Genetic and immunobiological diversities of porcine reproductive and respiratory syndrome genotype I strains   总被引：1，自引：0，他引：1  

Darwich L  Gimeno M  Sibila M  Diaz I  de la Torre E  Dotti S  Kuzemtseva L  Martin M  Pujols J  Mateu E 《Veterinary microbiology》2011,150(1-2):49-62

Genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV) has been based on ORF5/GP5 and ORF7/N protein variations. Complete viral genome studies are limited and focused on a single or a few set of strains. Moreover, there is a general tendency to extrapolate results obtained from a single isolate to the overall PRRSV population. In the present study, six genotype-I isolates of PRRSV were sequenced from ORF1a to ORF7. Phylogenetic comparisons and the variability degree of known linear B-epitopes were done considering other available full-length genotype-I sequences. Cytokine induction of all strains was also evaluated in different cellular systems. Non structural protein 2 (nsp2) was the most variable part of the virus with 2 out of 6 strains harboring a 74 aa deletion. Deletions were also found in ORF3 and ORF4. Phylogenetic analyses showed that isolates could be grouped differently depending on the ORF examined and the highest similarity with the full genome cluster was found for the nsp9. Interestingly, most of predicted linear B-epitopes in the literature, particularly in nsp2 and GP4 regions, were found deleted or varied in some of our isolates. Moreover, 4 strains, those with deletions in nsp2, induced TNF-α and 3 induced IL-10. These results underline the high genetic diversity of PRRSV mainly in nsp1, nsp2 and ORFs 3 and 4. This variability also affects most of the known linear B-epitopes of the virus. Accordingly, different PRRSV strains might have substantially different immunobiological properties. These data can contribute to the understanding of PRRSV complexity.  相似文献   

Potential diffusion of doramectin into a soil amended with female pig manure. A field experiment     

Gil-Díaz Mdel M  Pérez-Sanz A  Martín M  Lobo MC 《Journal of agricultural and food chemistry》2011,59(19):10635-10640

Doramectin is a veterinary drug used as an antihelminthic and is excreted mainly in the feces as the nonmetabolized drug. This study investigated the time profile of doramectin excretion in pig feces and the potential transfer and persistence of doramectin in the soil when the pig manure is used as an organic amendment to the soil. The concentration of doramectin in feces peaked at 143.0 ng/g in the dry feces 4 days after treatment. On day 62, the drug was still detected in the pig feces. After the land application of pig manure, the maximum concentration of doramectin in soil (ppb level) was detected 6 days after treatment. Seven months after the manure application, traces of doramectin were detected in the soil from the surface to a depth of 90 cm. Successive applications of manure from pigs treated with doramectin in a specific area could produce an accumulation of this drug in the soil.  相似文献   

An Indigenous Virulent Strain of Erwinia amylovora Lacking the Ubiquitous Plasmid pEA29     

Llop P  Donat V  Rodríguez M  Cabrefiga J  Ruz L  Palomo JL  Montesinos E  López MM 《Phytopathology》2006,96(8):900-907

ABSTRACT An atypical strain of Erwinia amylovora was isolated near an outbreak of fire blight at a nursery in Spain in 1996. It was obtained from a Crataegus plant showing typical symptoms and was identified as E. amy-lovora by biochemical tests and enrichment-enzyme-linked immuno-sorbent assay, but not by polymerase chain reaction using primers based on the pEA29 sequence. Nevertheless, with primers from chromosomal regions, the isolate gave the expected amplification band. This strain carries one plasmid of approximately 70 kb, with no homology with the 29-kb plasmid common to all pathogenic strains, or with a large plasmid present in some E. amylovora strains. Growth of the strain in minimal medium without thiamine was slower compared with cultures in the same medium with thiamine, a characteristic typical of strains cured of the 29-kb plasmid. Nevertheless, aggressiveness assays on pear, apple, and Pyracantha plants and in immature pear fruit showed that this strain exhibited a virulence level similar to other strains containing pEA29. To the best of our knowledge, this is the first report of the isolation from naturally infected plant material of a pathogenic strain of E. amylovora without pEA29, but with a plasmid of approximately 70 kb not previously described.  相似文献   

