Parameter estimates for reproductive and carcass traits in Nelore beef cattle.

The aim of this study was to estimate genetic parameters for scrotal circumference at 365 (SC365) and 450 (SC450) days of age, age at first calving (AFC), ribeye area (REA), backfat (BF) thickness, and rump fat (RF) thickness, in order to provide information on potential traits for Nelore cattle breeding program. Genetic parameters were estimated using the Average Information Restricted Maximum Likelihood method in single- and multitrait analyses. Four different animal models were tested for SC365, SC450, REA, BF, and RF in single-trait analyses. For SC365 and SC450, the maternal genetic effect was statistically significant (P < 0.01) and was included for multitrait analyses. The direct heritability estimates for SC365, SC450, AFC, REA, BF, and RF were equal to 0.31, 0.38, 0.24, 0.32, 0.16, and 0.19, respectively. Maternal heritability for SC365 and SC450 was equal to 0.06 and 0.08, respectively. The highest genetic correlations were found among the scrotal circumferences. Testing for the inclusion of maternal effects in genetic parameters estimation for scrotal circumference should be evaluated in the Nelore breeding program, mostly for correctly ranking the animal's estimated breeding values. Similar heritability estimates were observed for scrotal circumference, as well as favorable genetic correlations of this trait with AFC and carcass traits. Thus, scrotal circumference measured at 365 days of age could be a target trait for consideration in the Nelore selection index in order to improve most of the traits herein analyzed.

Padronização de teste de potência in vitro para vacinas que contenham toxoide alfa de Clostridium novyi tipo B / Standardization of an in vitro potency test for vaccines containing Clostridium novyi type B alpha-toxoid

Clostridium novyi tipo B é o patógeno responsável pela hepatite necrótica, causada pela ação da toxina alfa. O controle desta enfermidade é baseado na imunização dos animais com vacinas que contenham na sua composição toxóide alfa de C. novyi tipo B. O teste de potência deste imunógeno é realizado a partir de soros de coelhos imunizados, por meio da técnica de soroneutralização em camundongos. Portanto objetivou-se padronizar um teste de potência de toxóide alfa de C. novyi tipo B em linhagem de célula VERO, como método alternativo ao bioensaio animal. O coeficiente de correlação obtido pelas técnicas in vitro e in vivo foi de 98,38%, indicando ser possível a utilização do modelo estudado na substituição do modelo animal para teste de potência de toxoide alfa de C. novyi tipo B.

Clostridium novyi type B is the pathogen responsible for necrotizing hepatitis caused by the action of alpha toxin. The control of this disease is based on immunization of animals with vaccines containing alpha toxoid of C. novyi type B in its composition, and the evaluation of this toxoid is made by seroneutralization in mice. Therefore, the present study was aimed to standardize a test of the power of alpha toxoid of C. novyi type B cell line VERO, as an alternative to animal bioassay The correlation coefficient obtained by the in vitro and in vivo techniques was 98.38%, indicating the possible use of the model to replace the animal model to test the power of alpha toxoid of C. novyi type B.

Plasma brain-derived neurotrophic factor levels are associated with clinical severity in school age children with asthma.

BACKGROUND: Asthma is characterized by chronic inflammation of the airways with significant changes in leucocyte trafficking, cellular activation and tissue remodelling. Brain-derived neurotrophic factor (BDNF) has been involved with asthma and allergic diseases but its role as a severity marker in paediatric asthma has not been clinically assessed. OBJECTIVES: To evaluate plasma BDNF and inflammatory markers in order to address their relationships with disease severity in children (6-15 years) with controlled persistent asthma. METHODS: Children with persistent asthma were selected and lung function and skin prick tests were performed in all patients. Plasma BDNF levels and various inflammatory markers (CCL3, CCL11, CCL22, CCL24, CXCL8, CXCL9, CXCL10, soluble TNF receptors) were assessed by ELISAs. RESULTS: Subjects with moderate and severe asthma had higher BDNF levels than mild asthma and controls (P<0.001). The chemokines studied and soluble TNF receptors did not differ between the studied groups. CONCLUSION AND CLINICAL RELEVANCE: Our results indicate BDNF as a potential biomarker for clinical severity in children with asthma.

