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.

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.

Emprego de estirpes Leptospira spp. isoladas no Brasil na microtécnica de soroaglutinação microscópica aplicada ao diagnóstico da leptospirose em rebanhos bovinos de oito estados brasileiros / Use of Leptospira spp. strains isolated in Brazil in the microscopic agglutination test applied to diagnosis of leptospirosis in cattle herds in eight brazilian states

O objetivo do presente trabalho foi investigar a conveniência do emprego de estirpes de leptospiras autóctones isoladas no Brasil, na coleção de antígenos da microtécnica de soroaglutinação microscópica (SAM) aplicada a leptospirose. Foram amostradas por conveniência 109 propriedades e 9820 bovinos, fêmeas em idade reprodutiva, distribuídos em 85 municípios, dos Estados de Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina e São Paulo. Dos 9820 animais examinados, 5806 (59,12%) foram reagentes na SAM para pelo menos um sorovar com a coleção de 23 sorovares de referência. Com a coleção de antígenos de referência e dez estirpes autóctones houve 6400 (65,17%) reagentes, com diferença significativa entre as proporções (p=0,001). Os sorovares mais prováveis identificados com a coleção de antígenos de referência foram Hardjo (43,03%), Shermani (20 %), Wolffi (9,96%), Grippothyphosa (5,42%) e Pomona (4,28%). Com a coleção ampliada por dez estirpes isoladas no Brasil, os sorovares mais prováveis foram Hardjo (31,00%), Guaricura-M4/84 (22,50%), Shermani (15,43%), Wolffi (4,76%), Grippothyphosa (3,71%) e Autumnalis (3,24%). O sorovar Guaricura, estirpe M4/84, isolada de bovinos e búfalos no Estado de São Paulo, despontou como um dos três sorovares mais freqüentes nos Estados de Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais e São Paulo. A introdução de estirpes autóctones na coleção de antígenos da SAM propiciou a confirmação do diagnóstico de leptospirose em 594 animais (6,00%) classificados como não reagentes pela coleção de referência (p=0,001).

The aim of this study was to investigate the adequacy of the use of autochthonous strains of leptospires isolated in Brazil, added to antigen collection of the microscopic agglutination test (MAT) applied to the diagnosis of bovine leptospirosis. By means of non-probability sampling, 109 farms and 9,820 cattle, females at reproductive age were chosen from 85 municipalities in the states of Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina and São Paulo. Among the 9,820 examined animals, 5,806 (59.12%) were reactants at MAT for at least one serovar using the 23 reference serovars. Employing the collection of reference serovars and the ten autochthonous strains, 6,400 (65.24%) reactants and significant difference (p=0.001) was found. The most probable serovars identified by the collection of reference antigens were Hardjo (43.03%), Shermani (20%), Wolfi (9.96%), Grippothyphosa (5.42%) and Pomona (4.28%). With the collection amplified with the ten strains isolated in Brazil, the most probable serovars were Hardjo (31%), Guaricura-M4/84 (22.50%), Shermani (15.43%), Wolffi (4.76%), Grippothyphosa (3.71%) and Autumnalis (3.24%). The serovar Guaricura, strain M4/84, isolated from bovines and buffaloes in the State of São Paulo, was ranked as one of the three most probable serovars in the states of Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais and São Paulo. The addition of autochthonous strains to the MAT antigen collection provided the confirmation of the diagnosis of leptospirosis in 594 cattle (6%) which have been classified as non-reactants by the reference collection (p=0.001).

PCR Multiplex fluorescente para detecção de bactérias em sêmen bovino / Fluorescent Multiplex PCR for detection of bacteria in semen bovine