IL-17A regulates Eimeria tenella schizont maturation and migration in avian coccidiosis     

Emilio del Cacho  Margarita Gallego  Hyun Soon Lillehoj  Joaquín Quílez  Erik P Lillehoj  Ana Ramo  Caridad Sánchez-Acedo 《Veterinary research》2014,45(1):25

Although IL17A is associated with the immunological control of various infectious diseases, its role in host response to Eimeria infections is not well understood. In an effort to better dissect the role of IL17A in host-pathogen interactions in avian coccidiosis, a neutralizing antibody (Ab) to chicken IL17A was used to counteract IL17A bioactivity in vivo. Chickens infected with Eimeria tenella and treated intravenously with IL17A Ab, exhibited reduced intracellular schizont and merozoite development, diminished lesion score, compared with untreated controls. Immunohistological evaluation of cecal lesions in the parasitized tissues indicated reduced migration and maturation of second-generation schizonts and reduced lesions in lamina propria and submucosa. In contrast, untreated and infected chickens had epithelial cells harboring second-generation schizonts, which extend into the submucosa through muscularis mucosa disruptions, maturing into second generation merozoites. Furthermore, IL17A Ab treatment was associated with increased parameters of Th1 immunity (IL2- and IFNγ- producing cells), reduced levels of reactive oxygen species (ROS), and diminished levels of serum matrix metalloproteinase-9 (MMP-9). Finally, schizonts from untreated and infected chickens expressed S100, Wiskott-Aldrich syndrome protein family member 3 (WASF3), and heat shock protein-70 (HSP70) proteins as merozoites matured, whereas the expression of these proteins was absent in IL17A Ab-treated chickens. These results provide the first evidence that the administration of an IL17A neutralizing Ab to E. tenella-infected chickens inhibits the migration of parasitized epithelial cells, markedly reduces the production of ROS and MMP-9, and decreases cecal lesions, suggesting that IL17A might be a potential therapeutic target for coccidiosis control.  相似文献   

Bio-guided isolation of the cytotoxic corytenchine and isocoreximine from roots of Annona cherimolia     

Martínez-Vázquez M  De la Cueva Lozano DG  Estrada-Reyes R  González-Lugo NM  Ramírez Apan T  Heinze G 《Fitoterapia》2005,76(7-8):733-736

The roots of Annona cherimolia have been shown to contain the known tetrahydroprotoberberine alkaloids corytenchine (1) and isocoreximine (2), investigated for their cytotoxic properties.  相似文献   

Kinetic behavior of Fe(o,o-EDDHA)-humic substance mixtures in several soil components and in calcareous soils     

Cerdán M  Alcañiz S  Juárez M  Jordá JD  Bermúdez D 《Journal of agricultural and food chemistry》2007,55(22):9159-9169

Ferric ethylenediamine- N, N'-bis-(o-hydroxyphenylacetic)acid chelate (Fe(o, o-EDDHA)) is one of the most effective Fe fertilizers in calcareous soils. However, humic substances are occasionally combined with iron chelates in drip irrigation systems in order to lower costs. The reactivity of iron chelate-humic substance mixtures in several soil components and in calcareous soils was investigated through interaction tests, and their behavior was compared to the application of iron chelates and humic substances separately. Two commercial humic substances and two Fe(o, o-EDDHA) chelates (one synthesized in the laboratory and one commercial) were used to prepare iron chelate-humic substance mixtures at 50% (w/w). Various soil components (calcium carbonate, gibbsite, amorphous iron oxide, hematite, tenorite, zincite, amorphous Mn oxide, and peat) and three calcareous soils were shaken for 15 days with the mixtures and with iron chelate and humic substance solutions. The kinetic behavior of Fe(o, o-EDDHA) and Fe non-(o,o-EDDHA) (Fe bonded to (o,p-EDDHA) and other polycondensated ligands) and of the different nutrients solubilized after the interaction assay was determined. The results showed that the mixtures did not significantly reduce the retention of Fe(o, o-EDDHA) and Fe non-(o,o-EDDHA) in the soil components and the calcareous soils compared to the iron chelate solutions, but they did produce changes in the retention rate. Moreover, the competition between humic substances and synthetic chelating agents for complexing metal cations limited the effectiveness of the mixtures to mobilize nutrients from the substrates. The presence of Fe(o, p-EDDHA) and other byproducts in the commercial iron chelate had an important effect on the evolution of Fe(o, o-EDDHA) and the nutrient solubilization process.  相似文献   

