Estudo soro-epidemiológico da leptospirose canina de amostras coletadas em bairros residenciais de Cruz das Almas-BA, Brasil / Seroepidemiologic study of canine leptospirosis from samples collected in residensial neighbothoods in Cruz das Almas ­ BA, Brazil

A leptospirose é uma doença infectocontagiosa, causada por espiroquetas antigenicamente distintas da bactéria Leptospira interrogans. Os cães representam um importante elo na transmissão da leptospirose, visto que, aparentemente sadios, podem albergar leptospiras e eliminá-las no meio ambiente. Com o objetivo de se conhecer a prevalência sorológica anti-leptospírica em cães de Cruz das Almas - BA e os fatores de risco para essa zoonose, foram coletadas amostras de sangue de 200 cães. A prova diagnóstica utilizada foi a Soroaglutinação Microscópica, testando-se 19 sorovares. Das 200 amostras testadas, 60 foram reagentes. Os resultados demonstram que a sororeatividade dos cães representam risco de disseminação da leptospirose para outros animais e para o ser humano.

Leptospirosis is an infectious disease, caused by spirochetes antigenically distinct from the bacteria Leptospira interrogans. Dogs represent an important link in the transmission of leptospirosis, since, apparently healthy, they can house leptospires and eliminate them in the environment. In order to know the anti-leptospiric serological prevalence in dogs from Cruz das Almas - BA and the risk factors for this zoonosis, blood samples were collected from 200 dogs. The diagnostic test used was Microscopic Soroagglutination, testing 19 serovars. Of the 200 samples tested, 60 were reagents. The results demonstrate that the seroreactivity of dogs represents a risk of spreading leptospirosis to other animals and to humans.

Ocorrência de sorogrupos/sorovares de Leptospira spp. em cães com suspeita clínica de leptospirose em Santa Maria ­ RS / Occurrence of serogroups/serovars of Leptospira spp. in dogs with clinical suspicion of leptospirosis in Santa Maria ­ RS

A leptospirose é uma zoonose de distribuição mundial que pode acometer cães e ser altamente letal para a espécie. No Brasil, tal enfermidade tem caráter endêmico na espécie canina e configura-se como um sério problema de saúde pública. Objetivou-se verificar a ocorrência dos sorogrupos/sorovares de Leptospira spp. que mais acometem cães com suspeita clínica de leptospirose na cidade de Santa Maria ­ RS, Brasil, analisando sua titulação de anticorpos. No estudo, utilizou-se os laudos dos exames de soroaglutinação microscópica (SAM) para leptospirose de 218 cães provenientes da cidade de Santa Maria ­ RS durante o período de janeiro de 2015 a dezembro de 2019. Todos os laudos foram emitidos pelo Laboratório de Leptospirose (LabLepto - UFSM). Das 218 amostras de soro processadas nos cinco anos, 101 (46,33%) resultaram positivas para, pelo menos, um sorogrupo/sorovar testado. Este estudo demonstrou maior ocorrência do sorogrupo Icterohaemorrhagiae (53,37%) contemplado pelas sorovares Copenhageni e Icterohaemorrhagiae, com 49 (30,06%) e 38 (23,31%) soros reagentes, respectivamente. As titulações variaram de 100 a 6400, sendo que a mais recorrente encontrada nas amostras deste estudo foi 100, representando 47,85% dos títulos de anticorpos. Os dados obtidos neste estudo são de grande valia para o conhecimento dos sorogrupos/sorovares circulantes na região e sua epidemiologia podendo, inclusive, auxiliar para futuras formulações vacinais considerando sorogrupos/sorovares mais frequentemente detectados, contribuindo, assim, com a saúde pública.

Leptospirosis is a worldwide distribution zoonosis that can affect dogs and be highly lethal for the species. In Brazil, this disease is endemic in the canine species and represents a serious public health problem. The aim of this study was to verify the occurrence of Leptospira spp. that most affect dogs with clinical suspicion of leptospirosis in the city of Santa Maria ­ RS, Brazil, analyzing their antibody titers. In the study, we used the reports of microscopic agglutination tests (MAS) for leptospirosis in 218 dogs from the city of Santa Maria - RS during the period from January 2015 to December 2019. All reports were issued by the Leptospirosis Laboratory (LabLepto - UFSM). Of the 218 serum samples processed over the five years, 101 (46.33%) were positive for at least one serogroup/serovar tested. This study showed a higher occurrence of serogroup Icterohaemorrhagiae (53.37%) covered by serovars Copenhageni and Icterohaemorrhagiae, with 49 (30.06%) and 38 (23.31%) reagent sera, respectively. The titers ranged from 100 to 6400, and the most recurrent found in the samples in this study was 100, representing 47.85% of the antibody titers. The data obtained in this study are of great value for understanding the serogroups/serovars circulating in the region and their epidemiology, and may even contribute to future vaccine formulations considering the most frequently detected serogroups/serovars, thus contributing to public health.

First report of pathogenic Leptospira spp. in Tadaridabrasiliensis bats (family Molossidae) and Eptesicus furinalis (family Vespertilionidae) of Argentina. New host species in this country? / Primer reporte de Leptospira spp. patógena en murciélagos Tadaridabrasiliensis (familia: Molossidae) y Eptesicusfurinalis (familia: Vespertilionidae) en Argentina. ¿Nuevas especies hospedadoras en el país?

ABSTRACT Leptospirosis is an endemic disease caused byLeptospiraspp., a bacterium that affects animals and humans. In recent years, the number of reports of leptospirosis in wild animals has increased, which highlights the need to study the infectious agents in these animals. In this study, a duplex PCR for the detection of leptospiral DNA was performed on 50 kidney samples from bats, and a MAT (Microscopic Agglutination Test) for serological detection of anti-leptospiral antibodies was applied to 47 serum samples from bats from different regions of Buenos Aires Province, Argentina. DNA was extracted using Chelex-100 and duplex PCR was performed by targeting the detection of genessecYandflaB, of pathogenicLeptospiraspp. Of the 50 kidney samples, 3 were positive forEumopssp. andTadaridabrasiliensisby duplex PCR. Of the 47 serum samples, 12 were positive for different serovars:Leptospira interrogansserovars Icterohaemorrhagiae, Cynopteri and Bataviae, andLeptospira borgpeterseniiserovar Ballum. This is the first report of the detection of pathogenic leptospires by serology in bats belonging to theT. brasiliensisandEptesicus furinalisspecies in Argentina. In addition, this is the first report of the detection of pathogenic leptospiral DNA by PCR inT. brasiliensisspecies. The detection ofLeptospiraspp. in these wild animals shows that they may play an important role as wildlife reservoirs of leptospires.

