Biofilm production of Leptospira spp. strains

Background: Leptospirosis is a zoonosis that affects many species of mammals and occurs endemically in Brazil. The biofilm matrix provides structure and protection to the biofilm cells working as a physical barrier to antibiotic agents, which are attached or consumed by the matrix components. However, this attribute varies according to the matrix, antimicrobial agent and biofilm age. Leptospira may change morphologically according to environmental conditions, including cell aggregation and biofilm formation. Leptospira can colonize the ducts of kidney from hosts for a long time, forming a biofilm, which is believed to be an important factor for their maintenance in animals and in the environment. Thus, the objective of this research was to determine the biofilm formation capacity of four strains of Leptospira interrogans.Materials, Methods & Results: The strains were typified by WHO/FAO/OIE and National Collaborating Center for Reference and Research on Leptospirosis (Kit Biomedical Research, Amsterdam, Netherlands). Leptospira interrogans strains, two isolated from cattle and two isolated from dogs were biofilms tested for adhesion on polystyrene plates, extracellular matrix composition and confocal microscopy. In the plating adhesion test, the suspension was inoculated into 96-well sterile polystyrene microplates with flat bottom at a ratio of 1:200 in EMJH medium, followed by 24 h incubation at 28°C, with medium renewal after 12 h. After this period the wells were washed three times with sterile PBS and following incubation; the plates were dried in the oven at 60°C for 30 min and added 200 μL of 1% violet crystal for five min. Subsequently, the plates were washed with distilled water, after complete removal, 200 μL of acetic acid 33% was added and the readings were performed at 570 nm in the ELISA reader.[...]

Biofilm production of Leptospira spp. strains

Background: Leptospirosis is a zoonosis that affects many species of mammals and occurs endemically in Brazil. The biofilm matrix provides structure and protection to the biofilm cells working as a physical barrier to antibiotic agents, which are attached or consumed by the matrix components. However, this attribute varies according to the matrix, antimicrobial agent and biofilm age. Leptospira may change morphologically according to environmental conditions, including cell aggregation and biofilm formation. Leptospira can colonize the ducts of kidney from hosts for a long time, forming a biofilm, which is believed to be an important factor for their maintenance in animals and in the environment. Thus, the objective of this research was to determine the biofilm formation capacity of four strains of Leptospira interrogans.Materials, Methods & Results: The strains were typified by WHO/FAO/OIE and National Collaborating Center for Reference and Research on Leptospirosis (Kit Biomedical Research, Amsterdam, Netherlands). Leptospira interrogans strains, two isolated from cattle and two isolated from dogs were biofilms tested for adhesion on polystyrene plates, extracellular matrix composition and confocal microscopy. In the plating adhesion test, the suspension was inoculated into 96-well sterile polystyrene microplates with flat bottom at a ratio of 1:200 in EMJH medium, followed by 24 h incubation at 28°C, with medium renewal after 12 h. After this period the wells were washed three times with sterile PBS and following incubation; the plates were dried in the oven at 60°C for 30 min and added 200 μL of 1% violet crystal for five min. Subsequently, the plates were washed with distilled water, after complete removal, 200 μL of acetic acid 33% was added and the readings were performed at 570 nm in the ELISA reader.[...](AU)

First isolation and characterization of Leptospira interrogans serogroup Australis from swine in Brazil / Primeiro isolamento e caracterização da Leptospira interrogans sorogrupo Australis de suíno no Brasil

The purpose of this study was to report the first recovery and characterization of Leptospira interrogans (serogroup Australis) from urine of swine in Brazil. The isolate was studied by serogrouping, MLVA, PGFE, and partial sequencing of rrs and secY. It was serogrouped as serogroup Australis, probably serovar Bratislava (titre 1,600), and sequenced as Leptospira interrogans. The MLVA and PGFE profiles also suggested the isolate as serovar Bratislava, since they were indistinguishable from reference strains Balico and Jez Bratislava. This is the first Leptospira interrogans serogroup Australis isolate, probably serovar Bratislava, obtained in Brazil.(AU)

O objetivo deste estudo foi relatar o primeiro isolamento e caracterização de Leptospira interrogans (sorogrupo Australis) a partir da urina de suínos no Brasil. O isolado foi caracterizado por sorogrupagem, MLVA, PGFE, e sequenciamento parcial de rrs e secY. Este foi identificado como pertencente ao sorogurpo Australis, provavelmente sorovar Bratislava (título 1600) e sequenciado como Leptospira interrogans. Os perfis de MLVA e PGFE também sugeriram o isolado como sorovar Bratislava, uma vez que estes foram indistinguíveis das cepas de referência Balico e Jez Bratislva. Este é o primeiro isolado de Leptospira interrogans sorogrupo Australis, provavelmente sorovar Bratislava, obtido no Brasil.(AU)

Heterogenic colonization patterns by Leptospira interrogans in Rattus norvegicus from urban slums

Abstract We evaluated the renal colonization by Leptospira interrogans in Rattus norvegicus (rats), as it is the major natural reservoir of urban leptospirosis. We caught 72 R. norvegicus, out of which 32 were found to be positive for L. interrogans by immunofluorescence assay. From these rats, we selected 17 and divided them into six groups based on the mass-age/sex. We performed the immunohistochemistry test against L. interrogans in the kidney sections of the rats and systematically counted the colonized tubules (CTs) in 20 fields. The proportion of positive fields varied from 5% to 95%. The number of CTs in 20 fields varied from 0.5 to 85.5. These differences were not related to age or sex of the animals. The characterization of leptospiral colonization patterns in the natural reservoirs is important to better understand the host-pathogen interactions in leptospirosis.(AU)

Serosurvey of Leptospira interrogans, Brucella abortus and Chlamydophila abortus infection in free-ranging giant anteaters (Myrmecophaga tridactyla) from Brazil / Inquérito sorológico de Leptospira interrogans, Brucella abortus e Chlamydophila abortus em tamanduás-bandeira (Myrmecophaga tridactyla) de vida livre no Brasil