A GIS-based integrated approach predicts accurately post-fire Aleppo pine regeneration at regional scale     

Kostas S. Poirazidis  Konstantina Zografou  Panagiotis Kordopatis  Dionissios P. Kalivas  Margarita Arianoutsou  Dimitrios Kazanis  Evangelia Korakaki 《Annals of Forest Science》2012,69(4):519-529

Context

This study investigates post-fire natural regeneration of Aleppo pine (Pinus halepensis) forests at Ilia region (Peloponnesus, Greece) following the catastrophic fire of 2007.

Aims

The objective of this study is the prediction of P. halepensis post-fire regeneration at a regional scale through an integrated geographic information systems (GIS) model as a basis for post-fire management plans.

Methods

The model was developed in three interconnected stages: (1) field data collection, (2) development of two prediction models (based on interpolation of field data and multi-criteria evaluation (MCE) that combined factors known to affect regeneration), and (3) combination of applied models using Bayesian statistics.

Results

Post-fire pine regeneration presented high variation among the studied plots. Redundancy analysis revealed the positive effect of fallen branches and a negative correlation with altitude. Both modeling approaches (geostatistical and MCE) predicted the post-fire pine regeneration with high accuracy. A very significant correlation (r?=?0.834, p?<?0.01) was found between the combined final model and the actual number of counted seedlings, illustrating that less than 10?% of the studied area corresponds to sites of very low post-fire pine regeneration.

Conclusions

The combination of GIS models increased the prediction success of different levels of pine regeneration. Low-altitude areas with low grass cover overlying tertiary deposits were proved the most suitable for pine regeneration, while stands developing on limestone proved least suitable. The proposed methodology provides management authorities with a sound tool to quickly assess Aleppo pine post-fire regeneration potential.  相似文献   

Changes in Eucalyptus globulus Labill. saplings growth and physiological parameters following fire-induced stem and crown damage in a plantation in north-western Spain     

Enrique Jiménez  José A. Vega  Cristina Fernández  Pedro Pérez-Gorostiaga  Pedro Cuiñas  Teresa Fonturbel  Margarita Alonso  María J. Rozados  Salvador Bará 《European Journal of Forest Research》2012,131(6):1967-1978

Stems and crowns of young Eucalyptus globulus Labill. saplings were experimentally damaged by fire to assess the short-term effects on tree growth and selected physiological parameters (stem sap flow density, electrical resistance of stem cambium and leaf stomatal conductance). Four different treatments were considered: partial stem damage (42 % of the stem circumference girdled by the direct application of heat in the cambium zone), crown foliage damage (56 % of crown volume scorched by heating the foliage with a torch), combined stem and crown damage, and no damage (control). Saplings displayed high sensitivity to crown scorching, in terms of basal area growth. The relative growth of the basal area of crown-damaged and stem + crown-damaged trees was, respectively, 3.1 and 6.2 times lower than that of undamaged trees for the 4 months following treatment. In contrast, stem injury alone did not have any negative effect on stem growth. The results suggest that tree growth is scarcely affected by low intensity surface fire and prescribed burning that do not affect the crown. Sap flow density, cambial electrical resistance and leaf stomatal conductance were useful indicators of the loss of physiological activity caused by fire. Although in the case of partial crown damage these parameters reflected a slight compensatory effect, the response was not sufficient to balance the loss of photosynthetic area. The study only focused on the initial effects of fire-related damage, and further research is clearly needed to determine the long-term effects of such damage.  相似文献   