In vitro evaluation of Clostridium septicum alpha toxoid / Avaliação in vitro de toxoide alfa de Clostridium septicum

Aiming to investigate in vitro alternatives, a test for neutralizing antibody detection using cell culture was developed. This test was more sensitive than previous animal models, allowing for detection of substantially lower alpha toxin and anti-alpha toxin titers. Titers observed during in vivo and in vitro seroneutralization had a correlation of 99.12 percent, indicating that cell culture is a viable alternative in the evaluation of vaccine potency, screening of vaccinal seeds, and Clostridium septicum alpha toxin titration.

Padronizou-se um teste para detecção de anticorpos neutralizantes in vitro, em cultura de células. O modelo in vitro mostrou-se mais sensível que os testes com animais, permitindo a detecção de títulos de toxina e antitoxina alfa mais baixos. Os títulos observados na soroneutralização in vivo e in vitro, apresentaram correlação de 99,12 por cento, demonstrando ser a cultura de células uma alternativa viável na avaliação da potência de vacinas, triagem de sementes vacinais e titulação de toxina alfa de Clostridium septicum.

In vitro evaluation of Clostridium septicum alpha toxoid / Avaliação in vitro de toxoide alfa de Clostridium septicum

Aiming to investigate in vitro alternatives, a test for neutralizing antibody detection using cell culture was developed. This test was more sensitive than previous animal models, allowing for detection of substantially lower alpha toxin and anti-alpha toxin titers. Titers observed during in vivo and in vitro seroneutralization had a correlation of 99.12 percent, indicating that cell culture is a viable alternative in the evaluation of vaccine potency, screening of vaccinal seeds, and Clostridium septicum alpha toxin titration.(AU)

Padronizou-se um teste para detecção de anticorpos neutralizantes in vitro, em cultura de células. O modelo in vitro mostrou-se mais sensível que os testes com animais, permitindo a detecção de títulos de toxina e antitoxina alfa mais baixos. Os títulos observados na soroneutralização in vivo e in vitro, apresentaram correlação de 99,12 por cento, demonstrando ser a cultura de células uma alternativa viável na avaliação da potência de vacinas, triagem de sementes vacinais e titulação de toxina alfa de Clostridium septicum.(AU)

Mionecroses clostridiais bovinas / Bovine clostridial myonecrosis

As mionecroses são enfermidades altamente fatais, representadas pelo carbúnculo sintomático e edema maligno. Com o objetivo de determinar a ocorrência dos diferentes clostrídios envolvidos nas mionecroses em bovinos no Brasil, foi realizado um estudo retrospectivo a partir de 30 casos suspeitos de carbúnculo sintomático e edema maligno. Empregou-se a técnica de estreptavidina biotina peroxidase em tecidos de bovinos fixados em formol e incluídos em parafina de arquivos de patologia de diferentes estados do país. Foram detectados 21 Clostridium chauvoei (70%), cincoClostridium septicum(17%), seguidos de doisC. chauvoeiassociado aoC. septicum (7%), um C. chauvoei mais Clostridium sordellii (3%) e um C. chauvoei mais Clostridium novyi tipo A (3%). Este é o primeiro diagnóstico de C. novyi tipo A no Brasil, e o primeiro relato da ocorrência de C. chauvoei associado à lesão no miocárdio. Os achados da maior ocorrência de C. chauvoei e C. septicum corroboram com estudos anteriores no país. Estes dados sobre a ocorrência dos agentes responsáveis pelas mionecroses em diferentes estados do país são de extrema importância frente às decisões relativas ao controle dessas enfermidades.

