Risk factors and detection of brucella ovis in naturally infected rams and ewes / Fatores de risco e detecção de brucella ovis em carneiros e ovelhas naturalmente infectados

The objective of this study was to verify the occurrence of ovine brucellosis using Agar Gel Immunodiffusion (AGID) and Polymerase Chain Reaction (PCR) techniques, as well as to identify the main risk factors associated with infection in sheep flocks belonging to municipalities in the microregion from Teresina, PI, Brazil. A total of 100 urine and blood samples were collected from sheep aged 6 months or older. The urine samples were submitted to conventional PCR and the blood samples were examined by the AGID technique. Of the 100 blood samples, 17 (17%) were reactive to the AGID test. In conventional PCR of 100 urine samples, six (6%) were positive. Risk factors associated to infection by B. ovis included the rearing system (OR=0.19), feed management (OR=0.05), presence of dystotic births (OR=4.50), miscarriages (OR=3.75) and source of water offered to the animals (OR=0.19). Thus, it was concluded that it is possible to detect the occurrence of animals with ovine brucellosis since PCR is a reliable method to confirm infection. Furthermore, there are risk factors associated to infection by B. ovis in the municipalities studied.

Objetivou-se verificar a ocorrência da brucelose ovina através das técnicas de Imunodifusão em Gel de Ágar (IDGA) e Reação em Cadeia da Polimerase (PCR), bem como identificar os principais fatores de risco associados à infecção nos rebanhos ovinos pertencentes a municípios da microrregião de Teresina, PI, Brasil. Foram colhidas 100 amostras de urina e de sangue de ovinos com idade superior ou igual a seis meses. As amostras de urina foram submetidas a PCR convencional e as amostras de sangue à técnica de IDGA. Das 100 amostras de sangue 17 (17%) foram reagentes ao teste de IDGA. Já na PCR convencional das 100 amostras de urina, seis (6%) foram positivas. Ressalta-se que três animais foram positivos em ambos os testes. Como fatores associados à infecção por B. ovis, observou-se o tipo de sistema de criação (OR=0,19), o manejo alimentar (OR=0,05), presença de partos distócicos (OR=4,50), abortamentos (OR=3,75) e a fonte de água fornecida aos animais (OR=0,19). Assim, conclui-se que foi possível detectar a ocorrência de animais com brucelose ovina, uma vez que a PCR é um método confirmatório. Além disso, há fatores de risco associados à infecção por B. ovis nos municípios estudados.

Risk factors and detection of brucella ovis in naturally infected rams and ewes / Fatores de risco e detecção de brucella ovis em carneiros e ovelhas naturalmente infectados

The objective of this study was to verify the occurrence of ovine brucellosis using Agar Gel Immunodiffusion (AGID) and Polymerase Chain Reaction (PCR) techniques, as well as to identify the main risk factors associated with infection in sheep flocks belonging to municipalities in the microregion from Teresina, PI, Brazil. A total of 100 urine and blood samples were collected from sheep aged 6 months or older. The urine samples were submitted to conventional PCR and the blood samples were examined by the AGID technique. Of the 100 blood samples, 17 (17%) were reactive to the AGID test. In conventional PCR of 100 urine samples, six (6%) were positive. Risk factors associated to infection by B. ovis included the rearing system (OR=0.19), feed management (OR=0.05), presence of dystotic births (OR=4.50), miscarriages (OR=3.75) and source of water offered to the animals (OR=0.19). Thus, it was concluded that it is possible to detect the occurrence of animals with ovine brucellosis since PCR is a reliable method to confirm infection. Furthermore, there are risk factors associated to infection by B. ovis in the municipalities studied.

Objetivou-se verificar a ocorrência da brucelose ovina através das técnicas de Imunodifusão em Gel de Ágar (IDGA) e Reação em Cadeia da Polimerase (PCR), bem como identificar os principais fatores de risco associados à infecção nos rebanhos ovinos pertencentes a municípios da microrregião de Teresina, PI, Brasil. Foram colhidas 100 amostras de urina e de sangue de ovinos com idade superior ou igual a seis meses. As amostras de urina foram submetidas a PCR convencional e as amostras de sangue à técnica de IDGA. Das 100 amostras de sangue 17 (17%) foram reagentes ao teste de IDGA. Já na PCR convencional das 100 amostras de urina, seis (6%) foram positivas. Ressalta-se que três animais foram positivos em ambos os testes. Como fatores associados à infecção por B. ovis, observou-se o tipo de sistema de criação (OR=0,19), o manejo alimentar (OR=0,05), presença de partos distócicos (OR=4,50), abortamentos (OR=3,75) e a fonte de água fornecida aos animais (OR=0,19). Assim, conclui-se que foi possível detectar a ocorrência de animais com brucelose ovina, uma vez que a PCR é um método confirmatório. Além disso, há fatores de risco associados à infecção por B. ovis nos municípios estudados.

