970 resultados para enteric viruses
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In Latin America, rabies cases related to frugivorous bats have been reported since 1930's. Recently, two viruses isolated from Artibeus lituratus were proved to be vampire bat variants by monoclonal antibodies panels [2], but their genetic information is not well known. In this report, four rabies viruses were isolated from frugivorous bats (Artibeus spp.) in Brazil and their nucleoprotein gene sequences were determined. These isolates were found to be genotype 1 of lyssavirus and showed the maximum nucleotide sequence homology of 97.6-99.4% with vampire bat-related viruses in Brazil [6]. These results indicate that the Brazilian frugivorous bat rabies viruses in this study are closely related to vampire bat-related viruses that play a main role in rabies virus transmission to livestock in Brazil.
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Cucurbits species grown in 38 of 40 agricultural regions in the state of Sao Paulo, Brazil, were surveyed for the relative incidence of Cucumber mosaic virus (CMV), Papaya ringspot virus-type W (PRSV-W), Watermelon mosaic virus-2 (WMV-2), Zucchini lethal chlorosis virus (ZLCV), and Zucchini yellow mosaic virus (ZYMV) during May 1997 and June 1999. Samples from 621 plants, representing eight cultivated species, six wild species, and one commercial hybrid (Cucurbita moschata x C. maxima), were analyzed by plate trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA). PRSV-W and ZYMV were the most frequently found viruses, accounting for 49.1 and 24.8%, respectively, of 605 samples tested. ZLCV, CMV, and WMV-2 were detected in 7.8, 6.0, and 4.5% of 612, 497, and 423 samples tested, respectively. Double infection was found in 97 samples, and triple infection was found in 10 samples. Quadruple infection was detected in one C. pepo sample. Plants that were symptomatic but negative by PTA-ELISA might be due to abiotic agents, infection by virus for which antiserum was not available, such as Squash mosaic virus, or infection with an as yet uncharacterized virus.
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Dengue virus is a mosquito-borne flavivirus that has a large impact in global health. It is considered as one of the medically important arboviruses, and developing a preventive or therapeutic solution remains a top priority in the medical and scientific community. Drug discovery programs for potential dengue antivirals have increased dramatically over the last decade, largely in part to the introduction of high-throughput assays. In this study, we have developed an image-based dengue high-throughput/high-content assay (HT/HCA) using an innovative computer vision approach to screen a kinase-focused library for anti-dengue compounds. Using this dengue HT/HCA, we identified a group of compounds with a 4-(1-aminoethyl)-N-methylthiazol-2-amine as a common core structure that inhibits dengue viral infection in a human liver-derived cell line (Huh-7.5 cells). Compounds CND1201, CND1203 and CND1243 exhibited strong antiviral activities against all four dengue serotypes. Plaque reduction and time-of-addition assays suggests that these compounds interfere with the late stage of viral infection cycle. These findings demonstrate that our image-based dengue HT/HCA is a reliable tool that can be used to screen various chemical libraries for potential dengue antiviral candidates. © 2013 Cruz et al.
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Canine distemper virus (CDV) is a viral disease that affects dogs and many other carnivores. Clinical diagnosis of CDV is difficult due to the broad spectrum of signs that may be confounded with other respiratory and enteric diseases of dogs. Laboratory analysis is required to diagnose suspected cases. In this study, surface plasmon resonance (SPR) and electrochemical impedance spectroscopy (EIS) methodologies were developed for the detection of canine distemper virus simultaneously. The assay exhibited high specificity, as all the negative controls were not mistakenly detected. The CDV concentration was determined from successive injections into the apparatus, with a linear range from 1.1 to 116.0 ng mL-1. The system exhibited good reproducibility with 4.5% variation between runs after regeneration of the coated surface with a solution of 0.1 M glycine-HCL (pH 3.0). The capacitance and resistance values of the modified interface were calculated from EIS data using an equivalent circuit. It was possible to measure CDV in highly concentrated viruses with good specificity and reproducibility. © 2013 The Royal Society of Chemistry.
