Individual-based modelling and control of bovine brucellosis.

We present a theoretical approach to control bovine brucellosis. We have used individual-based modelling, which is a network-type alternative to compartmental models. Our model thus considers heterogeneous populations, and spatial aspects such as migration among herds and control actions described as pulse interventions are also easily implemented. We show that individual-based modelling reproduces the mean field behaviour of an equivalent compartmental model. Details of this process, as well as flowcharts, are provided to facilitate the reproduction of the presented results. We further investigate three numerical examples using real parameters of herds in the São Paulo state of Brazil, in scenarios which explore eradication, continuous and pulsed vaccination and meta-population effects. The obtained results are in good agreement with the expected behaviour of this disease, which ultimately showcases the effectiveness of our theory.

Phylogenetic Group of Escherichia coli Isolates from Broilers in Brazilian Poultry Slaughterhouse.

The aim of the study was to determine the phylogenetic groups of E. coli strains isolated from seemingly healthy broiler and broiler condemned suspected of colibacillosis in a Brazilian slaughterhouse. Samples from respiratory tract and edible giblets (liver and heart) of broilers with and without macroscopic lesions of colibacillosis were collected at slaughter. There were 84 strains isolated from broilers condemned of which 11 were obtained from swabs of the heart, 7 from the liver, and 66 from the respiratory tract. Of the 53 E. coli strains isolated from broilers not condemned, 5 were isolated from the heart, 4 from the liver, and 44 from the respiratory tract. E coli strains were tested via PCR for phylogenetic groups A, B1, B2, C, D, E, and F. Phylogroups A and B1 were the most common phylogroups of E. coli obtained from healthy and sick-appearing broiler carcasses. The results of the study showed that phylogroups B2 and E were associated with the heart samples and phylogroup A was associated with respiratory tract samples, phylogroup B1 with not condemned carcass, and phylogroup D with liver samples.

Survey of pyrethroid, macrocyclic lactone and antibacterial residues in bulk milk tank from Minas Gerais State, Brazil / Resíduos de piretróides, lactonas macrocíclicas e antimicrobianos em amostras de leite de tanque no estado de Minas Gerais

A survey of veterinary drug residues in bulk milk tank from Minas Gerais State, Brazil, was carried out through a broad scope analysis. Here, 132 raw milk samples were collected at 45 dairy farms in Minas Gerais from August 2009 to February 2010, and analyzed for 42 analytes, comprising pyrethroids, macrocyclic lactones and antibacterials, using liquid chromatography coupled with mass spectrometry in tandem mode and gas chromatography with electron capture detection. Within all milk samples, at least one veterinary drug residue was identified in 40 milk samples (30.30%) by confirmatory tests, whereas 16 samples (12.12%) showed the presence of at least two residues. With regard to the Brazilian maximum residue levels, 11 milk samples (8.33%) were non-compliant according to Brazilian Legislation. The veterinary drugs detected in the non-compliant milk samples include penicillin V (one sample), abamectin (one sample) and cypermethrin (nine samples). Furthermore, the antibacterial screening methods failed to identify most of the positive samples that were detected by confirmatory tests, leading to a large discrepancy between the screening and confirmatory antimicrobial tests. Thus, the present study indicated that the veterinary drugs residues still represents a great concern for the milk production chain.(AU)

Avaliou-se a presença de 42 analitos, incluindo piretróides, lactonas macrocíclicas e antimicrobianos em 132 amostras de leite de tanque proveniente de 45 propriedades leiteiras localizadas no Estado de Minas Gerais. Para tal, utilizou-se a cromatografia líquida acoplada a espectrofotometria de massas tandem e cromatografia gasosa com detector com captura de elétrons. Dentre todas as amostras de leite, 40 (30,30%) amostras de leite de tanque apresentaram a presença de pelo menos um analito, enquanto 16 amostras (12,12%) de leite demonstraram a presença de pelo menos dois analitos. Considerando os limites estabelecidos pela legislação brasileira, 11 amostras de leite (8,33%) seriam consideradas como não conforme. Ademais, os testes de triagem para detecção de antimicrobianos no leite não conseguiram identificar a maioria das amostras positivas nos testes confirmatórios, levando a grande discrepância entre estes testes. Desta forma, os resultados do presente estudo indicam que os períodos de descarte do leite, especialmente para piretróides, não foram plenamente respeitados por todos os produtores de leite. Além disto, uma discrepância entre os resultados dos testes confirmatórios e os testes de triagem foi observada.(AU)

The neutrophil function and lymphocyte profile of milk from bovine mammary glands infected with Streptococcus dysgalactiae.

