Phylogenetic analysis of the partial sequences of the env and tax BLV genes reveals the presence of genotypes 1 and 3 in dairy herds of Antioquia, Colombia.

Bovine leukemia virus (BLV) is a retrovirus that primarily infects dairy cows. Although few studies have also used the tax gene, phylogenetic studies of BLV use mostly the env gene. The aim of this work was to establish the circulating genotypes of BLV in specialized dairy cattle from Antioquia, Colombia. Twenty blood samples from Holstein Friesian cows were collected, and their DNA was isolated. A PCR was performed for a partial region of the env and tax genes. A phylogenetic analysis was carried out using the maximum likelihood and Bayesian methods for both genes. Nineteen sequences were identified as genotype 1 by env and tax genes. Only one sequence was clustered with genotype 3 and had the highest proportion of different nucleotide sites compared to other strains. Four amino acid substitutions in the 134 amino acid residue fragment of the Env protein were identified in the Colombian sequences, and three new amino acid substitutions were reported in the 296 amino acid residue fragment of the Tax protein. R43K (Z finger), A185T (Activation domain), and L105F changes were identified in the genotype 3 sample. This genotype has been reported in the United States, Japan, Korea, and Mexico, but so far, not in Colombia. The country has a high rate of imported live animals, semen, and embryos, especially from the United States. Although it is necessary to evaluate samples from other regions of the country, the current results indicate the presence of two BLV genotypes in specialized dairy herds.

Bovine leukosis virus, bovine viral diarrhea, and bovine neosporosis seroprevalence in specialized dairy herds in Antioquia-Colombia.

Enzootic bovine leukosis (EBL) is a chronic infectious disease caused by the bovine leukosis virus (BLV), a Deltaretrovirus. Bovine viral diarrhea (BVD) is an infectious disease caused by a pestivirus. Bovine neosporosis is caused by the obligate intracellular parasite Neospora caninum (Nc). These pathogens can have horizontal (postnatal) or vertical (transplacental) transmissions and affect the productive and reproductive performance of infected bovines. This work aimed to detect BLV, BVD, and Nc seroprevalence in specialized dairy cattle from the north, east, and Aburrá Valley regions of the Department of Antioquia, the highest in milk production regions in Antioquia. A total of 599 blood samples, obtained from 53 specialized dairy cattle herds, were evaluated by the ELISA test. The results revealed a seroprevalence of 41.13% for BLV (242/599), 28.48% (163/599) for Nc, and 22.7% (132/599) for BVD. Regarding the regional seroprevalence evaluation, BLV was found in 47.02% of the samples from the east, 36.87% from the north, and 46.02% from the Aburrá Valley. Nc was found in 31.03% of the samples from the east, 24.26% from the north, and 36.63% from Aburrá Valley. BVD was found in 21.62% of the samples from the east, 25.03% from the north region, and 10.39% of the samples from the Aburrá Valley. It is highlighted by these results that the north region, with the highest milk production in Antioquia, had the lowest BLV and Nc seroprevalences but the highest seroprevalence of BVD. BLV has increased in Antioquia in recent years, and as an immunosuppressive infection, opportunities for other pathogens are created by it. A significant statistical difference was found in the average prevalence of the pathogens according to the municipality, cattle breed, and region of origin of the sample. The seroprevalence of these pathogens in specialized dairy herds in Antioquia can be classified as medium-low. However, it is recommended that biosecurity practices should be maximized to avoid the spread of these pathogens due to the variability detected in the region, municipality, breed group, and herd age. The rapid and efficient diagnosis of these three pathogens through reliable methodologies will allow for the control of dissemination in dairy herds.

Bovine Viral Diarrhea Virus within and herd prevalence on pasture-based dairy systems, in southern Chile dairy farms.

Bovine Viral Diarrhea (BVD) is a ubiquitous endemic disease in most bovine populations that causes a negative economic impact on cattle production systems. However, true herd and individual prevalence in Chile have not been estimated based on statistical and epidemiological considerations and uncertainty regarding the infection's extension at animal and herd levels. In addition, the risk factors that can influence how the infection has spread among the cattle premises have not been assessed yet. Therefore, the study aimed to estimate true herd and animal prevalence of active BVDV infection in pasture-based dairy herds and to evaluate risk factors potentially associated with the status of herds and the within-herd prevalence, using a Bayesian approach. A cross-sectional study was performed over a random stratified (proportional to herd size) sample of one-hundred and fifty dairy herds selected in Chile's two leading dairy regions (Region de Los Ríos and Region de Los Lagos). We obtained 12.311 blood samples from lactating cows, but 4.998 randomly selected samples were processed due to budget constraints. For estimating BVDV Herd Prevalence (HP), a herd was considered infected if at least one positive animal to Ag-ELISA was found. In addition, a survey was completed on each farm, aiming to collect information to assess the influence of some variables over the state of the herds; both estimations were obtained using a Bayesian approach. True herd prevalence and true individual prevalence of BVDV active infection were estimated at 77 % and 3.5 % respectively, no significant differences were found between characteristics like herd size, location, vaccination, etc. Open herds and herds that mix herd categories are more likely to have higher BVDV prevalence.

Pathogenic Leptospira spp. Seroprevalence and Herd-Level Risk Factors Associated with Chilean Dairy Cattle.

Leptospirosis is a ubiquitous distributed zoonotic infectious disease present in wild and domestic animals. This study aimed to estimate within-herd and herd-level seroprevalence against pathogenic Leptospira spp. in dairy cows from southern Chile and identify risk factors associated with the herd-level status. We used a multi-stage strategy combined with a stratified sample strategy for randomly sampling 147 herds and 4876 lactating cows. We considered as infected a herd with at least one positive reactor to MAT. In addition, an epidemiological survey was applied to the herd's owners and a logistic regression (LR) model was constructed to analyze it. The overall within-herd prevalence was 5.9% (95% CI 4.9-6.8), the overall herd-level prevalence was 42.2% (95% CI 9.2-47.9), and there was variation in both between different herd sizes. L. borgpetersenii serovars Hardjo and Tarassovi and L. interrogans serovar Pomona were the more frequent serovars in non-vaccinated herds. A factor that decreases the risk of a farm being infected was Leptospira vaccine usage (OR = 0.04; 95% CI = 0.02-0.11), and variables that increase risk were using bulls for mating (OR = 3.43; 95% CI = 1.1-10.1) and continuous calving distribution (OR = 3.4; 95% CI = 1.3-8.8). The study's results will contribute to unravelling the infection burden in the main dairy area of the country and designing control strategies.