RESUMEN La leptospirosis es una enfermedad endémica causada porLeptospiraspp., una bacteria que afecta a animales y a humanos. En los últimos años, el número de reportes de leptospirosis en animales silvestres ha aumentado, lo que resalta la necesidad de analizar los agentes infecciosos en estos animales. En este estudio, se aplicó una reacción en cadena de la polimerasa (PCR) dúplex para la identificación del ADN leptospiral en 50 muestras de riñones de murciélagos y la prueba de aglutinación microscópica (MAT) para la detección serológica de anticuerpos antileptospira en 47 muestras de suero de murciélagos de diferentes regiones de la provincia de Buenos Aires, Argentina. El ADN fue extraído usando Chelex-100 y la PCR dúplex estuvo dirigida a la detección de los genessecYyflaBdeLeptospiraspp. patógena. De las 50 muestras de riñón, tres resultaron positivas por PCR dúplex paraEumopssp. yTadaridabrasiliensis. De las 47 muestras de suero, 12 fueron positivas a diferentes serovares:LeptospirainterrogansserovaresIcterohaemorrhagiae, Cynopteri y Bataviae, yLeptospiraborgpeterseniiserovarBallum. Este es el primer reporte de detección de leptospiras patógenas por serología en murciélagos pertenecientes a las especiesT. brasiliensisyEptesicusfurinalisen Argentina. Además, también es el primero en la localización de ADN leptospiral por PCR en la especieT. brasiliensis.La identificación deLeptospiraspp. en estos animales silvestres muestra que pueden desempeñar un papel importante como reservorios de leptospiras en la fauna silvestre.

Seroprevalencia de Leptospira spp. en equinos de tiro de comunidades indígenas mapuche de la Región de la Araucanía Chile / Seroprevalence of Leptospira spp. in draft horses from indigenous communities in the Araucanía Region, Chile

Resumen En la Región de la Araucanía no existen estudios sobre seroprevalencia de leptospirosis en equinos. Se analizaron muestras serológicas provenientes de 100 equinos de tiro de comunidades mapuche de cuatro comunas de la región mediante la técnica de microMAT. La seroprevalencia fue de 35% para al menos un serovar de Leptospira spp., siendo los serovares más frecuentes canicola (22%), grippotyphosa (21%), hardjo (13%) y pomona (10%). Se evidenció que las poblaciones equinas estudiadas están expuestas a la infección por Leptospira spp. y revelan un riesgo potencial de transmisión a sus propietarios.

Abstract In the Araucanía Region there are no studies on the seroprevalence of leptospirosis in horses. Serological samples from 100 draft horses from Mapuche communities of four communes in the region were analyzed using the microMAT technique. The seroprevalence was 35% for at least one serovar of Leptospira spp. being the most frequent serovars canicola (22%), grippotyphosa (21%), hardjo (13%) and pomona (10%). It was evident that the equine populations studied are exposed to infection by Leptospira spp. and reveal a potential risk of transmission to their owners.

Hematúria macroscópica em equinos associada à infecção por Leptospira interrogans / Macroscopic haematuria in horses associated with Leptospira interrogans infection

Hematúria é uma grave manifestação clínica de doença do sistema urinário, ocorrendo sob as formas micro ou macroscópica. Neste artigo relatam-se dois casos de hematúria macroscópica associada à infecção por Leptospira interrogans sorogrupo Canicola. O exame clínico inicial revelou hematúria macroscópica, taquicardia, taquipneia, febre, elevação do tempo de perfusão capilar, hipomotilidade intestinal, além de icterícia da mucosa oral. Leucocitose, proteinúria, glicosúria, piúria e azotemia foram achados comuns aos dois casos. Teste de Soroaglutinação Microscópica foi realizado para titulação de anticorpos contra Leptospira interrogans. Tratamento incluiu medidas terapêuticas de suporte (fluidoterapia), controle da hematúria e antibioticoterapia. Sete dias após manifestação dos sinais clínicos iniciais, ambos animais receberam alta hospitalar após remissão dos sinais clínicos.

Haematuria is a serious clinical manifestation of urinary system disease, occurring in micro or macroscopic forms. In this article two cases of macroscopic haematuria associated with Leptospira interrogans serogroup Canicolainfection are related. The initial clinical examination revealed macroscopic haematuria, tachycardia, tachypnea, fever, increased capillary perfusion time, intestinal hypomotility, in addition to jaundice of the oral mucosa. Leukocytosis, proteinuria, glycosuria, pyuria and azotemia were common findings in both cases. Microscopic serum agglutination test was performed for titration of antibodies against Leptospira interrogans. Treatment included supportive therapeutic measures (fluid therapy), hematuria control and antibiotic therapy. Seven days after the manifestation of the initial clinical signs, both animals were discharged from the hospital without complications.

Antibodies against Leptospira spp. in bovine serum samples from several Brazilian states analyzed in the period from 2007 to 2015 / [Anticorpos contra Leptospira spp. em amostra de soro bovino de diversos estados brasileiros analisados no período entre 2007 e 2015]

Bovine leptospirosis assumes great economic importance since it affects several production aspects. Therefore, knowledge about the occurrence and distribution of this disease is fundamental to adopt the correct prevention measures. The present study aimed to evaluate the frequency of anti-Leptospira spp. antibodies in 24,483 bovine serum samples received between 2007 to 2015 from 21 Brazilian states. Of these, 8,643 (35.3%) were reagents in the microscopic agglutination test to one or more serovars of Leptospira spp. The most frequent serovars were Wolffi (61.47%), Tarassovi (9.62%) and Pomona (7.20%). Hardjo serovar presented a prevalence of 6.27%. Among the 21 states analyzed, the State of Pernambuco had the highest frequency with 88.24% and the State of São Paulo was the origin of the largest number of analyzed samples (13,838), with a frequency of 31.54% of reagents. The results demonstrate a high exposure to several serovars of Leptospira spp. in bovine species in Brazilian states, showing the importance of adopting prophylactic measures in order to reduce the risk of infection in this specie.(AU)

