Vaccination of pigs with the S48 strain of Toxoplasma gondii – safer meat for human consumption     

Alison Burrells  Julio Benavides  German Cantón  Jo?o L Garcia  Paul M Bartley  Mintu Nath  Jackie Thomson  Francesca Chianini  Elisabeth A Innes  Frank Katzer 《Veterinary research》2015,46(1)

As clinical toxoplasmosis is not considered a problem in pigs, the main reason to implement a control strategy against Toxoplasma gondii (T. gondii) in this species is to reduce the establishment of T. gondii tissue cysts in pork, consequently reducing the risk of the parasite entering the human food chain. Consumption of T. gondii tissue cysts from raw or undercooked meat is one of the main sources of human infection, with infected pork being considered a high risk. This study incorporates a mouse bioassay with molecular detection of T. gondii DNA to study the effectiveness of vaccination (incomplete S48 strain) in its ability to reduce tissue cyst burden in pigs, following oocyst (M4 strain) challenge. Results from the mouse bioassay show that 100% of mice which had received porcine tissues from vaccinated and challenged pigs survived compared with 51.1% of mice which received tissues from non-vaccinated and challenged pigs. The presence (or absence) of T. gondii DNA from individual mouse brains also confirmed these results. This indicates a reduction in viable T. gondii tissue cysts within tissues from pigs which have been previously vaccinated with the S48 strain. In addition, the study demonstrated that the main predilection sites for the parasite were found to be brain and highly vascular muscles (such as tongue, diaphragm, heart and masseter) of pigs, while meat cuts used as human food such as chop, loin, left tricep and left semitendinosus, had a lower burden of T. gondii tissue cysts. These promising results highlight the potential of S48 strain tachyzoites for reducing the number of T. gondii tissues cysts in pork and thus improving food safety.  相似文献   

Bacteria associated with Glomus clarum spores influence mycorrhizal activity     

Lisette J.C XavierJames J Germida 《Soil biology & biochemistry》2003,35(3):471-478

The effects of bacteria associated with arbuscular mycorrhizal fungal (AMF) spores on spore germination, growth in vitro and on the pea-AMF symbiosis were evaluated. Bacterial colonies were recovered from untreated Glomus clarum NT4 spores and NT4 spores decontaminated with 5% chloramine-T for 30, 45 and 60 min on five different media. Both G+ and G− bacteria were recovered from untreated NT4 spores, whereas only G+ bacteria were isolated from decontaminated spores. An in vitro assessment of the effect of spore-associated bacteria on clean, decontaminated NT4 spores revealed that (i) most of the bacteria isolated from untreated spores generally did not significantly alter spore function, (ii) some bacteria isolated from clean, decontaminated spores inhibited or stimulated NT4 spore germination, (iii) stimulation of spore germination occurred only when bacteria were in contact with spores, and (iv) inhibition of spore germination was the result of volatile bacterial metabolites. A stimulatory bacterial isolate, Bacillus pabuli LA3, significantly (P<0.05) enhanced the shoot growth, AMF-colonization, shoot N content and P use efficiency of NT4-inoculated 6 week-old pea plants over that of plants co-inoculated with an inhibitory bacterial isolate, Bacillus chitinosporus LA6a and NT4.  相似文献   

Anaplasma marginale: lack of cross-protection between strains that share MSP1a variable region and MSP4     

Ocampo Espinoza V  Vázquez JE  Aguilar MD  Ortiz MA  Alarcón GJ  Rodríguez SD 《Veterinary microbiology》2006,114(1-2):34-40

In Mexico, there are no commercial alternatives for the immunoprophylaxis of bovine Anaplasmosis, a disease responsible for great economic losses. Blood derived Anaplasma marginale used for immunizing susceptible cattle has shown promising results for homologous protection and controversial results against unrelated strains. The present study examined, under controlled conditions, the cross-protective potential of an immunogen composed of blood derived A. marginale of three strains against challenge with strains not included in the immunogens. Groups 1 and 2 were immunized with blood derived Anaplasma from strains Mexico, Morelos and Yucatan, group 4 with strains Morelos, Veracruz and Yucatan, two more groups (2 and 5) of equal conditions were inoculated with an adjuvant alone. Groups 1, 4 and 5 were challenged with Mexico strain; groups 2 and 3 were challenge-inoculated with strain Veracruz; groups 3 and 5 with strains Veracruz and Mexico as controls. Only animals in group 1, immunized and challenged with strain Mexico showed adequate protection. Both groups challenged with strains not included in the immunogens developed poor protection, while all the controls had to be treated to prevent death.  相似文献   

Variants of the recently discovered avian gyrovirus 2 are detected in Southern Brazil and The Netherlands     

dos Santos HF  Knak MB  de Castro FL  Slongo J  Ritterbusch GA  Klein TA  Esteves PA  Silva AD  Trevisol IM  Claassen EA  Cornelissen LA  Lovato M  Franco AC  Roehe PM  Rijsewijk FA 《Veterinary microbiology》2012,155(2-4):230-236

