992 resultados para Tuberculosis in cattle


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Pós-graduação em Medicina Veterinária - FMVZ

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Members of the subfamily Alphaherpesvirinae use the epithelium of the upper respiratory and/or genital tract as preferential sites for primary replication. However, bovine herpesvirus 5 (BoHV5) is neurotropic and neuroinvasive and responsible for meningoencephalitis in cattle and in animal models. A related virus, BoHV1 has also been occasionally implicated in natural cases of neurological infection and disease in cattle. The aim of the present study was to assess the in vitro effects of BoHV1 and BoHV5 replication in neuron-like cells. Overall, cytopathic effects, consisting of floating rounded cells, giant cells and monolayer lysis, induced by both viruses at 48 h postinfection (p.i.) resulted in a loss of cell viability and high virus titres (r = 0.978). The BoHV1 Cooper strain produced the lowest titres in neuron-like cells, although viral DNA was detected in infected cells during all experiments. Virus replication in infected cells was demonstrated by immunocytochemistry, flow cytometry and qPCR assays. BoHV antigens were better visualized at 48 h p.i. and flow cytometry analysis showed that SV56/90 and Los Angeles antigens were present at higher levels. In spite of the fact that BoHV titres dropped at 48 h p.i, viral DNA remained detectable until 120 h p.i. Sensitive TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) and annexin V assays were used to identify apoptosis. BoHV5 induced death in approximately 50 % of cells within 24 h p.i., similar to what has been observed for BoHV1 Los Angeles. Infection with the BoHV1 Cooper strain resulted in 26.37 % of cells being in the early stages of apoptosis; 63.69 % of infected cells were considered viable. Modulation of mitochondrial function, as measured by mitochondrial membrane depolarization, was synchronous with the virus replication cycle, cell viability and virus titres at 48 h p.i. Our results indicate that apoptosis plays an important role in preventing neuronal death and provides a bovine-derived in vitro system to study herpesvirus-neuron interactions.

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Tuberculosis infection among humans transmitted by products of animal origin can be caused by Mycobacterium bovis, a concern in developing countries, because the number of human cases is relatively high compared with countries that have implemented programs to eradicate bovine tuberculosis for many years. Because it is a chronic disease with subclinical evolution, it is transmitted to other animals in the herd livestock resulting in high loss losses resulting high (10 to 25%), as well as the zoonotic nature of the disease on public health. This work aimed to study the histomorphology of granulomas in samples of lymph nodes and lungs of animals with suggestive lesions of tuberculosis, as well as those similar to the sanitary inspection. The animals clinically healthy ante-mortem, were slaughtered in a slaughterhouse in the northwestern state of Sao Paulo between April 2008 and April 2009, considering that carcasses had lymph nodes with lesions typical of tuberculosis, exhibiting nodular and hemorrhagic appearance. The caseous or calcified lesions, purulent or not, of various sizes and shapes, were also evaluated. Of the 307,661 animals slaughtered in the mentioned period, 494 gross suggestive lesions of tuberculosis and from 29 cities in the state of Sao Paulo, 16 from Mato Grosso do Sul, Goias 15, one from Mato Grosso and Paraná. Among these, 200 samples (40,5%) were processed for histopathological evaluation by hematoxylin-eosin (HE) and 90 (45%) were subjected to Ziehl-Neelsen (ZN) and examined by light microscopy. In HE staining, histopathological changes of tuberculosis were found in 197 (98,5%), classified according to the stage of development adopted by Wango et al.(31), where 29 samples were included in stage I (14,5%), 53 in stage II (26,5%), 87 in stage III (43,5%), 28 in stage IV (14%). In the ZN staining Mycobacterium sp was found in 89 (99%) of the specimens. The rate of tuberculosis in the herd studied was 0,16%. We conclude that the identification of the disease in slaughterhouses and meat companies from significant gross lesions, enables the implementation of effective measures, specifically the origin of the disease in cattle herds, providing control measures to prevent its spread.

