Evidence for the facultative intracellular behaviour of the fish pathogen Vibrio ordalii

Vibrio ordalii is an extracellular, Gram‐negative bacterium that produces vibriosis in salmonids. While pathogenesis is not fully understood, this bacterium has numerous likely genes for adhesion, colonization, invasion factors and, as recently suggested, intracellular behaviour. Therefore, this study aimed to clarify possible intracellular behaviour for V. ordalii Vo‐LM‐18 and ATCC 33509^T in the fish‐cell lines SHK‐1 and CHSE‐214. Confocal microscopy revealed Vo‐LM‐18 and ATCC 33509^T inside cytoplasm in both fish‐cell lines at 4 hr post‐inoculation (hpi). At 8 and 16 hpi, the proportion of fish cells invaded by both strains increased. Moreover, intracellular V. ordalii were observed after 8 hpi inside mouse embryonic fibroblasts (MEF), demonstrating that entry was not due to a cellular phagocytosis process. Flow cytometry confirmed immunocytochemistry results, with both V. ordalii evidencing statistically significant differences in the number of infected cells between 8 and 16 hpi. Interestingly, V. ordalii infection did not significantly damage fish cells, as determined by LDH liberation. Viable counts at 8 hpi detected, on average for both lines, 176 ± 47 CFU/ml of culturable intracellular Vo‐LM‐18 and ATCC 33509^T cells. These in vitro findings support the facultative intracellular behaviour of V. ordalii and may be of importance for understanding pathogenicity and survival in aquatic environments.     

Tissue composition,blood biochemistry and histology of digestive organs in Senegalese sole (Solea senegalensis) juveniles fed diets containing different plant protein ingredients

The aim of this study was to determine the impact of diets with different plant protein ingredients on proximate composition, tissue metabolites and tissue fatty acid composition, as well as hepatic and intestinal histological modifications in Senegalese sole (Solea senegalensis). Fish (21.5 ± 2.8 g body weight) were fed six isonitrogenous and isoenergetic diets during 11 weeks. A control diet containing fish meal as the main protein source was compared with five experimental diets replacing 30% fish meal protein by different plant protein sources: soybean meal (SBM), soybean protein concentrate (SPC), soybean protein isolate (SPI), wheat gluten meal (WGM) or pea protein concentrate (PPC). The inclusion of different plant protein did not significantly affect growth and proximate composition of fish. The hepatosomatic index was not significantly different to the control group; however, utilization of WGM significantly increased hepatocyte size. Plasma protein values and muscle triglycerides were influenced by the inclusion of SBM and WGM in the diets respectively. Feeding fish on SBM, WGM and PPC diets significantly enhanced n‐6 fatty acid levels in muscle, particularly linoleic acid. None of the plant protein ingredient used in the diets decreased arachidonic, eicosapentaenoic as well as docosahexaenoic acid values in liver and muscle. Overall, histological studies did not reveal the existence of any intestinal alterations induced by the inclusion of different plant proteins. Despite moderate changes produced by SBM, SPC and WGM, inclusion of dietary plant protein ingredients has no major impact on growth, tissue and blood biochemistry, fatty acid profile and gut integrity of Senegalese sole juveniles.     

Morphology and distribution of wheat and maize roots as affected by tillage systems and soil physical parameters in temperate climates: an overview

Congregated information on maize and wheat root morphology and their distribution as influenced by tillage and soil physical conditions is meager. Root growth under no-tillage (NT) or conventional tillage (CT) is variable: Under NT, higher bulk density slows root elongation and provides shorter roots but simulate root branching; results may be opposite depending on soil texture. Under CT, soil compaction may have negative effects on root growth, with roots exhibiting plasticity. In humid climates, low soil temperatures can reduce root length density (RLD) and increase the diameter of spring cereals under NT. Tillage intensity induces a different distribution of nutrients, a trend which increases with time resulting in higher RLD in the topmost layer of NT. Compared to maize it is difficult to present an overview of the effect on tillage on the RLD of wheat due to inconclusive results. Adequate placements of banded starter fertilizer will effectively build up an early root system of maize, especially at suboptimal growth temperatures. Many studies reported a higher or similar grain yield of maize or wheat under NT compared to CT in temperate climates. However, the limited information or the conflicting results will promote the topic for inclusion in future breeding programs.     