A genome of a virus preliminarily named avian gyrovirus 2 (AGV2), a close relative to chicken anemia virus, was recently discovered in a chicken in the state of Rio Grande do Sul, Southern Brazil. To study the occurrence of AGV2 in Rio Grande do Sul and the neighboring state Santa Catarina, a number of adult chickens (n=108 and n=48, respectively) were tested for the presence of AGV2 DNA. An AGV2-specific PCR was developed, optimized and used to analyze DNA extracted from clinical samples. AGV2 DNA was detected in 98/108 (90.7%) of samples collected in the state of Rio Grande do Sul and 29/48 (60.4%) of the samples collected in the state of Santa Catarina. In order to check whether AGV2 DNA would be detected in samples from a geographically distant region, DNA from brain samples of 21 diseased chickens from the Netherlands were tested independently, by the same method. In such specimens, 9/21 (42.9%) brain tissue samples were found to contain AVG2 DNA. Sequence analysis of some of the PCR products demonstrated that the amplified AGV2 sequences could vary up to 15.8% and could preliminarily be divided in three groups. This indicated the occurrence of variants of AGV2, which may reflect differences in geographical origin and/or in biological properties. The data presented here provides evidence that AGV2 seems fairly distributed in chickens in Southern Brazil and that AGV2 also circulates in the Netherlands. Besides, circulating viruses display genetic variants whose significance should be further examined, particularly to determine whether AGV2 would play any role in chicken diseases.  相似文献   

Production of a bovine IL-12p40 probe and application using in situ hybridization on ruminant fixed tissues     

Germán Cantón  Paul Bartley  Kathryn Bartley  Helen Todd  Francesca Chianini  Frank Katzer 《Veterinary immunology and immunopathology》2013,151(3-4):342-347

Pro-inflammatory cytokines (particularly IL-12) are important for initiating protective T helper 1 (Th1)-type immune responses and hence vital for combating intracellular infections and tumours. In situ hybridization (ISH) provides a powerful diagnostic tool allowing the identification and localization of cells producing these mediators in fixed tissues. The objective of this work was to produce a bovine IL-12p40 probe that allows detection of IL-12p40 mRNA in fixed tissues from different ruminant species. The RNA probe sequence is 447 bp in length and from a region with high cross-species-sequence homology (>97.3% homology) to the ovine, cervine, caprine and bubaline IL-12p40 genes. ISH was carried out on paraformaldehyde fixed tissues collected from cattle, sheep and goats. The probe was efficient in identifying IL-12p40 expressing cells in fixed tissues from all these species. In conclusion, the IL-12p40 probe was efficient in identifying and localizing cells that express IL-12p40, and provides a good immuno-diagnostic technique to characterize immune responses in fixed tissues.  相似文献   

Seasonal water relations in four co-existing native shrub species from Northeastern Mexico     

Humberto González-Rodríguez  Jorge Isaac Sarquís-Ramírez  Israel Cantú-Silva  Roque Gonzalo Ramírez-Lozano  Juan Manuel López-Hernández 《Arid Land Research and Management》2016,30(4):375-388

Seasonal xylem water potentials (Ψ, MPa) and their relationship to soil water content and evaporative demand components were studied in the shrub species Acacia amentacea, Celtis ehrenbergiana, Forestiera angustifolia, and Parkinsonia texana var. macra. Predawn (Ψpd) and midday (Ψmd) water potentials were estimated at 15 days intervals, between January 15 and October 30, 2009 using a Scholander pressure bomb at 06:00 h (predawn) and 14:00 h (midday), respectively. During the humid period, Ψpd ranged from ?0.30 MPa (C. ehrenbergiana), to ?0.90 MPa (P. texana). In contrast, over the driest period, Ψpd varied between ?2.18 (P. texana) and ?3.94 MPa (F. angustifolia). At midday, P. texana and F. angustifolia showed the highest (?1.14 MPa) and lowest (?3.38 MPa) Ψ values, respectively. Average soil water content accounted for 35 to 70% of the variation in predawn Ψ. Furthermore, both Ψ reflected the environmental conditions, as indicated by typical correlations observed. The studied shrub species exhibited what seem to be different strategies to avoid damage caused by drought. Thus, P. texana behaved rather as an isohydric plant able to deal well with severe, but short periods of drought. Under exceptionally dry environmental conditions, Ψpd undercut Ψmd values. Similar observations have been made by researchers studying plants in dry ecosystems. All studied native species are recommended for reforestation of the Tamaulipan shrublands, although C. ehrenbergiana and F. angustifolia seem to have limited tolerances for extreme water stress.  相似文献   

Chemistry of the Nudibranch Aldisa andersoni: Structure and Biological Activity of Phorbazole Metabolites     