Conocimientos, actitudes, prácticas y percepción de riesgo de los trabajadores de hatos lecheros de la Colonia 07 Montes frente a las zoonosis específicas / Knowledge, attitudes, practices and perception of risk of dairy herd workers in Colonia 07 Montes regarding specific zoonoses

Los trabajadores de hatos lecheros están en constante riesgo de contraer enfermedades zoonóticas como la brucelosis, tuberculosis, leptospirosis y carbunco bacteridiano, por la exposición a agentes biológicos y el contacto directo con animales durante el desarrollo de sus labores. Se describe el nivel de conocimientos, actitudes, prácticas, percepción de riesgo y las características sociodemográficas de los trabajadores de hatos lecheros de la colonia 07 Montes del distrito de Curuguaty, frente a las zoonosis, en el último trimestre del 2019. Fue un estudio cuantitativo, observacional, descriptivo, de corte transversal en el cual se utilizó un cuestionario con 33 preguntas aplicado a 121 trabajadores, con el que se recogieron variables demográficas, conocimientos, actitudes, prácticas y percepción de riesgo. Los datos se analizaron a través del programa estadístico SPSS. Para el análisis univariado, se empleó la estadística descriptiva para representar los datos expresados en frecuencias, porcentajes y tablas. El 52,9 % de los trabajadores tenía conocimiento sobre la brucelosis, tuberculosis y leptospirosis, el 74,4 % tenía actitudes positivas, el 66,9% implementaba prácticas positivas y el 52,9% percibía el riesgo. Menos del 75% de los trabajadores encuestados tenían conocimientos, actitudes, prácticas y percepciones de riesgo óptimos, lo que resulta preocupante considerando la exposición constante de los mismos a las enfermedades zoonóticas, es por ello que se deberían implementar estrategias educativas de carácter multisectorial concernientes a estas patologías y sus medidas preventivas a modo de mejorar esta situación

Dairy herd workers are at constant risk of contracting zoonotic diseases such as brucellosis, tuberculosis, leptospirosis and anthrax, due to exposure to biological agents and direct contact with animals during the performance of their work. The level of knowledge, attitudes, practices, risk perception and sociodemographic characteristics of dairy herd workers in the 07 Montes colony of the Curuguaty district against zoonosis was described in the last trimester of 2019. A quantitative, observational study, descriptive, cross-sectional, in which a questionnaire with 33 questions applied to 121 workers was used, with which demographic variables, knowledge, attitudes, practices and risk perception were collected. The data were analyzed through the SPSS statistical program. For the univariate analysis, descriptive statistics were used to represent the data expressed in frequencies, percentages and tables. It was observed that 52.9% of the workers had knowledge about zoonotic diseases, 74.4% had positive attitudes, 66.9% implemented positive practices and 52.9% perceived the risk. Less than 75% of the workers surveyed had optimal knowledge, attitudes, practices and perceptions of risk, which is worrying considering their constant exposure to zoonotic diseases, that is why multisectoral educational strategies should be implemented concerning these pathologies and their preventive measures to improve this situation

Risk factors for high bulk milk somatic cell counts in dairy herds from Campos das Vertentes region, Minas Gerais State, Brazil: a case-control study / Fatores de risco para contagens elevadas de células somáticas no leite de tanque em rebanhos de bovinos da região de Campos das Vertentes, Minas Gerais, Brasil: um estudo de caso-controle

High bulk milk somatic cell counts (BMSCC) are indicative of failures related to the control of mastitis in the herd, which compromises the quality of the milk and generates great losses for the producers and for the industry. A case-control study was carried out in dairy herds in the Campos das Vertentes region, Minas Gerais State, Brazil, in order to contribute to the knowledge of the risk factors involved with elevated BMSCC. The study involved 46 dairy herds, of which 30 were considered cases (BMSCC ≥700,000 cells/mL of milk) and 16 control farms (BMSCC ≤200,000 cells/mL of milk). Sixteen qualitative variables and four quantitative variables were analyzed. The results showed that the risk factors for BMSCC ≥700,000 cells/mL were the presence of Staphylococcus aureus and Streptococcus agalactiae pathogens in bulk milk, non-use of pre and post-dipping, non-use of disposable paper towel for drying of mammary glands, non-monitoring of mastitis in the herd by means of California Mastitis Test (CMT) or individual somatic cell counts (SCC), non-implementation of the milking line and therapy of dry cows and failures in hygiene of teats and udders before milking. Moderate correlations were also observed between the elevation of BMSCC and counts of S. aureus and BMSCC and counts S. agalactiae in bulk milk, and a moderate correlation between S. aureus and S. agalactiae counts in bulk milk. Failures with regard to the maintenance and use of milking equipment, including manual pressure application in milking assemblies, unregulated milking vacuum pressure, and vacuum loss during milking, and maintenance failures of the milking machine and bulk milk tank were also pointed out as important risk factors of BMSCC elevation. The results of this study provided subsidies for the elaboration of more effective programs for mastitis control and improvement of raw milk quality, reducing the losses caused by the disease to producers and industry.(AU)

Altas contagens de células somáticas no leite do tanque (CCSt) são indicativas de falhas relacionadas com o controle da mastite no rebanho, o que compromete a qualidade do leite e gera grandes perdas para os produtores e para a indústria. Visando identificar os fatores de risco envolvidos com a CCSt elevada, foi realizado um estudo de caso-controle em rebanhos bovinos leiteiros da região de Campos das Vertentes, em Minas Gerais. O estudo envolveu 46 propriedades, das quais 30 foram consideradas casos (CCSt ≥700.000 cels/mL de leite) e 16 propriedades controles (CCSt ≤200.000 cels/mL de leite). Foram analisadas 16 variáveis qualitativas e quatro variáveis quantitativas. Os resultados demonstraram que os fatores de risco para valores de CCSt ≥700.000 cels/mL de leite foram a presença dos patógenos Staphylococcus aureus e Streptococcus agalactiae, não utilização do pré e de pós-dipping, não utilização de papel toalha descartável para a secagem dos tetos, não monitoramento da mastite por meio do California Mastitis Test (CMT) ou CCS individual, não implementação da linha de ordenha e da terapia de vacas secas e falhas na higiene de tetos e de úbere antes da ordenha. Também se observaram correlações moderadas entre a CCSt e as contagens de S. aureus e entre CCSt e as contagens de S. agalactiae, e correlação moderada entre as contagens de S. aureus e de S. agalactiae no leite do tanque. Falhas com relação à manutenção e utilização dos equipamentos de ordenha, aplicação de pressão manual nos conjuntos da ordenha, pressão de vácuo da ordenha desregulada, perda de vácuo durante a ordenha e falhas de manutenção da ordenhadeira e do tanque de expansão foram também apontadas como fatores de risco para elevação da CCSt. Os resultados deste estudo possibilitaram identificar fatores de risco importantes para contagens elevadas de CCSt que poderão fornecer subsídios para a elaboração de programas de controle mais efetivos para a mastite e para a melhoria da qualidade do leite, mitigando o impacto que a doença causa para os produtores e para a indústria.(AU)