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Despite the efforts made to improve the production of bovine embryos in vitro, their efficiency is still low, since only 30-40% of developed blastocysts are obtained from oocytes after in vitro maturation (IVM), fertilization and cultured embryos. Assisted reproductive technologies have a limiting impact due a lack of oocytes capable to fertilization.The comprehension of mechanism involved in oocyte maturation are crucial to establish a culture system that allows a larger number production of good quality embryos. The study of the early stages of oocyte and follicle development in vivo is important for a better understanding of the molecular pathways that regulate oogenesis, folliculogenesis and oocyte maturation. Thus the physiological biochemical and molecular mechanisms involved in maturation may contribute to the increased efficiency of in vitro embryo production. Therefore, the aim of this literature review is to understand the basic mechanisms that underlie oocyte maturation in cattle, since oocyte and follicle cells in vivo formation to its use in the in vitro environment.

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The objective of this study was to determine the effect of the dietary inclusion of lipid-based diets (whole cottonseed and protected fat) on the centesimal composition, fatty acid profile, and sensory properties of meat from finishing Nellore cattle. The study was carried out from August to October 2009. Thirty nine uncastrated Nellore males with average initial body weight of 494.1 ± 10.1 kg and 36 months of age were housed for 63 days in pens with thirteen animals each. A completely randomized design with three treatments and thirteen replications was used. The treatments evaluated were: feed with 2.50% cottonseed (control diet); feed with 11.50% cottonseed; and feed with 3.13% cottonseed added of protected lipid (PL), all on a dry matter basis. No differences between treatments were observed for moisture, protein, and ash contents. However, the addition of protected fat caused an increase in the percentage of ether extract in the meat. Diets containing cottonseed or protected lipid did not affect fatty acid concentration in the meat. The intensity of the aroma, strange aroma, flavor, strange flavor, juiciness, color, and overall appearance were similar between treatments, except for tenderness, which was positively affected in cattle fed a diet in which the only lipid source was cottonseed. The study demonstrated that the addition of PL in the diets of finishing cattle led to greater levels of intramuscular fat, but to less tender meat than the other treatments.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Anthrax is not commonly considered so important a menace to swine as it is to other forms of live stock, in which the disease is apt to declare itself with terrifying severity. In comparison with the marked mortality frequently observed in cattle, the tangible losses caused by anthrax in swine seem negligible. As recent as 25 years ago, there still were observers who sincerely doubted the occurrence of the disease in hogs and this opinion found some support in the many reported failures to induce the infection in that animal species by artificial methods.

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Wildlife reservoirs of Mycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock. In Michigan, USA tuberculous white-tailed deer transmit M. bovis to cattle. One approach in dealing with this wildlife reservoir is to vaccinate deer in order to interrupt the cycle of deer to deer and deer to cattle transmission. Thirty-one white-tailed deer were assigned to one of three groups; 2 SC doses of 107 CFU of M. bovis BCG (n = 11); 1 SC dose of 107 CFU of M. bovis BCG (n = 10); or unvaccinated deer (n = 10). After vaccination, deer were inoculated intratonsilarly with 300 CFU of virulent M. bovis. Gross lesion severity scores of the medial retropharyngeal lymph node were significantly reduced in deer receiving 2 doses of BCG compared to unvaccinated deer. Vaccinated deer had fewer lymph node granulomas than unvaccinated deer, and most notably, fewer late stage granulomas characterized by coalescent caseonecrotic granulomas containing numerous acid-fast bacilli. BCG was isolated from 7/21 vaccinated deer as long as 249 days after vaccination. In one case BCG was transmitted from a vaccinated deer to an unvaccinated deer. In white-tailed deer BCG provides measurable protection against challenge with virulent M. bovis. However, persistence of vaccine within tissues as well as shedding of BCG from vaccinates remain areas for further investigation.