Com o objetivo de avaliar a frequência de anticorpos anti-Leptospira spp., foram analisadas 24.483 amostras de soro sanguíneo bovino, provenientes de 21 estados brasileiros, recebidas no período de 2007 a 2015. Destas, 8.643 (35,3%) foram reagentes no teste de soroaglutinação microscópica a uma ou mais sorovariedades de Leptospira spp., e as sorovariedades com maior frequência foram Wolffi (61,47%), Tarassovi (9,62%) e Pomona (7,20%). A sorovariedade Hardjo apresentou prevalência de 6,27%. Entre os 21 estados analisados, o estado de Pernambuco apresentou a maior frequência, com 88,24%, e o estado de São Paulo foi a origem do maior número de amostras para análise, 13.838, com frequência de 31,54% de reagentes.(AU)

Spatial distribution of serologically reactive sheep to Leptospira spp. in the northeast region of Brazil

Considering the importance of leptospirosis in sheep farming and public health and the significance of identifying which serogroups circulate in sheep within each region, the objective of this study was to determine the seroprevalence and spatial distribution of the most frequent serogroups causing infection by Leptospira sp. in ovine herds in the Northeast region of Brazil. Blood samples were collected from 4197 sheep from 229 herds in 7 Northeastern States. Sera were analyzed via microscopic agglutination test (MAT). The frequency of seroreactive sheep for Leptospira sp. was 14.06%. The states of Alagoas, Ceará, Paraíba, Piauí, Rio Grande do Norte, and Sergipe, located in the Caatinga biome, had the highest frequencies of serologically reactive sheep, and Maranhão, in the Cerrado biome, had the lowest frequency. The most frequent serogroups were Autumnalis (19.49%), Australis (15.76%) and Serjoe (14.41%). In the states of Ceará, Paraíba, Rio Grande do Norte, and Sergipe, 100% of their municipalities had at least one seroreactive animal. The highest frequencies of seropositive animals were found in the municipalities of União (50%), Passagem (49.06%), Canindé (48.89%), Igaci (28.95%), Gararu (31.2%), Pirapemas (17.5%), and Angicos (16%) located in the states of Piauí, Paraíba, Ceará, Alagoas, Sergipe, Maranhão and Rio Grande do Norte, respectively. The animal-level prevalence (14.06%) obtained in the present study is significant, especially considering the rustic nature of the species and the adverse conditions of the region for the infectious agent. In semi-arid conditions, it has been suggested that perhaps sheep do not seroconvert detectable titers on MAT with a cut-off point of 1:100. It is important to highlight that the ovine population in the Northeast region of Brazil is composed of mixed animals, which have been considered more resistant to infection by Leptospira spp. Also, environmental factors hostile to the survival of the infectious agent in the studied region should be taken into consideration, since they may have influenced the seropositive animal-level prevalence. A noteworthy variation was observed in agglutinin titers, which ranged from 100 to 1,600, where 80.2% of the positive samples had titers ≤ 200. It is important to highlight that more elevated titers (≥ 400) were obtained in all seven states, which may suggest an acute infection caused by a non-adapted serovar, indicating that preventive and control measures focused on possible infection sources for sheep should be adopted. Although some states showed the same serogroups as the most frequent, a variety of serogroups was observed in municipalities, which may indicate different sources of infection, whether interspecies, intraspecies, or via alternative routes of transmission in semi-arid conditions, such as venereal. This indicates that even though sheep are more resistant to infection, they become exposed due to the environment or management conditions. As such, identification, isolation, and treatment of the affected animals are alternative measures recommended for prevention and control of leptospirosis in sheep in the semi-arid region. It is evident that despite the lack of rain observed in the last decade in the Northeast region of Brazil, which prevented the formation of favorable environments for the presence of Leptospira, the infectious agent remains among the sheep, as well as other production and wild animals in the region. Some factors may be contributing to this scenario, such as the fact that sheep farming in the region is = characterized mainly by subsistence systems, where veterinary assistance and adequate sanitary management are absent, thus increasing the possibility of contact with Leptospira. (AU)

Primer aislamiento de Leptospira borgpetersenii serovar Hardjo tipo Hardjo Bovis a partir de un caso clínico en Argentina / First isolation of Leptospira borgpetersenii serovar Hardjo type Hardjo Bovis from aclinical case in cattle in Argentina

Resumen Se describe el primer aislamiento y la tipificación molecular de Leptospira borgpetersenii serovar Hardjo Bovis en Argentina, obtenido a partir de orina de vacas abortadas de unrodeo de cría ubicado en Saladillo, provincia de Buenos Aires. Los abortos coincidieron con unperíodo de importantes inundaciones, en el que varios animales presentaron títulos serológicossospechosos y posterior seroconversión. El porcentaje de abortos alcanzó el 3,5% del total delrodeo, compuesto por 1700 vacas, y se aisló el microorganismo en 7 de 20 muestras de orinaobtenidas.

Abstract We here describe the first isolation and molecular typing of Leptospira borgpe-tersenii serovar Hardjo Bovis in Argentina, obtained from urine of aborted cows from abreeding herd located in Saladillo, Buenos Aires Province. The abortions occurred in coincidence with important floods with many cows presenting suspicious serological titers and subsequentseroconversion. The percentage of abortions was 3.5% of a herd of 1700 cows and the microor-ganism was isolated from 7 of the 20 urine samples obtained.

Differential diagnoses in 83 dogs with icterus / Diagnósticos diferenciais em 83 cães com icterícia

Icterus (jaundice) is a yellowish pigmentation resulting from the depositing of bilirubin in tissues due to its high plasmatic concentration. The pathogenesis of icterus includes metabolic changes or obstructed bilirubin excretion and it is classified as pre-hepatic, hepatic and post-hepatic. This study aimed to evaluate and classify different causes of icterus in dogs during post mortem examination. These dogs were examined from 2014 to 2017, using macroscopic and histologic exams as well as ancillary tests. Eighty-three dogs were examined macroscopically and microscopically. They were separated into groups of icterus types: 24 (28.9%) dogs had pre-hepatic icterus, 45 (54.2%) had hepatic, 13 (15.7%) pre-hepatic and hepatic and one (1.2%) had post-hepatic icterus. Many factors were identified as a cause of icterus, including infectious agents (51/83), neoplasms (13/83), hepatic degeneration (11/83), chronic hepatic diseases (6/83), and obstructive causes (1/87). Among the infectious causes, leptospirosis, ehrlichiosis and disorders suggestive of septicemia were diagnosed. Neoplasms associated with icterus were cholangiocarcinoma, hemangiosarcoma and lymphoma. Other causes of icterus included degenerative diseases, such as lipidosis and glycogen degeneration. Hepatic fibrosis (cirrhosis) as a chronic disease and cholelithiasis also produced icterus. PCR was performed to confirm leptospirosis and ehrlichiosis. Samples of total DNA were used to amplify a fragment of a gene from Leptospira interrogans and Ehrlichia canis. In some dogs, co-infection of these agents was detected. The classification and identification of icterus etiologies in dogs is very important due to the number of diseases with this alteration, where ante mortem diagnosis is not always easily performed when some of these conditions are present.(AU)