Risk factors for high bulk milk somatic cell counts in dairy herds from Campos das Vertentes region, Minas Gerais State, Brazil: a case-control study / Fatores de risco para contagens elevadas de células somáticas no leite de tanque em rebanhos de bovinos da região de Campos das Vertentes, Minas Gerais, Brasil: um estudo de caso-controle

High bulk milk somatic cell counts (BMSCC) are indicative of failures related to the control of mastitis in the herd, which compromises the quality of the milk and generates great losses for the producers and for the industry. A case-control study was carried out in dairy herds in the Campos das Vertentes region, Minas Gerais State, Brazil, in order to contribute to the knowledge of the risk factors involved with elevated BMSCC. The study involved 46 dairy herds, of which 30 were considered cases (BMSCC ≥700,000 cells/mL of milk) and 16 control farms (BMSCC ≤200,000 cells/mL of milk). Sixteen qualitative variables and four quantitative variables were analyzed. The results showed that the risk factors for BMSCC ≥700,000 cells/mL were the presence of Staphylococcus aureus and Streptococcus agalactiae pathogens in bulk milk, non-use of pre and post-dipping, non-use of disposable paper towel for drying of mammary glands, non-monitoring of mastitis in the herd by means of California Mastitis Test (CMT) or individual somatic cell counts (SCC), non-implementation of the milking line and therapy of dry cows and failures in hygiene of teats and udders before milking. Moderate correlations were also observed between the elevation of BMSCC and counts of S. aureus and BMSCC and counts S. agalactiae in bulk milk, and a moderate correlation between S. aureus and S. agalactiae counts in bulk milk. Failures with regard to the maintenance and use of milking equipment, including manual pressure application in milking assemblies, unregulated milking vacuum pressure, and vacuum loss during milking, and maintenance failures of the milking machine and bulk milk tank were also pointed out as important risk factors of BMSCC elevation. The results of this study provided subsidies for the elaboration of more effective programs for mastitis control and improvement of raw milk quality, reducing the losses caused by the disease to producers and industry.(AU)

Altas contagens de células somáticas no leite do tanque (CCSt) são indicativas de falhas relacionadas com o controle da mastite no rebanho, o que compromete a qualidade do leite e gera grandes perdas para os produtores e para a indústria. Visando identificar os fatores de risco envolvidos com a CCSt elevada, foi realizado um estudo de caso-controle em rebanhos bovinos leiteiros da região de Campos das Vertentes, em Minas Gerais. O estudo envolveu 46 propriedades, das quais 30 foram consideradas casos (CCSt ≥700.000 cels/mL de leite) e 16 propriedades controles (CCSt ≤200.000 cels/mL de leite). Foram analisadas 16 variáveis qualitativas e quatro variáveis quantitativas. Os resultados demonstraram que os fatores de risco para valores de CCSt ≥700.000 cels/mL de leite foram a presença dos patógenos Staphylococcus aureus e Streptococcus agalactiae, não utilização do pré e de pós-dipping, não utilização de papel toalha descartável para a secagem dos tetos, não monitoramento da mastite por meio do California Mastitis Test (CMT) ou CCS individual, não implementação da linha de ordenha e da terapia de vacas secas e falhas na higiene de tetos e de úbere antes da ordenha. Também se observaram correlações moderadas entre a CCSt e as contagens de S. aureus e entre CCSt e as contagens de S. agalactiae, e correlação moderada entre as contagens de S. aureus e de S. agalactiae no leite do tanque. Falhas com relação à manutenção e utilização dos equipamentos de ordenha, aplicação de pressão manual nos conjuntos da ordenha, pressão de vácuo da ordenha desregulada, perda de vácuo durante a ordenha e falhas de manutenção da ordenhadeira e do tanque de expansão foram também apontadas como fatores de risco para elevação da CCSt. Os resultados deste estudo possibilitaram identificar fatores de risco importantes para contagens elevadas de CCSt que poderão fornecer subsídios para a elaboração de programas de controle mais efetivos para a mastite e para a melhoria da qualidade do leite, mitigando o impacto que a doença causa para os produtores e para a indústria.(AU)

Staphylococcus aureus and Streptococcus agalactiae: prevalence, resistance to antimicrobials, and their relationship with the milk quality of dairy cattle herds in Minas Gerais state, Brazil / Staphylococcus aureus e Streptococcus agalactiae: prevalência, resistência aos antimicrobianos e suas relações com a qualidade do leite em rebanhos leiteiros de Minas Gerais, Brasil

Bovine mastitis is the most frequent disease worldwide in dairy herds, causing high economic losses to producers and industry, as well as having implications for public health due to the zoonotic potential of some agents involved in its etiology and the increased risk of antimicrobial residues in milk and its derivatives. Considering the multifactorial aspect of this disease, knowledge of the agents involved in its etiology and their antimicrobial susceptibility profiles is very important. This study was conducted with 306 dairy herds from the Campo das Vertentes region, located in the south of Minas Gerais state, whose owners were milk suppliers to a dairy in the same region. The study involved approximately 34,000 dairy cows and covered an area of approximately 12,564 km2. In these herds, prevalence rates of Staphylococcus aureus and Streptococcus agalactiae and their relationship with bulk milk somatic cell counts (BMSCC), total bacterial counts (TBC), and daily production were evaluated. In addition, analyses of resistance of these pathogens to the antimicrobials most commonly used in the treatment of mastitis in dairy herds were performed. Microbiological analyses of milk samples from collect from bulk milk tanks were performed aiming to evaluate the prevalence of S. aureus and S. agalactiae. For these proposes, the modified Baird-Parker Agar medium was used for detection of S. aureus and the modified Edwards Agar medium, enriched with 5% defibrinated sheep blood, was used for detection of S. agalactiae. The disc diffusion technique was applied to evaluate antimicrobial resistance. Results show high prevalence rates of S. aureus (70.3%) and S. agalactiae (67.0%) in the dairy farms studied, with 47.71% of the herds showing both pathogens. Associations between BMSCC and the presence of pathogens S. aureus and S. agalactiae and between TBC and the presence of S. agalactiae were observed, demonstrating the influence of these pathogens in milk quality. No variation was observed in the distribution of S. aureus and S. agalactiae in the different strata of daily production. High levels of resistance and multi-resistance were observed among the pathogens S. aureus and S. agalactiae. The results indicate the need for more effective control measures for mastitis caused by S. aureus and S. agalactiae in the dairy herds of the region studied and more judicious use of antimicrobials in order to reduce the problem of resistance to them.(AU)