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Pós-graduação em Ciência Odontólogica - FOA
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Pós-graduação em Odontologia - FOA
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This study presents the first results from Brazil using SF6 tracer technique adapted from cattle to evaluate the capability of condensed tannin (CT) present in three tropical legume forages, Leucaena leucocephala (LEU), Styzolobium aterrimum (STA), and Mimosa caesalpiniaefolia Benth (MIM) to reduce enteric CH4 production in Santa Ins sheep. Twelve male lambs [27.88 +/- 2.85 kg body weight (BW)] were allocated in individual metabolic cages for 20-day adaptation followed by 6 days for measuring dry matter intake (DMI) and CH4 emission. All lambs received water, mineral supplement, and Cynodon dactylon v. coast-cross hay ad libitum. The treatments consisted of soybean meal (710 g/kg) and ground corn (290 g/kg) [control (CON)]; soybean meal (150 g/kg), ground corn (30 g/kg), and Leucaena hay (820 g/kg) (LEU); soybean meal (160 g/kg), ground corn (150 g/kg), and Mucuna hay (690 g/kg) (STA); and soybean meal (280 g/kg), ground corn (190 g/kg), and Mimosa hay (530 g/kg) (MIM); all calculated to provide 40 g/kg CT (except for CON). DMI (in grams of DMI per kilogram BW per day) was lower for LEU (22.0) than CON (29.3), STA (31.2), and MIM (31.6). The LEU group showed emission of 7.8 g CH4/day, significantly lower than CON (10.5 g CH4/day), STA (10.4 g CH4/day), and MIM (11.3 g CH4/day). However, when the CH4 emission per DMI was considered, there were no significant differences among treatments (0.37, 0.36, 0.33, and 0.35 g CH4/g DMI/kg BW/day, respectively, for CON, LEU, STA, and MIM). The sheep receiving STA had shown a tendency (p = 0.15) to reduce methane emission when compared to the CON group. Therefore, it is suggested that tropical tanniniferous legumes may have potential to reduce CH4 emission in sheep, but more research is warranted to confirm these results.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study evaluated the occurrence of enteric bacteria and pseudomonads resistant to tetracycline and beta-lactams in the oral cavity of patients exhibiting gingivitis (n=89); periodontitis (n=79), periodontally healthy (n=50) and wearing complete dentures (n=41). Microbial identification and presence of resistance markers associated with the production of beta-lactamases and tetracycline resistance were performed by using biochemical tests and PCR. Susceptibility tests were carried out in 201 isolates of enteric cocci and rods. Resistance to ampicillin, amoxicillin/clavulanic acid, imipenem, meropenem and tetracycline was detected in 57.4%, 34.6%, 2.4%, 1.9% and 36.5% of the isolates, respectively. beta-lactamase production was observed in 41.2% of tested microorganisms, while the most commonly found beta-lactamase genetic determinant was gene bla(TEM). Tetracycline resistance was disseminated and a wide scope of tet genes were detected in all studied microbial genus.
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Several large dsDNA-containing viruses such as poxviruses (smallpox) and herpes viruses are well known among the scientific community, as well as the general populace, because they cause human diseases. The large dsDNA insect-infecting baculoviruses are also well known in the scientific community because they are used both as biological control agents and as protein expression systems. However, there are other large dsDNA-containing viruses, including the giant 1.2-Mb mimivirus, which are less well known even though all of them play important roles in everyday life. Seven of these virus families are reviewed in this book.
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INFLUENZA A virus (IAV) (family Orthomyxoviridae) is a highly infectious respiratory pathogen of birds and mammals, including human beings and horses (Palese and Shaw 2007). The virus is classified into different subtypes based on the antigenic properties of the haemagglutinin (HA) and neuraminidase (NA) proteins. Sixteen HA subtypes (H1 to H16) and nine NA subtypes (N1 to N9) have been identified (Fouchier and others 2005). Two subtypes, H3N8 and H7N7, have been isolated from horses. The H7N7 subtype was first isolated from a horse in Czechoslovakia in 1956 (Prague/56) (Sovinova and others 1958), and the H3N8 subtype was first isolated from a horse in Miami, USA, in 1963 (Waddell and others 1963). The H7N7 subtype has not been isolated from horses for three decades and is presumed to be extinct (Webster 1993). The H3N8 subtype is currently a common cause of disease in horses worldwide. In horses, influenza is characterized by an abrupt onset of pyrexia, depression, coughing and nasal discharge, and is often complicated by secondary bacteria infections that can lead to pneumonia and death (Hannant and Mumford 1996). Although H3N8 is a major cause of morbidity in horses throughout the world, information on the seroprevalence of IAV in horses and other domestic animals in Mexico is limited.