Genetic diversity of Melon necrotic spot virus and Olpidium isolates from different origins

The geographic incidence, genetic diversity and phylogenetic relationships of Melon necrotic spot virus (MNSV) and Olpidium isolates were studied in three cucurbit species from several Latin American and European countries on different collecting dates. Of the 112 cucurbit samples analysed, 69 from Guatemala, Honduras, Mexico, Panama and Spain were DAS‐ELISA‐positive for MNSV. Olpidium bornovanus and O. virulentus infections, and MNSV infections mixed with these Olpidium species, were observed for all these countries. Twenty‐nine MNSV isolates from all the origins where the virus was detected were selected and amplified by RT‐PCR. The resulting RT‐PCR of the p29, p89, p7A, p7B and p42 proteins was used to estimate the genetic diversity and the phylogenetic relationships of the MNSV population. The sequences obtained in this study were compared with the MNSV sequences of the NCBI database, and three groups were recovered by nucleotide composition according to geographical origins: the EU‐LA genotype group (with two subgroups: EU and LA, European and Latin American isolates, respectively), the JP melon genotype group (Japanese melon reference isolates) and the JP watermelon genotype group (Japanese watermelon reference isolates). The genetic diversity in the entire p7A and p7B proteins of MNSV suggests that these coding regions are under strong selective pressure. Additionally, the rDNA‐ITS region was analysed in 40 O. bornovanus and O. virulentus isolates associated with each geographical location and host examined. Phylogenetic analysis showed two groups for each Olpidium species, and these groupings were related to the host from which they were originally isolated.     

Nitrogen Leaching Of Spring Wheat Genotypes (Triticum Aestivum L.) Varying In Nitrogen-Related Traits

Efficient use of nitrogen (N) by wheat crop and hence prevention of possible contamination of ground and surface waters by nitrates has aroused environmental concerns. The present study was conducted in drainage lysimeters for three years (1998–2000) to identify whether spring wheat genotypes (Triticum aestivum L.) that differ in N-related traits differ in N leaching and to relate parameters of N use efficiency (NUE) with parameters of N leaching. For this reason two spring wheat cultivars (‘Albis’ and ‘Toronit’) and an experimental line (‘L94491’) were grown under low (20 kg N ha^?1) and ample N supply (270 kg N ha^?1). The genotypes varied in parameters of NUE but not in N leaching. Grain yield of the high-protein line (‘L94491’) was, on average, 11% lower than that of ‘Toronit’ but among genotypes had significantly higher N in the grain (%), grain N yield, and N harvest index. Nitrogen lost through leaching was considerably low (0.42–0.52 g m^?2) mainly due to low volume of percolating water or the ability of the genotypes to efficiently exploit soil mineral N. There were no clear relationships between N-related genotype traits and N leaching, but across all treatments significantly negative correlations between volume of leachate and the amount of N in the total biomass and grain N yield existed.     

Evaluation of the Lime-Cooking and Tortilla Making Properties of Quality Protein Maize Hybrids Grown in Mexico

Eleven experimental and three commercial white quality protein maize (QPM) hybrids and two regular endosperm controls were planted at Celaya, Guanajuato, Mexico with the aim of comparing grain physical characteristics, protein quality, lime-cooking and tortilla making properties. All genotypes were planted under irrigation using a density of 80,000 plants/ha and fertilized with 250 kg N-60 P-60 K per hectare. When compared with the controls these QPM genotypes had lower test (77.4 vs. 76.5 kg/hL) and 1,000 kernel weights (327 vs. 307 g), softer endosperm texture (2.5 vs. 1.8 where 1 = soft, 2 intermediate and 3 hard endosperm), lower protein (10.0 vs. 8.0%), higher nixtamal water uptake after 30 min lime-cooking (50.0 vs. 53.1% moisture) and lower pericarp removal scores. The lower thousand-kernel weight and softer endosperm texture observed in the QPM genotypes lowered the optimum lime-cooking time as estimated with regression equations. Most QPM genotypes had higher amounts of lysine, tryptophan and albumins/globulins when compared with the controls. QPMs HEC 424973, HEC 774986 and HEC 734286 had the best grain traits for nixtamalization and therefore the best potential for industrial utilization. The commercial use of these QPM hybrids should benefit Mexicans who depend on tortillas as the main staple.     

