Single-step purification and evaluation of recombinant BP26 protein for serological diagnosis of Brucella ovis infection in rams

To investigate the value of the BP26 protein in the serological diagnosis of ovine brucellosis caused by Brucella ovis, recombinant BP26 protein was produced in Echerichia coli and purified for use in an indirect enzyme-linked immunosorbent assay (I-ELISA). The majority of the recombinant protein was recovered from the supernatant of sonicated recombinant E. coli cells in a soluble form. This facilitated the purification of the recombinant BP26 protein which was achieved by using ion-exchange chromatography. After one step of purification, the purity of the recombinant BP26 protein was analyzed by using SDS-PAGE, Coomassie blue staining, and Western blot with a monoclonal antibody (MAb) directed against the BP26 protein. The degree of purity appeared satisfactory so that it could be directly used in I-ELISA. Although the recombinant BP26-ELISA appeared less useful than I-ELISA using the B. ovis hot saline (HS) extract as antigen, the high number of sera from B. ovis infected rams found positive (90%) in the recombinant BP26-I-ELISA indicated that the BP26 protein may be an additional suitable antigen for serological diagnosis of B. ovis infection in rams.     

Effect of Climoedaphic Heterogeneity on Woody Plant Dominance in the Argentine Caldenal Region

Woody plant encroachment is widespread throughout drylands of the world, but rates and patterns of encroachment at the regional scale can be mediated by soil and climate. Climoedaphic properties may therefore help to explain patterns of woody plant dominance. In the Caldenal region of central Argentina, which is experiencing widespread woody plant encroachment, we used stratified and targeted inventory of vegetation and soils alongside climate data to classify vegetation states and then identify factors indicating resistance to woody plant encroachment. We found that three climoedaphic contexts differed in the degree of woody plant dominance. Sandsheet landforms had the lowest likelihood of a shrub thicket state. Within loamy soils, sites with deep soil carbonates in warmer and wetter climates were less likely to feature a shrub thicket state than sites with shallow carbonates in cooler and drier climates. These contexts serve as a basis for recognizing different ecological sites to assist mapping and prioritization of management interventions in the Caldenal region. Simple inventory-based approaches can be helpful for designing land management recommendations in other ecosystems.     

Coccygeal chordoma in a dog.

A 4-cm diameter spherical mass was removed from the region of the second coccygeal vertebra of a 6-year-old female Doberman Pinscher dog. The mass had been present for 7 months and was described as multilobular and smooth. Histologically, the neoplasm consisted of small spindle-shaped cells surrounding lobules of large vacuolated polygonal cells. Mucin was present within most lobules. The large polygonal cells stained positively with antibodies against vimentin, cytokeratin, and S-100 protein. Although the spindle-shaped cells stained positively with antibodies against vimentin, they only occasionally contained cytokeratin. The histology and immunohistochemistry are consistent with that reported for chordoma. Although 4 chordomas have previously been reported in dogs, this is the first case in which immunohistochemistry has been used to support the histological diagnosis. Neither recurrence nor metastasis was reported 10 months after surgical excision.