Este estudo teve como objetivo avaliar o limiar de detecção da técnica de PCR multiplex fluorescente aliada a eletroforese capilar na detecção de agentes infecciosos em amostras de sêmen experimentalmente contaminadas com concentrações decrescentes das bactérias Brucella abortus, Leptospira interrogans sorovar pomona, Campylobacter fetus e Haemophilus somnus. Amostras de sêmen bovino foram experimentalmente contaminadas com concentrações decrescentes de bactérias obtidas através de diluições seriadas na base 10 de modo a obter-se amostras contendo desde 1 vez até 10-7 bactérias/mL a partir da concentração inicial de Leptospira pomona, Brucella abortus, Campylobacter fetus e Haemophilus somnus. As diluições foram efetuadas individualmente para cada bactéria, bem como nas diferentes concentrações necessárias para a padronização do teste de multiplex PCR. As extrações de DNA de todas as soluções contendo espermatozóides e bactérias analisadas no presente estudo foram realizadas segundo protocolo descrito por Heinemann et al. (2000). Os produtos de PCR multiplex foram avaliados por eletroforese em gel de poliacrilamida 8% e separação eletroforética por sistema capilar em equipamento automático de análise de fragmentos de DNA MegaBace. Observou-se a amplificação de fragmentos de 193pb, 330pb, 400pb e 415pb a partir do DNA de B. abortus, L. pomona, H. somnus, C. fetus, respectivamente. Na análise por eletroforese capilar de produtos da PCR multiplex do DNA para detecção simultânea dos quatro patógenos observou-se a sinal de positividade até a diluição de 10-3 bactérias/mL vezes da concentração inicial da solução estoque de cada bactéria. A técnica de PCR multiplex aliada à eletroforese capilar foi usada pela primeira vez para o diagnóstico direto de quatro bactérias patogênicas no sêmen, demonstrando ser um método rápido na detecção de bactérias causadoras de doenças reprodutivas.

This study aimed to evaluate the threshold of detection of fluorescent multiplex PCR coupled with capillary electrophoresis for detection of infectious agents in semen samples from experimentally infected with decreasing concentrations of the bacteria Brucella abortus, Leptospira interrogans serovar pomona, Campylobacter fetus and Haemophilus somnus. Samples of bovine semen were experimentally infected with decreasing concentrations of bacteria obtained from serial dilutions in the base 10 so as to obtain samples containing a long time until 10-7 bacteria/mL from the initial concentration of Lepstospira pomona, Brucella abortus, Haemophilus somnus and Campylobacter fetus. The dilutions were made individually for each bacterium, as well as in different concentrations needed to standardize the multiplex PCR test. DNA extractions of all solutions containing sperm and bacteria analyzed in this study were performed according to protocol described by Heinemann et al. (2000). The multiplex PCR products were analyzed by electrophoresis on 8% polyacrylamide gel and capillary electrophoretic separation system for automated equipment in the analysis of DNA fragments MegaBACE. We observed amplification of fragments of 193pb, 330pb, 415pb and 400bp from the DNA of B. abortus, L. pomona, H. somnus, C. fetus respectively. The analysis by capillary electrophoresis of multiplex PCR products of DNA for simultaneous detection of the four pathogens was observed by detecting the dilution of 10-3 bacteria / mL times the initial concentration of the stock solution of each bacterium. The multiplex PCR coupled with capillary electrophoresis was first used for the direct diagnosis of four pathogenic bacteria in semen, proving to be a rapid method to detect bacteria that cause reproductive disorders.

Survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction

This work reports a survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction (PCR). Seventy pampas deer were captured in the dry season and surveyed using PCR, microscopic agglutination test (MAT) (n = 51) and by both techniques (n = 47). PCR detected infections in two pampas deer and MAT detected infections in three. Through sequencing and phylogenetic analyses, the PCR-amplified fragment detected in deer was identified as Leptospira interrogans. Serovars Pomona and Butembo were detected using MAT and the highest titre was 200 for serovar Pomona. Epidemiological aspects of the findings are discussed.

Characterization of Leptospira borgpetersenii isolates from field rats (Rattus norvegicus) by 16S rRNA and lipL32 gene sequencing

The main goal of this study was to evaluate the prevalence of leptospirosis among field rodents of Tiruchirappalli district, Tamil Nadu, India. In total 35 field rats were trapped and tested for seroprevalence by the microscopic agglutination test (MAT). Isolation of leptospires was performed from blood and kidney tissues and characterized to serovar level. Genomospecies identification was carried out using 16S rRNA and lipL32 gene sequencing. The molecular phylogeny was constructed to find out species segregation. Seroprevalence was about 51.4 percent, and the predominant serovars were Autumnalis, Javanica, Icterohaemorrhagiae and Pomona. Two isolates from the kidneys were identified as serovar Javanica of Serogroup Javanica, and sequence based molecular phylogeny indicated these two isolates were Leptospira borgpetersenii.

Differential response of cytokines induced by Leptospira interrogans, serogroup Pomona, serovar Pomona, in mouse and human cell lines.

