Production of autoantibodies associated with polyclonal activation in Yersinia enterocolitica 0:8-infected mice

Polyclonal lymphocyte stimulation is one of the immunomodulatory mechanisms induced by arthritogenic pathogens. In this study we examined the polyclonal activation potential of a virulent strain of Y. enterocolitica serotype O:8 (WA 2707+) and its plasmidless isogenic pair (WA 2707-). SPF Swiss mice were infected intragastrically and spleen cells were obtained on days 7, 14, 21, 28, 35 and 42 after infection. The number of cells secreting nonspecific immunoglobulins of IgG, IgM and IgA isotypes was determined by the ELISPOT technique. The presence of serum-specific antibodies was investigated by ELISA and the presence of autoantibodies by dot-blot assay. Although the patterns of infection of the two bacterial strains were almost the same, only the animals infected with the virulent strain presented clinical anomalies. Neither arthritic nor inflammatory signs were observed in the joints of the infected animals. The greatest activation observed was that of the nonspecific IgM-secreting cells, and their peak of secretion occurred between the 28th and the 42nd day after infection, for both strains of Y. enterocolitica O:8. Only the animals infected with the virulent strain (WA 2707+) produced IgG-specific antibodies in the serum, from the 28th day after infection. The serum of animals infected with either strain showed reactivity to all the autologous constituents tested, mainly on the 28th and 42nd day after infection. It was concluded that infection of mice with either the virulent strain of Y. enterocolitica O:8 or with its plasmidless isogenic pair resulted in the polyclonal activation of the splenic B lymphocytes including some autoreactive clones.

Impact of sub-inhibitory concentrations of amoxicillin on helicobacter pylori virulence factors

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

Estrutura da população e epidemiologia de Moniliophthora roreri no Magdalena Medio Colombiano

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação de metodologias na definição de fluxos acumulados a partir de modelos digitais de elevação do terreno aplicado a suscetibilidade de inundações

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo genético de populações de soja com fonte de resistência à Heterodera glycines (raça 3) oriundas de topocruzamentos tipo alimento x tipo grão

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho de gotejadores usando efluente de esgoto tratado para irrigação

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Avaliação da Translocação Microbiana em Gestantes Infectadas pelo HIV

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Selecting for rust (Puccinia psidii) reistance in Euclyptus grandis in São Paulo state, Brazil

In Brazil, Eucalyptus grandis is a key species for wood production. However, some genotypes are susceptible to rust (Puccinia psidii), mainly in São Paulo State, where climatic conditions are favorable for its development. Rust represents a high economic risk to forest companies because of the high potential of damage to commercial eucalypt plantations. The aims of the present study were (i) to select progenies of E. grandis for stability and adaptability regarding resistance to rust at different locations; (ii) compare the selections under these different climatic conditions; and (iii) compare rust severity in the field with the theoretical model. We observed that climatic conditions were extremely influential factors for rust development, but even under favorable conditions for disease development, we found rust-resistant progenies. In sites unfavorable for rust development, we detected highly susceptible progenies. We found significant correlation among the genetic material, environmental conditions and disease symptoms, however, we observed a simple genotype-environmental interaction and significant genetic variability among the progenies. The average heritability was high among the progenies in all sites, indicating substantial genetic control for rust resistance. We also observed a good relationship between rust severity in the field and the theoretical model that considered annual average temperature and leaf wetness.

Ribavirin has an in vitro antiviral effect in rabies virus infected neuronal cells but fails to provide benefit in experimental rabies in mice

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

Integração de dados geofísicos e geológicos na caracterização morfológica de ocorrência de cobre na borda norte da Bacia do Camaquã (RS)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inter-relação de Meloidogyne enterolobii e Pratylenchus brachyurus em variedades de goiabeiras

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Spatial Management of Wildlife Disease

The spread of wildlife diseases is a major threat to livestock, human health, resource-based recreation, and biodiversity conservation (Cleaveland, Laurenson, and Taylor). The development of economically sound wildlife disease-management strategies requires an understanding of the links between ecological functions (e.g., disease transmission and wildlife dispersal) and economic choices, and the associated tradeoffs. Spatial linkages are particularly relevant. Yet while ecologists have long-argued that space is important (Hudson et al.), prior economic work has largely ignored spatial issues. For instance, Horan and Wolf analyzed a case study of bovine tuberculosis (bTB) in Michigan deer, a problem where the disease appears to be confined to a single, spatially confined, wildlife population—an island. But wildlife disease matters generally are not spatially confined. Barlow, in analyzing bTB in possums in New Zealand, accounted for immigration of susceptible possums into a disease reservoir. However, he modeled immigration as fixed and unaffected by management. Bicknell, Wilen, and Howitt, also focusing on possums in New Zealand, developed a model that incorporates simple density-dependent net migration. This allowed the authors to account for endogenous immigration when deriving optimal culling strategies.