A serological survey for antibodies against Leptospira interrogans, Brucella abortus, and Chlamydophila abortus was conducted in 21 clinically healthy, free-ranging giant ant- eaters (Myrmecophaga tridactyla) from Parque Nacional das Emas (Goiás State, Brazil; n=6), Parque Nacional da Serra da Canastra (Minas Gerais State, Brazil; n=9), and RPPN SESC Pantanal (Mato Grosso State, Brazil; n=6) between July 2001 and September 2006. Sera were screened for antibodies against 22 serovars of Leptospira interrogans with a microscopic agglutination test. Twelve tested positive for L. interrogansserovars sentot (n=5 in PN Emas, n=2 in PN Serra da Canastra), butembo (n=2 in PN Serra da Canastra), autumnalis, bataviae, and shermani/icterohaemorrhagiae(n=1 each in SESC Pantanal)One adult female tested positive for B. abortus with the buffered plate antigen test. All sera were negative for C. abortususing the complement fixation text. This is the first report of pathogens that may interfere with the reproduction and population dynamics of free-ranging giant anteaters.(AU)

Inquéritos sorológicos para detecção de anticorpos contra Leptospira interrogans, Brucella abortus, e Chlamydophila abortus foram realizados em 21 tamanduás-bandeira (Myrmecophaga tridactyla) de vida livre do Parque Nacional das Emas (Goiás, Brasil, n=6), o Parque Nacional da Serra da Canastra (Minas Gerais, Brasil, n=9) e RPPN SESC Pantanal (Mato Grosso, Brasil, n=6) entre julho de 2001 e setembro de 2006. Os sor os foram testados para anticorpos contra 22 sorotipos de Leptospira interrogans com um teste de aglutinação microscópica. Doze animais foram considerados positivos para L. interrogans sorovares sentot (n=5 em PN Emas, n=2 em PN Serra da Canastra), butembo (n=2 em PN Serra da Canastra), autumnalis, bataviae e shermani/icterohaemorrhagiae(n=1 para cada sorovar em SESC Pantanal). Uma fêmea adulta testou positivo para B. abortuscom o teste do antígeno tamponado. Todos os soros se mostraram negativos para C. abortusatravés do teste de fixação do complemento. Este é o primeiro relato de patógenos que podem interferir na dinâmica reprodutiva de populações de tamanduás em estado selvagem.(AU)

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

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.(AU)

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.(AU)

CARACTERIZAÇÃO MOLECULAR E SOROLÓGICA DE ISOLADOS DE LEPTOSPIRA A PARTIR DE CÃES NATURALMENTE INFECTADOS

Estudos sorológicos para caracterização da leptospirose em cães no nosso cenário epidemiológico são pouco frequente e discordantes. Adicionalmente, as informações quanto a circulação das espécies, sorogrupos e sorovares nesses animais também são escassas. O presente estudo objetivou isolar e caracterizar cepas autóctones de Leptospira sp. em amostras de urina e sangue total obtidos de cães naturalmente infectados e com suspeita clínica de leptospirose atendidos no período de agosto de 2012 a setembro de 2017. Amostras de sangue e urina foram coletadas de 70 animas e destinadas ao Teste de Aglutinação Microscópica (MAT) e ao cultivo bacteriano. A MAT mostrou que 74,29% das amostras foram reativas. Icterohemorrhagiae (sv. Copenhageni M20) foi o sorogrupo de maior predominância com 33/52 (63,46%) de reatividade, seguido por Australis (sv. Bratislavae (5) sv. Autralis (2) com 7/52 (13,47%)). Em relação à distribuição dos títulos, 14/52 (26,92%) das amostras tiveram títulos de 200 seguido de 10/52 (19,23%) das amostras reagiram para os títulos de 400 e 800. Isolamos bactérias com morfologia e movimentação característicos de leptospiras em 13 (9,28%) amostras dentre as 140 testadas (70 de urina e 70 de sangue). A determinação da espécie foi realizada com base na identidade das sequências parciais do gene rrs (16S rRNA), enquanto o sorogrupo presuntivo dos isolados foi estabelecido através da MAT, utilizando um painel de 18 anti-soros representativos para 15 sorogrupos patogênicos. A identificação de sorovar foi feita pelo Teste de Aglutinação Microscópica com Absorção Cruzada (CAAT) com três anticorpos referentes ao sorogrupo Icterohaemorrhagiae: Mab F70 C14 (sorovar Icterohaemorrhagiae), Mab F70 C24 (sorovar Copenhegeni) e Mab F89 C12 (todos os sorovares do sorogrupo Icterohaemorrhagiae exceto Copenhageni). Todas as cepas foram caracterizadas como pertencetes à espécie Leptospira interrogans. A sorogrupagem demonstrou que nove isolados fazem parte do sorogrupo Icterohaemorrhagiae Sorovar (sv) Copenhageni. Entretanto, em quatro isolados (C29, C41, C51 e C72) foi possível determinar apenas que eram pertencentes ao sorogrupo Icterohaemorrhagiae, sendo o resultado em nível de sorovar indeterminado. Demonstramos que há a circulação da espécie Leptospira interrogans, sorogrupo Icterohaemorrhagiae, sv. Copenhageni. Adicionalmente, sugerimos que possa haver a circulação de um sorovar ainda não identificado. Desta forma, já se pode inferir a necessidade de revisão dos protocolos vacinais adotados.

