Leptospira seroprevalence in capybaras from a Brazilian urban area

Background: Leptospirosis remains the most widespread zoonotic disease in the world. As a clinical entity it is strongly associated with regional occupational and environmental exposures. While the exact global disease burden remains unknown, recent estimates by the leptospirosis Burden Epidemiology Reference Group (LERG) at the World Health Organization have set the number of human cases of severe leptospirosis to over 500,000 per year. This number almost certainly represents an under-representation due to poor surveillance and difficult diagnosis. Leptospira spp. belong to the order Spirochaetales, family Leptospiraceae, composed by 13 pathogenic Leptospira species with more than 260 serovars. Wildlife species are commonly considered to be important epidemiological carriers, mainly because of their frequent reactivity to Leptospira serovars native to their habitat. Capybara (Hydrochaeris hydrochaeris), a known leptospirosis host, is a widespread species in South America. However, reports regarding the importance of this animal in the epidemiology of leptospirosis are rare. Therefore, the objective of this study was to report the results of leptospirosis serological survey of capybaras from a residential park area in southeastern Brazil. Materials, Methods & Results: A total of 172 capybaras were sampled at Itú Municipality, state of São Paulo, southeastern Brazil [...](AU)

Leptospira seroprevalence in capybaras from a Brazilian urban area

Background: Leptospirosis remains the most widespread zoonotic disease in the world. As a clinical entity it is strongly associated with regional occupational and environmental exposures. While the exact global disease burden remains unknown, recent estimates by the leptospirosis Burden Epidemiology Reference Group (LERG) at the World Health Organization have set the number of human cases of severe leptospirosis to over 500,000 per year. This number almost certainly represents an under-representation due to poor surveillance and difficult diagnosis. Leptospira spp. belong to the order Spirochaetales, family Leptospiraceae, composed by 13 pathogenic Leptospira species with more than 260 serovars. Wildlife species are commonly considered to be important epidemiological carriers, mainly because of their frequent reactivity to Leptospira serovars native to their habitat. Capybara (Hydrochaeris hydrochaeris), a known leptospirosis host, is a widespread species in South America. However, reports regarding the importance of this animal in the epidemiology of leptospirosis are rare. Therefore, the objective of this study was to report the results of leptospirosis serological survey of capybaras from a residential park area in southeastern Brazil. Materials, Methods & Results: A total of 172 capybaras were sampled at Itú Municipality, state of São Paulo, southeastern Brazil [...]

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.

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)

Leptospirose bovina: aumento na incidência da Leptospira interogans sorovar butembo no rebanho do estado de Santa Catarina, Brasil / Bovine leptospirosis: increased incidence of Leptospira interogans serovar butembo in the herd of the State of Santa Catarina, Brazil

Os problemas reprodutivos são as principais manifestações clínicas da leptospirose crônica em fêmeas bovinas, sendo freqüentemente os únicos sinais observados no rebanho. Leptospira interogans sorovar hardjo é o mais predominante e importante porque compromete o desempenho reprodutivo dos rebanhos acometidos, porém levantamentos sorológicos no Brasil têm revelado resultados variados quanto à ocorrência dos sorovares nesta espécie animal. O sorovar butembo, normalmente quando encontrado, está presente em pequena parcela dos resultados positivos, porém, nosso levantamento apontou um aumento na prevalência deste sorovar nas amostras recebidas e processadas no período de Janeiro de 2005 a Dezembro de 2008. Desta maneira o objetivo deste trabalho foi relatar um aumento na detecção do variante sorológico butembo em soros bovinos provenientes do estado de Santa Catarina, nas amostras analisadas pelo Laboratório de leptospirose (Lablepto) da Universidade Federal de Santa Maria (UFSM).

Reproductive problems are the main clinical manifestations of leptospirosis in cows and it is often the only signs observed in the herd. Leptospira Interogans serovar hardjo is the most prevalent and important because it affects the reproductive performance of herds, but serological surveys in Brazil have shown mixed results regarding the occurrence of serovars in animal species. The serovar butembo, usually when found, is present in small proportion of positive results, however, our survey indicated an increase in the prevalence of this serovar in the samples received and processed from January 2005 to December 2008. Thus, the objective of this study was to report an increase in the detection of serological variant butembo in bovine serum from the state of Santa Catarina, in the samples analyzed by the Laboratory of leptospirosis (Lablepto) from Universidade Federal de Santa Maria (UFSM).