Leptospira interrogans, the causative agent of leptospirosis, is an important zoonotic bacterium. The mechanisms and roles of cytokine induction in both humans and animals remain unclear. Therefore, the IFN-gamma, IL-6, IL-10 and IL-12 levels were measured by enzyme-linked immunosorbent assay (ELISA) in human THP-1 and mouse RAW 264.7 monocyte cell lines following stimulation with heat-killed Leptospira interrogans serogroup Pomona serovar Pomona, L. biflexa, E. coli or Salmonella group B. The production of IL-6 and IL-12 were higher and rose more rapidly in the RAW 264.7 cells with all bacteria. The IL-10 was not detected in the RAW 264.7 cells when induced by leptospires. The IFN-gamma level in human peripheral blood mononuclear cells (PBMCs) induced by leptospires was also significantly lower than with other bacteria. When IL-10 and IL-12 mRNA expressions were detected in hamster's spleen, their patterns were similar to what was observed in THP-1 in that IL-12 was only slightly increased while IL-10 expression was high. Moreover, the IFN-gamma expression could not be detected in hamsters. The more potent cytokine responses in the RAW 264.7 cells may indirectly reflect the disease outcome in mice which render them to be a good reservoir of leptospirosis. Whether these cytokines have contributed to immunoprotection during the L. interrogans infection remains to be further investigated.

Aplicação de um programa integrado de controle da leptospiroseem eqüinos no Rio de Janeiro, Brasil / Application of an integrated program of leptospirosis control in horsesfrom Rio de Janeiro, Brazil

Um plantel localizado na região serrana do Rio de Janeiro com 140 éguas e oito garanhões foi estudado em março de 2006.Realizou-se sorodiagnóstico para leptospirose de todos os animais do plantel e 82 (55,4%) foram soropositivos.O serovar.Bratislava foi o mais freqüente e identificado em 72 (87,8%) amostras reativas. Diante dos achados, um amplo programa decontrole da infecção foi elaborado, incluindo abordagens vacinais, medicamentosas e epidemiológicas. Doze meses após aimplementação do programa de controle (maio de 2007) constatou-se redução no índice de abortamento de 12% para 4%,morte embrionária de 10% para 2% e morte neonatal de 8% para 1%, totalizando 7% de prejuízos reprodutivos, perante 30%observados antes da implementação do programa de controle. Nesta ocasião, selecionaram-se randomicamente 31 fêmeaspara testagem sorológica. Onze animais (35,48%) apresentaram sororreatividade, a maioria com baixos títulos. Em relação àdistribuição do serovar infectante, sv. Bratislava foi ainda o mais freqüente. Desta forma, conclui-se que a ampla abordagem,incluindo simultaneamente a vacinação, antibioticoterapia e a administração de alguns aspectos ambientais foi imprescindívelpara o sucesso no controle da enfermidade neste rebanho.

A flock from Rio de Janeiro with 140 mares and eight stallions was studied in March, 2006. Serodiagnosis for leptospirosis wasperformed in all the animals and 82 (55.4%) were seroreactive. The serovar Bratislava was the most frequent, in 72 (87.8%) ofthe reactive samples. Considering those findings a broad control program of the disease was applied, including vaccines,antibiotics and epidemiological measures. Twelve months after the beginning of the program (May, 2007) abortion reduced from12% to 4%, embryonic death from 10% to 2% and neonatal death from 8% to 1%, with total reproductive losses decreasing from30% to 7%. In this moment, 31 mares were randomly tested and eleven (35.48%) were seroreactive, most of them with low titres.Bratislava was still the most frequent serovar. Therefore, we conclude that the broad approach of the control program, whichincluded vaccines, antibiotics and correction of some environmental aspects was mandatory for the efficacy of the diseasecontrol.

Identificação da Leptospira interrogans sorovar pomona em camundongos geneticamente selecionados, para a alta e baixa produção de anticorpos, através da técnica de imunoperoxidase em tecido renal e isolamento bacteriano em meio de Fletcher / Identification of Leptospira interrogans serovar pomona in mice genetically selected for high and low antibody production, by means of the immunoperoxidase technique in renal tissue and bacterial isolation in Fletcher medium

O presente trabalho teve por objetivo identificar a presença da Leptospira interrogans sorovar pomona em camundongos geneticamente selecionados para a alta e baixa resposta a anticorpos. Todos os animais foram submetidos ao isolamento bacteriano, imunohistoquímica (imunoperoxidase) em cortes de tecido renal e coloração através da hematoxilina-eosina. A técnica de imunoperoxidase apresentou-se pouco mais sensível em relação ao cultivo, entretanto, ambas foram bons parâmetros de identificação do agente. Presença de lesões renais mais intensas ocorreram em períodos em que houve maior número de bactérias isoladas em meio de cultivo. Camundongos da linhagem HIV-A conseguiram eliminar as leptospiras com maior eficiência e rapidez em relação as linhagem LIV-A, entretanto o estudo demonstrou que ambas linhagens da seleção IV-A foram eficientes em controlar o processo infeccioso.

