Cover Image,Volume 16, Issue 1

The cover image, by Alexandra Keller et al., is based on the Original Article The JAK2/STAT5 signaling pathway as a potential therapeutic target in canine mastocytoma, DOI: 10.1111/vco.12311

     

Survey on the Listeria contamination of ready-to-eat food products and household environments in Vienna, Austria

Qualitative and quantitative contamination of ready-to-eat food-stuffs with the pathogen Listeria monocytogenes was studied in 1586 samples collected from 103 supermarkets (n = 946) and 61 households (n = 640) in Vienna, Austria. Seventeen groups of ready-to-eat foods were classified into three risk categories for contamination (CP1-CP3). Three to four samples were randomly collected at the retail level from each CP. Regarding the households, the sampling procedure was started with food items of CP1, and if not available, was continued with sampling of food items of CP2 and finally of CP3. Additionally, 184 environmental samples (swabs from the kitchen area, dust samples from the vacuum cleaner) and faecal samples (household members and pet animals) were included. One-hundred and twenty-four (13.1%) and 45 (4.8%) samples out of 946 food samples collected from food retailers tested positive for Listeria spp. and L. monocytogenes, respectively, with five smoked fish samples exceeding the tolerated limit of 100 CFU/g food. Food-stuffs associated with the highest risk of contamination were twice as frequently contaminated with L. monocytogenes as food-stuffs associated with a medium risk of contamination. Products showing the highest contamination rate were fish and seafood (19.4%), followed by raw meat sausages (6.3%), soft cheese (5.5%) and cooked meat products/patés (4.5%). The overall contamination rate of foods collected at the household level was more than two times lower. Only 5.6% and 1.7% of 640 food-stuffs analysed tested positive for Listeria spp. and L. monocytogenes, respectively. However, CP1 foods were rarely collected. Pulsed-field gel electrophoresis (PFGE) typing of the collected L. monocytogenes isolates revealed a high degree of diversity between the isolates, with some exceptions. PFGE typing of isolates harvested from green-veined cheese revealed a match among strains, although the manufacturer seemed to be distinguishable. Typing of household strains revealed an epidemiological link within one family. In this case, food-stuffs and the kitchen environment were contaminated by an indistinguishable isolate. In addition, the same isolate was collected from a pooled faecal sample of the household members suggesting that consumption of even low contaminated food items (<100 CFU/g) results in Listeria shedding after the passage through the gut.     

M-MODE ECHOCARDIOGRAPHIC REFERENCE VALUES IN CATS IN THE FIRST THREE MONTHS OF LIFE

Thirty-five young cats were studied by echocardiography from the 2nd to 12th weeks of life to analyze correlation between body weight, body surface area, age and heart rate with fourteen echocardiographic parameters. There was a positive linear correlation (r = 0.49-0.78) between the independent variables (body weight, body surface area, age) and left ventricular wall thickness and diameter, aortic diameter and left atrial diameter, whereas there was a negative correlation (r = -0.39 and r = -0.43) between the heart rate and left ventricular diameter during systole and diastole. No linear dependence of the fractional shortening, ejection fraction, percentage thickening of the interventricular septum and left ventricular posterior wall, LA/AO ratio, and the ratio IVSED/LVWED to the independent variables was observed.     

ULTRASONIC DIAGNOSIS OF OVARIAN CYSTS IN TEN GUINEA PIGS

Ten guinea pigs with an ovarian cyst had clinical signs of anorexia, alopecia, or depression. Ultrasonographic features of the 2- to 3-cm diameter fluid-filled cysts included compartmentalization and connection to the ovary. In two animals, a unilateral cyst was present, and in two others, the cysts were bilateral. Diagnosis of the disease by plain radiography is difficult because of the similar opacity of ovarian cysts, abdominal neoplasms, and trichobezoars.     

