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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Leptospirosis in native mixed-breed sheep slaughtered in a semiarid region of Brazil / Leptospirose em ovinos mestiços abatidos em uma região semiárida do Brasil

ABSTRACT: Sheep breeding is an economic activity of great value for the Brazilian livestock industry, and infectious diseases can significantly compromise its productivity. The aim of this study was to detect Leptospira spp. in mixed breed sheep from a semiarid region of the State of Paraíba, Northeast Brazil. In total, 49 blood and renal tissue samples, as well as 25 urine samples, were collected from 49 sheep in the slaughter line. The microscopic agglutination test (MAT) was used to verify the presence of anti -Leptospira spp. antibodies in blood samples. Renal tissue and urine samples were analyzed by both PCR and bacterial culture. Sero reactivity was observed in 8.2% (4/49) of animals. Three renal samples were positive for leptospiral DNA by PCR although all urine samples were negative. No leptospires in pure culture were recovered from the samples tested. Low prevalence of Leptospira spp. observed by serology and PCR suggested that the rusticity of the mixed-breed sheep may have contributed to the low occurrence of leptospirosis in the semiarid region investigated.

RESUMO: A criação de ovinos é uma atividade econômica de grande valor para a indústria pecuária brasileira. As doenças infecciosas podem comprometer significativamente a sua produtividade. O objetivo deste estudo foi detectar Leptospira spp. em ovinos sem raça definida a partir de uma região semiárida do estado da Paraíba, Nordeste do Brasil. Quarenta e nove amostras de sangue e tecido renal, bem como amostras de urina, de 25 das 49 ovelhas, foram coletados na linha de abate. A presença de anticorpos anti -Leptospira spp. foi verificada com o teste de aglutinação microscópica (SAM). As amostras de urina e rins foram processadas por PCR e cultura bacteriológica. Sororreatividade foi observada em 8,2% (4/49) dos animais. Em relação à PCR, três amostras renais foram positivas, no entanto, todas as amostras de urina foram negativas. Nenhuma cultura pura de leptospiras foi recuperada a partir das amostras testadas. Levando em consideração a baixa frequência de positividade na sorologia e PCR, é possível sugerir que a rusticidade das ovelhas de raças mestiças colaborou para a baixa ocorrência de leptospirose na região semiárida investigada.

Epidemiological characterization of leptospirosis in horses in the state of Pernambuco, northeastern Brazil / Caracterização epidemiológica da leptospirose em equinos do estado de Pernambuco, nordeste do Brasil

An epidemiological survey aiming to determine the occurrence of anti-Leptospira antibodies and to identify risk factors was carried out in horses of the Pajeú microregion, state of Pernambuco. Sera from 100 horses from 38 properties in four counties in the region were examined by the microscopic agglutination test (MAT), using 24 Leptospira spp. serovars as antigens. Of the 100 samples tested, 28 (28%) were positive. Most prevalent serovars were Patoc (35.71%), Butembo (32.14%) and Sentot (14.30%). Supply of pasture as forage (odds ratio =7.80; 95% confidence interval - 95%CI 1.71-35.50; p=0.008) was identify as risk factor. It is suggested the need for studies on agent isolation and characterization of its pathogenicity, as well as it is recommended the rodent control in deposits of feed and environment.(AU)

Foi realizado um inquérito epidemiológico objetivando determinar a ocorrência de anticorpos anti-Leptospira e elencar os fatores de risco em equinos da microrregião do Pajeú, estado de Pernambuco. Foram examinados 100 soros de equinos provenientes de 38 propriedades de 4 municípios da região, pela prova de soroaglutinação microscópica (SAM), utilizando 24 sorovares de Leptospira spp. como antígeno. Das 100 amostras testadas, 28 (28%) foram reagentes. Os sorovares mais frequentes foram Patoc (35,71%), Butembo (32,14%) e Sentot (14,30%). O uso de pasto como volumoso (odds ratio =7,80; intervalo de confiança de 95% - IC95% 1,71-35,50; p=0,008) foi identificado como fator de risco. Sugere-se a necessidade de estudos acerca do isolamento do agente e da caracterização de sua patogenicidade, bem como se recomenda o controle de roedores em depósitos de ração e no ambiente.(AU)