A mastite bovina é a doença de maior frequência em rebanhos leiteiros em nível mundial, acarretando grandes prejuízos econômicos aos produtores e à indústria. Além disso, esta enfermidade tem implicações na saúde pública, devido ao potencial zoonótico de alguns agentes envolvidos em sua etiologia e por aumentar os riscos de resíduos de antimicrobianos no leite e derivados. Considerando o aspecto multifatorial da mastite bovina, o conhecimento dos agentes envolvidos em sua etiologia e os perfis de suscetibilidade aos antibióticos é de suma importância. O estudo envolveu 306 fazendas de leite da região de Campo das Vertentes, localizada no sul de Minas Gerais, cujos proprietários eram fornecedores de leite para um laticínio da região, totalizando aproximadamente 34.000 animais e abrangendo uma área aproximada 12.564 km2. Nestes rebanhos, avaliaram-se a prevalência de Staphylococcus aureus e Streptococcus agalactiae e a relação destes agentes com os índices de contagem de células somáticas do leite do tanque de expansão (CCSt), contagem bacteriana total (CBT) e produção diária. Analisou-se também a resistência destes patógenos aos antimicrobianos mais comumente utilizados no tratamento da mastite em rebanhos leiteiros. Análises microbiológicas de amostras de leite dos tanques de expansão foram realizadas para se determinar as prevalências dos patógenos S. aureus e S. agalactiae. Para a detecção de S. aureus, utilizou-se o meio seletivo Ágar Baird-Parker modificado e para a detecção de S. agalactiae, o meio seletivo Ágar Edwards modificado, enriquecido com 5% de sangue ovino desfibrinado. Foi utilizada a técnica de difusão em discos para a avaliação de resistência aos antimicrobianos. Os resultados apontaram altas prevalências de S. aureus (70,3%) e de S. agalactiae (67,0%), com 47,71% dos rebanhos examinados apresentando ambos os agentes. Verificaram-se associações entre a CCSt e a presença dos patógenos S. aureus e S. agalactiae, e também entre a CBT e a presença de S. agalactiae, demonstrando a interferência negativa destes patógenos nestes quesitos de qualidade. Não se observaram variações nas distribuições dos patógenos S. aureus e nem S. agalactiae em função da produção diária das propriedades estudadas. Níveis elevados de resistência e de multirresistência foram observados para ambos os agentes. Os resultados apontam a necessidade de medidas mais efetivas de controle para S. aureus e S. agalactiae nos rebanhos da região estudada e do uso mais criterioso dos antimicrobianos, visando minimizar o problema da resistência aos mesmos.(AU)

Staphylococcus aureus and Streptococcus agalactiae: prevalence, resistance to antimicrobials, and their relationship with the milk quality of dairy cattle herds in Minas Gerais state, Brazil / Staphylococcus aureus e Streptococcus agalactiae: prevalência, resistência aos antimicrobianos e suas relações com a qualidade do leite em rebanhos leiteiros de Minas Gerais, Brasil

Bovine mastitis is the most frequent disease worldwide in dairy herds, causing high economic losses to producers and industry, as well as having implications for public health due to the zoonotic potential of some agents involved in its etiology and the increased risk of antimicrobial residues in milk and its derivatives. Considering the multifactorial aspect of this disease, knowledge of the agents involved in its etiology and their antimicrobial susceptibility profiles is very important. This study was conducted with 306 dairy herds from the Campo das Vertentes region, located in the south of Minas Gerais state, whose owners were milk suppliers to a dairy in the same region. The study involved approximately 34,000 dairy cows and covered an area of approximately 12,564 km2. In these herds, prevalence rates of Staphylococcus aureus and Streptococcus agalactiae and their relationship with bulk milk somatic cell counts (BMSCC), total bacterial counts (TBC), and daily production were evaluated. In addition, analyses of resistance of these pathogens to the antimicrobials most commonly used in the treatment of mastitis in dairy herds were performed. Microbiological analyses of milk samples from collect from bulk milk tanks were performed aiming to evaluate the prevalence of S. aureus and S. agalactiae. For these proposes, the modified Baird-Parker Agar medium was used for detection of S. aureus and the modified Edwards Agar medium, enriched with 5% defibrinated sheep blood, was used for detection of S. agalactiae. The disc diffusion technique was applied to evaluate antimicrobial resistance. Results show high prevalence rates of S. aureus (70.3%) and S. agalactiae (67.0%) in the dairy farms studied, with 47.71% of the herds showing both pathogens. Associations between BMSCC and the presence of pathogens S. aureus and S. agalactiae and between TBC and the presence of S. agalactiae were observed, demonstrating the influence of these pathogens in milk quality. No variation was observed in the distribution of S. aureus and S. agalactiae in the different strata of daily production. High levels of resistance and multi-resistance were observed among the pathogens S. aureus and S. agalactiae. The results indicate the need for more effective control measures for mastitis caused by S. aureus and S. agalactiae in the dairy herds of the region studied and more judicious use of antimicrobials in order to reduce the problem of resistance to them.(AU)

A mastite bovina é a doença de maior frequência em rebanhos leiteiros em nível mundial, acarretando grandes prejuízos econômicos aos produtores e à indústria. Além disso, esta enfermidade tem implicações na saúde pública, devido ao potencial zoonótico de alguns agentes envolvidos em sua etiologia e por aumentar os riscos de resíduos de antimicrobianos no leite e derivados. Considerando o aspecto multifatorial da mastite bovina, o conhecimento dos agentes envolvidos em sua etiologia e os perfis de suscetibilidade aos antibióticos é de suma importância. O estudo envolveu 306 fazendas de leite da região de Campo das Vertentes, localizada no sul de Minas Gerais, cujos proprietários eram fornecedores de leite para um laticínio da região, totalizando aproximadamente 34.000 animais e abrangendo uma área aproximada 12.564 km2. Nestes rebanhos, avaliaram-se a prevalência de Staphylococcus aureus e Streptococcus agalactiae e a relação destes agentes com os índices de contagem de células somáticas do leite do tanque de expansão (CCSt), contagem bacteriana total (CBT) e produção diária. Analisou-se também a resistência destes patógenos aos antimicrobianos mais comumente utilizados no tratamento da mastite em rebanhos leiteiros. Análises microbiológicas de amostras de leite dos tanques de expansão foram realizadas para se determinar as prevalências dos patógenos S. aureus e S. agalactiae. Para a detecção de S. aureus, utilizou-se o meio seletivo Ágar Baird-Parker modificado e para a detecção de S. agalactiae, o meio seletivo Ágar Edwards modificado, enriquecido com 5% de sangue ovino desfibrinado. Foi utilizada a técnica de difusão em discos para a avaliação de resistência aos antimicrobianos. Os resultados apontaram altas prevalências de S. aureus (70,3%) e de S. agalactiae (67,0%), com 47,71% dos rebanhos examinados apresentando ambos os agentes. Verificaram-se associações entre a CCSt e a presença dos patógenos S. aureus e S. agalactiae, e também entre a CBT e a presença de S. agalactiae, demonstrando a interferência negativa destes patógenos nestes quesitos de qualidade. Não se observaram variações nas distribuições dos patógenos S. aureus e nem S. agalactiae em função da produção diária das propriedades estudadas. Níveis elevados de resistência e de multirresistência foram observados para ambos os agentes. Os resultados apontam a necessidade de medidas mais efetivas de controle para S. aureus e S. agalactiae nos rebanhos da região estudada e do uso mais criterioso dos antimicrobianos, visando minimizar o problema da resistência aos mesmos.(AU)