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Tuberculosis due to Mycobacterium bovis in captive Cervidae was identified as an important disease in the United States in 1990 and prompted the addition of captive Cervidae to the USDA Uniform Methods and Rules for eradication of bovine tuberculosis. As well, M. bovis infection was identified in free-ranging white-tailed deer in northeast Michigan in 1995. Tuberculosis in both captive and free-ranging Cervidae represents a serious challenge to the eradication of M. bovis infection from the United States. Currently, the only approved antemortem tests for tuberculosis in Cervidae are the intradermal tuberculin skin test and the blood tuberculosis test (BTB). At present, the BTB is not available in North America. Tuberculin skin testing of Cervidae is time-consuming and involves repeated animal handling and risk of injury to animals and humans. This study evaluated the potential of a new blood-based assay for tuberculosis in Cervidae that would decrease animal handling, stress, and losses due to injury. In addition, a blood-based assay could provide a more rapid diagnosis. Twenty 6–9-month-old white-tailed deer, male and female, were experimentally inoculated by instillation of 300 colony-forming units of M. bovis in the tonsillar crypts. Seven, age-matched uninfected deer served as controls. Blood was collected on days 90, 126, 158, 180, 210, 238, 263, and 307 after inoculation and was analyzed for the production of interferon-γ (IFN-γ) in response to incubation with M. bovis purified protein derivative (PPDb), M. avium PPDa, pokeweed mitogen (PWM), or media alone. Production of IFN-g in response to PPDb was significantly greater (P < 0.05) at all time points in samples from M. bovis–infected deer as compared with uninfected control deer, whereas IFN-γ production to PWM did not differ significantly between infected and control deer. Measurement of IFN-γ production to PPDb may serve as a useful assay for the antemortem diagnosis of tuberculosis in Cervidae.

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OBJECTIVE: Pleural tuberculosis is the most frequently occurring form of extra pulmonary disease in adults. In up to 40% of cases, the lung parenchyma is concomitantly involved, which can have an epidemiological impact. This study aims to evaluate the pleural and systemic inflammatory response of patients with pleural or pleuropulmonary tuberculosis. METHODS: A prospective study of 39 patients with confirmed pleural tuberculosis. After thoracentesis, a high resolution chest tomography was performed to evaluate the pulmonary involvement. Of the 39 patients, 20 exhibited only pleural effusion, and high resolution chest tomography revealed active associated-pulmonary disease in 19 patients. The total protein, lactic dehydrogenase, adenosine deaminase, vascular endothelial growth factor, interleukin-8, tumor necrosis factor-alpha, and transforming growth factor-beta(1) levels were quantified in the patient serum and pleural fluid. RESULTS: All of the effusions were exudates with high levels of adenosine deaminase. The levels of vascular endothelial growth factor and transforming growth factor-beta(1) were increased in the blood and pleural fluid of all of the patients with pleural tuberculosis, with no differences between the two forms of tuberculosis. The tumor necrosis factor-alpha levels were significantly higher in the pleural fluid of the patients with the pleuropulmonary form of tuberculosis. The interleukin-8 levels were high in the pleural fluid of all of the patients, without any differences between the forms of tuberculosis. CONCLUSION: Tumor necrosis factor-alpha was the single cytokine that significantly increased in the pleural fluid of the patients with pulmonary involvement. However, an overlap in the results does not permit us to suggest that cytokine is a biological marker of concomitant parenchymal involvement. Although high resolution chest tomography can be useful in identifying these patients, the investigation of fast acid bacilli and cultures for M. tuberculosis in the sputum is recommended for all patients who are diagnosed with pleural tuberculosis.

