Meta-analysis of brucellosis vaccinology in natural hosts / Meta-análise da vacinologia de brucelose em hospedeiros naturais

Brucellosis is a relevant zoonotic disease for which the most important tool for control is vaccination of susceptible animals. Assessment of vaccine efficacy in natural hosts is based on prevention of abortion and Brucella infection in organs of immunized animals. A meta-analysis of experimental vaccination of Brucella spp. natural hosts was performed, including 45 PubMed and/or Scopus-indexed publications, representing 116 individual experiments. Difference of risk was calculated as an indicator of protection, and a temporal analysis (1980-2016) demonstrated that experimental vaccines tested on natural hosts provided levels of protection that were stable over the past decades. The meta-regression model developed in this study included different vaccine categories (attenuated, inactivated, mutant, subunit, and vectored) considering the difference of risk as the dependent variable. The subcutaneous route of vaccination provided better protection when compared to the intramuscular and oral routes of vaccination. Surprisingly, inactivated vaccines provided better protection than live naturally attenuated vaccine strains (spontaneous mutations) that were considered the reference, whereas subunit vaccines provided lower levels of protection. This is the first meta-analysis of Brucella vaccinology in the natural hosts. These results are useful for the development of new vaccination protocols for controlling animal brucellosis.(AU)

Brucelose é uma doença zoonótica relevante, para a qual a vacinação de animais susceptíveis é a ferramenta mais importante de controle. Avaliação da eficácia vacinal em hospedeiros naturais é baseada na prevenção de aborto e da colonização de órgãos pela Brucella spp. em animais imunizados. Foi realizada meta-análise de estudos de vacinação experimental de Brucella spp. em hospedeiros naturais, incluindo 45 publicações indexadas pela PubMed e/ou Scopus, representando 116 experimentos individuais. Diferença de risco foi calculada como indicador de proteção e uma análise temporal (1980-2016) demonstrou que vacinas experimentais testadas em hospedeiros naturais promoveram níveis de proteção que foram estáveis ao longo das últimas décadas. O modelo de meta-regressão desenvolvido neste estudo incluiu diferentes categorias de vacinas (atenuada, inativada, mutante, subunidade e vetorial) considerando a diferença de risco como variável dependente. A via de vacinação subcutânea promoveu melhor proteção quando comparada às vias intramuscular e oral. Surpreendentemente, vacinas inativadas promoveram melhor proteção que vacinas vivas atenuadas (com mutações espontâneas) que foram consideradas como referência, enquanto vacinas de subunidades promoveram menor proteção. Este é o primeiro estudo de meta-análise da vacinologia de Brucella em hospedeiros naturais. Estes resultados são úteis para o desenvolvimento de novos protocolos vacinais para controle de brucelose animal.(AU)

Diagnosis of canine brucellosis: comparison of various serologic tests and PCR.

Canine brucellosis is an infectious and contagious disease associated with reproductive losses in breeding kennels. As a zoonotic disease, it poses a risk to human health, especially for veterinarians and breeders who handle materials potentially contaminated with Brucella canis. However, canine brucellosis is a neglected and underestimated disease given the difficulties in establishing a definitive diagnosis. We evaluated the frequency of detection of B. canis in 5 breeding kennels by using various serologic methods and PCR. Circulation of B. canis in these kennels was confirmed by bacterial isolation. The frequency of positive serologic results varied from 6.3% by AGID to 16.5% by dot-ELISA. There was no positive serology for smooth Brucella. PCR testing was positive in 13.9% of samples. The only detection tests with reasonable agreement were PCR and 2ME-MAT. The diagnosis of canine brucellosis remains challenging. The use of a single laboratory method, or even the use of different laboratory methods, may not be sufficient to reach a definitive diagnosis.

Oral fluid for detection of exposure to Lawsonia intracellularis in naturally infected pigs.

To demonstrate the utility of oral fluid (OF) for indirect diagnostic detection of Lawsonia intracellularis (Li), 15 pig farms were studied. Serum and fecal samples were collected from 20 animals from five different age groups on each farm. OF samples were collected from animals in two pens of the same age groups. Serum and OF samples were analyzed in an immunoperoxidase in monolayer assay (IPMA) for the detection of anti-Li immunoglobulin G (IgG) and A (IgA). Compatible results were found between PCR and IgG in OF in four of the five ages evaluated. Simultaneous detection of IgG in serum and OF was mainly observed on farms showing clinical signs suggestive of porcine proliferative enteropathy (PPE). These findings demonstrate the potential usefulness of OF in detecting anti-Li antibodies as a diagnostic tool that can be used to monitor PPE in herds with clinical signs compatible with the disease.