Leptospirose e tritricomonose: isolamento em propriedade com problemas reprodutivos no sul do Brasil / Leptospirosis and tritrichomonosis: property in isolation with reproductive problems in southern Brazil / Leptospirosis y tritricomonosis: aislamiento en propiedad con problemas reproductivos en el sur de Brasil

O objetivo do estudo foi pesquisar quais os agentes etiológicos presentes em touros de duas propriedades rurais com elevados índices de repetição de cio. Da propriedade A foram analisados 23 touros, dos 58 integrados no rebanho, e na propriedade B foram analisados 15 reprodutores. Destes animais, foi colhido sangue para exame de leptospirose e realizado lavado prepucial para cultura de tritricomonose. Na propriedade A, em nenhuma das amostras avaliadas isolou-se trofozoítas de Tritrichomonas foetus. No soro de 15 touros (65,2%) testados para Leptospira foi verificada reação para um ou mais sorovares de L. hardjo, L. wolffi, L. icterohaemorrhagiae e L. butembo, em titulações que oscilaram entre 1/100 e 1/400. Na propriedade B não foi verificada titulação para leptospirose, mas em um dos animais isolaram e reproduziram trofozoìtas de T. foetus em laboratório. Do restante dos animais, cinco foram considerados suspeitos em microscópico óptico, não sendo confirmado o parasitismo em lâmina corada com Giemsa. Todos os bovinos da propriedade A foram submetidos ao tratamento com sulfato de estreptomicina em dose única de 25mg kg-1. O animal positivo para T. foetus foi descartado e os demais estão sendo monitorados mensalmente. Tanto Leptospirose como tritricomonose são enfermidades capazes de acarretar problemas reprodutivos em bovinos no sul do Brasil.(AU)

The aim of this study was to research the etiological agents present in bulls from a property with high estrus repetition rate. Twenty three out of 58 bulls in the property A and 15 of the property B were analyzed. Blood samples and preputial washes for leptospirosis and tritrichomonosis research were collected, respectively. In the property A, none of the evaluated animals showed the presence of Tritrichomonas foetus trophozoites, although 15 bulls (65,2%) tested for Leptospira reacted with one or more sorovars of L. hardjo, L. wolffi, L. icterohaemorrhagiae and L. butembo with titles between 100 and 400. Animals from property B were negative for leptospirosis and the isolation and reproduction of T. foetus in laboratory was possible only in one animal. Five other animals were considered suspect in the direct smear technique, although they were negative in the Giemsa staining method. All animals from property A received a single dose of streptomycin sulfate (25mg kg-1) which drastically reduced the estrus repetition rate. The animal with tritrichomonosis was taken out of the herd and the others have been monitored monthly. Even leptospirosis as tritrichomonosis are diseases directly linked with reproductive problems in southern Brazil.(AU)

El objetivo de este estudio fue investigar cuales son los agentes etiológicos presentes en toros de dos propiedades rurales con elevados índices repetitivos de celo. De la propiedad “A” fueron analizados 23 toros, de los 58 que integran el rebaño, en la propiedad “B” fueron analizados 15 reproductores. De estos animales, se extrajo muestras de sangre para examen de leptospirosis y se realizó lavado prepucial para cultivo de tritricomonosis. En la propiedad “A”, en ninguna de las muestras evaluadas se aisló trofozoítos de Tritrichomonas foetus, ya en el suero de 15 toros (65,2%) testeados para Leptospira fue verificada reacción para uno o más sorovares de L. hardjo, L. wolffi, L. icterohaemorrhagiae y L. butembo en titulaciones que oscilaron entre 1/100 y 1/400. En la propiedad “B” no fue verificada titulación para leptospirosis, pero en uno de los animales se aisló y se reprodujeron trofozoítos de T. foetus en laboratorio. En los demás animales, cinco fueron considerados sospechosos en microscopio óptico, no siendo confirmado el parasitismo en lámina coloreada con Giemsa. Todos los bovinos de la propiedad A fueron sometidos al tratamiento con sulfato de estreptomicina en dosis única de 25mg kg-1. El animal positivo para T. foetus fue descartado y los demás están siendo monitoreados mensualmente. Tanto Leptospirosis como tritricomonosis son enfermedades capaces de provocar problemas reproductivos en bovinos en el sur de Brasil.(AU)