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)

In vivo evaluation of antiseptics and disinfectants on control of Caseous Lymphadenitis: clinical, haematological, serological and microbiological monitoring / Avaliação in vivo de antissépticos e desinfetantes no controle da Linfadenite Caseosa: acompanhamento clínico, hematológico, sorológico e microbiológico

The objective of this experiment was to evaluate the efficacy of iodine tincture at 10% and sodium hypochlorite at 2.5% applied into the abscess of animals affected by Caseous Lymphadenitis (CL). Eighteen ewes were used, assorted into three groups: one treated with iodine tincture at 10% (IT), another one with sodium hypochlorite at 2.5% (SH) and the last group underwent the conventional treatment (CT). Conventional treatment was based on surgical drainage and chemical cauterization of the lesion with iodine tincture at 10%. Natural rupture of six abscesses from IT group was observed and in five of them the viability of Corynebacterium pseudotuberculosis was confirmed on the lesion place, after rupture of lymph node. As for the SH group, spontaneous rupture was observed in five out of six abscesses treated, and the microorganism was identified on the lesion of five animals, after rupture. In the sixth animal of this group, abscess involution was noticed. A severe swelling was identified in the region of lymph node treated, resulting in wide lesion in animals from groups IT and SH. No difference (p > 0,05) was found in blood parameters due to treatments. As for the serological monitoring of animals, comparative analysis between months within each group showed that months 1, 2, 3 and 4 were different (p 0,05) from month 0, for groups IT and SH. For CT group, there was no difference (p > 0,05) between months 1 to 5 and 0. Then, the application of iodine tincture at 10% or sodium hypochlorite at 2.5% into the abscess of animals affected by CL, at stage in which lesions are detected through inspection, is not effective for its control.

Objetivou-se com este experimento avaliar a eficácia da tintura de iodo a 10% e do hipoclorito de sódio a 2,5% aplicados no interior do abscesso de animais acometidos pela Linfadenite Caseosa (LC). Foram utilizadas 18 fêmeas ovinas, divididas em 3 grupos: o primeiro foi tratado com tintura de iodo a 10% (TI), o segundo com hipoclorito de sódio a 2,5% (HS) e o último grupo foi submetido ao tratamento convencional (CT). O tratamento convencional da doença consistia na drenagem e cauterização química dos abscessos, utilizando-se solução de iodo a 10%. Foi observada a ruptura natural dos seis abscessos do grupo TI, sendo que em cinco deles a viabilidade do Corynebacterium pseudotuberculosis foi confirmada no local da lesão, após a ruptura do linfonodo. Quanto ao grupo HS, a ruptura espontânea foi observada em cinco dos seis abscessos tratados, sendo o microrganismo identificado na lesão dos cinco animais após o rompimento. No sexto animal desse grupo, foi constatada a involução do abscesso. Foi verificado um edema intenso na região do linfonodo tratado com formação de uma lesão de grande extensão nos animais dos grupos TI e HS. Não foi detectada diferença (p > 0,05) nos parâmetros hematológicos em decorrência dos tratamentos avaliados. Quanto ao acompanhamento sorológico dos animais, a análise estatística comparativa entre os meses, dentro de cada grupo, mostrou que os meses 1, 2, 3 e 4 foram diferentes (p 0,05) do mês 0 para os grupos TI e HS. No grupo CT, não houve diferença (p > 0,05) entre os meses de 1 a 5 e o mês 0. Conclui-se que a aplicação de tintura de iodo a 10% ou hipoclorito de sódio a 2,5% no interior do abscesso de animais acometidos pela LC, em estágio no qual as lesões são detectadas por meio da inspeção, não é eficaz para o seu controle.