Serological studies for the characterization of leptospirosis in dogs in our epidemiological scenario are infrequent and discordant. In addition, information on the circulation of species, serogroups and serovars in these animals is also scarce. The present study aimed to isolate and characterize autochthonous strains of Leptospira sp. in urine and whole blood samples obtained from naturally infected and clinically suspected leptospirosis dogs from August 2012 to September 2017. Samples of blood and urine were collected from 70 animals for the Microscopic Agglutination Test (MAT) and bacterial culture. The MAT showed that 74.29% of the samples were reactive. Icterohemorrhagiae (sv. Copenhageni M20) was the most prevalent serogroup with 33/52 (63.46%) reactivity, followed by Australis (sv. Bratislavae (5) sv. Autralis (2) with 7/52 (13.47%)). Regarding the distribution of titers, 14/52 (26.92%) of the samples had titers of 200 followed by 10/52 (19.23%) of the samples reacted for the 400 and 800 titers. We isolate bacteria with characteristic morphology and movement of leptospires in 13 (9.28%) samples from 140 tested (70 urine and 70 blood). Species determination was performed based on the identity of the rrs (16S rRNA) partial sequences, while the presumptive serogroup of the isolates was established through MAT using a panel of 18 representative antisera to 15 pathogenic serogroups. Identification of serovar was done by the Cross-Absorption Microscopic Agglutination Test (CAAT) with three antibodies related to the serogroup Icterohaemorrhagiae: Mab F70 C14 (serovar Icterohaemorrhagiae), Mab F70 C24 (serovar Copenhegeni) and Mab F89 C12 (all serogroups of the serogroup Icterohaemorrhagiae except Copenhageni). All strains were characterized as belonging to the species Leptospira interrogans. Serogroups showed that nine isolates were part of the serovar Icterohaemorrhagiae Serovar (sv) Copenhageni. However, in four isolates (C29, C41, C51 and C72), it was possible to determine only that they belonged to the serogroup Icterohaemorrhagiae, and the result was at the indeterminate serovar level. We show that there is circulation of the species Leptospira interrogans, serogroup Icterohaemorrhagiae, sv. Copenhageni. Additionally, we suggest that there may be a circulation of a yet unidentified serovar. In this way, it is possible to infer the need to review the vaccine protocols adopted.

Produção e purificação de imunoglobulinas Y policlonais anti-Leptospira spp / Production and purification of polyclonal anti-Leptospira immunoglobulin Y

Objetivou-se verificar se galinhas imunizadas com uma solução de Leptospira interrogans inativadas e proteínas de membrana externa do sorovar Hardjo, poderiam produzir anticorpos policlonais específicos anti-leptospiras, detectáveis em testes ELISA. Foram imunizados oito galinhas com 25 semanas de idade, da raça White Leghorn, sendo três imunizadas com uma suspensão de leptospiras inativadas, três com uma solução de proteínas de membrana externa extraída do sorovar Hardjo e duas controle. Coletas de sangue foram realizadas quinzenalmente e de ovos diariamente. A IgY foi purificada a partir da gema dos ovos utilizando para a delipidação o método de diluição em água ácida e a precipitação com sulfato de amônio. Nos testes ELISA realizados para verificar a especificidade da IgY, foi demonstrada a produção de anticorpos anti-Leptospira, tanto no soro quanto nas gemas purificadas. O pico de produção de anticorpos específicos ocorreu na 5º semana após a primeira imunização. Ficou demonstrada a possibilidade da indução da produção de anticorpos específicos em galinhas imunizadas com leptospiras do sorovar Hardjo inativadas, bem como, com proteínas de membrana externa (PME) extraidas desse sorovar. As galinhas imunizadas com uma suspensão de leptospiras inativadas ou com PME de Leptospira interrogans do sorovar Hardjo produziram anticorpos reativos a PME Hardjo detectáves por teste ELISA.(AU)

The aim was to determine whether hens immunized with an inactivated suspension of Leptospira and a solution of outer membrane proteins extracted from the serovar Hardjo, could produce specific polyclonal antibodies to Leptospira, detected in ELISA assay. Eight hens White Leghorn race with 25-weeks-old were immunized, three with an inactivated suspension of Leptospira, three with a solution of outer membrane proteins (OMP) extracted from the serovar Hardjo and two controls immunized with saline. Blood samples were collected fortnightly and eggs daily. The IgY was purified from the egg yolk using the method for the delipidation of dilution with water acidic and ammonium sulfate precipitation. The ELISA assay was performed to verify the specificity of the IgY, these was possible to observe the production of specific antibody to Leptospira both in serum and purified egg yolk. The specific antibody titers peaked in the fifth week post immunization. The production of polyclonal IgY was effective for producing high titers of specific antibodies.(AU)

Pesquisa de agentes infecciosos selecionados em tatus da região do Pantanal sul-mato-grossense

O Pantanal é considerado uma das maiores planícies inundáveis do mundo e possui uma rica biodiversidade. Das onze espécies de tatus registradas no Brasil, sete ocorrem no Pantanal. Os tatus dividem suas áreas de vida com diversas outras espécies silvestres e com o gado, pois a produção extensiva de bovinos de corte é a principal atividade econômica da região. Estudos anteriores demonstraram exposição à Brucella abortus e Leptospira interrogans em diversas espécies silvestres no Pantanal, porém sabe-se pouco quanto à exposição e/ou presença desses agentes em tatus neste bioma. Dessa forma, o presente estudo teve por objetivo determinar a prevalência de anticorpos anti-Brucella e anti-Leptospira interrogans através do teste do Antígeno Acidificado Tamponado (AAT) e Soroaglutinação Microscópica (SAM) em amostras de soro de tatus de vida livre, provenientes do Pantanal da Nhecolândia e realizar a pesquisa direta do DNA dos agentes através do emprego da técnica de Reação em Cadeia da Polimerase (PCR) em amostras de sangue. Foram testados 48 indivíduos de quatro espécies, sendo Dasypus novemcinctus (n=2), Cabassous unicinctus (n=8), Euphractus sexcinctus (n=16) e Priodontes maximus (n=22). Não foi observado produto amplificado pela PCR em nenhum animal testado, da mesma forma, nenhum tatu apresentou anticorpos anti-Brucella pelo AAT. Na sorologia para L. Interrogans foi encontrada prevalência de 31,25 % (5/16) em E. sexcinctus e 18,18% (4/22) em P. maximus. Esses indivíduos foram positivos para os sorovares Autumnalis/Butembo, Cynopteri/Cynopteri e Pomona/Pomona, com títulos variando de 1: 200 a 1: 1600. Os resultados obtidos reforçam a importância da vigilância de patógenos em populações de vida livre, especialmente quando existe contato com animais de produção, além de contribuir para o conhecimento de agentes infecciosos em tatus da região do Pantanal.