Comparative survival and growth performance of European lobster larvae,Homarus gammarus,reared on dry feed and conspecifics

A bottleneck of crustacean larval culture concerns nutrition and associated cannibalism in communal rearing systems, which impact on larval survival, development and growth. For early‐stage European lobster, Homarus gammarus larvae, feeding ecology and body composition are largely unknown. We initiated four progressive feeding experiments (novel feed types, feeding regime and feed size and cannibalism effects) on growth and survival, to inform and update husbandry protocols. Performance of larvae offered a dry commercial feed was not significantly different compared with a conventional wet plankton feed of the same ration and size grade (both within 600–1,000 μm). Further experiments found that the same ration of dry feed offered six times daily improved development and growth, over the conventional regime of three times daily. Small‐grade dry feed (particles: 250–360 μm) improved larval performance compared with a larger feed (360–650 μm). Larvae were also fed different proportions of dry feed and/or conspecifics in both communal and individual rearing systems (the latter preventing cannibalism via segregation). Individually reared larvae, fed only dead conspecifics, displayed the greatest survival (80%) to postlarvae. This underlines the impact of cannibalism on survival and nutrition in H. gammarus larviculture. A final experiment analysed H. gammarus zoea 1 composition, identifying deficiencies in ash and carbohydrate in lobster feeds. This suggests a need for a species‐specific, formulated dry feed for H. gammarus larviculture. Our research represents the first investigation of H. gammarus larval composition and dietary requirements and highlights decreased growth potential associated with providing nutrition solely from generic commercial feed.     

Indicative properties of fly‐ash affected forest soils in Northeastern Germany

Many forest ecosystems in Germany are strongly influenced by emissions of pollutants like SO₂ and alkaline dusts. To quantify and evaluate the consequences of long‐term fly ash deposition on forest soils, a study was conducted in pine stands (Pinus sylvestris) in the Dübener Heide in Northeastern Germany. This forest area has been influenced mainly by emissions from coal‐fired power plants and the chemical industry of the industrial region Bitterfeld‐Wolfen‐Zschornewitz since the early 1900. The study sites are located along a fly ash deposition gradient of 8, 16, 14, 18, and 25 km away from the main emission source in Bitterfeld (sites 1, 2, 3, 4, and 5, respectively). Samples of the organic horizons (Oi, Oe, and Oa) and mineral topsoil (0—10 cm) were taken in fall 1998 and analyzed for their ferromagnetic susceptibility and total ash content. Scanning electron microscopy (SEM) and energy dispersive X‐ray microanalysis (EDX) were performed on selected samples to differentiate between the pedogenic and atmospheric origin of the mineral components in the organic horizons. As a result of the long‐term deposition, ferromagnetic fly ash components are mainly accumulated in the Oe and Oa horizons of the forest soils studied. Ferromagnetic susceptibility was significantly higher (p ≤ 0.05) in the Oe horizon of sites 1 and 2 compared to sites 3, 4, and 5. Unusually high total ash contents for organic horizons of > 74 % were determined in the Oa at all sites. SEM revealed 3 distinct features of persistent fly ash deposits from coal‐fired power plants within the organic horizons that can be defined as ”︁stable glasses” with magnetic properties, aluminum‐silicate‐minerals, and slag fragments. SEM and EDX indicated that a great portion of the mineral particles found in the organic horizons of forests soils influenced by fly ash are from atmospheric sources. For detection of atmospheric lignite‐derived deposition into forest soils, the Oe and Oa horizons have to be considered as specific diagnostic horizons because they show indicative properties for such soils.     

Effects of High and Low Molecular Weight Glutenin Subunits on Rheological Dough Properties and Breadmaking Quality of Wheat

