Bovine Leptospirosis in Caatinga Biome, Brazil: New Insights into Diagnosis and Epidemiology.

Bovine leptospirosis causes economic losses and raises public health concerns. It is possible that there are peculiarities in the epidemiology of leptospirosis in regions with a semiarid climate, such as the Caatinga biome in Brazil, where the climate is hot and dry, and the etiological agent require alternative routes of transmission. This study aimed to close knowledge gaps to the diagnosis and epidemiology of Leptospira spp. infection in cows from the Caatinga biome, Brazil. Samples of the blood, urinary tract (urine, bladder and kidney) and reproductive tract (vaginal fluid, uterus, uterine tube, ovary and placenta) were collected from 42 slaughtered cows. Diagnostic tests included were the microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Anti-Leptospira spp. antibodies were found in 27 (64.3%) of the animals analyzed using MAT at a 1:50 dilution (cut-off 50), while 31 (73.8%) animals had at least one organ/fluid where the presence of Leptospira spp. DNA was identified, and 29 animals (69%) were positive at bacteriological culture. The highest sensitivity values for MAT were obtained at the cut-off point of 50. In conclusion, even under hot and dry climate conditions, it is possible that Leptospira spp. can spread through alternative routes such as venereal transmission; moreover, a cut-off of 50 is recommended for the serological diagnosis of cattle from the Caatinga biome.

Vertical transmission and kinetic of antibodies anti-Neospora caninum in naturally infected lambs in the semiarid region of Brazil.

Aimed with this study to evaluate vertical transmission of Neospora caninum in naturally infected sheep and to monitor the kinetics of antibodies against this protozoon in their lambs. Therefore, 48 pregnant ewes, from five herds, were divided into two groups: G1 - positive for anti-N. caninum antibodies, with 19 animals; and G2 - seronegative, with 29 animals. Blood samples were taken from the ewes and their lambs, immediately after birth, before ingesting colostrum, and 2, 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. Analysis on serum antibodies was performed using the indirect immunofluorescent antibody test. Among the 19 seropositive mothers, six (31.6%) gave birth to lambs seropositive before ingesting colostrum and it was found that these lambs remained positive until the end of the study (56 days). Only one of the lambs, from a ewe that presented an antibody titer of 200, seroconverted after ingestion of colostrum. All the lambs that had been born from negative mothers remained negative throughout the experimental period. It was concluded that transplacental transmission was an important form of diffusion of N. caninum in the herds studied and that seropositive lambs maintained circulating antibodies during the period analyzed.

Vertical transmission and kinetic of antibodies anti-Neospora caninum in naturally infected lambs in the semiarid region of Brazil / Transmissão vertical e cinética de anticorpos anti-Neospora caninum em cordeiros naturalmente infectados na região Semiárida do Brasil

Abstract Aimed with this study to evaluate vertical transmission of Neospora caninum in naturally infected sheep and to monitor the kinetics of antibodies against this protozoon in their lambs. Therefore, 48 pregnant ewes, from five herds, were divided into two groups: G1 - positive for anti-N. caninum antibodies, with 19 animals; and G2 - seronegative, with 29 animals. Blood samples were taken from the ewes and their lambs, immediately after birth, before ingesting colostrum, and 2, 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. Analysis on serum antibodies was performed using the indirect immunofluorescent antibody test. Among the 19 seropositive mothers, six (31.6%) gave birth to lambs seropositive before ingesting colostrum and it was found that these lambs remained positive until the end of the study (56 days). Only one of the lambs, from a ewe that presented an antibody titer of 200, seroconverted after ingestion of colostrum. All the lambs that had been born from negative mothers remained negative throughout the experimental period. It was concluded that transplacental transmission was an important form of diffusion of N. caninum in the herds studied and that seropositive lambs maintained circulating antibodies during the period analyzed.