Pantanal is considered one of the worlds largest wetlands. Seven of the eleven species of armadillos that occur in Brazil, from a total of 21 recognized species in the world, have been recorded in this area. The main local economic activity is beef cattle production, which leads to intense wildlife-livestock contact, potentially increasing wildlife exposure to several pathogens, including those with zoonotic and economic relevance. Previous studies demonstrated that several wildlife species have been exposed to Brucella abortus and Leptospira interrogans in Pantanal; however, the exposure and/or presence of zoonotic pathogens in armadillos in this biome is still poorly understood. In order to address this question, we employed conventional polymerase chain reaction (PCR), the Rose Bengal Test (RBT) and the Microscopic Agglutination Test (MAT) to investigate the exposure and/or infection by Brucella abortus and Leptospira interrogans in blood samples of four armadillos species: nine-banded armadillo (Dasypus novemcinctus) (n=2), southern nakedtailed armadillo (Cabassous unicinctus) (n=8), yellow armadillo (Euphractus sexcinctus) (n=16) and giant armadillo (Priodontes maximus) (n=22) caught at Nhecolândia, Pantanal, Brazil. We did not detect Brucella abortus by PCR or exposure to this pathogen via the RBT in the evaluated armadillos. On the other hand, the Microscopic Agglutination Test (MAT) detected Leptospira interrogans exposure in 31.25 % (5/16) of E. sexcinctus and 18.18% (4/22) P. maximus specimens. These individuals were positive to serovars Autumnalis/Butembo, Cynopteri/Cynopteri and Pomona/Pomona, this latter with titers ranging from 1:200 to 1:1600. Our results reinforce the importance of pathogen surveillance in wildlife living in areas of livestock production and further contribute to the study of zoonotic pathogens in armadillos in the Pantanal region.

Activities of the enzymes NTPDase, 5´-nucleotidase and adenosine deaminase in platelets of rats experimentally infected with Leptospira interrogans Serovar icterohaemorrhagiae / Activities of the enzymes NTPDase, 5´-nucleotidase and adenosine deaminase in platelets of rats experimentally infected with Leptospira interrogans Serovar icterohaemorrhagiae

Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5´-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection.Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10

Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5´-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection.Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10

Activities of the enzymes NTPDase, 5'-nucleotidase and adenosine deaminase in platelets of rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae

Background: Leptospirosis, a spirochetal zoonotic disease caused by different serovars of Leptospira interrogans, is increasingly recognized as an important cause of hemorrhagic fever. Although the haemorrhagic potential of leptospirosis was noted by Weil (1886) as early as 1886, its pathophysiology is still not clearly elucidated, particularly regarding the cause and mechanisms of bleeding. Studies with ectonucleoside triphosphate diphosphohydrolase (NTPDase; EC 3.6.1.5; CD39), 5'-nucleotidase (EC 3.1.3.5; CD73) and adenosine deaminase (ADA) have demonstrated the involvement of these enzymes in thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. Since leptospirosis is a disease increasingly recognized as an important cause of hemorrhagic fever, the aim of this study was to evaluate these enzymes activities and parameters of platelet aggregation in platelets from rats experimentally infected with Leptospira interrogans serovar icterohaemorrhagiae during different periods of experimental infection. Materials, Methods & Results: For this purpose, thirty-six adult male rats were divided into two groups: A, as uninfected control (subgroups A1, A2 and A3); and B, infected (subgroups B1, B2 and B3). Group B was inoculated intraperitoneally (Day 0) with 2 x 108 organisms per rat. Blood samples were collected on days 05 (A1 and B1), 10 (A2 and B2) and 20 (A3 and B3) post-inoculation (PI). In the infected group, platelet count had a decrease on day 10 PI and prothrombin time (PT) had an increase on day 5 PI. In the same group, platelet aggregation decreased (P < 0.01) day 10 PI. The hydrolysis of ATP in platelets was also decreased (P < 0.05) on day 10 PI, when compared to the control group. By the other side, ADP hydrolysis was increased (P < 0.05) on days 5 and 10 PI. 5'-nucleotidase activity was significantly increased on day 5 (P < 0.01) and 20 (P < 0.05) PI. Results of adenosine deamination into inosine by ADA in platelets showed a signifi cant (P < 0.01) increase on days 5 and 10 PI in the infected group. Discussion: Studies with NTPDase, 5'nucleotidase and ADA have demonstrated the involvement of these enzymes in the thromboregulation mechanisms, and altered enzymatic activities have been reported in many diseases. It has been established that extracellular adenosine nucleotides and adenosine are versatile signaling molecules known to participate in an array of platelet functions. For example, the nucleotide ADP is the main promoter of platelet aggregation, while adenosine can act as a vasodilator and an inhibitor of platelet aggregation. In addition, high concentrations of ATP have been shown to inhibit ADP-induced aggregation in vitro, while low concentrations of ATP can significantly enhance platelet aggregation. In our experimental study the coagulation cascade was activated, since when the activities of NTPDase, 5'-nucleotidase and ADA were analyzed is possible to suggest that levels of ATP were decreased, unlike of ADP and AMP levels, supposedly increased during determinate periods of our experiment. Adenosine levels were also enhanced due to the higher levels of its precursors. This cascade activation may be a mechanism of bleeding prevention front to leptospires infection, especially the ones caused by serovar icterohaemorrhagiae.