High molecular weight (HMW) or low molecular weight (LMW) subunits of different chemical state (reduced, reoxidized with KBrO₃, or KIO₃) or gliadins were added in 1% amounts to a base flour of the wheat cultivar Rektor and mixed with water. The corresponding doughs were then characterized by microscale extension tests and by microbaking tests and were compared to doughs from the base flour without additives. The maximum resistance of dough was strongly increased by HMW subunits in a reduced state and by HMW subunits reoxidized with KBrO₃. A moderate increase of resistance was caused by HMW subunits reoxidized with KIO₃ and by LMW subunits reoxidized with KBrO₃ or KIO₃. This resistance was strongly lowered by LMW subunits in a reduced state and by gliadins. The extensibility of dough was significantly increased only by gliadins and reduced HMW subunits; HMW subunits reoxidized with KBrO₃ had no effect, and all other fractions had a decreasing effect. In particular, glutenin subunits reoxidized with KIO₃ induced marked decrease of extensibility, resulting in bell‐shaped curve extensigrams, which are typical for plastic properties. The effect of reoxidized mixtures (2:1) of HMW and LMW subunits on maximum resistance depended on the oxidizing agent and on the conditions (reoxidation separated or together); extensibility was generally decreased. Bread volume was increased by addition of HMW subunits (reduced or reoxidized with KBrO₃) and decreased by LMW subunits (reoxidized with KBrO₃ or KIO₃) and by a HMW‐LMW subunit mixture (reoxidized with KBrO₃). The volume was strongly decreased by addition of reduced LMW subunits. A high bread volume was related to higher values for both resistance and extensibility.     

Comparative survival and growth performance of European lobster Homarus gammarus post‐larva reared on novel feeds

One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by‐products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post‐larval lobsters from post‐larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze‐dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven‐dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring‐based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non‐heat‐treated shrimp products are a promising feed ingredient for post‐larval European lobsters.     

Mobile and readily available C and N fractions and their relationship to microbial biomass and selected enzyme activities in a sandy soil under different management systems

Within different land‐use systems such as agriculture, forestry, and fallow, the different morphology and physiology of the plants, together with their specific management, lead to a system‐typical set of ecological conditions in the soil. The response of total, mobile, and easily available C and N fractions, microbial biomass, and enzyme activities involved in C and N cycling to different soil management was investigated in a sandy soil at a field study at Riesa, Northeastern Germany. The management systems included agricultural management (AM), succession fallow (SF), and forest management (FM). Samples of the mineral soil (0—5, 5—10, and 10—30 cm) were taken in spring 1999 and analyzed for their contents on organic C, total N, NH₄⁺‐N and NO₃^—‐N, KCl‐extractable organic C and N fractions (Corg_(KCl) and Norg_(KCl)), microbial biomass C and N, and activities of β‐glucosidase and L‐asparaginase. With the exception of Norg_(KCl), all investigated C and N pools showed a clear relationship to the land‐use system that was most pronounced in the 0—5 cm profile increment. SF resulted in greater contents of readily available C (Corg_(KCl)), NH₄⁺‐N, microbial biomass C and N, and enzyme activities in the uppermost 5 cm of the soil compared to all other systems studied. These differences were significant at P ≤ 0.05 to P ≤ 0.001. Comparably high C_mic:C_org ratios of 2.4 to 3.9 % in the SF plot imply a faster C and N turnover than in AM and FM plots. Forest management led to 1.5‐ to 2‐fold larger organic C contents compared to SF and AM plots, respectively. High organic C contents were coupled with low microbial biomass C (78 μg g^—1) and N contents (10.7 μg g^—1), extremely low C_mic : C_org ratios (0.2—0.6 %) and low β‐glucosidase (81 μg PN g^—1 h^—1) and L‐asparaginase (7.3 μg NH₄‐N g^—1 2 h^—1) activities. These results indicate a severe inhibition of mineralization processes in soils under locust stands. Under agricultural management, chemical and biological parameters expressed medium values with exception for NO₃^—‐N contents which were significantly higher than in SF and FM plots (P ≤ 0.005) and increased with increasing soil depth. Nevertheless, the depth gradient found for all studied parameters was most pronounced in soils under SF. Microbial biomass C and N were correlated to β‐glucosidase and L‐asparaginase activity (r ≥ 0.63; P ≤ 0.001). Furthermore, microbial biomass and enzyme activities were related to the amounts of readily mineralizable organic C (i.e. Corg_(KCl)) with r ≥ 0.41 (P ≤ 0.01), suggesting that (1) KCl‐extractable organic C compounds from field‐fresh prepared soils represent an important C source for soil microbial populations, and (2) that microbial biomass is an important source for enzymes in soil. The Norg_(KCl) pool is not necessarily related to the size of microbial biomass C and N and enzyme activities in soil.<?show $6#>