Resumo Objetivou-se avaliar a ocorrência da transmissão vertical de Neospora caninum em ovelhas naturalmente infectadas e monitorar a cinética de anticorpos para esse protozoário nos cordeiros. Portanto, foram selecionadas 48 matrizes prenhes, provenientes de cinco propriedades, e estas foram divididas em dois grupos: G1- 19 matrizes positivas para anticorpos anti-N. caninum antes da prenhez; e G2 - 29 matrizes soronegativas. Foram realizadas colheitas sanguíneas nas mães e cordeiros, no G1 e G2, imediatamente após a parição, antes da ingestão do colostro. Também foi possível realizar colheitas de sangue com 2, 7, 14, 21, 28, 35, 42, 49 e 56 dias após o nascimento. A pesquisa de anticorpos séricos foi realizada por meio da Reação de Imunofluorescência Indireta (RIFI). Das 19 matrizes soropositivas, seis (31,6%) pariram cordeiros soropositivos antes da ingestão do colostro, os quais mantiveram-se positivos até o final do experimento (56 dias). Apenas um dos cordeiros, filho de uma ovelha com título de anticorpos 200, soroconverteu após ingestão do colostro. Todos os cordeiros, filhos de mães negativas, mantiveram-se negativos durante todo o período experimental. Conclui-se que a transmissão transplacentária é uma importante forma de difusão do N. caninum nos rebanhos estudados e que os descendentes infectados, durante a gestação, mantiveram anticorpos circulantes durante o período analisado.

Vertical transmission and kinetic of antibodies anti-Neospora caninum in naturally infected lambs in the semiarid region of Brazil / Transmissão vertical e cinética de anticorpos anti-Neospora caninum em cordeiros naturalmente infectados na região Semiárida do Brasil

Aimed with this study to evaluate vertical transmission of Neospora caninum in naturally infected sheep and to monitor the kinetics of antibodies against this protozoon in their lambs. Therefore, 48 pregnant ewes, from five herds, were divided into two groups: G1 - positive for anti-N. caninum antibodies, with 19 animals; and G2 - seronegative, with 29 animals. Blood samples were taken from the ewes and their lambs, immediately after birth, before ingesting colostrum, and 2, 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. Analysis on serum antibodies was performed using the indirect immunofluorescent antibody test. Among the 19 seropositive mothers, six (31.6%) gave birth to lambs seropositive before ingesting colostrum and it was found that these lambs remained positive until the end of the study (56 days). Only one of the lambs, from a ewe that presented an antibody titer of 200, seroconverted after ingestion of colostrum. All the lambs that had been born from negative mothers remained negative throughout the experimental period. It was concluded that transplacental transmission was an important form of diffusion of N. caninum in the herds studied and that seropositive lambs maintained circulating antibodies during the period analyzed.(AU)

Objetivou-se avaliar a ocorrência da transmissão vertical de Neospora caninum em ovelhas naturalmente infectadas e monitorar a cinética de anticorpos para esse protozoário nos cordeiros. Portanto, foram selecionadas 48 matrizes prenhes, provenientes de cinco propriedades, e estas foram divididas em dois grupos: G1- 19 matrizes positivas para anticorpos anti-N. caninum antes da prenhez; e G2 29 matrizes soronegativas. Foram realizadas colheitas sanguíneas nas mães e cordeiros, no G1 e G2, imediatamente após a parição, antes da ingestão do colostro. Também foi possível realizar colheitas de sangue com 2, 7, 14, 21, 28, 35, 42, 49 e 56 dias após o nascimento. A pesquisa de anticorpos séricos foi realizada por meio da Reação de Imunofluorescência Indireta (RIFI). Das 19 matrizes soropositivas, seis (31,6%) pariram cordeiros soropositivos antes da ingestão do colostro, os quais mantiveram-se positivos até o final do experimento (56 dias). Apenas um dos cordeiros, filho de uma ovelha com título de anticorpos 200, soroconverteu após ingestão do colostro. Todos os cordeiros, filhos de mães negativas, mantiveram-se negativos durante todo o período experimental. Conclui-se que a transmissão transplacentária é uma importante forma de difusão do N. caninum nos rebanhos estudados e que os descendentes infectados, durante a gestação, mantiveram anticorpos circulantes durante o período analisado.(AU)

Leptospira sp. vertical transmission in ewes maintained in semiarid conditions.