Risk factors for high bulk milk somatic cell counts in dairy herds from Campos das Vertentes region, Minas Gerais State, Brazil: a case-control study

ABSTRACT: High bulk milk somatic cell counts (BMSCC) are indicative of failures related to the control of mastitis in the herd, which compromises the quality of the milk and generates great losses for the producers and for the industry. A case-control study was carried out in dairy herds in the Campos das Vertentes region, Minas Gerais State, Brazil, in order to contribute to the knowledge of the risk factors involved with elevated BMSCC. The study involved 46 dairy herds, of which 30 were considered cases (BMSCC 700,000 cells/mL of milk) and 16 control farms (BMSCC 200,000 cells/mL of milk). Sixteen qualitative variables and four quantitative variables were analyzed. The results showed that the risk factors for BMSCC 700,000 cells/mL were the presence of Staphylococcus aureus and Streptococcus agalactiae pathogens in bulk milk, non-use of pre and post-dipping, non-use of disposable paper towel for drying of mammary glands, non-monitoring of mastitis in the herd by means of California Mastitis Test (CMT) or individual somatic cell counts (SCC), non-implementation of the milking line and therapy of dry cows and failures in hygiene of teats and udders before milking. Moderate correlations were also observed between the elevation of BMSCC and counts of S. aureus and BMSCC and counts S. agalactiae in bulk milk, and a moderate correlation between S. aureus and S. agalactiae counts in bulk milk. Failures with regard to the maintenance and use of milking equipment, including manual pressure application in milking assemblies, unregulated milking vacuum pressure, and vacuum loss during milking, and maintenance failures of the milking machine and bulk milk tank were also pointed out as important risk factors of BMSCC elevation. The results of this study provided subsidies for the elaboration of more effective programs for mastitis control and improvement of raw milk quality, reducing the losses caused by the disease to producers and industry.

RESUMO: Altas contagens de células somáticas no leite do tanque (CCSt) são indicativas de falhas relacionadas com o controle da mastite no rebanho, o que compromete a qualidade do leite e gera grandes perdas para os produtores e para a indústria. Visando identificar os fatores de risco envolvidos com a CCSt elevada, foi realizado um estudo de caso-controle em rebanhos bovinos leiteiros da região de Campos das Vertentes, em Minas Gerais. O estudo envolveu 46 propriedades, das quais 30 foram consideradas casos (CCSt 700.000 cels/mL de leite) e 16 propriedades controles (CCSt 200.000 cels/mL de leite). Foram analisadas 16 variáveis qualitativas e quatro variáveis quantitativas. Os resultados demonstraram que os fatores de risco para valores de CCSt 700.000 cels/mL de leite foram a presença dos patógenos Staphylococcus aureus e Streptococcus agalactiae, não utilização do pré e de pós-dipping, não utilização de papel toalha descartável para a secagem dos tetos, não monitoramento da mastite por meio do California Mastitis Test (CMT) ou CCS individual, não implementação da linha de ordenha e da terapia de vacas secas e falhas na higiene de tetos e de úbere antes da ordenha. Também se observaram correlações moderadas entre a CCSt e as contagens de S. aureus e entre CCSt e as contagens de S. agalactiae, e correlação moderada entre as contagens de S. aureus e de S. agalactiae no leite do tanque. Falhas com relação à manutenção e utilização dos equipamentos de ordenha, aplicação de pressão manual nos conjuntos da ordenha, pressão de vácuo da ordenha desregulada, perda de vácuo durante a ordenha e falhas de manutenção da ordenhadeira e do tanque de expansão foram também apontadas como fatores de risco para elevação da CCSt. Os resultados deste estudo possibilitaram identificar fatores de risco importantes para contagens elevadas de CCSt que poderão fornecer subsídios para a elaboração de programas de controle mais efetivos para a mastite e para a melhoria da qualidade do leite, mitigando o impacto que a doença causa para os produtores e para a indústria.

Identification of subclinical mastitis caused by Mycoplasma spp. from screenings of bulk tanks / Identificação de mastite subclínica causada por Mycoplasma spp. de triagem de tanques de expansão

Mastitis caused by Mycoplasma spp., regardless of species, are considered highly contagious pathogens and, usually was not responsive to antimicrobial therapy. Five dairy herds, comprising 489 animals and 1,956 mammary glands, were used in this study. Milk samples were obtained from bulk tanks and subjected to polymerase chain reaction (PCR) for the identification of Mollicutes, Mycoplasma spp., and Mycoplasma bovis. Moreover, individual samples from cases of clinical and subclinical mastitis in quarters of the dairy herds' animals that yielded a positive PCR upon bulk tank analysis were subjected to molecular analysis. Only one bulk tank was positive for class Mollicutes by PCR. All positive samples classified as mastitis teats had their DNA extracted and tested by PCR for both class Mollicutes and M. bovis. Of these, two (2.08%) were positive for Mycoplasma genus, although none was positive for M. bovis. This result suggests that the PCR of bulk tanks is a viable tool in monitoring and preventing mastitis infections caused by Mycoplasma spp.(AU)

Mastites bovinas causadas por Mycoplasma spp., independentemente da espécie causadora, são consideradas de alta contagiosidade e geralmente não responsivas à terapia antimicrobiana. Cinco propriedades leiteiras foram utilizadas neste estudo, totalizando 489 animais e 1956 quartos mamários. As amostras de leite foram obtidas de tanques de expansão e submetidas à reação em cadeia da polimerase (PCR) para pesquisa de Mollicutes, Mycoplasma spp. e Mycoplasma bovis. Apenas um tanque de uma propriedade foi positivo na PCR para a classe Mollicutes. Amostras individuais de casos de mastite subclínica provenientes de propriedade com tanque positivo também foram submetidas à análise molecular; dessas, duas delas (2,08%) foram positivas para a classe Mollicutes e para o gênero Mycoplasma, entretanto nenhuma foi positiva para a espécie Mycoplasma bovis. Isso sugere que a PCR de tanques de expansão de propriedades leiteiras demonstra ser uma ferramenta viável no monitoramento e na prevenção de infecções por Mycoplasma spp.(AU)