Icterícia é a pigmentação amarelada decorrente da deposição de bilirrubina em tecidos devido à elevada concentração plasmática. A patogênese da icterícia inclui alterações no metabolismo ou na excreção de bilirrubina, sendo classificada em pré-hepática, hepática ou pós-hepática. O objetivo desse estudo foi identificar, avaliar e classificar as causas de icterícia em cães necropsiados de 2014 a 2017, associando as lesões macroscópicas, histológicas e exames complementares. Foram avaliados macro- e microscopicamente 83 cães com diferentes intensidades de icterícia. Os cães foram separados em grupos de acordo com o tipo de icterícia: 24 (28,9%) cães com icterícia pré-hepática, 45 (54,2%) cães com icterícia hepática, 13 (15,7%) com icterícia pré-hepática e hepática e um (1,2%) com icterícia pós-hepática. Foram identificadas várias etiologias associadas à icterícia, dentre elas pode-se destacar, agentes infecciosos (51/83), neoplasmas (13/83), processos degenerativos (11/83), crônicos (6/83) e obstrutivos (1/83). Dentre as causas infecciosas, destacam-se a leptospirose, a erliquiose e as lesões sugestivas de septicemia. Entre os neoplasmas associados com icterícia destacaram-se o colangiocarcinoma, hemangiossarcoma e linfoma. Outras causas de icterícia incluiriam os processos degenerativos como as degenerações gordurosa e glicogênica. Fibrose hepática (cirrose) e colelitíase foram também diagnosticados como causa de icterícia. A PCR foi utilizada para o diagnóstico confirmatório de leptospirose e erliquiose. Amostras de DNA total foram utilizadas para amplificar um fragmento dos genes de Leptospira interrogans e de Ehrlichia canis. Em alguns cães foi detectada co-infecção por estes agentes. A classificação e a identificação das causas de icterícia em cães são relevantes devido ao grande número de doenças que apresentam essa alteração, muitas vezes sem diagnóstico ante mortem.(AU)

Causes of abortion in dairy cows in Uruguay / Causas de aborto em bovinos de leite no Uruguai

A case series study was conducted to determine the frequency of causes of abortion in dairy cattle in Uruguay. The sample size of 102 cases was composed of 53 fetuses, 35 fetuses with placentas, and 14 placentas without an associated fetus. All cases underwent gross and microscopic pathologic examinations as well as microbiological and serological testing. The etiology was determined in 54 (53%) of cases, 51 of which were caused by infectious agents. Within the observed 102 cases, 30 (29%) were caused by Neospora caninum, six (6%) by Coxiella burnetii and two (2%) by Campylobacter fetus subsp. venerealis. Bovine Parainfluenza-3 virus and Salmonella enterica serovar Newport caused one abortion each. Opportunistic bacteria (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes, and Providencia stuartii) were associated with 11 abortions. In two cases the fetal death was attributed to dystocia, and in one case the fetus had a congenital mesothelioma. Bovine viral diarrhea virus (BVDV) infection was identified in three fetuses; two of which were co-infected with and had typical lesions of N. caninum. No lesions were observed in the other fetus infected by BVDV. Leptospira interrogans was identified in one fetus without lesions. Despite the relatively low overall success rate in establishing an etiological diagnosis in cases of abortion in cattle, a systemic workup of bovine abortion is necessary to establish prevention and control strategies. This also facilitates monitoring and surveillance of reproductive diseases in dairy cattle, some of which represent a risk to public health.(AU)

Uma série de casos foi estudada para determinar a frequência de causas do aborto em bovinos leiteiros no Uruguai. A amostra, de 102 casos, foi composta por 53 fetos, 35 fetos com placentas e 14 placentas sem feto associado. Todos os casos foram submetidos a exames patológicos macroscópicos e microscópicos, além de testes microbiológicos e sorológicos. A etiologia foi determinada em 54 (53%) dos casos, 51 dos quais foram causados por agentes infecciosos. Nos 102 casos observados, 30 (29%) foram causados por Neospora caninum, seis (6%) por Coxiella burnetii e dois (2%) por Campylobacter fetus subsp. venerealis. O vírus da Parainfluenza-3 e Salmonella enterica serovar Newport causaram um aborto cada. Bactérias oportunistas (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes e Providencia stuartii) foram associadas a 11 abortos. Em dois casos, a morte fetal foi atribuída a distocia e, em um caso, o feto apresentava mesotelioma congênito. A infecção pelo vírus da diarreia viral bovina (BVDV) foi identificada em três fetos; dois dos quais foram co-infectados e apresentavam lesões típicas de N. caninum. Não foram observadas lesões no outro feto infectado pelo BVDV. Leptospira interrogans foi identificada em um feto sem lesões. Apesar da relativamente baixa taxa de sucesso no diagnóstico etiológico nos casos de aborto em bovinos, é necessário o diagnóstico sistemático dos abortos para estabelecer estratégias de prevenção e controle. Isso também facilita o monitoramento e a vigilância de doenças reprodutivas em bovinos leiteiros, algumas das quais representam um risco para a saúde pública.(AU)

Seroprevalence and incidence of Leptospira spp. in domestic dogs in the Southeast region of São Paulo State, Brazil / Soroprevalência e incidência de Leptospira spp. em cães domésticos na região sudeste do estado de São Paulo, Brasil

Leptospirosis is a zoonotic disease caused by Leptospira and domestic dogs can act as host of some serovars. In order to analyze the transmission dynamics in a dog population, with and without immunization, a longitudinal study was carried out with a focus to evaluate antibody response and to identify serovars. Blood samples were collected in three consecutive years (2015 to 2017) from 331, 373 and 347 dogs respectively. The dog seroprevalence in each year was 11%, 7% and 14%, respectively, and the incidence in 2016 was 5% and in 2017, 14%. The most frequent serovars were Cynopteri and Butembo in 2015, Cynopteri, Butembo and Hardjoprajitno in 2016, and Canicola and Butembo in 2017. Dogs can play a role as sentinel animals and hosts of Leptospira serovars. The percentage of seropositive dogs due to vaccination was higher than the previous years without immunization and lower than in previous years for other serovars, which we interpret as evidence for the importance of immunization. These parameters associated with active canine population control are important for prevention and control of leptospirosis not only in dogs but alsoto inhibit the transmission between dogs and humans.(AU)