Leptospirosis is a globally distributed disease associated with reproductive failures in livestock; however, its pathogenesis has not been fully elucidated. Results from the present study indicate there is a presence of Leptospira sp. in organs and fluids of fetuses from ewes slaughtered in the semiarid region of Brazil. Twenty-nine fetuses from 23 ewes determined to be Leptospira sp.-positive using PCR were sampled (14 and 15 in dry and rainy seasons, respectively). Fetal samples of blood, central nervous system (CNS), lung, liver, spleen, stomach contents, peritoneal fluid, kidney, bladder, urine and reproductive system were collected. Diagnostic methods included the microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Of the 29 fetuses, 24 (82.8 %) had at least one Leptospira sp.-positive organ or fluid, as determined using PCR, and of a total of 209 samples, 62 (29.7 %) contained leptospiral DNA. Of the 99 samples collected during the dry season, 42 (42.4 %) were positive, and of 110 samples collected during the rainy season, 20 (18.2 %) were positive (P = 0.0001). There was deoxyribonucleic acid (DNA) sequencing of three samples of kidney, CNS and liver, and in all of these, there was 99.3 % similarity with Leptospira interrogans. Leptospires were present in cultures of pooled samples from fetuses with deformities. Results indicate there is vertical (maternal-to-fetus) transmission which would represent an alternative transmission route for the spread of Leptospira sp. in ewes, suggesting molecular detection is essential in the investigation of leptospirosis in fetuses to identify animals that have been infected with this bacterium.

Use of serological and molecular techniques for detection of Leptospira sp. carrier sheep under semiarid conditions and the importance of genital transmission route.

It is possible that there are peculiarities in the epidemiology of leptospirosis in regions with a semiarid climate, where the environment is often adverse, allowing the occurrence of alternative transmission routes. The objective of the work was to generate contributions to the diagnosis and epidemiology of Leptospira sp. infection in sheep reared in semiarid conditions, using serological, molecular and microbiological techniques for diagnosis in dry and rainy seasons. Samples of blood, vaginal fluid, urine, bladder, kidney, uterus, uterine tube, ovary and placenta were collected from 104 sheep (52 animals per season - dry and rainy) slaughtered in the Brazilian semiarid. Diagnostic tests performed were microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Anti-Leptospira sp. antibodies were found in 26 (25%) of the animals analyzed by MAT at 1:50 dilution (cut-off 50), while 69 (66.3%) animals had at least one organ/fluid with the presence of Leptospira sp. DNA. Overall, PCR was performed on 758 fragments of organs/fluids from the genital and urinary tracts, and 519 (68.5%) samples tested positive. PCR-positivity was statistically different in dry (46.2%) and rainy (11.5%) seasons for vaginal fluid. It was possible to perform the DNA sequencing in nine samples with 99% similarity to L. interrogans and recovery of viable strains in three samples of vaginal fluid. Regardless of the biological material used in PCR to detect carrier animals and the season, the highest MAT sensitivity values were obtained with cut-off 50 compared to 100. The results obtained indicate that, even in the adverse environmental conditions of the semiarid region, leptospires may survive and propagate by alternative routes of transmission, such as sexual, and the presence of PCR-positive genital tracts in ewes suggests that sexual transmission may play an important role in the epidemiology of the disease in sheep in Brazilian semiarid. In addition, it is suggested the use of titer 50 as cut-off point at serology in semiarid conditions.

Parasitos zoonóticos em solos de praças públicas no município de Sousa, Paraíba / Zoonotic parasites in soils of public squares in themunicipality of Sousa, Paraíba