Characterization of homologous and heterologous adaptive immune responses in porcine reproductive and respiratory syndrome virus infection     

Díaz I  Gimeno M  Darwich L  Navarro N  Kuzemtseva L  López S  Galindo I  Segalés J  Martín M  Pujols J  Mateu E 《Veterinary research》2012,43(1):30

The present study characterized the homologous and heterologous immune response in type-I porcine reproductive and respiratory syndrome virus (PRRSV) infection. Two experiments were conducted: in experiment 1, eight pigs were inoculated with PRRSV strain 3262 and 84 days post-inoculation (dpi) they were challenged with either strain 3262 or strain 3267 and followed for the next 14 days (98 dpi). In experiment 2, eight pigs were inoculated with strain 3267 and challenged at 84 dpi as above. Clinical course, viremia, humoral response (neutralizing and non-neutralizing antibodies, NA) and virus-specific IFN-γ responses (ELISPOT) were evaluated all throughout the study. Serum levels of IL-1, IL-6, IL-8, TNF-α and TGF-β were determined (ELISA) after the second challenge. In experiment 1 primo-inoculation with strain 3262 induced viremia of ≤ 28 days, low titres of homologous NA but strong IFN-γ responses. In contrast, strain 3267 induced longer viremias (up to 56 days), higher NA titres (≤ 6 log₂) and lower IFN-γ responses. Inoculation with 3267 produced higher serum IL-8 levels. After the re-challenge at 84 dpi, pigs in experiment 1 developed mostly a one week viremia regardless of the strain used. In experiment 2, neither the homologous nor the heterologous challenge resulted in detectable viremia although PRRSV was present in tonsils of some animals. Homologous re-inoculation with 3267 produced elevated TGF-β levels in serum for 7–14 days but this did not occur with the heterologous re-inoculation. In conclusion, inoculation with different PRRSV strains result in different virological and immunological outcomes and in different degrees of homologous and heterologous protection.  相似文献   

Dust mite species in the households of mite-sensitive dogs with atopic dermatitis     

Farmaki R  Saridomichelakis MN  Leontides L  Papazahariadou MG  Gioulekas D  Koutinas AF 《Veterinary dermatology》2012,23(3):222-e45

Background – The presence of important house dust and storage mite species in the microenvironment of atopic dogs has not been thoroughly investigated. Objectives – To compare the presence and population of five dust mite species (Dermatophagoides farinae, Dermatophagoides pteronyssinus, Acarus siro, Tyrophagus putrescentiae and Lepidoglyphus destructor) among households with mite‐sensitive atopic dogs (Group A), households with clinically healthy dogs (Group B) and households without pets (Group C, n = 25) in Greece. Animals – Twenty mite‐sensitive atopic dogs and 20 clinically healthy dogs. Methods – Dust samples were collected with a vacuum cleaner from owners’ mattresses (all groups) and from dogs’ sleeping areas (Groups A and B) or living room couch (Group C), once every season of the year. Following dust flotation, mites were counted and identified. Results – Dermatophagoides farinae was the most prevalent (60, 40 and 64% in Groups A, B and C, respectively), followed by D. pteronyssinus (45, 35 and 48%, respectively), whereas the three storage mites were found in fewer households. No major differences could be found between Groups A and B or between households with (Groups A and B) and without dogs (Group C) regarding the presence or numbers of the five dust mite species. Conclusions and clinical importance – The presence and population of five common house dust and storage mite species does not differ among Greek households with mite‐sensitive atopic dogs, households with healthy dogs and households without pets.  相似文献