Eficácia dos tratamentos estabelecidos pelo Manual da IETS, em oócitos, expostos à Leptospira interrogans / Effectiveness of treatments established by the Manual of IETS, in oocytes, exposed to Leptospira interrogans

Avaliou-se a eficácia dos tratamentos, definidos pela International Embryo Transfer Society (IETS), de oócitos bovinos, maturados in vitro e expostos experimentalmente à Leptospira interrogans sorovar Grippotyphosa. Os oócitos foram obtidos por meio de punção folicular, selecionados e distribuídos em quatro grupos, expostos ao patógeno e submetidos aos diferentes tipos de tratamentos. Foram expostos à cepa na concentração de 4,7.10(5)/µL, virulenta e não adaptada ao meio de manutenção EMJH, e, de 6,3.10(5)/µL, avirulenta e adaptada ao meio, por 24 horas. Os grupos tratados com tripsina ou antibióticos apresentaram eficácia de 21,7 por cento, e o grupo lavado sequencialmente 33,4 por cento. Os tratamentos não foram eficazes para os contaminados com a cepa avirulenta. Concluiu-se que as normas de controle de qualidade estabelecidas pela IETS poderiam ser revisadas e, possivelmente, redefinidas, uma vez que a eficácia dos tratamentos, provavelmente, não depende somente da espécie do patógeno, pois há interferência da virulência e de ação dos tratamentos sobre o tipo de patógeno.(AU)

The research purpose was to evaluate the effectiveness of treatments established by the IETS, in bovine oocytes maturated in vitro, exposed experimentally to Leptospira interrogans serovar Grippotyphosa. The oocytes were obtained through follicular puncture, selected and randomly allotted in four groups, exposed to the pathogen and subjected to different types of treatments. They were exposed to the strain in the concentration of 4.7x10(5)/µL virulent and not adapted to the EMJH, and to 6,3x10(5)/µL, virulent and adapted to the medium, for 24 hours. The treatments presented for the groups with trypsin or antibiotics, 21.7 percent efficiency, and the group washed sequentially presented 33.4 percent efficiency. The treatments were not effective for those infected with avirulent strain. In the statistical analysis, by χ², was found significance in the results obtained. The standards of quality control established by IETS could be reviewed and possibly redefined, since the effectiveness of treatment probably depends not only on the species of the pathogen, but is also affected by its virulence and treatment effectiveness.(AU)

Estudo soroepidemiológico de leptospirose em equinos utilizados para tração urbana / Leptospirosis seroepidemiological study in horses used for urban traction

Este trabalho analisou a associação entre a ocorrência da leptospirose em equinos de tração em áreas urbanas do município de Uberlândia (MG), com os seguintes fatores de risco: presença de roedores, contato com outras espécies animais, local de repouso e manejo sanitário. A presença ou a ausência de anticorpos anti-Leptospira nas 79 amostras de sangue equino foi avaliada pelo teste de soroaglutinação microscópica (SAM) em campo escuro. As informações referentes à presença de roedores, contato com outras espécies animais, local de repouso e manejo sanitário foram obtidas por meio de questionário. As variáveis avaliadas, por serem do tipo categórico, foram submetidas à análise de correspondência múltipla. A taxa de positividade para anticorpo anti-Leptospira foi de 44,30%, e os sorovares mais encontrados foram: icterohaemorrhagiae (21,51%), hardjo (15,05%) e castellonis (10,75%). A presença de roedores, contato com outras espécies animais e ausência de manejo sanitário apresentaram associação com a infecção em equinos, e a alta frequência de aglutininas anti-Leptospira encontrada no soro sanguíneo demonstra a susceptibilidade destes animais aos sorovares de Leptospira interrogans.(AU)

This study aimed at investigating the association of the occurrence of leptospirosis in horses employed for traction in urban areas of the city of Uberlândia-MG with the following risk factors: presence of rodents, contact with other animal species, resting place and sanitary management. The presence or absence of anti-Leptospira antibody was assessed in 79 horse blood samples by means of the microscopic agglutination test (MAT) in dark field. Information regarding the presence of rodents, the contact with other animal species, the resting place, and the sanitary management were obtained by means of a questionnaire. For being of categorical type, these variables were subjected to the multiple correspondence analysis. The rate of antibodies anti-Leptospira positivity was 44.30% and the most commonly found serovars were icterohaemorrhagiae (21.51%), hardjo (15.05%), and castellonis (10.75%). The presence of rodents, the contact with other animal species and the lack of sanitary management were associated with the horse infection, and the high frequency of anti-Leptospira agglutinins detected in serum samples from the analyzed horses showed that these animals are susceptible to the Leptospira interrogans serovars.(AU)

MASTITIS AND MILK DROP SYNDROME / Leptospira interrogans INFECTION IN SANTA INES EWES FROM DISTRITO FEDERAL / MASTITE E SÍNDROME DA QUEDA DO LEITE / INFECÇÃO POR Leptospira interrogans EM OVELHAS DA RAÇA SANTA INÊS NO DISTRITO FEDERAL

The aim of the present work was to determine the relationship between clinical mastitis and Leptospira interrogans / Milk Drop Syndrome in Santa Inês ewes. One thousand sheep were examined on 12 farms in the Distrito Federal, Brazil, as to their clinical condition, in order to identify animals with clinical mastitis. The animals were divided into two groups: animals which presented clinical mastitis symptoms (G1) and animals which did not have clinical mastitis symptoms (G2). Blood samples were collected from all ewes of the two groups. The microscopic agglutination test was performed in order to identify the seropositive animals to Leptospira spp. Four (4.08%) animals of the first group were seropositives to Leptospira spp., of which three were positives to Hardjoprajitno (Norma) and Hardjoprajitno (OMS) sorovars and one to both Australis and Autumnalis sorovars. In the second group, two (5.26%) animals were seropositives to both Hardjoprajitno (Norma) and Hardjoprajitno (OMS) sorovars. A relationship between Leptospira spp. infection / milk drop syndrome and the presence of clinical mastitis in ewes (p > 0.05) was not observed.KEYWORDS: Animal health; disease; infection; sheep.