Os espaços coletivos com grande circulação de pessoas e animais tutelados ou errantes, como as praças públicas, podem gerar um problema para a saúde pública, uma vez que os animais podem eliminar fezes contaminadas por parasitos nesses locais, desempenhando um importante papel epidemiológico na transmissão de zoonoses parasitárias. Portanto, este trabalho teve como objetivo avaliar a contaminação por parasitos zoonóticos em dez praças públicas da cidade de Sousa, Paraíba, bem como avaliar o melhor método de diagnóstico de infestação ambiental por estes parasitas. Foram feitas coletas de solo em cinco pontos diferentes de cada praça, por raspagem superficial em quadrantes delimitados por 15 cm, sendo coletados 200g da parte central de cada ponto. Os métodos de diagnósticos utilizados foram Flutuação Simples, Sedimentação Simples, Faust e Centrífugo-Flutuação em Solução de Sacarose. Das praças avaliadas, 90% (9/10) obtiveram pelo menos uma amostra positiva. O gênero de parasito mais frequente foi Ancylostoma spp., presente em 70% (7/ 10) das praças analisadas; seguido por Strongyloides spp., coccídeos e Taenia spp., em 40% (4/10); Toxocara spp., em 30% (3/10); e Cystoisospora spp. e Trichuris spp., em 10% (1/10). O método de Sedimentação Simples foi o mais eficaz, resultando em 44% (22/50) de amostras positivas. Os demais métodos não atingiram 15% de positividade. Concluiu-se que as praças públicas analisadas encontram-se altamente infestadas por parasitos zoonóticos, representando um risco a saúde pública no município de Sousa-PB.(AU)

Collective spaces with large circulation of people and animals domiciled or wandering, such as public squares, can generate a public health problem, since the animals can eliminate feces contaminated by parasites in these places, playing an important epidemiological role for zoonosis transmission. Therefore, the objective of this work was to evaluate the contamination by zoonotic parasites in ten public squares of the city of Sousa, Paraíba, as well as to evaluate the best method for the diagnosis of environmental infestation by these parasites. Soil samples were collected at five different points of each square, by surface scraping in quadrants delimited by 15 cm, with 200g of the central part of each point being collected. The diagnostic methods used were Simple Flotation, Simple Sedimentation, Faust and Centrifugal-Fluctuation in Sucrose Solution. At least one positive sample in 90% (9/10) of the evaluated squares. The most frequent parasite genus was Ancylostoma spp., present in 70% (7/10) of the analyzed squares; followed by Strongyloides spp., coccidia and Taenia spp., in 40% (4/10); Toxocara spp., in 30% (3/10); and Cystoisospora spp. and Trichuris spp., in 10% (1/10). The Simple Sedimentation method was the most effective, resulting in 44% (22/50) of positive samples. The other methods did not reach 15% positivity. It was concluded that the analyzed public squares are highly infested by zoonotic parasites, representing a public health risk in the municipality of Sousa-PB.(AU)

Parasitos zoonóticos em solos de praças públicas no município de Sousa, Paraíba / Zoonotic parasites in soils of public squares in the municipality of Sousa, Paraíba

Os espaços coletivos com grande circulação de pessoas e animais tutelados ou errantes, como as praças públicas, podem gerar um problema para a saúde pública, uma vez que os animais podem eliminar fezes contaminadas por parasitos nesses locais, desempenhando um importante papel epidemiológico na transmissão de zoonoses parasitárias. Portanto, este trabalho teve como objetivo avaliar a contaminação por parasitos zoonóticos em dez praças públicas da cidade de Sousa, Paraíba, bem como avaliar o melhor método de diagnóstico de infestação ambiental por estes parasitas. Foram feitas coletas de solo em cinco pontos diferentes de cada praça, por raspagem superficial em quadrantes delimitados por 15 cm, sendo coletados 200g da parte central de cada ponto. Os métodos de diagnósticos utilizados foram Flutuação Simples, Sedimentação Simples, Faust e Centrífugo-Flutuação em Solução de Sacarose. Das praças avaliadas, 90% (9/10) obtiveram pelo menos uma amostra positiva. O gênero de parasito mais frequente foi Ancylostoma spp., presente em 70% (7/ 10) das praças analisadas; seguido por Strongyloides spp., coccídeos e Taenia spp., em 40% (4/10); Toxocara spp.,em 30% (3/10); eCystoisospora spp. e Trichuris spp., em 10% (1/10). O método de Sedimentação Simples foi o mais eficaz, resultando em 44% (22/50) de amostras positivas. Os demais métodos não atingiram 15% de positividade. Concluiu-se que as praças públicas analisadas encontram-se altamente infestadas por parasitos zoonóticos, representando um risco a saúde pública no município de Sousa-PB.

