Experimental infection of specific pathogen-free pigs with Campylobacter: excretion in faeces and transmission to non-inoculated pigs

Campylobacter species are leading agents of human bacterial gastroenteritis and consumption of food of animal origin is a major source of infection. Although pigs are known to frequently exhibit high counts of Campylobacter in their faeces, more information is needed about the dynamics of this excretion. An experimental trial was conducted to evaluate the faecal excretion of Campylobacter by 7-week-old specific pathogen-free piglets inoculated per os with three Campylobacter strains (one C. coli isolated from a pig, one C. coli and one C. jejuni from chickens) alone or simultaneously (5x10(7)CFU/strain). Non-inoculated pigs were housed in adjacent pens. Pigs were monitored for 80 days for clinical signs and by bacteriological analysis of faeces. Pigs inoculated with porcine C. coli or with a mix of the three strains excreted from 10(3) to 10(6)CFU/g of faeces with a slight decrease at the end of the trial. Animals inoculated with poultry C. coli or C. jejuni strain excreted a lower quantity and some of them stopped excreting. At the end of the trial, only C. coli was detected in the faeces of pigs inoculated simultaneously with the three bacteria. Moreover, the transmission of Campylobacter was noticed between pens for the two C. coli strains and all the neighbouring animals became shedders with a level of excretion similar to the inoculated pigs. Intermittence in the Campylobacter excretion was also observed. Finally, our study highlighted a host preference of Campylobacter, namely C. coli seems to have a higher colonization potential for pigs than C. jejuni.     

Symmetrical onychomadesis in Norwegian Gordon and English setters

This study reports the condition onychomadesis affecting multiple claws in Norwegian Gordon and English setters. Medical records of and claw biopsies from 18 Gordon and four English setters with onychomadesis of multiple claws were obtained from July 2005 to January 2007. Only dogs with symmetrical onychomadesis and no signs of concurrent disease were included. Histopathological features varied between dogs, but typically included interface dermatitis with subepidermal cleft formation, pigment incontinence, basal cell vacuolization and necrosis, spongiosis and lymphocytic exocytosis, a lymphocytic, plasmacytic subepidermal inflammation, and fibroplasia. In two dogs, histopathological signs of a superficial infection were present. The age of onset of disease varied between 2 and 7 years with a mean of 3.9 years, and was not correlated with vaccination time. Six of the affected dogs also had siblings with the disease. Due to the close relationship of the affected dogs, pedigree map analysis was not possible. Three dogs were euthanized because of the disease and two had regrowth of normal claws. Seventeen dogs had persistent onychodystrophy that typically was nonpainful during therapy which in most dogs consisted of fatty acid supplementation or prednisolone.     

Tracking the Transport of Silver Nanoparticles in Soil: a Saturated Column Experiment

Silver nanoparticles (AgNPs) can enter the environment when released from products containing them. As AgNPs enter soil, they are often retained in the soil profile and/or leached to the groundwater. This research assessed the transport of AgNPs in their “particle form” through the soil profile using a series of columns. Three soil types were put into soil columns: LSH (loam with high organic matter (OM)), LSL (loam with low OM), and Sand (no OM). The results showed that AgNP transport and retention in soil as well as particle size changes are affected by soil organic matter (OM) and the cation exchange capacity (CEC) of soil. OM affected the transport and retention of AgNPs. This was evident in the LSH columns where the OM concentration was the highest and the AgNP content the lowest in the soil layers and in the effluent water. The highest transported AgNP content was detected in the Sand columns where OM was the lowest. CEC had an impact on the particle size of the AgNPs that were retained in the soil layers. This was clear in columns packed with high CEC-containing soils (LSL and LSH) where AgNP particle size decreased more substantially than in the columns packed with sand. However, the decrease in AgNP sizes in the effluent water was less than the decrease in particle size of AgNPs transported through but retained in the soil. This means that the AgNPs that reached the effluent were transported directly from the first layer through the soil macropores. This work highlights the ability to track AgNPs at low concentrations (50 μg kg^?1) and monitor the changes in particle size potential as the particles leach through soil all of which increases our knowledge about AgNP transport mechanisms in porous media.     

Relaxations Below Glass Transition Temperature in Bread and Its Components

Dry glassy bread, cooked gluten, and gelatinized wheat starch-sucrose mixtures were prepared. Dielectric properties were studied as a function of temperature at different frequencies ranging from 100 to 1,000 kHz. Both bread and starch samples exhibited a tan δ peak at -53°C at 10 kHz, which is associated with a secondary relaxation characterized by an activation energy of 50 kJ/mol. The gluten sample did not show any relaxation in the temperature range studied. The magnitude of the relaxation peak was sensitive to the sucrose concentration of the starch sample. The higher the sucrose content, the greater the amplitude of the peak. Such an effect is attributed to a greater β-relaxation induced by an increasing number of relaxing units or increasing size of the loosely packed regions of the glass. However, it cannot be concluded whether the relaxation is associated with a group present on both starch and sucrose or that the sucrose has an enhancing effect on starch mobility.     