O presente trabalho foi realizado com o objetivo de estudar a relação entre a mastite clínica e a infecção por Leptospira interrogans / síndrome da queda do leite em ovelhas da raça Santa Inês. Examinaram-se 1000 ovelhas, em 12 fazendas do Distrito Federal, quanto à sua condição clínica, com o objetivo de detectar animais com mastite clínica. Considerando um estudo de caso controle, os animais foram divididos em dois grupos: aqueles que apresentavam sinais de mastite clínica (G1) e os que não apresentavam sinais de mastite clínica (G2). Colheram-se amostras de sangue das ovelhas dos dois grupos e utilizou-se o teste de soroaglutinação microscópica para identificar aquelas soropositivas para Leptospira spp. Dos animais do primeiro grupo, quatro (4,08%) foram soropositivos para Leptospira spp, sendo três positivos para as sorovariedades Hardjoprajitno (Norma) e Hardjoprajitno (OMS) e um animal positivo para as sorovariedades Australis e Autumnalis. Dos animais do segundo grupo, dois (5,26%) foram soropositivos, ambos para as sorovariedades Hardjoprajitno (Norma) e Hardjoprajitno (OMS). Não foi observada relação entre a síndrome da queda do leite / infecção por Leptospira spp e a presença de mastite clínica nas ovelhas (p > 0,05).PALAVRAS-CHAVE: Doença; infecção; ovino; saúde animal.

Leptospirose canina relacionada a sazonalidade no município de Uberlândia / Relation of canine leptospirosis and seasonality in Uberlândia city, MG

Objetivou-se avaliar a relação da frequência de cães sororeagentes a Leptospira spp. às variáveis climáticas do município de Uberlândia, Minas Gerais, bem como, determinar os principais sorovares presentes na população canina estudada. Devido ao contato direto existente entre o homem e os cães, estes são importantes fontes de infecção da leptospirose humana. A incidência da doença na América Latina aumenta associada ao crescimento desordenado da população e as condiçõesclimáticas que propiciam a manutenção do agente no meio, como altas temperaturas, umidade e ocorrência de enchentes. Foram examinadas 150 amostras, de soro sanguíneo de cães hígidos domiciliados e rurais, de ambos os sexos e várias idades, 75 coletadas no período das águas (Dezembro à Maio) e 75 no período seco do ano (Junho à Novembro). Todas as amostras foram submetidas ao exame de Soroglutinação Microscópica (SAM). As frequências de cães sororeagentes nos diferentes períodos foram comparadas e relacionadas com as variáveis: temperatura, umidade relativa do ar e precipitação pluviométrica, por meio do teste não paramétrico Qui-quadrado corrigido (p=0,05). Encontrou-se frequência de 38%, com o predomínio do sorovar Autumnalis (15,79%), seguido de Bratislava e Canicola (14,03%); Tarassovi (10,53%); Pomona e Icterohaemorrhagiae (8,77%). Notou-se uma diferença significativa na incidência da Leptospirose nos cães avaliados nos diferentes períodos do ano, com maior frequência no período chuvoso. Estes resultados apontam a necessidade da adoção de estratégias diferenciadas intensificando as medidas de controle e erradicação da doença, principalmente no período chuvoso em que ocorre a elevação significativa da leptospirose canina no município de Uberlândia, MG

This study aimed to assess the relation between the frequency of seropositives dogs for Leptospira interrogans with climatic variables in the city of Uberlândia, Minas Gerais, as well as determine the main serovars present in the canine population studied. The direct contact existing between canine and human it’s an important source of infection. The incidence of the disease in America Latina countries increases associated with disorderly growth of the population and climatic conditions that favor the maintenance of the agent in the environmental as high temperatures, humidity, and the occurrence of floods. Blood serum from 150 domiciled and rural dogs, of both sexes and several ages was investigated. Samples were collected in dry and wet periods of the year. All the animals were submitted to the microscopic agglutination test (MAT). The frequencies of seropositive dogs in different periods were compared and related to the variables temperature, relative humidity and rainfall, using the nonparametric test of two binomial proportions (p = 0.05). The prevalence found was 38%, the most reactive serovars were Autumnalis (15.79%), followed by Bratislava and Canicola (14.03%); Tarassovi (10.53%); Icterohaemorrhagiae and Pomona (8.77%). It was noted a significant difference in the incidence of leptospirosis in dogs evaluated in the two periods of the year. These results indicate the need to adopt different strategies intensifying control measures and eradication of disease, especially in the rainy season which occurs in significant elevation of canine leptospirosis in Uberlandia, MG.KEY

Leptospirose canina relacionada a sazonalidade no município de Uberlândia / Relation of canine leptospirosis and seasonality in Uberlândia city, MG

Objetivou-se avaliar a relação da frequência de cães sororeagentes a Leptospira spp. às variáveis climáticas do município de Uberlândia, Minas Gerais, bem como, determinar os principais sorovares presentes na população canina estudada. Devido ao contato direto existente entre o homem e os cães, estes são importantes fontes de infecção da leptospirose humana. A incidência da doença na América Latina aumenta associada ao crescimento desordenado da população e as condiçõesclimáticas que propiciam a manutenção do agente no meio, como altas temperaturas, umidade e ocorrência de enchentes. Foram examinadas 150 amostras, de soro sanguíneo de cães hígidos domiciliados e rurais, de ambos os sexos e várias idades, 75 coletadas no período das águas (Dezembro à Maio) e 75 no período seco do ano (Junho à Novembro). Todas as amostras foram submetidas ao exame de Soroglutinação Microscópica (SAM). As frequências de cães sororeagentes nos diferentes períodos foram comparadas e relacionadas com as variáveis: temperatura, umidade relativa do ar e precipitação pluviométrica, por meio do teste não paramétrico Qui-quadrado corrigido (p=0,05). Encontrou-se frequência de 38%, com o predomínio do sorovar Autumnalis (15,79%), seguido de Bratislava e Canicola (14,03%); Tarassovi (10,53%); Pomona e Icterohaemorrhagiae (8,77%). Notou-se uma diferença significativa na incidência da Leptospirose nos cães avaliados nos diferentes períodos do ano, com maior frequência no período chuvoso. Estes resultados apontam a necessidade da adoção de estratégias diferenciadas intensificando as medidas de controle e erradicação da doença, principalmente no período chuvoso em que ocorre a elevação significativa da leptospirose canina no município de Uberlândia, MG(AU)