Streptococcus dysgalactiae is a bacterium that accounts for a notable proportion of both clinical and subclinical intramammary infections (IMIs). Thus, the present study explores the function of milk neutrophils and the lymphocyte profile in mammary glands naturally infected with Streptococcus dysgalactiae. Here, we used 32 culture-negative control quarters from eight clinically healthy dairy cows with low somatic cell counts and 13 S. dysgalactiae-infected quarters from six dairy cows. Using flow cytometry, we evaluated the percentage of milk monocytes/macrophages and neutrophils, expression of CD62L, CD11b and CD44 by milk neutrophils, the levels of intracellular reactive oxygen species (ROS) production and phagocytosis of Staphylococcus aureus by milk neutrophils, and neutrophil viability. Furthermore, the percentages of B cell (CD21(+)) and T lymphocyte subsets (CD3(+)/CD4(+)/CD8(-); CD3(+)/CD8(+)/CD4(-); and CD3(+)/CD8(-)/CD4(-)), and the expression of CD25 by T milk lymphocytes (CD3(+)) and T CD4(+) milk cells were also assessed by flow cytometry using monoclonal antibodies. The present study showed a higher SCC and percentage of milk neutrophils, and a decrease in the percentage of milk monocytes/macrophages from S. dysgalactiae-infected quarters when compared to uninfected ones. We also observed a higher expression of CD11b by milk neutrophils and a tendency toward a decrease in neutrophil apoptosis rate in S. dysgalactiae-infected quarters. In addition, the S. dysgalactiae-infected quarters had higher percentages of milk T cells (CD3(+)) and their subset CD3(+)CD8(+)CD4(-) cells. Overall, the present study provided new insights into S. dysgalactiae IMIs, including distinct lymphocyte profiles, and a tendency toward an inhibition of apoptosis in milk neutrophils.

Technological level and epidemiological aspects of sheep husbandry in Minas Gerais, southeastern Brazil / Nível tecnológico e aspectos epidemiológicos da ovinocultura no estado de Minas Gerais, Sudeste do Brasil

Epidemiological and health aspects of sheep husbandry were assessed on 213 sheep flocks in 142 municipalities from the state of Minas Gerais, southeastern Brazil. An updated questionnaire was filled out for each flock, requesting data on the farm, the flock and the farmer by the veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária). Thirteen important variables were selected and scored to determine the technological level of the 117 farms; 0.9% of them was classified as high technological level, 45.3% as medium technological level and 53.0% as low technological level. Lamb production was the main objective of the farms and the main features were low-frequencies of individual identification of animals (16.9%), technical assistance (31.9%), use of quarantine for newly acquired animals (0.9%) the separation of animals by age group (3.7%) and requeste the sanitary certificate at purchasing of animals (11.7%). The main health problems reported were abortion (23.9%), keratoconjunctivitis (17.9%), contagious ecthyma (13.6%), pneumonia (10.3%), diarrhea (9.3%) and caseous lymphadenitis (6.1%). Information of the epidemiological situation and the mainly health measures used in the sheep farms are important to improve the productivity and quality of the lamb...

Os aspectos epidemiológicos e sanitários da ovinocultura foram levantados em 213 rebanhos ovinos em 142 municípios do estado de Minas Gerais, sudeste do Brasil. Um questionário atualizado foi preenchido para cada rebanho, com informações sobre a fazenda, o rebanho e do fazendeiro, por veterinários do Instituto Mineiro de Agropecuária. Treze variáveis importantes foram selecionadas e pontuadas para determinar o nível tecnológico em 117 fazendas; 0,9% foram classificadas como de alto nível tecnológico, 45,3% como de médio nível tecnológico e 53,0% como de baixo nível tecnológico. A produção de carne de cordeiro foi o principal objetivo das fazendas amostradas e as principais características foram baixa frequência de identificação individual dos animais (16,9%), assistência técnica (31,9%), uso de quarentena para os animais recém-adquiridos (0,9%), separação de animais por faixa etária (3.7%) e solicitação de certificados sanitários na compra de animais (11,7%). Os principais problemas sanitários relatados foram o aborto (23,9%), ceratoconjuntivite (17,9%), ectima contagioso (13,6%), pneumonia (10,3%), diarreia (9,3%) e linfadenite caseosa (6,1%). Informações sobre a situação epidemiológica e das principais medidas sanitárias utilizadas nas propriedades com ovinos são importantes para melhorar produtividade e a qualidade da carne ovina...