Genoveffa Nuzzo  Maria Letizia Ciavatta  Robert Kiss  V��ronique Mathieu  Helene Leclercqz  Emiliano Manzo  Guido Villani  Ernesto Mollo  Florence Lefranc  Lisette D��Souza  Margherita Gavagnin  Guido Cimino 《Marine drugs》2012,10(8):1799-1811

The first chemical study of the Indo-Pacific dorid nudibranch Aldisa andersoni resulted in the isolation of five chlorinated phenyl-pyrrolyloxazoles belonging to the phorbazole series. Two new molecules, 9-chloro-phorbazole D and N1-methyl-phorbazole A, co-occurring with known phorbazoles A, B and D, have been characterized. Phorbazoles were found to be present mainly in the external part of the mollusc. The structures of the new compounds were determined by interpretation of spectroscopic data, mainly NMR and mass spectrometry and by comparison with the literature data. Evaluation of feeding-deterrence activity as well as in vitro growth inhibitory properties in human cancer cells was also carried out.  相似文献   

Proteomic analysis reveals suppression of bark chitinases and proteinase inhibitors in citrus plants affected by the citrus sudden death disease     

Cantú MD  Mariano AG  Palma MS  Carrilho E  Wulff NA 《Phytopathology》2008,98(10):1084-1092

Citrus sudden death (CSD) is a disease of unknown etiology that greatly affects sweet oranges grafted on Rangpur lime rootstock, the most important rootstock in Brazilian citriculture. We performed a proteomic analysis to generate information related to this plant pathogen interaction. Protein profiles from healthy, CSD-affected and CSD-tolerant stem barks, were generated using two-dimensional gel electrophoresis. The protein spots were well distributed over a pI range of 3.26 to 9.97 and a molecular weight (MW) range from 7.1 to 120 kDa. The patterns of expressed proteins on 2-DE gels made it possible to distinguish healthy barks from CSD-affected barks. Protein spots with MW around 30 kDa and pI values ranging from 4.5 to 5.2 were down-regulated in the CSD-affected root-stock bark. This set of protein spots was identified as chitinases. Another set of proteins, ranging in pI from 6.1 to 9.6 with an MW of about 20 kDa, were also suppressed in CSD-affected rootstock bark; these were identified as miraculin-like proteins, potential trypsin inhibitors. Down-regulation of chitinases and proteinase inhibitors in CSD-affected plants is relevant since chitinases are well-known pathogenesis-related protein, and their activity against plant pathogens is largely accepted.  相似文献   

Genetic characterization of porcine circovirus type 2 in captive wild boars in southern Brazil     

Sato  José Paulo Hiroji  Gava  Danielle  Schaefer  Rejane  Cantão  Maurício Egídio  Ciacci-Zanella  Janice Reis  de Barcellos  David Emilio Santos Neves 《Tropical animal health and production》2017,49(5):1071-1075

Tropical Animal Health and Production - Porcine circovirus type 2 (PCV2) has been identified in pig population in Brazil since 2000, but scarce studies involving wild boars with PCV2 infection are...  相似文献   

Discriminating soil crust type,development stage and degree of disturbance in semiarid environments from their spectral characteristics     

S. Chamizo  A. Stevens  Y. Cantón  I. Miralles  F. Domingo  B. Van Wesemael 《European Journal of Soil Science》2012,63(1):42-53

Biological soil crusts (BSCs) are increasingly recognized as common features in arid and semiarid ecosystems and play an important role in the hydrological and ecological functioning of these ecosystems. However, BSCs are very vulnerable to, in particular, human disturbance. This results in a complex spatial pattern of BSCs in various stages of development. Such patterns, to a large extent, determine runoff and erosion processes in arid and semiarid ecosystems. In recent years, visible and near infrared (Vis‐NIR) diffuse reflectance spectroscopy has been used for large‐scale mapping of the distribution of BSCs. Our goals were (i) to demonstrate the efficiency of Vis‐NIR spectroscopy in discriminating vegetation, physical soil crusts, various developmental stages of BSCs, and various types of disturbance on BSCs and (ii) to develop a classification system for these types of ground cover based on Vis‐NIR spectroscopy. Spectral measurements were taken of vegetation, physical crusts and various types of BSCs prior to, and following, trampling or removal with a scraper in two semiarid areas in SE Spain. The main spectral differences were: (i) absorption by water at about 1450 nm, more intense in the spectra of vegetation than in those of physical crusts or BSCs, (ii) absorption features at about 500 and 680 nm for the BSCs, which were absent or very weak for physical crusts, (iii) a shallower slope between about 750 and 980 nm for physical crusts and early‐successional BSCs than for later‐successional BSCs and (iv) a steeper slope between about 680 and 750 nm for the most developed BSCs. A partial least squares regression‐linear discriminant analysis of the spectral data resulted in a reliable classification (Kappa coefficients over 0.90) of the various types of ground cover and types of BSC disturbance. The distinctive spectral features of vegetation, physical crusts and the various developmental stages of BSCs were used to develop a classification system. This will be a promising tool for mapping BSCs with hyperspectral remote sensing.  相似文献