This study aimed to assess the relation between the frequency of seropositives dogs for Leptospira interrogans with climatic variables in the city of Uberlândia, Minas Gerais, as well as determine the main serovars present in the canine population studied. The direct contact existing between canine and human its an important source of infection. The incidence of the disease in America Latina countries increases associated with disorderly growth of the population and climatic conditions that favor the maintenance of the agent in the environmental as high temperatures, humidity, and the occurrence of floods. Blood serum from 150 domiciled and rural dogs, of both sexes and several ages was investigated. Samples were collected in dry and wet periods of the year. All the animals were submitted to the microscopic agglutination test (MAT). The frequencies of seropositive dogs in different periods were compared and related to the variables temperature, relative humidity and rainfall, using the nonparametric test of two binomial proportions (p = 0.05). The prevalence found was 38%, the most reactive serovars were Autumnalis (15.79%), followed by Bratislava and Canicola (14.03%); Tarassovi (10.53%); Icterohaemorrhagiae and Pomona (8.77%). It was noted a significant difference in the incidence of leptospirosis in dogs evaluated in the two periods of the year. These results indicate the need to adopt different strategies intensifying control measures and eradication of disease, especially in the rainy season which occurs in significant elevation of canine leptospirosis in Uberlandia, MG.KEY(AU)

Lipid Peroxidation and Antioxidant Enzymes Activity of Wistar Rats Experimentally Infected with Leptospira interrogans

Background: Leptospirosis is a zoonotic disease with world-wide distribution, caused by various serovars of Leptospira interrogans and is presumed to be the most widespread zoonosis. Hematological and biochemical changes associated with renal and hepatic pathology are commonly observed in leptospirosis. All leptospires are aerobes and therefore might be expected to generate peroxides during respiration. Enzymatic reduction of H 2 0 2 by leptospires has been reported by researchers. The pathogenesis may be related to direct effects of leptospiral compounds or inflammatory response due to oxidative stress. The present investigation was designed to study the lipid peroxidation and the activity of antioxidant enzymes in rats experimentally infected with L. interrogans . Materials, Methods & Results: Fifty four male adult rats (Wistar) specific pathogen free, weighing in average 200 grams were used. Rats were divided in nine groups, six animals each group, eight infected groups and one as not infected. Inoculation was performed intraperitoneally (Day 1), using different serovars of L. interrogans distributed by groups: hardjo (group A), wolffi (group B), grippotyphosa (group C), canicola (group D), Icterohaemorrhagiae (group E), bratislava (group F), pomona (group G) and butembo (group H) . Group I was composed by not-infected rats, serving as the negative control group. On day 15 PI all animals were anesthetized with isoflurane for blood collection and subsequently decapitated. Liver, spleen, kidney and brain were collected from all animals. Blood was allocated in tube without anticoagulant for serum acquisition to measurement of thiobarbituric acid reactive substances (TBARS). Lipid peroxidation (TBARS levels), superoxide dismutase (SOD), catalase (CAT) and non-protein thiols (NPSH) were measured in the liver, spleen and kidney, and TBARS were also evaluated in serum and brain. [...]

Lipid Peroxidation and Antioxidant Enzymes Activity of Wistar Rats Experimentally Infected with Leptospira interrogans

Background: Leptospirosis is a zoonotic disease with world-wide distribution, caused by various serovars of Leptospira interrogans and is presumed to be the most widespread zoonosis. Hematological and biochemical changes associated with renal and hepatic pathology are commonly observed in leptospirosis. All leptospires are aerobes and therefore might be expected to generate peroxides during respiration. Enzymatic reduction of H 2 0 2 by leptospires has been reported by researchers. The pathogenesis may be related to direct effects of leptospiral compounds or inflammatory response due to oxidative stress. The present investigation was designed to study the lipid peroxidation and the activity of antioxidant enzymes in rats experimentally infected with L. interrogans . Materials, Methods & Results: Fifty four male adult rats (Wistar) specific pathogen free, weighing in average 200 grams were used. Rats were divided in nine groups, six animals each group, eight infected groups and one as not infected. Inoculation was performed intraperitoneally (Day 1), using different serovars of L. interrogans distributed by groups: hardjo (group A), wolffi (group B), grippotyphosa (group C), canicola (group D), Icterohaemorrhagiae (group E), bratislava (group F), pomona (group G) and butembo (group H) . Group I was composed by not-infected rats, serving as the negative control group. On day 15 PI all animals were anesthetized with isoflurane for blood collection and subsequently decapitated. Liver, spleen, kidney and brain were collected from all animals. Blood was allocated in tube without anticoagulant for serum acquisition to measurement of thiobarbituric acid reactive substances (TBARS). Lipid peroxidation (TBARS levels), superoxide dismutase (SOD), catalase (CAT) and non-protein thiols (NPSH) were measured in the liver, spleen and kidney, and TBARS were also evaluated in serum and brain. [...](AU)

Revisão sobre a leptospirose canina no Brasil / Canine leptospirosis in Brazil - a review / Revisión sobre la leptospirosis canina en Brasil

Com o objetivo de conhecer os sorovares de Leptospira sp mais frequentemente envolvidos na leptospirose canina, foi realizada uma revisão dos trabalhos publicados entre 2003 e 2013 no Brasil. Leptospira interrogans sorovar Canicola e o sorovar Copenhageni foram os sorovares mais frequentemente isolados de cães doentes ou aparentemente hígidos. Os sorovares Icterohaemorrhagiae, Pomona e a Leptospira noguchi também foram isolados, embora em apenas uma única oportunidade. Títulos de anticorpos contra os sorovares Canicola, Copenhageni, Icterohaemorrhagiae, Pyrogenes, Autumnalis, Ballum, Bratislava, Tarassovi, Butembo, Grippotyphosa, Andamana, Hardjobovis e outros foram encontrados nos inquéritos sorológicos realizados. Embora a soroprevalência de 7,15% a 48,2% encontrada pelos autores indique a exposição dos cães a leptospiras patogênicas, a existência de reações cruzadas entre os sorovares e as reações paradoxais dificultam a identificação do sorovar infectante. Conclui-se pela necessidade de isolamento e a caracterização sorológica e molecular dos isolados para a determinação do sorovar infectante e seu papel patogênico para os cães.