Identification of subclinical mastitis caused by Mycoplasma spp. from screenings of bulk tanks / Identificação de mastite subclínica causada por Mycoplasma spp. de triagem de tanques de expansão

Mastitis caused by Mycoplasma spp., regardless of species, are considered highly contagious pathogens and, usually was not responsive to antimicrobial therapy. Five dairy herds, comprising 489 animals and 1,956 mammary glands, were used in this study. Milk samples were obtained from bulk tanks and subjected to polymerase chain reaction (PCR) for the identification of Mollicutes, Mycoplasma spp., and Mycoplasma bovis. Moreover, individual samples from cases of clinical and subclinical mastitis in quarters of the dairy herds' animals that yielded a positive PCR upon bulk tank analysis were subjected to molecular analysis. Only one bulk tank was positive for class Mollicutes by PCR. All positive samples classified as mastitis teats had their DNA extracted and tested by PCR for both class Mollicutes and M. bovis. Of these, two (2.08%) were positive for Mycoplasma genus, although none was positive for M. bovis. This result suggests that the PCR of bulk tanks is a viable tool in monitoring and preventing mastitis infections caused by Mycoplasma spp.(AU)

Mastites bovinas causadas por Mycoplasma spp., independentemente da espécie causadora, são consideradas de alta contagiosidade e geralmente não responsivas à terapia antimicrobiana. Cinco propriedades leiteiras foram utilizadas neste estudo, totalizando 489 animais e 1956 quartos mamários. As amostras de leite foram obtidas de tanques de expansão e submetidas à reação em cadeia da polimerase (PCR) para pesquisa de Mollicutes, Mycoplasma spp. e Mycoplasma bovis. Apenas um tanque de uma propriedade foi positivo na PCR para a classe Mollicutes. Amostras individuais de casos de mastite subclínica provenientes de propriedade com tanque positivo também foram submetidas à análise molecular; dessas, duas delas (2,08%) foram positivas para a classe Mollicutes e para o gênero Mycoplasma, entretanto nenhuma foi positiva para a espécie Mycoplasma bovis. Isso sugere que a PCR de tanques de expansão de propriedades leiteiras demonstra ser uma ferramenta viável no monitoramento e na prevenção de infecções por Mycoplasma spp.(AU)

Research of Klebsiella pneumoniae in dairy herds / Pesquisa de Klebsiella pneumoniae em rebanhos leiteiros

Klebsiella pneumoniae is a common environmental agent of clinical and subclinical mastitis affecting dairy herds, and may be present in the final product decreasing its quality. Mastitis caused by K. pneumoniae is even more severe due to its poor response to antibiotic therapy, rapid evolution to toxic shock and death of the animal. This paper aimed to study the prevalence of this pathogen among dairy herds in ten farms located in different municipalities of São Paulo State based on size and use of milking technology. All mammary glands of all lactating cows were screened using the California Mastitis Test (CMT) and a strip cup. A single aseptic milk sample (20mL) was collected from all CMT-positive quarters and bulk tanks, whereas swab samples were collected from feces, hind limbs of the animals, bedding and milking parlor. Identification of K. pneumoniae was performed using conventional microbiology culture, biochemical assay and Polimerase Chain Reaction. The primers were designed and tested at the Laboratory of Molecular Biology applied to Zoonoses (FMVZ, Unesp-Botucatu) targeting the 16S rRNA gene. This study included 1067 animals. Six cases of intramammary infection by K. pneumoniae were detected in six different cows in two farms. Moreover, K. pneumoniae was isolated in 77 swabs (34 from bedding in 9 farms, 7 from waiting rooms in 5 farms, 6 from milking parlors in 4 farms, 11 from rectums in six farms, and 19 from hindlimbs in 7 farms. Molecular analysis confirmed the agent was K. pneumoniae. At least one strain of the agent was identified in a certain site in all farms, showing the need of maintaining the hygiene in dairy farms...

Klebsiella pneumoniae é um agente ambiental comum de mastite clínica e subclínica que afetam vacas leiteiras e pode estar presente no produto final, reduzindo a sua qualidade. Mastite causada por K. pneumoniae é ainda mais grave devido à sua má resposta à antibioticoterapia, rápida evolução para choque tóxico e morte do animal. Este trabalho teve como objetivo estudar a prevalência deste patógeno entre os rebanhos leiteiros em dez fazendas localizadas em diferentes municípios do Estado de São Paulo com base no tamanho do rebanho e uso de tecnologia de ordenha. Todas as glândulas mamárias das vacas em lactação foram examinadas usando o California Mastitis Test (CMT) e caneca de fundo telado. Foram colhidas amostras de leite (20mL) de todos os quartos CMT- positivos e dos tanques de expansão, também foram colhidos swab de fezes, membros posteriores dos animais, cama dos animais e sala de ordenha. O isolamento e identificação de K. pneumoniae foi realizada através de cultura microbiológica convencional, ensaio bioquímico e Reação em Cadeia da Polimerase, utilizando primers desenhados e testados no Laboratório de Biologia Molecular aplicada à Zoonoses (FMVZ, Unesp-Botucatu) com base na região do gene de 16S rRNA. Este estudo incluiu 1067 animais. Foram detectados seis casos de infecção intramamária por K. pneumoniae em seis diferentes animais em duas fazendas. Ainda, K. pneumoniae foi isolada em 77 swabs (34 de camas em 9 propriedades, 7 de salas de pré-ordenha em 5 propriedades, 6 de salas de ordenha em 4 propriedades, 11 do reto de animais em 6 propriedades e 19 de membros posteriores em 7 propriedades. A análise molecular confirmou o agente K. pneumoniae. K. pneumoniae foi isolada pelo menos em uma localização em todas as propriedades leiteiras., salientando a necessidade de manter a higiene nas fazendas leiteiras a fim de controlar a mastite por esse patógeno...

