risk factor inundation could indicate that, independently of search activities, there was an outbreak.

Haemorrhagic pneumonitis: A rare presentation of leptospirosis.

Leptospirosis is an uncommon zoonosis. As a systemic disease, it presents itself by multisystem involvement. Pulmonary involvement with leptospirosis often is manifested by respiratory symptoms; but pneumonia commonly is not a prominent clinical manifestation of the illness. We report a case of leptospiral pneumonia in which pulmonary manifestations were primary clinical features of the illness. The prompt resolution of chest x-ray on institution of treatment is noteworthy.

Avaliaçäo dos níveis de aglutininas anti-leptospira em cäes no município de Patos - PB, Brasil / Evaluation of anti-leptospire agglutinines leves in dogs from Patos - Paraíba state, Brazil

Dentre os animais domésticos urbanos, a principal fonte de infecçäo da leptospirose humana säo os cäes, pois estes vivem em contato direto com o homem, podendo eliminar leptospiras vivas através da urina durante meses sem apresentar nenhum sinal clínico. Os cäes representam um importante elo de transmissäo da leptospirose, visto que aparentemente sadios, podem albergar leptospiras e eliminá-las ao meio ambiente, propício a disseminaçäo para outras espécies, inclusive aos seres humanos. O objetivo do trabalho foi avaliar os níveis de aglutininas anti-leptospira em cäes no município de Patos-PB. O material examinado constituiu-se de 114 amostras de soro sangüíneo de cäes atendidos no Hospital Veterinário, com ou sem quadro clínico de leptospirose, durante o período de agosto/97 a julho/98. O soro sangüíneo foi processado segundo a técnica de soroaglutinaçäo microscópica (SAM), no Laboratório de Doenças Transmissíveis - CSTR/CAMPUS VII/UFPB. Após a avaliaçäo dos resultados, observou-se a prevalência de 20 por cento das amostras com predominância dos seguintes sorotipos: autumnalis, australis, butembo, grippotyphosa, pomona, panamá, wolffi, pyrogenes, icterohaemorrhagiae, hardjo e cynopten, com destaque para o sorotipo autumnalis (34,78 por cento). A análise estatística, utilizando o programa EPIDAT 1.0, segundo o teste näo-paramétrico do qui-quadrado com nível de significância de 5 por cento, possibilitou observar diferenças significativas entre as variáveis estudadas no que diz respeito às regiöes administrativas e à natureza dos ressultados.

Clinical, bacteriologic and histopathologic studies on induced leptospirosis in stray dog pups.

Eighteen 8-12 days old stray dog (canis familiaris mongrel) pups of either sex; 6 pups each in test groups and control group were infected with lepotspiral serovars autumnalis and canicola. The experimental animals, clinical, bacteriologic and histopathologic kinetics were observed. Both the serovars had evoked typical clinical manifestations. Leptospiraemia could be demonstratedin between the post inoculation (PI) days 1 & 5. Leptospiruria commensed in between the PI days 5 & 7 and lasted throughout the study period. Histopathologic study did not reveal any marked pathologic changes except hydropic changes in the liver of both the test groups.