Clostridial myonecroses are highly fatal diseases, characterized by black leg and malignant oedema. In order to determine the occurrence of the different agents involved in Brazilian clostridial myonecrosis, a retrospective study was conducted concerning 30 suspected cases of blackleg and gas gangrene using a streptavidin-biotin peroxidase technique in formalin-fixed, paraffin-embedded tissues of cattle from the archives of pathology of different states of Brazil. The clostridia predominantly detected wereClostridium chauvoei(70%), followed by Clostridium septicum (5 cases or 17%), C. chauvoei plus C. septicum (2 cases or 7%), C. chauvoei plus Clostridium sordellii (1 case or 3%), C. chauvoei plus Clostridium novyi type A (1 case or 3%). This is the first diagnosis of C. novyi type A in Brazil. The findings of the higher occurrence of C. chauvoei and C. septicum concur with previous works in Brazil. This article also includes the first report in Brazil of the occurrence of C. chauvoei associated with a lesion in the myocardium. Thus, this study supplies important data about the occurrence of the agents responsible for clostridial myonecrosis in different states of Brazil, these data being important for decisions relative to control of these diseases.

Molecular cloning and expression of epsilon toxin from Clostridium perfringens type D and tests of animal immunization.

Epsilon toxin produced by Clostridium perfringens types B and D causes enterotoxemia in sheep, goats and calves. Enterotoxemia can cause acute or superacute disease, with sudden death of the affected animal. It provokes huge economic losses when large numbers of livestock are affected. Therapeutic intervention is challenging, because the disease progresses very rapidly. However, it can be prevented by immunization with specific immunogenic vaccines. We cloned the etx gene, encoding epsilon toxin, into vector pET-11a; recombinant epsilon toxin (rec-epsilon) was expressed in inclusion bodies and was used for animal immunization. Serum protection was evaluated and cross-serum neutralization tests were used to characterize the recombinant toxin. To analyze the potency of the toxin (as an antigen), rabbits were immunized with 50, 100 or 200 microg recombinant toxin, using aluminum hydroxide gel as an adjuvant. Titers of 10, 30 and 40 IU/mL were obtained, respectively. These titers were higher than the minimum level required by the European Pharmacopoeia (5 IU/mL) and by the USA Code of Federal Regulation (2 IU/mL). This rec-epsilon is a good candidate for vaccine production against enterotoxemia caused by epsilon toxin of C. perfringens type D.

MIONECROSES CLOSTRIDIAIS BOVINAS

ABSTRACT Clostridial myonecroses are highly fatal diseases, characterized by black leg and malignant oedema. In order to determine the occurrence of the different agents involved in Brazilian clostridial myonecrosis, a retrospective study was conducted concerning 30 suspected cases of blackleg and gas gangrene using a streptavidin-biotin peroxidase technique in formalin-fixed, paraffin-embedded tissues of cattle from the archives of pathology of different states of Brazil. The clostridia predominantly detected wereClostridium chauvoei(70%), followed by Clostridium septicum (5 cases or 17%), C. chauvoei plus C. septicum (2 cases or 7%), C. chauvoei plus Clostridium sordellii (1 case or 3%), C. chauvoei plus Clostridium novyi type A (1 case or 3%). This is the first diagnosis of C. novyi type A in Brazil. The findings of the higher occurrence of C. chauvoei and C. septicum concur with previous works in Brazil. This article also includes the first report in Brazil of the occurrence of C. chauvoei associated with a lesion in the myocardium. Thus, this study supplies important data about the occurrence of the agents responsible for clostridial myonecrosis in different states of Brazil, these data being important for decisions relative to control of these diseases.

RESUMO As mionecroses são enfermidades altamente fatais, representadas pelo carbúnculo sintomático e edema maligno. Com o objetivo de determinar a ocorrência dos diferentes clostrídios envolvidos nas mionecroses em bovinos no Brasil, foi realizado um estudo retrospectivo a partir de 30 casos suspeitos de carbúnculo sintomático e edema maligno. Empregou-se a técnica de estreptavidina biotina peroxidase em tecidos de bovinos fixados em formol e incluídos em parafina de arquivos de patologia de diferentes estados do país. Foram detectados 21 Clostridium chauvoei (70%), cincoClostridium septicum(17%), seguidos de doisC. chauvoeiassociado aoC. septicum (7%), um C. chauvoei mais Clostridium sordellii (3%) e um C. chauvoei mais Clostridium novyi tipo A (3%). Este é o primeiro diagnóstico de C. novyi tipo A no Brasil, e o primeiro relato da ocorrência de C. chauvoei associado à lesão no miocárdio. Os achados da maior ocorrência de C. chauvoei e C. septicum corroboram com estudos anteriores no país. Estes dados sobre a ocorrência dos agentes responsáveis pelas mionecroses em diferentes estados do país são de extrema importância frente às decisões relativas ao controle dessas enfermidades.