Research of Klebsiella pneumoniae in dairy herds / Pesquisa de Klebsiella pneumoniae em rebanhos leiteiros

Klebsiella pneumoniae is a common environmental agent of clinical and subclinical mastitis affecting dairy herds, and may be present in the final product decreasing its quality. Mastitis caused by K. pneumoniae is even more severe due to its poor response to antibiotic therapy, rapid evolution to toxic shock and death of the animal. This paper aimed to study the prevalence of this pathogen among dairy herds in ten farms located in different municipalities of São Paulo State based on size and use of milking technology. All mammary glands of all lactating cows were screened using the California Mastitis Test (CMT) and a strip cup. A single aseptic milk sample (20mL) was collected from all CMT-positive quarters and bulk tanks, whereas swab samples were collected from feces, hind limbs of the animals, bedding and milking parlor. Identification of K. pneumoniae was performed using conventional microbiology culture, biochemical assay and Polimerase Chain Reaction. The primers were designed and tested at the Laboratory of Molecular Biology applied to Zoonoses (FMVZ, Unesp-Botucatu) targeting the 16S rRNA gene. This study included 1067 animals. Six cases of intramammary infection by K. pneumoniae were detected in six different cows in two farms. Moreover, K. pneumoniae was isolated in 77 swabs (34 from bedding in 9 farms, 7 from waiting rooms in 5 farms, 6 from milking parlors in 4 farms, 11 from rectums in six farms, and 19 from hindlimbs in 7 farms. Molecular analysis confirmed the agent was K. pneumoniae. At least one strain of the agent was identified in a certain site in all farms, showing the need of maintaining the hygiene in dairy farms.(AU)

Klebsiella pneumoniae é um agente ambiental comum de mastite clínica e subclínica que afetam vacas leiteiras e pode estar presente no produto final, reduzindo a sua qualidade. Mastite causada por K. pneumoniae é ainda mais grave devido à sua má resposta à antibioticoterapia, rápida evolução para choque tóxico e morte do animal. Este trabalho teve como objetivo estudar a prevalência deste patógeno entre os rebanhos leiteiros em dez fazendas localizadas em diferentes municípios do Estado de São Paulo com base no tamanho do rebanho e uso de tecnologia de ordenha. Todas as glândulas mamárias das vacas em lactação foram examinadas usando o California Mastitis Test (CMT) e caneca de fundo telado. Foram colhidas amostras de leite (20mL) de todos os quartos CMT- positivos e dos tanques de expansão, também foram colhidos swab de fezes, membros posteriores dos animais, cama dos animais e sala de ordenha. O isolamento e identificação de K. pneumoniae foi realizada através de cultura microbiológica convencional, ensaio bioquímico e Reação em Cadeia da Polimerase, utilizando primers desenhados e testados no Laboratório de Biologia Molecular aplicada à Zoonoses (FMVZ, Unesp-Botucatu) com base na região do gene de 16S rRNA. Este estudo incluiu 1067 animais. Foram detectados seis casos de infecção intramamária por K. pneumoniae em seis diferentes animais em duas fazendas. Ainda, K. pneumoniae foi isolada em 77 swabs (34 de camas em 9 propriedades, 7 de salas de pré-ordenha em 5 propriedades, 6 de salas de ordenha em 4 propriedades, 11 do reto de animais em 6 propriedades e 19 de membros posteriores em 7 propriedades. A análise molecular confirmou o agente K. pneumoniae. K. pneumoniae foi isolada pelo menos em uma localização em todas as propriedades leiteiras., salientando a necessidade de manter a higiene nas fazendas leiteiras a fim de controlar a mastite por esse patógeno.(AU)

Manipulação hormonal e fatores que influenciam na eficiência reprodutiva de vacas leiteiras

In dairy herds, since the 70s, it has been observed that with the increase in milk production has also been associated with increased number of services per conception. This decreased fertility of dairy cows is associated with several factors such as the greater metabolism of steroid hormones, consequently inadequate circulating hormones to promote optimal endocrine environment for follicle growth and conceptus development. Furthermore, the increase in milk production is associated with an increased incidence of diseases related to dairy herds, increased susceptibility to heat stress and higher incidence of anovulation. Accordingly, hormone treatments may be used in order to increase the fertility of dairy herds. Thus, this article discusses particular aspects of the reproductive physiology of dairy cows, as well as factors affecting the reproductive efficiency of dairy herds.(AU)

Em rebanhos leiteiros, desde a década de 70, tem se observado que o aumento gradativo da produção de leite vem acompanhado do aumento do número de serviços por concepção. Essa queda da fertilidade está associada a diversos fatores como maior velocidade da metabolização de hormônios esteroides e, consequentemente, concentrações hormonais inadequadas para promover um ambiente endócrino ideal para o crescimento folicular e uterino para o desenvolvimento do concepto. Além disso, o aumento de produção de leite está associado a maiores incidências de doenças e condição anovulatória, bem como à maior susceptibilidade das vacas ao estresse calórico. Com isso, tratamentos hormonais podem ser utilizados visando aumentar a fertilidade de rebanhos leiteiros. Desta forma, o presente artigo discorre sobre aspectos envolvendo à fisiologia reprodutiva e dos fatores que afetam a eficiência reprodutiva de vacas leiteiras.(AU)

Manipulação hormonal e fatores que influenciam na eficiência reprodutiva de vacas leiteiras

In dairy herds, since the 70s, it has been observed that with the increase in milk production has also been associated with increased number of services per conception. This decreased fertility of dairy cows is associated with several factors such as the greater metabolism of steroid hormones, consequently inadequate circulating hormones to promote optimal endocrine environment for follicle growth and conceptus development. Furthermore, the increase in milk production is associated with an increased incidence of diseases related to dairy herds, increased susceptibility to heat stress and higher incidence of anovulation. Accordingly, hormone treatments may be used in order to increase the fertility of dairy herds. Thus, this article discusses particular aspects of the reproductive physiology of dairy cows, as well as factors affecting the reproductive efficiency of dairy herds.

Em rebanhos leiteiros, desde a década de 70, tem se observado que o aumento gradativo da produção de leite vem acompanhado do aumento do número de serviços por concepção. Essa queda da fertilidade está associada a diversos fatores como maior velocidade da metabolização de hormônios esteroides e, consequentemente, concentrações hormonais inadequadas para promover um ambiente endócrino ideal para o crescimento folicular e uterino para o desenvolvimento do concepto. Além disso, o aumento de produção de leite está associado a maiores incidências de doenças e condição anovulatória, bem como à maior susceptibilidade das vacas ao estresse calórico. Com isso, tratamentos hormonais podem ser utilizados visando aumentar a fertilidade de rebanhos leiteiros. Desta forma, o presente artigo discorre sobre aspectos envolvendo à fisiologia reprodutiva e dos fatores que afetam a eficiência reprodutiva de vacas leiteiras.