Development of a Model of Natural Infection with Mycobacterium bovis in White-Tailed Deer

The objective of this study was to develop a suitable experimental model of natural Mycobacterium bovis infection in white-tailed deer (Odocoileus virginianus), describe the distribution and character of tuberculous lesions, and to examine possible routes of disease transmission. In October 1997, 10 mature female white-tailed deer were inoculated by intratonsilar instillation of 2 3 103 (low dose) or 2 3 105 (high dose) colony forming units (CFU) of M. bovis. In January 1998, deer were euthanatized, examined, and tissues were collected 84 to 87 days post inoculation. Possible routes of disease transmission were evaluated by culture of nasal, oral, tonsilar, and rectal swabs at various times during the study. Gross and microscopic lesions consistent with tuberculosis were most commonly seen in medial retropharyngeal lymph nodes and lung in both dosage groups. Other tissues containing tuberculous lesions included tonsil, trachea, liver, and kidney as well as lateral retropharyngeal, mandibular, parotid, tracheobronchial, mediastinal, hepatic, mesenteric, superficial cervical, and iliac lymph nodes. Mycobacterium bovis was isolated from tonsilar swabs from 8 of 9 deer from both dosage groups at least once 14 to 87 days after inoculation. Mycobacterium bovis was isolated from oral swabs 63 and 80 days after inoculation from one of three deer in the low dose group and none of four deer in the high dose group. Similarly, M. bovis was isolated from nasal swabs 80 and 85 days after inoculation in one of three deer from the low dose group and 63 and 80 days after inoculation from two of four deer in the high dose group. Intratonsilar inoculation with M. bovis results in lesions similar to those seen in naturally infected white-tailed deer; therefore, it represents a suitable model of natural infection. These results also indicate that M. bovis persists in tonsilar crypts for prolonged periods and can be shed in saliva and nasal secretions. These infected fluids represent a likely route of disease transmission to other animals or humans.

Susceptibility of Raccoons (Procyon lotor) to Infection with Mycobacterium bovis

Tuberculosis due to Mycobacterium bovis infection is endemic in white-tailed deer (Odocoileus virginianus) in the northeastern portion of the lower Michigan peninsula (USA). Various wild carnivores and omnivores, including raccoons (Procyon lotor), are infected with M. bovis within the endemic area. To investigate the pathogenesis of tuberculosis in raccoons and the likelihood of M. bovis transmission from infected raccoons to other susceptible hosts, we experimentally inoculated raccoons with single oral doses of M. bovis (ranging from 30 to 1.7 x 105 colony forming units [CFU]), five daily oral doses of M. bovis (ranging from 10 to 1 x 105 CFU), or a single intravenous (IV) dose of 1 x 105 CFU of M. bovis, from November 1998 through December 2000. Granulomatous lesions consistent with tuberculosis, or tissue colonization with M. bovis, were seen in one of five raccoons in the single low oral dose group, one of five raccoons in the multiple low oral dose group, two of five raccoons in the multiple medium oral dose group, five of five raccoons in the multiple high oral dose group, and five of five raccoons in the IV inoculated group. In orally inoculated raccoons, lesions were most common in the tracheobronchial and mesenteric lymph nodes and lung. Excretion of M. bovis in saliva or nasal secretions was noted in all IV inoculated raccoons and two of five multiple low oral dose raccoons. Mycobacterium bovis was not isolated from urine or feces from any experimentally inoculated raccoons. The need for multiple large oral doses to establish infection, and the low number of orally inoculated raccoons that excreted M. bovis in nasal secretions or saliva, suggest that widespread tuberculosis among raccoons is unlikely.

Hydrogeologic Setting and Ground-Water Flow Simulations of the Eastern High Plains Regional Study Area, Nebraska

The transport of anthropogenic and natural contaminants to public-supply wells was evaluated in a part of the High Plains aquifer near York, Nebraska, as part of the U.S. Geological Survey National Water-Quality Assessment Program. The aquifer in the Eastern High Plains regional study area is composed of Quaternary alluvial deposits typical of the High Plains aquifer in eastern Nebraska and Kansas, is an important water source for agricultural irrigation and public water supply, and is susceptible and vulnerable to contamination. A six-layer, steady-state ground-water flow model of the High Plains aquifer near York, Nebraska, was constructed and calibrated to average conditions for the time period from 1997 to 2001. The calibrated model and advective particle-tracking simulations were used to compute areas contributing recharge and travel times from recharge areas to selected public-supply wells. Model results indicate recharge from agricultural irrigation return flow and precipitation (about 89 percent of inflow) provides most of the ground-water inflow, whereas the majority of ground-water discharge is to pumping wells (about 78 percent of outflow). Particle-tracking results indicate areas contributing recharge to public-supply wells extend northwest because of the natural ground-water gradient from the northwest to the southeast across the study area. Particle-tracking simulations indicate most ground-water travel times from areas contributing recharge range from 20 to more than 100 years but that some ground water, especially that in the lower confined unit, originates at the upgradient model boundary instead of at the water table in the study area and has travel times of thousands of years.