A surveillance of enteropathogens in piglets from birth to seven days of age in Brazil / Levantamento dos enteropatógenos de leitões do nascimento a sete dias de idade no Brasil

The purpose of the study was to evaluate the real importance of anaerobic enteropathogens and rotavirus in contrast to more common agents as cause of diarrhea in piglets within the first week of life. Sixty 1- to 7-day-old piglets, 30 diarrheic and 30 non-diarrheic (control), from 15 different herds were selected, euthanized and necropsied. Samples of the jejunum, ileum, colon, cecum and feces were collected from the piglets and analyzed to determine the presence of the following enteropathogens: enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens types A and C, Clostridium difficile, rotavirus and Isospora suis. Among diarrheic piglets, 23.3% were positive for C. difficile, 70% for C. perfringens type A cpb2+, 14.3% for rotavirus and 10% for ETEC. Among non-diarrheic control piglets, 10% were positive for C. difficile, 76.7% for C. perfringens type A cpb2+, 0% for rotavirus, 3.3% for ETEC and 3.3% for I. suis. C. perfringens type C was not detected in any of the animals. Histological lesions characteristic of C. difficile, E. coli and rotavirus were observed. However, no C. perfringens type A suggestive lesions were detected. There was a positive correlation between mesocolon edema and the presence of C. difficile toxins. Although C. perfringens type A cpb2+ was the most frequently detected enteropathogen, there was no association between its presence and diarrhea or macro or microscopic changes. C. difficile and Rotavirus were the most relevant pathogens involved with neonatal diarrhea in this study, and histopathology associated with microbiological test proved to be the key to reach a final diagnosis.

O objetivo do presente estudo foi avaliar a real importância de enteropatógenos anaeróbios e rotavirus em comparação à outros agentes mais comuns como causa de diarreia em leitões até cinco dias de idade. Leitões com 0 a 7 dias de vida, 30 diarreicos e 30 não diarreicos (controles) de 15 granjas diferentes foram eutanasiados e necropsiados. Amostras de jejuno, íleo, colon e ceco foram coletadas e submetidas à detecção dos seguintes enteropatógenos: Escherichia coli enterotoxigênica (ETEC), Clostridium perfringens, Clostridium difficile, rotavirus e Isospora suis. Entre os animais diarréicos, 23.3% foram positivos para C. difficile, 70% para C. perfringens tipo A cpb2+, 14.3% para rotavirus e 10% para ETEC. Entre os leitões não-diarréicos, 10% foram positivos para C. difficile, 76.7% para C. perfringens tipo A cpb2+, 3.3% para ETEC e 3.3% for I. suis. C. perfringens tipo C não foi detectado em nenhum animal. Lesões histológicas características de C. difficile, E. coli e rotavirus foram observadas. Por outro lado, nenhuma lesão sugestiva de C. perfringens foi detectada. Foi possível observar uma correlação positiva entre edema de mesocolon e presença das toxinas A/B. Apesar de C. perfringens tipo A cpb2+ ter sido o patógeno mais encontrado, nenhuma associação com lesões foi encontrada. C. difficile e Rotavirus foram os agentes mais relevantes associados à diarreia neonatal, e ficou demonstrada a relevância de associação de histopatologia com testes de detecção microbiológica para se firmar um diagnóstico.