Rheological Properties of Soft Wheat Flour Doughs: Effect of Salt and Triglycerides

The small deformation rheological properties of wheat flour doughs in relation to their structure and hydration were studied by dynamic mechanical thermal analysis, differential scanning calorimetry, and electron spin resonance. The effect of salt and triglycerides was also examined and compared with results we obtained previously on starch dispersions. Moisture content was adjusted to 48 or 60% (w/w, wb). Samples contained 0–16% NaCl (g/100 g of flour‐water) and 0–18% triolein or lard (g/100 g of flour‐water). The obtained results suggested that starch has an active role in determining the evolution of dough rheological characteristics during heating. The main factors controlling rheological behavior during thermal treatment are the volume fraction and deformability of starch granules. Gluten changes the viscoelasticity of the continuous phase and competes with starch for water. The addition of sodium chloride to flour dispersions shifted the structural disorganization and rigidity increased during heating to higher temperatures. At >7% NaCl, the reverse effect was observed. The mechanism controlling the effect of salt on dough rheological behavior was explained in terms of effect on water properties and on starch structure and hydration. Triglycerides had a lubricant effect (i.e., lowering G′ modulus) on the wheat flour dough system. These effects are of great importance for production and quality of bakery products.     

Sustained exercise improves vertebral histomorphometry and modulates hormonal levels in rainbow trout

Abnormal compressions and fusions of vertebral bodies are frequently observed in reared rainbow trout and could result from chronic and unbearable muscle pressures acting on the axial skeleton during intensive growth. Sustained swimming at moderate speeds was shown to induce many positive effects on growth and swimming performances in salmonids, but yet little is known about its effects on vertebral remodeling processes and related hormonal regulation. Rainbow trout were subjected to three different swimming speeds (0, 1.0 and 1.5 body length (BL) s^− 1), starting one month after they were first fed (65 mm) and ending when they reached 260 mm in size (market-size of 275 g). At the end of the experiment, 20 trout were sampled in each lot (N = 60) and blood samples were taken. Vertebrae abnormalities were assessed by radiological examinations. Vertebrae from the middle axial region (V32–38) were selected to evaluate bone mineralization (BM) and total bone area (Tt-B.Ar.) on radiographed transverse sections (125 ± 10 μm). Assays were performed to evaluate mineral homeostasis (calcemia and phosphatemia), bone cell activities (alkaline phosphatase, ALP, and tartrate-resistant acid phosphatase, TRAP) and bone regulating hormones (calcitonin, CT and thyroid hormones, THs). Sustained exercise reduced the appearance of fused vertebrae, enhanced vertebral BM and decreased vertebral Tt-B.Ar., while it increased circulating CT and TH levels. No variations were observed on mineral homeostasis and bone cell activities. Increasing the swimming speed up to 1.5 BL s^− 1 had positive effects on the vertebral skeleton, and therefore, seems to be a suitable approach to prevent aggravation of vertebral abnormalities in juvenile trout. The changes observed in vertebral features are interpreted as a compromise between the necessity to mobilize vertebral mineral ions in response to various physiological demands and to maintain vertebral strength against mechanical constraints.     

Fate of polyphenols and antioxidant activity of barley throughout malting and brewing

Phenolic contents of barley and malt extracts and their corresponding antioxidant activities were investigated using a chromatographic online antioxidant detection system. Ethyl acetate extracts of barley and malt were separated using reverse phase HPLC and compounds eluting from the column were submitted to two UV–visible detections: one for the phenolic compounds; and the other for the reduced form of the radical cation 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+) after the compounds were allowed to react online with it. Prodelphinidin B3 and procyanidin B3 were identified as two major contributors in the antioxidant activity of barley, in addition to catechin. Malting had a dramatic impact on these three compounds by resulting in a sharp decrease in their detected amounts and the associated antioxidant activities. Two other antioxidants, ferulic and sinapic acids, showed a better ability to withstand not only malting but also brewing steps. As for the overall phenolic content and antioxidant capacity, the study showed that malting allowed a better release and/or extraction of phenolic compounds, while the first brewing step caused the most significant damage by drastically decreasing the total polyphenols and their activity. Hopping however did not significantly affect neither the phenolic content nor the antioxidant activity.