Physicochemical characterization of goat milk produced in the Comarca Lagunera,Mexico

The purpose of this study was to determine goat milk physicochemical parameters during the feed scarcity season. An evaluation was made for 398 milk samples from 80 multiparous goats belonging to three different production systems: (S1) mechanized milking grazing pasture and harvested residue (alfalfa) and grain supplemented; (S2) system grazing native pasture; and (S3) system grazing native pasture and grain supplemented. The general averages were: fat (FT) 4.0 ± 0.20%, protein (PR) 3.3 ± 0.05%, lactose (LC) 4.9 ± 0.09%, nonfat solids (NFS) 8.9 ± 0.13%, total solids (TS) 14.5 ± 0.20%, temperature (TM) 24.6 ± 1.06°C, and acidity (pH) 6.7 ± 0.049. Most of the physicochemical components of milk were affected (p < 0.0001) by the production system × month interaction and production system × group × month interaction. The FT content was higher (p < 0.05) in S2 (4.56 ± 0.18) than in S1 (3.64 ± 0.20) and S3 (3.50 ± 0.20). LC differed (p < 0.05) in S2 (5.07 ± 0.08) than in S1 (4.77 ± 0.09) and S3 (4.70 ± 0.09). No differences were observed for the rest of the variables (p < 0.05) among the production systems. The study unveiled a higher content of FT, LC, NFS, PR, and TS for S2 than for S1 and S3. This higher content may be explained because S2 only grazed on herbs and shrubs, in contrast to S1 and S3 which were additionally supplemented with grain concentrates.     

Ascorbic acid–cyclodextrin complex alters the expression of genes associated with lipid metabolism in bovine in vitro produced embryos

Ascorbic acid (AC) used as antioxidant in embryo culture is very sensitive and degrades unavoidably in aqueous solution. Methyl‐β‐cyclodextrin (CD) improved the stability of AC in solution to elevated temperature, light, humidity and oxidation. The aim of this study was to evaluate the effect of the complex AC‐CD during in vitro maturation (IVM) or in vitro culture (IVC) on oocyte developmental competence and subsequent embryo development and quality. AC‐CD (100 µM) was added to IVM media, and maturation level and embryo development were examined. Matured oocytes, their cumulus cells and produced blastocysts were snap‐frozen for gene expression analysis by RT‐qPCR. Besides, in vitro‐produced zygotes were cultured with 100 µM of AC‐CD and blastocysts were as well snap‐frozen for gene expression analysis. A group without AC‐CD (control^?) and other with CD (control⁺) were included. No differences were found on maturation, cleavage or blastocyst rates. However, in matured oocytes, AC‐CD downregulated BAX, GPX1 and BMP15. In cumulus cells, AC‐CD downregulated BAX/BCL2 and GSTA4 while upregulated BCL2 and CYP51A1. The expression of SL2A1, FADS1, PNPLA and MTORC1 was downregulated in blastocysts derived from oocytes matured with AC‐CD, while in blastocysts derived from zygote cultured with AC‐CD, CYP51A1 and IGF2R were downregulated and PNPLA2 was upregulated. In conclusion, AC‐CD in both IVM and IVC media may reduce accumulated fat by increasing lipolysis and suppressing lipogenesis in blastocysts derived from both oocytes and zygotes cultured with AC‐CD, suggesting that CD improves the quality of embryos and bioavailability of AC during IVM and IVC.     

Concurrent Diseases and Conditions in Dogs with Splenic Vein Thrombosis

Background: Splenic venous thrombosis (SVT) is usually considered an incidental finding on abdominal ultrasound examination but can indicate the presence of underlying disease. Concurrent disease processes and conditions in dogs with SVT have not been identified previously. Objectives: To identify concurrent diseases and conditions in dogs with SVT. Animals: Eighty dogs with SVT. Methods: Retrospective review. Medical records from 1994 through 2008 were searched for dogs with SVT identified by ultrasound examination. These records were then reviewed for signalment, medical history, clinicopathologic testing, diagnostic imaging, and clinical diagnosis. Results: The most common concurrent conditions were neoplasia (54%), exogenous corticosteroid administration (43%), systemic inflammatory response syndrome (26%), disseminated intravascular coagulation (20%), pancreatitis (18%), and immune‐mediated disease (16%). The most common neoplastic disease was lymphoma, and the most common immune‐mediated disease was immune‐mediated hemolytic anemia. Protein‐losing nephropathy and naturally occurring hyperadrenocorticism were identified in <10% of the dogs. Concurrent splenic infarcts were identified in 33% of dogs, and concurrent portal vein thrombi were found in 18% of dogs. Conclusions: SVT is a sonographic finding of clinical importance, and dogs with SVT can have 1 or more coexisting diseases.