Management practices to control gastrointestinal parasites in sheep farms in Minas Gerais, southeastern Brazil / Práticas de manejo para controle de parasitas gastrointestinais em fazendas com ovinos em Minas Gerais, Sudeste do Brasil

Parasite related problems are considered one of the major health problems for sheep breeding, causing considerable economic losses to commercial husbandry. The aim of this study was to determine the technological level and the level of knowledge of farmers regarding management practices to control gastrointestinal parasites in sheep in Minas Gerais state, southeastern Brazil. The analysis was based on 213 questionnaires applied by official veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária, IMA), covering 16.6% of all counties. From two hundred and thirteen sheep farms sampled, 117 farms had their technological level determined. From the samples, 0.9% were characterized as high level, 45.3% as medium, and 53.0% as low technological level. The flock size ranged from 2 to 1843 with an average of 80.5 sheep per farm. The majority of the sheep production systems was extensive/semi-extensive (74.5%). The management practices adopted by the farmers to reduce parasitism were: split young and adult animals (5.6%), change pasture after deworm the animals (5.2%), use quarantine for incoming animals (2.3%), deworm newly arrived sheep (1.5%), and have regular technical assistance (31.9%). Although 76.5% of the farmers medicate the animals, treatments were performed without any major technical criteria, with an average interval of 4.6 months. The most commonly used drug families were macrocyclic lactones (38.5%) and benzimidazoles (24.9%). The management practices adopted in Minas Gerais are based on old recommendations and may not return in a good set of strategies to prevent parasite infections. Field observations reinforce the finding where farmers have obtained unsatisfactory results in maintaining the health and productivity level of their enterprises.

Problemas relacionados com parasitas são considerados um dos principais problemas sanitários na criação de ovinos, causando consideráveis perdas econômicas para criação comercial. O objetivo deste estudo foi determinar o nível tecnológico e o nível de conhecimento dos criadores sobre práticas de manejo para o controle de parasitas gastrintestinais em ovinos no estado de Minas Gerais, sudeste do Brasil. A análise foi baseada em 213 questionários aplicados pelos veterinários oficiais da Agência de Governo Estudal de Saúde Animal (Instituto Mineiro de Agropecuária, IMA), cobrindo 16,6% de todos os municípios. Duzentos e treze propriedades com ovinos foram amostradas e 117 tiveram o seu nível tecnológico determinado. A partir da amostra, 0,9% foi caracterizado como nível elevado, de 45,3%, como de médio e 53,0% como baixo nível tecnológico. O tamanho do rebanho variou de 2 a 1843 com uma média de 80,5 ovinos por propriedade. A maioria dos sistemas de produção de ovinos eram extensivos/semi-extensivos (74,5%). As práticas de manejo adotadas pelos criadores para reduzir o parasitismo foram: separar animais jovens e adultos (5,6%), mudança de pastagem após vermifugar os animais (5,2%), uso de quarentena para animais recem adiquiridos (2,3%), vermifugação de ovelhas recém-chegadas (1,5%) e assistência técnica regular (31,9%). Apesar de 76,5% dos criadores vermifugarem os animais, os tratamentos foram realizados sem qualquer critério técnico importante, com um intervalo médio de 4,6 meses. As famílias de drogas mais comumente usadas foram lactonas macrocíclicas (38,5%) e benzimidazóis (24,9%). As práticas de manejo adotadas em Minas Gerais são baseadas em recomendações antigas e não em estratégias para prevenir infecções parasitárias. As observações de campo reforçam os achados em que os proprietários obtiveram resultados insatisfatórios na manutenção dos níveis de saúde e produtividade de seus empreendimentos.

Clinical aspects and dynamics of auricular parasitosis in Gir cattle / Aspectos clínicos e dinâmica de parasitoses auriculares em bovinos da raça Gir

We evaluated the dynamics of ear infestations caused by Rhabditis spp. and Raillietia spp., which were correlated with animal age, intensity of clinical signs and climate factors. Sixty-four Gir cattle were distributed into three groups: GA - 23 calves with 4 to 6 months of age; GB - 18 calves with 7 to 12 months of age; and GC - 23 heifers with 13 to 33 months of age. Five samplings, defined as S1, S2, S3, S4 and S5 were performed every three months from August 2008 to August 2009. The ear secretion was collected using the auricular washing method for the right ear and a swab for the left ear. A clinical assessment of the animals was performed, and they were classified according to the presence and severity of otitis. The highest relative frequency of rhabditosis was 52.2% in GC at the last sampling. In the first sampling, 42.2% of the animals were infested by Raillietia spp. The older cattle were more susceptible to infestations by both parasites. No correlation of Rhabditis spp. and Raillietia spp. parasitism with climate factors was found. The results showed that both parasites could infest Gir cattle, and in most cases, there was no co-infestation. Only older animals parasitized by the nematode showed clinical signs of the disease.