Antimicrobial susceptibility of Clostridium perfringens strains isolated from broiler chickens / Sensibilidade antimicrobiana de estirpes de Clostridium perfringens isoladas de aves de corte

Clostridium perfringens is a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen that causes necrotic enteritis and colangio hepatitis. The minimum inhibitory concentration (MIC) of seven different compounds used for therapy, growth promotion or prevention of coccidiosis was determined by agar dilution method for 55 C. perfringens strains isolated from the intestines of broiler chickens. All strains showed high susceptibility to penicillin, avilamycin, monensin and narasin. Only 7.3% of the strains showed an intermediated sensitivity to lincomycin, and 49 (89.1%) were considered susceptible. For tetracycline and bacitracin, 41.8% and 47.3% of strains, respectively, were considered resistant.

Clostridium perfringens é um habitante normal da microbiota intestinal de frangos, sendo um agente potencialmente patogênico, causador de enterite necrótica e colangio-hepatite.A concentração inibitória mínima (CIM) de sete drogas utilizadas na terapêutica, como agentes promotores de crescimento ou na prevenção de coccidiose foi determinada pelo método de diluição em ágar para 55 estirpes de C. perfringens isoladas do intestino de frangos de corte. Todas as estirpes revelaram alta sensibilidade à penicilina, avilamicina, narasin e monensina, apenas 7,3% demonstraram CIM intermediário para lincomicinae 89.1% foram consideradas sensíveis. Para tetraciclina e bacitracina, 41,8% e 47.3% das amostras, respectivamente, foram consideradas resistentes.

Antimicrobial susceptibility of Clostridium perfringens strains isolated from broiler chickens.

Clostridium perfringens is a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen that causes necrotic enteritis and colangio hepatitis. The minimum inhibitory concentration (MIC) of seven different compounds used for therapy, growth promotion or prevention of coccidiosis was determined by agar dilution method for 55 C. perfringens strains isolated from the intestines of broiler chickens. All strains showed high susceptibility to penicillin, avilamycin, monensin and narasin. Only 7.3% of the strains showed an intermediated sensitivity to lincomycin, and 49 (89.1%) were considered susceptible. For tetracycline and bacitracin, 41.8% and 47.3% of strains, respectively, were considered resistant.

Antimicrobial susceptibility of Clostridium perfringens strains isolated from broiler chickens

Clostridium perfringens is a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen that causes necrotic enteritis and colangio hepatitis. The minimum inhibitory concentration (MIC) of seven different compounds used for therapy, growth promotion or prevention of coccidiosis was determined by agar dilution method for 55 C. perfringens strains isolated from the intestines of broiler chickens. All strains showed high susceptibility to penicillin, avilamycin, monensin and narasin. Only 7.3% of the strains showed an intermediated sensitivity to lincomycin, and 49 (89.1%) were considered susceptible. For tetracycline and bacitracin, 41.8% and 47.3% of strains, respectively, were considered resistant.

Clostridium perfringens é um habitante normal da microbiota intestinal de frangos, sendo um agente potencialmente patogênico, causador de enterite necrótica e colangio-hepatite. A concentração inibitória mínima (CIM) de sete drogas utilizadas na terapêutica, como agentes promotores de crescimento ou na prevenção de coccidiose foi determinada pelo método de diluição em ágar para 55 estirpes de C. perfringens isoladas do intestino de frangos de corte. Todas as estirpes revelaram alta sensibilidade à penicilina, avilamicina, narasin e monensina, apenas 7,3% demonstraram CIM intermediário para lincomicina e 89.1% foram consideradas sensíveis. Para tetraciclina e bacitracina, 41,8% e 47.3% das amostras, respectivamente, foram consideradas resistentes.