Collective spaces with large circulation of people and animals domiciled or wandering, such as public squares, can generate a public health problem, since the animals can eliminate feces contaminated by parasites in these places, playing an important epidemiological role for zoonose transmission. Therefore, the objective of this work was to evaluate the contamination by zoonotic parasites in ten public squares of the city of Sousa, Paraíba, as well as to evaluate the best method for the diagnosis of environmental infestation by these parasites. Soil samples were collected at five different points of each square, by surface scraping in quadrants delimited by 15 cm, with 200g of the central part of each point being collected. The diagnostic methods used were Simple Flotation, Simple Sedimentation, Faust and Centrifugal-Fluctuation in Sucrose Solution. At least one positive sample in 90% (9/10) of the evaluated squares. The most frequent parasite genus was Ancylostoma spp., present in 70% (7/10) of the analyzed squares; followed by Strongyloides spp., coccidia and Taenia spp., in 40% (4/10); Toxocara spp., in 30% (3/10); and Cystoisospora spp. and Trichurisspp., in 10% (1/10). The Simple Sedimentation method was the most effective, resulting in 44% (22/50) of positive samples. The other methods did not reach 15% positivity. It was concluded that the analyzed public squares are highly infested by zoonotic parasites, representing a public health risk in the municipality of Sousa-PB.

Parasitos zoonóticos em solos de praças públicas no município de Sousa, Paraíba / Zoonotic parasites in soils of public squares in themunicipality of Sousa, Paraíba

Os espaços coletivos com grande circulação de pessoas e animais tutelados ou errantes, como as praças públicas, podem gerar um problema para a saúde pública, uma vez que os animais podem eliminar fezes contaminadas por parasitos nesses locais, desempenhando um importante papel epidemiológico na transmissão de zoonoses parasitárias. Portanto, este trabalho teve como objetivo avaliar a contaminação por parasitos zoonóticos em dez praças públicas da cidade de Sousa, Paraíba, bem como avaliar o melhor método de diagnóstico de infestação ambiental por estes parasitas. Foram feitas coletas de solo em cinco pontos diferentes de cada praça, por raspagem superficial em quadrantes delimitados por 15 cm, sendo coletados 200g da parte central de cada ponto. Os métodos de diagnósticos utilizados foram Flutuação Simples, Sedimentação Simples, Faust e Centrífugo-Flutuação em Solução de Sacarose. Das praças avaliadas, 90% (9/10) obtiveram pelo menos uma amostra positiva. O gênero de parasito mais frequente foi Ancylostoma spp., presente em 70% (7/ 10) das praças analisadas; seguido por Strongyloides spp., coccídeos e Taenia spp., em 40% (4/10); Toxocara spp., em 30% (3/10); e Cystoisospora spp. e Trichuris spp., em 10% (1/10). O método de Sedimentação Simples foi o mais eficaz, resultando em 44% (22/50) de amostras positivas. Os demais métodos não atingiram 15% de positividade. Concluiu-se que as praças públicas analisadas encontram-se altamente infestadas por parasitos zoonóticos, representando um risco a saúde pública no município de Sousa-PB.

Collective spaces with large circulation of people and animals domiciled or wandering, such as public squares, can generate a public health problem, since the animals can eliminate feces contaminated by parasites in these places, playing an important epidemiological role for zoonosis transmission. Therefore, the objective of this work was to evaluate the contamination by zoonotic parasites in ten public squares of the city of Sousa, Paraíba, as well as to evaluate the best method for the diagnosis of environmental infestation by these parasites. Soil samples were collected at five different points of each square, by surface scraping in quadrants delimited by 15 cm, with 200g of the central part of each point being collected. The diagnostic methods used were Simple Flotation, Simple Sedimentation, Faust and Centrifugal-Fluctuation in Sucrose Solution. At least one positive sample in 90% (9/10) of the evaluated squares. The most frequent parasite genus was Ancylostoma spp., present in 70% (7/10) of the analyzed squares; followed by Strongyloides spp., coccidia and Taenia spp., in 40% (4/10); Toxocara spp., in 30% (3/10); and Cystoisospora spp. and Trichuris spp., in 10% (1/10). The Simple Sedimentation method was the most effective, resulting in 44% (22/50) of positive samples. The other methods did not reach 15% positivity. It was concluded that the analyzed public squares are highly infested by zoonotic parasites, representing a public health risk in the municipality of Sousa-PB.