A leptospirose é uma zoonose causada pelo agente etiológico Leptospira. Cães domésticos atuam como hospedeiro de diversos sorovares deste agente. Com intuito de analisar a dinâmica da leptospirose em uma população canina, com e sem imunização, um estudo longitudinal foi realizado avaliando a resposta sorológica destes animais e identificando seus sorovares. Foram coletadas amostras de 331, 373 e 347 cães em três anos consecutivos (2015 a 2017). As soroprevalências foram de 11%, 7% e 14%, respectivamente, e a incidência em 2016 foi de 5% e em 2017 de 14%. Os sorovares mais frequentes foram Cynopteri e Butembo em 2015, Cynopteri, Butembo e Hardjoprajitno em 2016, e Canicola e Butembo em 2017. Estes cães estão atuando como bio-indicadores da presença de Leptospira na região do estudo, incluindo sorovares zoonóticos, e contribuindo com a sua manutenção no ambiente. A soropositividade para sorovares protegidos pela vacina foi mais alta do que nos anos anteriores à imunização, enquanto para os sorovares não protegidos pela vacina diminuiu, demonstrando a importância da imunização para essa população de cães. Medidas de prevenção e controle para a leptospirose, como imunização e controle populacional canino, são recomendadas no local para inibir a transmissão do agente entre as populações de cães e humanos envolvidas.(AU)

High proportion of cattle and sheep seropositive and renal carriers of Leptospira sp. under semiarid conditions / Alta proporção de bovinos e ovinos soropositivos e portadores renais de Leptospira sp. em condições semiáridas

The aims of this study were to perform serological and molecular detection of Leptospira sp. infection in cattle and sheep under semiarid conditions. Based on a preliminary study performed in our research group, we selected six rural properties showing a positivity ≥ 60% for Sejroe serogroup with titer ≥ 200 measured in serological tests from cattle. In the present study, blood and urine samples were collected from 99 females of reproductive age (51 cattle and 48 sheep) for serological diagnosis, molecular detection and Leptospira sp. attempt to strain recovery. Of the 99 analyzed animals 38.4% (38/99) were positively reactive at the serological tests. Of them, 49% (25/51) were cattle and 27.1% (13/48) sheep. The serogroups detected in cattle were Sejroe (36.8%), Hebdomadis (26.3%), Australis (10.5%), Djasiman (10.5%), Ballum (5.3%), Pomona (5.3%), and Cynopteri (5.3%) with titers of 100­800. In sheep, the reactive serogroups were Australis (27.3%), Ballum (27.3%), Djasiman (18.1%), Tarassovi (9.1%), Icterohaemorrhagiae (9.1%), and Cynopteri (9.1%) with titers of 100­400.Leptospiral DNA was detected in nine urine samples, including five cattle and four sheep. Property 1 showed the highest serological positivity frequencies for both cattle (70.6%) and sheep (70.6%). Similarly, the highest frequency of DNA detection was also found (eight samples, 89%). In this property, we observed the existence of consorted rearing of cattle and sheep with close coexistence between these species. In semiarid conditions, transmission among animals of the same species seems to be the main form of Leptospira sp. dissemination in cattle and sheep herds. However, the contribution of other domestic and wild animals cannot be discarded. The practice of consorted rearing of cattle and sheep and their close coexistence may facilitate the spread of the pathogen in rural properties.

Os objetivos deste estudo foram realizar detecção sorológica e molecular da infecção por Leptospira sp. em bovinos e ovinos em condições semiáridas. Com base em estudo preliminar realizado em nosso grupo de pesquisa, foram selecionadas seis propriedades rurais com soropositividade ≥ 60% para o sorogrupo Sejroe com título ≥ 200 em bovinos. No presente estudo, amostras de sangue e urina foram coletadas de 99 fêmeas em idade reprodutiva (51 bovinos e 48 ovinos) para diagnóstico sorológico, detecção molecular e tentativa de recuperação de estirpesde Leptospira sp. Dos 99 animais analisados, 38,4% (38/99) foram sororeativos nos testes sorológicos. Destes, 49% (25/51) eram bovinos e 27,1% (13/48) ovinos. Os sorogrupos detectados em bovinos foram Sejroe (36,8%), Hebdomadis (26,3%), Australis (10,5%), Djasiman (10,5%), Ballum (5,3%), Pomona (5,3%) e Cynopteri (5,3%) com títulos de 100 a 800. Nos ovinos, os sorogrupos reativos foram Australis (27,3%), Ballum (27,3%), Djasiman (18,1%), Tarassovi (9,1%), Icterohaemorrhagiae (9,1%) e Cynopteri (9,1%) com títulos de 100-400. O DNA leptospiral foi detectado em nove amostras de urina, incluindo cinco bovinos e quatro ovinos. A propriedade 1 apresentou as maiores frequências de positividade sorológica para bovinos (70,6%) e ovinos (70,6%). Da mesma forma, a maior frequência de detecção de DNA também foi encontrada (oito amostras, 89%). Nesta propriedade observou-se a existência de criação consorciada de bovinos e ovinos com estreita convivência entre estas espécies. Em condições semiáridas, a transmissão entre animais da mesma espécie parece ser a principal forma de disseminação de Leptospira sp. em rebanhos bovinos e ovinos. No entanto, a contribuição de outros animais domésticos e selvagens não pode ser descartada. A prática de criação consorciada de bovinos e ovinos e sua estreita convivência podem facilitar a disseminação do patógeno em propriedades rurais.