Data on network of live cattle exports from Brazil.

This report describes the network of live cattle exports from Brazil using Microsoft Office Excel® files, Terraview®, Maporama®, Pajek® and Google Maps® softwares. The database contains estimates obtained from the Ministry of Agriculture, Livestock and Food Supply (MAPA) and underwent descriptive, spatial and flow network. The network of live cattle exports from Brazil was determined using data from 27,517 Animal Transit Certificates (ATC) and 579 Veterinary Certificate for International Trade. International departure points, municipalities and states of origin, destination countries, purpose of export and compliance with sanitary requirements for exports, cattle movement and the main transportation corridors were showed through flow network. The states that exported live cattle were Pará, Rio Grande do Sul, Tocantins, São Paulo, Minas Gerais and Maranhão. Vila do Conde Port, located in Barcarena municipality in the state of Pará, was the main international departure point of animals, which were intended mostly for immediate slaughter in the importing country. The internal cattle transportation corridors of the main counties and farms that provide animals for exports in 2009 were mapped.

Meta-Analysis and Advancement of Brucellosis Vaccinology.

BACKGROUND/OBJECTIVES: In spite of all the research effort for developing new vaccines against brucellosis, it remains unclear whether these new vaccine technologies will in fact become widely used. The goal of this study was to perform a meta-analysis to identify parameters that influence vaccine efficacy as well as a descriptive analysis on how the field of Brucella vaccinology is advancing concerning type of vaccine, improvement of protection on animal models over time, and factors that may affect protection in the mouse model. METHODS: A total of 117 publications that met the criteria were selected for inclusion in this study, with a total of 782 individual experiments analyzed. RESULTS: Attenuated (n = 221), inactivated (n = 66) and mutant (n = 102) vaccines provided median protection index above 2, whereas subunit (n = 287), DNA (n = 68), and vectored (n = 38) vaccines provided protection indexes lower than 2. When all categories of experimental vaccines are analyzed together, the trend line clearly demonstrates that there was no improvement of the protection indexes over the past 30 years, with a low negative and non significant linear coefficient. A meta-regression model was developed including all vaccine categories (attenuated, DNA, inactivated, mutant, subunit, and vectored) considering the protection index as a dependent variable and the other parameters (mouse strain, route of vaccination, number of vaccinations, use of adjuvant, challenge Brucella species) as independent variables. Some of these variables influenced the expected protection index of experimental vaccines against Brucella spp. in the mouse model. CONCLUSION: In spite of the large number of publication over the past 30 years, our results indicate that there is not clear trend to improve the protective potential of these experimental vaccines.

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.

Trends in animal rabies surveillance in the endemic state of Minas Gerais, Brazil.

Rabies is a viral zoonosis affecting mammal species and causes large economic losses. Included among the neglected diseases, it is still insufficiently addressed by governments and the international community, despite formal surveillance and control programs. This study used a dataset of 10,112 rabies diagnoses in animals provided by the Brazilian passive surveillance system from 2001 to 2012. The positivity rate of the tested samples was 26.4%, and a reduction in the total samples sent during the last six years was observed. The kernel density map indicated case concentration in the south region and a decrease in density of rabies cases in the second period studied (2007 to 2012). The directional trend of positive rabies diagnoses remained in the south region, as shown by the standard deviational ellipse. The spatial scan statistic identified three large clusters of positive diagnoses, one in the first period (2001-2006) and two in the second period (2007-2012), indicating an expansion of risk areas. The decrease in rabies cases from 2006 to 2012 does not necessarily reflect lower viral circulation or improvement in actions by epidemiological surveillance; this decrease could indicate a deficiency in epidemiological surveillance during the observation period due to the increase in the silent areas. Surveillance should maintain an increasing or constant number of tests during the years in addition to a reduction in the number of outbreaks of rabies, which would indicate a lower positivity rate. The findings in this study indicate deterioration in the effectiveness of the passive surveillance for rabies. The number of rabies cases, total number of tests performed and positivity rate are good indicators for evaluating passive surveillance. This paper can function as a guide for the assessment and improvement of the actions in passive surveillance of rabies.

Influence of race and crossbreeding on casein micelles size.

Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the correlation of milk CN micelles diameter from Holstein and Zebu crossbreds with milk composition (protein, fat, lactose, total and nonfat solids and milk urea nitrogen), somatic cell count (SCC), age, lactation stage and production. Average casein micelles diameters of milk samples obtained from 200 cows were measured using photon correlation spectroscopy and multiple regression analysis was used to find relationship between variables. CN micelle diameter, SCC and nonfat solids were different between animals with different Holstein crossbreed ratios, which suggests influence of genetic factors, mammary gland health and milk composition. Overall, results indicate the potential use of CN micelle diameter as a tool to select animals to produce milk more suitable to cheese production.

Clinical findings related to intramammary infections in meat-producing ewes.

The aim of this study was to investigate the relationship between clinical findings and bacterial isolation in milk samples of meat-producing ewes. The study was conducted in 17 commercial flocks and 550 udder halves from suckling Santa Ines ewes. Initially, the clinical examination of the mammary glands and teats was performed by visual inspection and palpation of the teats and udder halves; then a scoring system was devised for all the findings. After that, the strip cup test and the California mastitis test (CMT) were performed. Then, milk samples for somatic cell counts (SCCs) and bacteriological analyses were collected. Staphylococci bacteria were the main etiological agent isolated in the present study. Upon investigation of the correlations between bacterial isolation and the clinical findings, only the presence of teat injury, pendulous udder, and alterations in the palpation of the teat were associated with bacterial isolation. A significant correlation between bacteriologically positive milk samples and CMT and SCC was also found. Thus, some clinical findings appeared as a risk factor for bacteriologically positive milk samples and can be used as a tool in mastitis control programs. However, a complete and extensive diagnosis, an appropriate therapy, and an efficient mastitis control program will require the combination of clinical examination, microbiological tests, and SCC.

The severity of dental caries in adults aged 35 to 44 years residing in the metropolitan area of a large city in Brazil: a cross-sectional study.

BACKGROUND: In recent decades, studies in the field of public health have increasingly focused on social determinants that affect the health-illness process. The epidemiological perspective considers oral health to be a reflection of socioeconomic and environmental aspects, and it is particularly influenced by the social context. The aim of the present study was to assess the association between the severity of dental caries among adults aged 35 to 44 years and characteristics on the different levels at which the determinants of caries operate (individual, social structure and social context). METHODS: A home-based, cross-sectional field study was carried out involving a sample of 1,150 adults (35 to 44 years of age) residing in metropolitan Belo Horizonte, Brazil. The DMFT (decayed, missing, filled tooth) index (≥14) was used to determine the severity of dental caries. Bivariate and multivariate analyses were carried out using the Poisson regression model with the level of significance set at 5% (p < 0.05) and 95% confidence intervals. RESULTS: The majority of the participants (68.5%) had high caries severity. The rate of high-severity caries in the group between 40 and 44 years of age was 1.15-fold (CI: 1.04-1.26) greater than that among those aged 35 to 39 years. A greater prevalence of high caries severity was found among those who frequently visited the dentist (PR = 1.18; CI: 1.07-1.30), those with a lower income (PR = 1.11; CI: 1.01-1.23), those who reported that their neighborhood did not come together in the previous year to petition political leaders for benefits (PR = 1.16; CI: 1.05-1.28) and those who are unable to make decisions (without empowerment) (PR = 1.12; CI: 1.01-1.24). CONCLUSIONS: The present study revealed high dental caries severity in adults, which was associated with individual characteristics, health-related behavior and social structure and contextual variables. These findings underscore the importance of considering social determinants involved in the health-illness process when carrying out epidemiological studies on dental caries.

A review of Neospora caninum in dairy and beef cattle--a Canadian perspective.

Neospora caninum is one of the most important causes of abortion in cows. The occurrence of N. caninum infection in beef and dairy cattle has been reported worldwide, and in most provinces in Canada. The objective of this review is to summarize our current understanding of N. caninum in dairy and beef cattle for Canadian bovine practitioners. The review covers the life cycle of the agent, its mechanisms of transmission, clinical signs, and tests for diagnosing the infection. Data on the prevalence of the infection in Canadian dairy and beef cattle are reviewed and briefly compared with estimates from other parts of the world. Most importantly for Canadian bovine practitioners, the impacts of the infection, risk factors for its occurrence, and methods of control are also discussed. By reviewing the scientific literature on N. caninum from a Canadian perspective, culling decisions based on the interpretation of diagnostic tests are more effectively made in the control of N. caninum-associated disease.