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The embryonic developmental block occurs at the 8-cell stage in cattle and is characterized by a lengthening of the cell cycle and an increased number of embryos that stop development. The maternal-embryonic transition arises at the same stage resulting in the transcription of many genes. Gene expression studies during this stage may contribute to the understanding of the physiological mechanisms involved in the maternal-embryonic transition. Herein we identified genes differentially expressed between embryos with high or low developmental competence to reach the blastocyst stage using differential display PCR. Embryos were analysed according to developmental kinetics: fast cleavage embryos showing 8 cells at 48 h post insemination (hpi) with high potential of development (F8), and embryos with slow cleavage presenting 4 cells at 48 hpi (54) and 8 cells at 90 hpi (S8), both with reduced rates of development to blastocyst. The fluorescence DDPCR method was applied and allowed the recovery of 176 differentially expressed bands with similar proportion between high and low development potential groups (52% to F8 and 48% in S4 and S8 groups). A total of 27 isolated fragments were cloned and sequenced, confirming the expected primer sequences and allowing the identification of 27 gene transcripts. PI3KCA and ITM2B were chosen for relative quantification of mRNA using real-time PCR and showed a kinetic and a time-related pattern of expression respectively. The observed results suggest the existence of two different embryonic genome activation mechanisms: fast-developing embryos activate genes related to embryonic development, and slow-developing embryos activate genes related to cellular survival and/or death.

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Cryptosporidium parvum infection is very important with respect to public health, owing to foodborne and waterborne outbreaks and gastrointestinal illness in immunocompetent and immunocompromised persons. In cattle, infection with this species manifests either as a subclinical disease or with diarrheal illness, which occurs more often in the presence of other infectious agents than when alone. The aim of this study was to develop a real-time polymerase chain reaction (PCR) assay for the detection of C. parvum in calf fecal samples and to compare the results of this assay with those of the method routinely used for the diagnosis of Cryptosporidium spp., nested PCR targeting the 18S rRNA gene. Two hundred and nine fecal samples from calves ranging in age from 1 day to 6 months were examined using real-time PCR specific for the actin gene of C. parvum and by a nested PCR targeting the 18S rRNA gene of Cryptosporidium spp. Using real-time PCR detection, 73.2% (153 out of 209) of the samples were positive for C. parvum, while 56.5% (118 out of 209) of the samples were positive for Cryptosporidium spp. when the nested PCR amplification method was used for the detection. The analytical sensitivity of the real-time PCR was approximately one C. parvum oocyst. There was no significant nonspecific DNA amplification of any of the following species and genotype: Cryptosporidium andersoni, Cryptosporidium baileyi, Cryptosporidium bovis, Cryptosporidium canis, Cryptosporidium galli, Cryptosporidium ryanae, Cryptosporidium serpentis, or avian genotype II. Thus, we conclude that real-time PCR targeting the actin gene is a sensitive and specific method for the detection of C. parvum in calf fecal samples.

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In the last several years, the use of dendritic cells has been studied as a therapeutic strategy against tumors. Dendritic cells can be pulsed with peptides or full-length protein, or they can be transfected with DNA or RNA. However, comparative studies suggest that transfecting dendritic cells with messenger RNA (mRNA) is superior to other antigen-loading techniques in generating immunocompetent dendritic cells. In the present study, we evaluated a new therapeutic strategy to fight tuberculosis using dendritic cells and macrophages transfected with Hsp65 mRNA. First, we demonstrated that antigen-presenting cells transfected with Hsp65 mRNA exhibit a higher level of expression of co-stimulatory molecules, suggesting that Hsp65 mRNA has immunostimulatory properties. We also demonstrated that spleen cells obtained from animals immunized with mock and Hsp65 mRNA-transfected dendritic cells were able to generate a mixed Th1/Th2 response with production not only of IFN-γ but also of IL-5 and IL-10. In contrast, cells recovered from mice immunized with Hsp65 mRNA-transfected macrophages were able to produce only IL-5. When mice were infected with Mycobacterium tuberculosis and treated with antigen-presenting cells transfected with Hsp65 mRNA (therapeutic immunization), we did not detect any decrease in the lung bacterial load or any preservation of the lung parenchyma, indicating the inability of transfected cells to confer curative effects against tuberculosis. In spite of the lack of therapeutic efficacy, this study reports for the first time the use of antigen-presenting cells transfected with mRNA in experimental tuberculosis.