Epidemiological relevance of dogs for the prevention of Toxoplasma gondii, Neospora caninum and Leptospira spp / Relevância epidemiológica de cães para a prevenção de Toxoplasma gondii, Neospora caninum e Leptospira spp

Abstract This study evaluated the seroprevalence of Toxoplasma gondii, Neospora caninum and Leptospira spp. in dogs from Foz do Iguaçu, Paraná, Brazil. Indirect immunofluorescent antibody test was used to detect antibodies anti-T.gondii and anti-N. caninum. Immunoenzymatic assay and microscopic serum agglutination were used for screening antibodies anti-T.gondii and anti-Leptospira spp., respectively. The results were: 67.02% of the samples reactive for T.gondii and 1.38% for N. caninum, both without statistically significant variables. For Leptospira spp. the results indicated seroprevalence of 23.11%. The analysis of the variables without distinction of serovar showed association for intrinsic characteristics as breed, age, nutritional status and dog category. The extrinsic variables as city region and access to the street presented association (p<0.05). The most prevalent serovars were: Canicola 59.47%; Bratislava 13.07% and Butembo 15.68%. Variables that make up the adjusted multiple analysis model using Leptospira spp. were: age, breed and nutritional status; serovar Canicola, sex, nutritional status and area (p<0.05); serovar Bratislava, lymphadenomegaly and presence of fleas (p<0.05). Given the results obtained, dogs can be used as sentinels for toxoplasmosis and leptospirosis in Foz do Iguaçu and other cities with similar outcomes. In addition, preventive measures should be taken by health authorities because they are zoonoses and humans are also at risk.

Resumo Este estudo avaliou a soroprevalência de Toxoplasma gondii, Neospora caninum e Leptospira spp. em cães de Foz do Iguaçu, Paraná, Brasil. O teste de imunofluorescência indireta foi utilizado para detectar anticorpos anti-T. gondii e anti-N. caninum. Ensaio imunoenzimático e soroaglutinação microscópica foram utilizados para pesquisa de anticorpos anti-T. gondii e anti-Leptospira spp., respectivamente. Os resultados obtidos foram: 67,02% (435/649) das amostras reativas para T. gondii e, 1,38% (9/649) para N. caninum, ambas com ausência de variáveis significativas estatisticamente. Para Leptospira spp. os resultados indicaram soroprevalência de 23,11% (153/649). A análise das variáveis sem distinção de sorovar mostraram associação para caraterísticas intrísecas como raça, idade, estado nutricional e categoria de cães. Para as variáveis extrínsecas, a região da cidade e ter acesso à rua mostraram associação estatística (p<0,05). Os sorovares mais prevalentes foram: Canicola com 59,47% (91/153); Bratislava 13,07% (20/153) e Butembo 15,68% (24/153). As variáveis que compõem o modelo de análise multivariada ajustada usando como desfecho Leptospira spp. foram: idade, raça, estado nutricional e área. Para o sorovar Canicola, as variáveis significantes (p<0,05) foram sexo, estado nutricional e área; para o sorovar Bratislava, as variáveis significantes (p<0,05) foram linfadenomegalia e presença de pulgas. Dos resultados obtidos, cães podem ser usados como sentinelas para infecção por T. gondii e Leptospira spp. na cidade de Foz do Iguaçu e em outras cidades com desfechos similares. Além disso, medidas preventivas devem ser tomadas pelas autoridades de saúde, pois são zoonoses e os seres humanos também estão em risco.

Caracterización epidemiológica de la infección por Leptospira spp. en caballos de trabajo y en personas ocupacionalmente expuestas en seis unidades de la Policía Nacional de Colombia / Epidemiological characterization of Leptospira spp. infection in working horses and in an occupationally exposed population in six Colombian police stations

Resumen Introducción. Los caballos de trabajo de la Policía Nacional tienen un estrecho contacto con sus manejadores y la población en general durante las actividades recreativas y de patrullaje, lo cual puede favorecer la transmisión de la leptospirosis en los caballos y el personal ocupacionalmente expuesto. Objetivo. Caracterizar epidemiológicamente la leptospirosis mediante pruebas de serología, urocultivo y reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) en caballos de trabajo y personal con riesgo ocupacional pertenecientes a seis unidades de la Policía Nacional de Colombia. Materiales y métodos. Se evaluaron 153 caballos machos castrados y 123 personas en las seis unidades en los municipios de Manizales, Pereira, Armenia, Ibagué, Tuluá y Cali. Se utilizaron tres formatos estructurados para recabar información y se obtuvieron muestras sanguíneas de las personas y de los caballos, las cuales se procesaron con la prueba de aglutinación microscópica (Macroscopic Agglutination Test, MAT) para 24 serogrupos. Se practicó el examen clínico de los caballos y se obtuvieron muestras de orina para el urocultivo y la PCR convencional. Resultados. La seroprevalencia de Leptospira spp. fue de 3,25 % (n=4) en las personas y de 85 % (n=130) en los caballos. Entre los caballos, los serogrupos Djasiman y Shermani fueron los más prevalentes. El urocultivo fue positivo en el 64,7 % (99/153) de las muestras, en tanto que los análisis de PCR fueron negativos. Se encontró una asociación estadísticamente significativa de la frecuencia de salida de las instalaciones (p=0,009) y la presencia de fauna silvestre (p=0,051) con la infección por el serogrupo Shermani. Conclusión. Las características epidemiológicas de la leptospirosis en los caballos sugieren una presentación endémica de la infección y su papel como reservorios de la bacteria; sin embargo, debe dilucidarse la patogenia de la enfermedad con estudios complementarios.

Abstract Introduction: Police working horses are in close contact with their managers and the general population during recreational and patrol activities, which can favor the transmission of leptospirosis among the horses and the occupationally exposed personnel. Objective. To characterize epidemiologically leptospirosis through serology, urine culture and PCR in working horses and in the occupationally exposed population in six police stations in Colombia. Materials and methods. We tested 153 castrated male horses and 123 people in six police stations in the municipalities of Manizales, Pereira, Armenia, Ibagué, Tuluá, and Cali. Three structured formats were applied and blood samples were obtained from people and horses, which were processed with the Macroscopic Agglutination Test, (MAT) for 24 serogroups. Horses were subject to a clinical examination, and urine samples were obtained for urine culture and conventional PCR. Results. The seroprevalence of human Leptospira spp. was 3.25% (n=4) while in horses it was 85% (n=130). Among the horses, serogroups Djasiman and Shermani were the most prevalent. The urine culture was positive in 64.7% (99/153) of the samples, whereas PCR analyzes were negative. A statistically significant association was found between the frequency of exiting the facilities (p=0.009) and the presence of wildlife (p=0.0051) with the infection by serogroup Shermani. Conclusion. The epidemiological characteristics of leptospirosis in horses suggest an endemic presentation of the infection and its role as reservoirs of the bacteria; however, it is necessary to elucidate the pathogenesis of the disease with complementary studies.