Avaliou-se a dinâmica da infestação auricular causada por Rhabditis spp. e por Raillietia spp., relacionando-a com a idade dos animais, com a intensidade dos sinais clínicos e com os fatores climáticos. Utilizaram-se 64 bovinos Gir, distribuídos em três grupos: GA - 23 bezerros de quatro a seis meses de idade, GB - 18 bezerros de sete a 12 meses e GC - 23 novilhas de 13 a 33 meses. Foram feitas cinco coletas a cada três meses. A secreção auricular foi coletada utilizando o método de lavagem auricular na orelha direita e um swab na orelha esquerda. Fez-se avaliação clínica dos animais classificando-os de acordo com a presença e gravidade da otite. A maior frequência relativa da rhabditiose encontrada foi de 52,2%, no GC na ultima coleta. Na primeira coleta, 42,2% dos animais estavam infestados pela Raillietia spp. Os bovinos mais velhos foram mais suscetíveis às infestações de ambos os parasitos. Não foi encontrada correlação entre o parasitismo por Rhabditis spp. e por Raillietia spp. e os fatores climáticos. Concluiu-se que ambos os parasitas podem infestar bovinos da raça Gir e na maioria dos casos, não ocorreram infestações simultâneas. Apenas os animais mais velhos, parasitados pelo nematóide, apresentaram sinais clínicos da doença.

Validation of an immunoperoxidase monolayer assay for total anti-Vaccinia virus antibody titration.

Vaccinia virus (VACV) has been associated with zoonotic exanthemic outbreaks affecting bovids and human beings, with significant public health and economic impacts. Rapid and reliable diagnostic methods are needed to detect and epidemiologically monitor antibodies to VACV. The current study describes the development of an immunoperoxidase monolayer assay (IPMA) for detection of total VACV antibodies in bovine serum. The assay was validated by comparison with a plaque reduction neutralization test (PRNT). Kappa index of agreement, diagnostic sensitivity, specificity, and accuracy of the IPMA were -1.008, 100%, 96%, and 98%, respectively, when compared with PRNT on 148 field bovine sera. Repeatability tests on 32 field-positive serum samples revealed that intraclass coefficient correlation was 0.86. In experimentally infected cattle, VACV antibodies were detectable by IPMA 4 days postinfection, which was more than 2 weeks earlier than with the PRNT, indicating that IPMA could be a more sensitive test than the latter. In 4 naturally VACV-diseased cows monitored for 13 months, IPMA could detect VACV antibodies up to 13 months, a longer time than PRNT. The IPMA is simpler to produce and perform when compared with PRNT and is time saving and suitable for large-scale surveys of VACV infection in bovine.

Cardiorespiratory and blood gas alterations during laparoscopic surgery for intra-uterine artificial insemination in dogs.

Cardiorespiratory and blood gas alterations were evaluated in 6 healthy dogs that underwent a laparoscopic procedure using isoflurane anesthesia and carbon dioxide (CO(2)) pneumoperitoneum for 30 min. Heart rate, respiratory rate, body temperature, venous blood pH, partial pressure of CO(2) and oxygen, oxygen saturation, total carbon dioxide (TCO(2)) and bicarbonate were monitored. Significant alterations were hypercapnia, hypoventilation, and respiratory acidosis.

Distribution of antibodies against porcine circovirus type-2 (PCV2) in single site and multi-site farrow-to-finish farms in Brazil.

A comparative serologic study was performed in seven single site (SS) farrow-to-finish farms and four multi-site (MS) farrow-to-finish farms, with or without post-weaning multisystemic wasting syndrome (PMWS). In each farm, 30 blood samples were collected for each category of the production cycle: sows, farrowing crate, nursery, grower pigs, and finishing pigs. Sera were evaluated for the presence of antibodies to porcine circovirus type-2 (PCV2) via immunoperoxidase monolayer assay. Serologic profiles for PCV2 were different between SS and MS farms. Seroconversion following the decline in maternal antibodies occurred at a later stage on SS farms (grower pigs) than MS farms (nursery pigs). MS farms tended to have lower antibody titers than SS farms in the categories of sow, piglet, and nursery, while higher antibody titers were found in grower pigs. Characterization of serologic profiles for different farms may provide important information for the adoption of vaccination programs.