The present work had the objective of identifying the presence of Leptospira interrogans serovar pomona in mice that had been genetically selected for high and low response to antibodies. All the animals were subjected to bacterial isolation, immunohistochemical analysis (immunoperoxidase) in renal tissue sections and hematoxylin-eosin staining. The immunoperoxidase technique was little more sensitive than culturing, but both were good parameters for agent identification. More severe renal lesions were present at times when there were greater numbers of bacteria isolated in culture medium. Mice of the lineage HIV-A were able to eliminate the Leptospira more efficiently and faster than the lineage LIV-A could. However, the study demonstrated that both lineages of the IV-A selection were efficient in controlling the infectious process.

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.

Alcalinización de la orina humana para el aislamiento experimental de leptospiras / Alkalinization of human urine for the experimental isolation of leptospiras

Se estudió el efecto de diferentes agentes alcalinizantes de la orina sobre el aislamiento de leptospiras. Se obtuvieron mejores resultados al emplear la solución básica de NaOH 1N y en la orina inoculada 1 h después de haber sido alcalinizada

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

Influência da via de inoculação sobre o estabelecimento e a evolução da leptospirose em hamsters (Mesocricetus auratus) experimentalmente infectados com Leptospira interrogans sorovar pomona / The influence of the route of inoculation on the development of the leptospiral infection in hamsters (Mesocricetus auratus) experimentally infected with Leptospira interrogans serovar pomona

Foi investigada a influência da via de inoculação sobre o estabelecimento e a evolução da leptospirose em hamsters (Mesocricetus auratus) experimentalmente infectados com Leptospira interrogans sorovar pomona. As vias de inoculação ensaiadas foram: intraperitoneal, subcutânea, oral, conjuntival e escarificação cutânea. O inóculo infeccioso foi constituído por uma cultura em meio de Fletcher, com 20 a 30 leptospiras por campo microscópio no aumento de 200 vezes. Os animais controle foram inoculados apenas com meio de Fletcher. Foram colhidas amostras de soro sanguíneo e fragmentos de rins na fase agônica da doença ou no 21º dia pós-infecção, quando todos os animais foram sacrificados. Para a pesquisa de leptospiras, foi feito o exame direto com microscopia óptica em campo escuro e cultivo em meio de Fletcher, pela técnica das diluições seriadas. A detecção de aglutininas anti-leptospiras foi realizada pela técnica de soroaglutinação microscópica. A instalação e evolução da leptospirose foram afetadas pela via de inoculação. A via oral foi a menos efetiva em estabelecer a infecção. Não foi observada associação estatística entre a freqüência de portadores e a via de inoculação.

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.

Considerações em torno da epidemia de leptospiroses na cidade de Recife em 1966. Aspectos epidemiológicos, laboratoriais e clínicos / Leptospirosis: epidemiological, clinical and laboratory studies of an outbreak observed in Recife, Pernambuco, Brazil, in 1966

Os autores descreveram o surto de leptospirose ocorrido em Recife, Pernambuco, Brasil durante os meses de junho e julho de 1966, após as enchentes que inundaram aquela cidade. Foram referidos cento e oitenta e um casos, dos quais cento e oitenta foram confirmados pela soro-aglutinação realizada no Instituto Adolfo Lutz de São Paulo. Outro caso foi confirmado pela necropsia. A leptospira dominante foi a L. icterohaemorrhagiae, responsável por cento e setenta casos; as demais foram a L. australis com cinco casos, a L. pomona com três casos e a L. andamana com dois casos. Os sintomas observados foram descritos e discriminada a frequência de cada um deles; houve casos anictéricos, e a mortalidade foram 3,3%. Além da penicilina em doses maciças, foi utilizada a dimetiltetraciclina com bons resultados. (AU)

The authors reported an outbreak of leptospirosis duríng June and July, 1966, followíng severe floods that afflicted the city of Recife, Pernambuco, Brazil. From the one hundred eight-one cases reported, one was confirmed by necropsy and the remaíníng by sero-aglutínatíons tests conducted in the Instituto Adolfo Lutz, of São Paulo, Brasil. The predominant leptospire was L. icterohaemorrhagiae found in one hundred and seventy cases, followed by L. australis (five cases), L. pomona (three cases), and L. andamana (two cases). The symptoms observed were described and coments made, regarding the frequency of each symptom: the mortalíty rate was 3.3 per cent. (AU)