Soropositividade para Leptospira sp. e sorogrupos predominantes em cães do Pantanal Brasileiro / Seropositivity for Leptospira sp. and predominant serogroups in dogs from the Brazilian Pantanal

Em face à grande importância que a leptospirose possui no contexto sanitário mundial, tanto no aspecto humano como animal, este estudo teve por objetivo realizar a pesquisa de anticorpos anti-Leptospira sp. pela técnica de Soroaglutinação Microscópica (SAM) em 429 amostras de soros de cães provenientes de quatro municípios (Poconé/MT, Santo Antônio de Leverger/MT, Barão de Melgaço/MT e Corumbá/MS) localizados na região do Pantanal Brasileiro, bem como foram verificadas possíveis associações entre os resultados dos exames sorológicos e respostas aos questionários epidemiológicos aplicados aos proprietários. Do total de cães avaliados pela SAM (título ≥100), verificou-se que 34 (7,93%; IC 95%: 5,63%-11,00%) cães tinham anticorpos anti-Leptospira sp. Os títulos encontrados variaram entre 100 e 1600 e todos os municípios analisados tinham cães sororreagentes ao agente pesquisado. O sorogrupo reator mais frequente foi o Icterohaemorrhagiae, seguido pelo Australis. Por outro lado, foram observadas menores proporções de cães reagentes aos sorogrupos Tarassovi, Hebdomadis, Autumnalis e Grippotyphosa. As variáveis associadas com a ocorrência de leptospirose foram habitat rural (P<0,01) e área alagável (P=0,01). Estes resultados demonstram que os cães da região pantaneira tiveram contato com agentes do gênero Leptospira, o que representa uma informação relevante para a saúde pública local devido à importância zoonótica da doença.

Given the great importance that leptospirosis has the global health context, both in human and animal aspect, this study aimed to search for antibodies anti-Leptospira sp. by the technique of microscopic agglutination test (MAT) in 429 samples of sera from dogs from four municipalities (Poconé/MT, Santo Antônio de Leverger/MT, Barão de Melgaço/MT and Corumbá/MS) located in the Brazilian Pantanal region, in order for determine associations between the results of the serological tests and answers to epidemiological questionnaires applied to owners. Of the total dogs evaluated by MAT (titer ≥100), it was verified that 34 (7.93%, 95% CI: 5.63% -11.00%) dogs had antibodies against Leptospira sp. The titers found ranged from 100 to 1600 and all municipalities analyzed had seroreactive dogs for the investigated agent. The most frequent serogroup reactor was Icterohaemorrhagiae, followed by Australis. On the other hand, smaller proportions of reactive dogs were observed for serogroups Tarassovi, Hebdomadis, Autumnalis and Grippotyphosa. The variables associated with the occurrence of leptospirosis were rural habitat (P<0.01) and flooded area (P=0.01). These results demonstrate that dogs from the Pantanal region had contact with agents of the genus Leptospira, which represents information relevant to local public health due to the zoonotic importance of the disease.

Coxiella burnetii associated with BVDV (Bovine Viral Diarrhea Virus), BoHV (Bovine Herpesvirus), Leptospira spp, Neospora caninum, Toxoplasma gondii and Trypanosoma vivax in reproductive disorders in cattle / Coxiella burnetii associada ao BVDV (Vírus da Diarreia Viral Bovina), BoHV (Vírus do Herpes Bovino), Leptospira spp, Neospora caninum, Toxoplasma gondii e Trypanosoma vivax em distúrbios reprodutivos em bovinos

Abstract This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella burnetii. The used tests were Virus Neutralization Assay for IBR and BVD, Microscopic Agglutination Test for Leptospira spp., Indirect Fluorescent Antibody Test (IFAT) for C. burnetii and Toxoplasma gondii, and Enzyme-Linked Immunosorbent Assay for Neospora caninum and Trypanosoma vivax. Seropositivity for C. burnetii was 13.7% with titers from 128 to 131,072; 57.8% for BoHV-1, with titers between 2 and 1,024; 47.1% for BVDV-1a, with titers from 10 to 5,120; 89.2% for N. caninum; 50% for T. vivax; and 52.0% for Leptospira spp., with titers between 100 to 800 (the following serovars were found: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona and Icterohaemorrhagiae); 19.6% for T. gondii with titer of 40. This is the first study that has identified C. burnetii in cattle associated with BoHV and BVDV, N. caninum, Leptospira spp., T. gondii and T. vivax. Thus, future studies should be conducted to investigate how widespread this pathogen is in Brazilian cattle herds.

Resumo Este é um estudo transversal para avaliar a presença de anticorpos em ruminantes contra patógenos selecionados e associados a distúrbios reprodutivos em bovinos de quatro estados brasileiros, incluindo o agente zoonótico Coxiella burnetii. Os testes utilizados foram Teste de Vírus-Neutralização para BoHV e BVDV, teste de Aglutinação Microscópica para Leptospira spp., Reação de Imunofluorescência Indireta for C. burnetii e Toxoplasma gondii, e Ensaio de Imunoabsorção Enzimática para Neospora caninum e Trypanosoma vivax. A soropositividade para C. burnetii foi de 13,7% com títulos de 128 a 131.072; 57,8% para BoHV-1, com títulos entre 2 a 1.024; 47,1% para BVDV-1a, com títulos de 10 a 5.120; 89,2% para N. caninum; 50% para T. vivax; e 52,0% para Leptospira spp., com títulos entre 100 a 800 (sorovares encontrados: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona e Icterohaemorrhagiae) 19,6% para T. gondii com título de 40. Este é o primeiro estudo que evidencia a participação de C. burnetii em bovinos associada ao Vírus da Rinotraqueíte bovina infecciosa e da diarreia viral bovina, N. caninum, Leptospira spp., T. gondii e T. vivax em bovinos. Desta forma, futuros estudos devem ser conduzidos a fim de investigar o quão disseminado se encontra este patógeno em rebanhos bovinos brasileiros.