ELISA indirecta para el diagnóstico de fasciolosis bovina en leche / Indirect ELISA for diagnosing bovine fasciolosis from milk samples / ELISA indireta para o diagnostico de fasciolíase bovina no leite

Resumen Se estandarizó una prueba de ELISA para la detección de anticuerpos anti-F. hepatica en leche de bovinos. Se emplearon 80 muestras, de las cuales 44 se usaron como control positivo y 36 como control negativo. Como control de reactividad cruzada se utilizaron muestras de bovinos que presentaron en las heces huevos de un paramphistomido. La sensibilidad y especificidad diagnóstica de la prueba fueron del 80% y del 72,2% respectivamente, con un intervalo de confianza del 95%. Los resultados obtenidos son comparables con los reportados en estudios realizados en otros países. Se propone la prueba estandarizada como herramienta diagnóstica alternativa y de tamizaje en estudios epidemiológicos de fasciolosis.

Abstract We standardized an ELISA test for the detection of anti-F. hepatica antibodies in bovine milk. A total of 80 samples were used, of which 44 were used as positive controls and 36 as negative controls. Milk samples from bovines presenting paramphistomidae eggs in feces were used as cross-reactivity controls. Sensitivity and specificity of the diagnostic test were 80 and 72,2%, respectively, with 95% confidence interval. These results are comparable with those reported in studies conducted in other countries. We propose this standardized test as an alternative diagnostic and screening tool in epidemiological studies of fasciolosis.

Resumo Estandardizou-se um teste de ELISA para a detecção de anticorpos anti Fasciola hepatica no leite de bovinos. Empregaram-se 80 amostras, das quais 44 usaram-se como controle positivo e 36 como controle negativo. Como controle da reatividade cruzada utilizaram-se amostras de bovinos que apresentaram ovos de um paramphistomido nas fezes. A sensibilidade e especificidade diagnosticam do teste foi de 80 e 72% respectivamente, com um intervalo de confiança de 95%. Os resultados obtidos são comparáveis com os reportados em estudos realizados em outros países. Propõe-se o teste estandardizado como ferramenta diagnostica alternativa e de tamisado em estudos epidemiológicos de fasciolíase.

California mastitis test in the diagnostic of subclinical mastitis / California mastitis test no diagnóstico da mastite subclínica

Milk production in Brazil is undoubtedly one of the most important Brazilian agroindustrial complex. Moves large sums of money, the dairy industry employs millions of the people, having potential to provide the domestic and foreign markets. Besides surpassing year by year the index production. The quality of milk is increasingly demanded by consumers and there are bonus programs for milk with low somatic cell counts, which reveal, indirectely, the udder sanity. Mastitis, the udder inflamation, is the main factor that substantially compromises the milk quality. Several methods can diagnose the incidence of subclinical mastitis in dairy herds. One these methods, the California Mastitis Test (CMT) has as advantages being practical, low cost and the results are immediately available. The CMT method consists of adding the anionic neutral detergent to a milk sample in order to disrupt milk somatic cell membranes and release nucleic material. The viscousity formed by this reaction allows estimating the number of somatic cells (immunity cells) presents in the milk. According to the degree of gelatinization obtained in this reaction, the interpretation of the scores varies from zero, no viscosity, to three crosses, highly viscous. This study was aimed to evaluate the CMT of eight dairy herds of different farms in Sao Paulo state, described by the letters A to H. The scores 1, 2 and 3 we

O artigo não apresenta resumo em português.

California mastitis test in the diagnostic of subclinical mastitis / California mastitis test no diagnóstico da mastite subclínica

Milk production in Brazil is undoubtedly one of the most important Brazilian agroindustrial complex. Moves large sums of money, the dairy industry employs millions of the people, having potential to provide the domestic and foreign markets. Besides surpassing year by year the index production. The quality of milk is increasingly demanded by consumers and there are bonus programs for milk with low somatic cell counts, which reveal, indirectely, the udder sanity. Mastitis, the udder inflamation, is the main factor that substantially compromises the milk quality. Several methods can diagnose the incidence of subclinical mastitis in dairy herds. One these methods, the California Mastitis Test (CMT) has as advantages being practical, low cost and the results are immediately available. The CMT method consists of adding the anionic neutral detergent to a milk sample in order to disrupt milk somatic cell membranes and release nucleic material. The viscousity formed by this reaction allows estimating the number of somatic cells (immunity cells) presents in the milk. According to the degree of gelatinization obtained in this reaction, the interpretation of the scores varies from zero, no viscosity, to three crosses, highly viscous. This study was aimed to evaluate the CMT of eight dairy herds of different farms in Sao Paulo state, described by the letters A to H. The scores 1, 2 and 3 we

O artigo não apresenta resumo em português.

Reação de imunofluorescência indireta para detecção de anticorpos anti-Neospora caninum em amostras coletivas de leite / Indirect fluorescent antibody test to detection of Neospora caninum antibodies in samples of bulk milk

O objetivo deste estudo foi determinar a presença de anticorpos anti-Neospora caninum em amostras coletivas de leite, através da reação de imunofluorescência indireta (RIFI). Para isso, foram coletadas amostras do leite dos tanques refrigerados de 36 rebanhos, das quais foram selecionadas 14 para coletas de amostras individuais de soro sanguíneo e de leite das vacas. Encontrou-se correlação em 12 dos 14 rebanhos selecionados para a amostragem individual dos animais, em comparação à detecção de anticorpos nas amostras coletivas de leite. Foi observada uma concordância de 76 por cento comparando-se o resultado das amostras coletivas com os resultados individuais de leite. Observaram-se baixos títulos de anticorpos (50) no soro sanguíneo dos animais soropositivos, cujos resultados da RIFI no leite coletivo e no sangue foram discordantes. Assim, a partir dos resultados deste estudo, pode-se concluir que a utilização de testes sorológicos para detecção de anticorpos anti-N. caninum em amostras coletivas de leite através da RIFI pode ser uma opção ao diagnóstico para a triagem de rebanhos positivos bem como para estudos epidemiológicos.

The aim of this study was to determine the presence of anti-N. caninum in the bulk milk samples by indirect immunofluorescence assay (IFAT). For this, it was collected samples of milk from refrigerated tanks from 36 herds, of which 14 were selected for sampling of individual blood serum and milk of cows. It was found concordance for 12 of the 14 herds selected for samples of individual animals, compared to the detection of antibodies in the bulk milk samples. Concordance was of 76 percent when comparing the results of the pooled sample with the results of individual milk. It was observed low antibody titers (50) in the serum of animals positive whose results in IFA of bulk milk and blood were discordant. Thus, with the results of this study, it can be concluded that the use of serological tests for detection of anti-N. caninum in the bulk milk samples from the IFAT could be an alternative diagnosis for the screening of positive herds as well as for epidemiological studies.