Data from the Brazilian literature published between 2003 and 2013 was surveyed in order to identify the Leptospira sp serovars most frequently involved in canine leptospirosis in Brazil. The serovars Canicola and Copenhageni from Leptospira interrogans were the most frequently isolated ones from both sick and apparently healthy dogs. Serovars Icterohaemorrhagiae and Pomona, as well as Leptospira noguchi were isolated on a single occasion. Seroloqic surveys performed throughout the country revealed antibody titers to Canicola, Copenhageni, Icterohaemorrhagiae, Pyragenes, Autumnalis, Ballum, Bratislava, Tarassovi, Butembo, Grippotyphosa, Andamana, Hardjobovis, among others. Although the seroprevalence of 7.15% to 48.2% suggests exposure of surveyed animals to pathogenic leptospirae, the cross-reactivity among serovars and paradoxical reactions render the identification of the infecting serovar in each case difficult. Therefore, the isolation of leptospirae and their serological and molecular characterization are mandatory to determine the infecting serovar and its role as a pathogen for dogs.

Con el objetivo de conocer los sorovares de Leptospira sp más frecuentemente implicados en la leptospirosis canina en Brasil, fue realizada una revisión de los trabajos publicados entre 2003 a 2013. Los serovares Canicola e Copenhageni de Leptospira interrogans son los que se aíslan con mayor frecuencia en perros enfermos o aparentemente normales. También se aislaron, en sólo una ocasión, los serovares Icterohaemorrhagiae, Pomona y Leptospira noguchi. También se encontraron anticuerpos contra los serovares Canicola, Copenhageni, Icterohaemorrhagiae, Pyrogenes, Autumnalis, Ballum, Bratislava, Tarassovi, Butembo, Grippotyphosa, Andamana, Hardjobovis. A pesar de que los autores encontraron una seroprevalencia entre el 7,15 y el 48,2%, lo que indicaría una exposición de los perros a leptospiras patógenas, la posibilidad de que se produzcan reacciones cruzadas entre los diferentes serovares y la presencia de reacciones paradoxales pueden dificultar la identificación del serovar infectante. Se puede concluir que es necesario el cultivo bacteriano seguido de la caracterización serológica y molecular de los microorganismos aislados, a fin de determinar cual es el serovar infectante y su papel en la patogenia de la leptospirosis en los perros.

Revisão sobre a leptospirose canina no Brasil / Canine leptospirosis in Brazil - a review / Revisión sobre la leptospirosis canina en Brasil

Com o objetivo de conhecer os sorovares de Leptospira sp mais frequentemente envolvidos na leptospirose canina, foi realizada uma revisão dos trabalhos publicados entre 2003 e 2013 no Brasil. Leptospira interrogans sorovar Canicola e o sorovar Copenhageni foram os sorovares mais frequentemente isolados de cães doentes ou aparentemente hígidos. Os sorovares Icterohaemorrhagiae, Pomona e a Leptospira noguchi também foram isolados, embora em apenas uma única oportunidade. Títulos de anticorpos contra os sorovares Canicola, Copenhageni, Icterohaemorrhagiae, Pyrogenes, Autumnalis, Ballum, Bratislava, Tarassovi, Butembo, Grippotyphosa, Andamana, Hardjobovis e outros foram encontrados nos inquéritos sorológicos realizados. Embora a soroprevalência de 7,15% a 48,2% encontrada pelos autores indique a exposição dos cães a leptospiras patogênicas, a existência de reações cruzadas entre os sorovares e as reações paradoxais dificultam a identificação do sorovar infectante. Conclui-se pela necessidade de isolamento e a caracterização sorológica e molecular dos isolados para a determinação do sorovar infectante e seu papel patogênico para os cães.(AU)

Data from the Brazilian literature published between 2003 and 2013 was surveyed in order to identify the Leptospira sp serovars most frequently involved in canine leptospirosis in Brazil. The serovars Canicola and Copenhageni from Leptospira interrogans were the most frequently isolated ones from both sick and apparently healthy dogs. Serovars Icterohaemorrhagiae and Pomona, as well as Leptospira noguchi were isolated on a single occasion. Seroloqic surveys performed throughout the country revealed antibody titers to Canicola, Copenhageni, Icterohaemorrhagiae, Pyragenes, Autumnalis, Ballum, Bratislava, Tarassovi, Butembo, Grippotyphosa, Andamana, Hardjobovis, among others. Although the seroprevalence of 7.15% to 48.2% suggests exposure of surveyed animals to pathogenic leptospirae, the cross-reactivity among serovars and paradoxical reactions render the identification of the infecting serovar in each case difficult. Therefore, the isolation of leptospirae and their serological and molecular characterization are mandatory to determine the infecting serovar and its role as a pathogen for dogs.(AU)

Con el objetivo de conocer los sorovares de Leptospira sp más frecuentemente implicados en la leptospirosis canina en Brasil, fue realizada una revisión de los trabajos publicados entre 2003 a 2013. Los serovares Canicola e Copenhageni de Leptospira interrogans son los que se aíslan con mayor frecuencia en perros enfermos o aparentemente normales. También se aislaron, en sólo una ocasión, los serovares Icterohaemorrhagiae, Pomona y Leptospira noguchi. También se encontraron anticuerpos contra los serovares Canicola, Copenhageni, Icterohaemorrhagiae, Pyrogenes, Autumnalis, Ballum, Bratislava, Tarassovi, Butembo, Grippotyphosa, Andamana, Hardjobovis. A pesar de que los autores encontraron una seroprevalencia entre el 7,15 y el 48,2%, lo que indicaría una exposición de los perros a leptospiras patógenas, la posibilidad de que se produzcan reacciones cruzadas entre los diferentes serovares y la presencia de reacciones paradoxales pueden dificultar la identificación del serovar infectante. Se puede concluir que es necesario el cultivo bacteriano seguido de la caracterización serológica y molecular de los microorganismos aislados, a fin de determinar cual es el serovar infectante y su papel en la patogenia de la leptospirosis en los perros.(AU)