Occurrence of serological reactions for serogroup Sejroe (CTG and Prajtino) in female buffalo in the state of Pernambuco, Brazil

ABSTRACT The objective of this study was to evaluate the occurrence of anti-Leptospira spp. antibodies in female buffalo in the state of Pernambuco. A total of 123 female buffalo blood samples were collected from five properties distributed in the state of Pernambuco. The microscopic agglutination test was used to study anti-Leptospira spp. antibodies. The occurrence of anti-Leptospira spp. antibodies was 28.5% (35/123; CI 20.7-37.3%) and on different properties, the occurrence ranged from 28.6% to 80.0%, with 100% of the properties showing animals with positive results. The serovars of the serogroup Sejroe with a higher incidence were Hardjoprajtino (CTG strain, 49.1%) and Hardjo (Prajtino genotype, 43.2%), followed by serogroup Grippotyphosa with the Grippotyphosa serovar (3.9%), serogroup Pomona with the Pomona serovar (1.9%), and the Icterohaemorrhagiae serovar Copenhageni (1.9%). This was the first record of the occurrence of anti-Lepstospira spp. antibodies in female buffalo in the state of Pernambuco. Control measures are necessary to prevent health and economic losses, given that the agent involved affects animal reproduction, triggering drops in conception rates or even clinical cases of abortion.

Prevalence and risk factors to Leptospira sp. infection in dogs attended at veterinary clinics in João Pessoa, Paraíba State, Northeastern Brazil / Prevalência e fatores de risco da infecção por Leptospira sp. em cães atendidos em clínicas veterinárias em João Pessoa, Paraíba, Nordeste do Brasil

This study investigated the prevalence and risk factors associated with Leptospira sp. in dogs attended at veterinary clinics in the city of João Pessoa, State of Paraíba, Northeast Brazil. A total of 384 blood samples from dogs from 34 veterinary clinics were used from April 2015 to May 2016. The serological Leptospira sp diagnosis was carried out through Microscopic Agglutination Test (MAT), using a collection of 20 pathogenic antigens and adopting a 1:100 dilution as cutoff point. An epidemiological questionnaire was applied to the animal's owners to obtain the information used in risk factors analysis. The prevalence of seropositive animals was 11.7% (45/384), with reactions for serogroups Icterohaemorrhagiae (62.3%), Grippotyphosa (22.2%), Canicola (13.3%), Djasiman 2%) and Pomona (2.2%). The following risk factors were identified: age from 49 to 72 months (odds ratio = 2.74); Age > 72 months (odds ratio = 3.22); and monthly cleaning of the environment where the animals were kept (odds ratio = 10.70). We concluded that dogs attended at veterinary clinics in João Pessoa are exposed to Leptospira sp infection, with predominance of serogroups kept by wild or synanthropic animals, and suggest a monthly periodic environment cleaning where the animals are kept.(AU)

O presente trabalho investigou a prevalência e os fatores de risco associados à infecção por Leptospira sp. em cães atendidos em clínicas veterinárias da cidade de João Pessoa, Estado da Paraíba, Nordeste do Brasil. Foram utilizadas 384 amostras sanguíneas de cães provenientes de 34 clínicas veterinárias no período de abril de 2015 a maio de 2016. O diagnóstico da infecção por Leptospira sp. foi realizado com o emprego reação de Soroaglutinação Microscópica (SAM), utilizando uma coleção com 20 antígenos patogênicos e adotando como ponto de corte a diluição 1:100. Foi aplicado um questionário epidemiológico aos proprietários dos animais para obtenção de dados a serem utilizados na análise de fatores de risco. A prevalência de animais soropositivos foi de 11,7% (45/384), com reações para os sorogrupos Icterohaemorrhagiae (62,3%), Grippotyphosa (22,2%), Canicola (13,3%), Djasiman (2,2%) e Pomona (2,2%). Foram identificados os seguintes fatores de risco: idade entre 49 e 72 meses (odds ratio = 2,74), idade maior que 72 meses (odds ratio = 3,22), e limpeza mensal do ambiente onde os animais permanecem (odds ratio = 10,70). Conclui-se que cães atendidos em clínicas veterinárias de João Pessoa estão expostos à infecção por Leptospira sp., com predominância de sorogrupos mantidos por animais selvagens, e foi sugerida a realização da limpeza periódica do ambiente ocupado pelos animais.(AU)

Development and validation of a modified TaqMan based real-time PCR assay targeting the lipl32 gene for detection of pathogenic Leptospira in canine urine samples

Abstract A modified TaqMan real-time polymerase chain reaction targeting a 138 bp fragment within the lipl32 gene was developed to identify exclusively pathogenic Leptospira spp. in dog urine samples. Thirty-five samples from dogs with suspected clinical leptospirosis and 116 samples from apparently healthy dogs were tested for presence of leptospiral DNA using the TaqMan-based assay. The results were compared with those from a well-established conventional PCR targeting the 16S RNA encoding gene associated with nucleotide sequencing analysis. The overall agreement between the assays was 94.8% (confidence interval [CI] 95% 88-100%). The newly developed assay presented 91.6% (CI 95% 71.5-98.5%) relative sensitivity (22[+] lipl32 PCR/24[+] 16S RNA and sequencing), 100% (CI 95% 96.3-100%) relative specificity and 98.7% accuracy (CI 95% 94.8-100%). The lipl32 assay was able to detect and quantify at least 10 genome equivalents/reaction. DNA extracted from 17 pathogenic Leptospira spp., 8 intermediate/saprophytic strains and 21 different pathogenic microorganisms were also tested using the lipl32 assay, resulting in amplification exclusively for pathogenic leptospiral strains. The results also demonstrated high intra and inter-assay reproducibility (coefficient of variation 1.50 and 1.12, respectively), thereby qualifying the newly developed assay as a highly sensitive, specific and reliable diagnostic tool for leptospiral infection in dogs using urine specimens.

Efficacy of leptospiral commercial vaccines on the protection against an autochtonous strain recovered in Brazil

Abstract In swine and bovines, leptospirosis prevention and control is carried out via vaccination of susceptible animals using bacterins. However, the efficiency of leptospirosis vaccines has been questioned. This work aimed to investigate the potency of five leptospirosis vaccines sold commercially in Brazil, challenging the animals with one autochthonous strain of Leptospira, Canicola serovar, denoted LO4, isolated from swine. The standard protocol was followed, and renal carriers of Leptospira were identified among the surviving animals by culture and PCR. Of the five vaccines tested, only two proved effective. None of the surviving animals was positive by culture; however, one animal was positive by PCR. Three of the five vaccines sold commercially in Brazil for the immunization of swine or bovines failed the test of the efficacy to protect the vaccinated animals following challenge with an autochthonous Leptospira strain, Canicola serovar. The two vaccines provided protection against the renal carrier state in the surviving animals. The criteria used to produce leptospirosis bacterins sold commercially in Brazil must be reviewed. The industry should support researches on leptospiral vaccinology to improve the quality of the present vaccines and discover new immunogenic strains, because it is known that vaccination is one of the most important tools to increase the reproduction rates in livestock.