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Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus, Family Flaviviridae. The virus can infect many species of animals of the order Artiodactyla. The BVDV genome encodes an auto protease, Npro, that degrades interferon regulatory factor-3 (IRF-3) reducing type I interferon (IFN-I) production from host cells. Bovine respiratory syncytial virus (BRSV) is a member of the genus Pneumovirus, Family Paramyxoviridae. Concurrent infection with BVDV and BRSV causes more severe respiratory and enteric disease than infection with either virus alone. Our hypothesis was that Npro modulates the innate immune responses to BVDV infection and enhances replication of BVDV or BRSV co-infection. The noncytopathic BVDV2 viruses NY93/c N- Npro 18 EGFP (a mutant with modified Npro fused with enhanced green fluorescent protein), NY93 infectious clone (NY93/c), wild-type NY93-BVDV2 (NY93-wt), and BRSV were evaluated in this study. The objectives of this study were: (1) to characterize the replication kinetics and IFN-I induction in Madin-Darby bovine kidney (MDBK) cells following infection with each of the BVDV isolates, and (2) to characterize the influence of BVDV-mediated IFN-I antagonism on enhancement of BRSV replication in bovine turbinate (BT) cells. NY93/c N- Npro 18 EGFP replicated 0.4 – 1.6 TCID50 logs lower than NY93-wt in MDBK cells. NY93/c N- Npro 18 EGFP-infected MDBK cells synthesized IFN-I significantly higher than NY93/c- and NY93-wt-infected MDBK cells. BT cells co-infected with NY93/c N- Npro 18 EGFP/BRSV or NY93-wt/BRSV were evaluated to determine the effects of co-infection on BRSV replication and IFN-I induction in BT cells. BRSV RNA levels in NY93-wt/BRSV co-infected BT cells were 2.49, 2.79, and 2.89 copy number logs significantly greater than in NY93/c N- Npro 18 EGFP/BRSV co-infected BT cells on days 5, 7, and 9 post-infection, respectively. BVDV RNA levels in NY93/c N- Npro 18 EGFP-infected BT cells were 1.64 – 4.38 copy number logs lower than in NY93-wt-infected BT cells. NY93/c N- Npro 18 EGFP single and co-infected BT cells synthesized IFN-I significantly higher than NY93-wt single and co-infected BT cells. In summary, these findings suggest: (1) NY93/c N- Npro 18 EGFP BVDV2 induced higher levels of IFN-I than BVDV2-wt and may be useful as a safer, replicating BVDV vaccine, and (2) Enhancement of BRSV infection by BVDV co-infection is mediated by antagonism of IFN-I.
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The main objective of the present work was to study nutritive strategies for lessening the CH4 formation associated to ruminant tropical diets. In vitro gas production technique was used for evaluating the effect of tannin-rich plants, essential oils, and biodiesel co-products on CH4 formation in three individual studies and a small chamber system to measure CH4 released by sheep for in vivo studies was developed. Microbial rumen population diversity from in vitro assays was studied using qPCR. In vitro studies with tanniniferous plants, herbal plant essential oils derived from thyme, fennel, ginger, black seed, and Eucalyptus oil (EuO) added to the basal diet and cakes of oleaginous plants (cotton, palm, castor plant, turnip, and lupine), which were included in the basal diet to replace soybean meal, presented significant differences regarding fermentation gas production and CH4 formation. In vivo assays were performed according to the results of the in vitro assays. , when supplemented to a basal diet (Tifton-85 hay sp, corn grain, soybean meal, cotton seed meal, and mineral mixture) fed to adult Santa Ines sheep reduced enteric CH4 emission but the supplementation of the basal diet with EuO did not affect ( > 0.05) methane released. Regarding the microbial studies of rumen population diversity using qPCR with DNA samples collected from the in vitro trials, the results showed shifts in microbial communities of the tannin-rich plants in relation to control plant. This research demonstrated that tannin-rich , essential oil from eucalyptus, and biodiesel co-products either in vitro or in vivo assays showed potential to mitigate CH4 emission in ruminants. The microbial community study suggested that the reduction in CH4 production may be attributed to a decrease in fermentable substrate rather than to a direct effect on methanogenesis.