Detection of Salmonella in food,feed and veterinary samples by EU laboratories

The European Union Reference Laboratory (EURL) for Salmonella organises interlaboratory comparison studies on bacteriological detection of Salmonella in different matrices (veterinary, food and animal feed) amongst National Reference Laboratories for Salmonella of the 27 European Member States (EU-MS). The EURL also gives non-EU Member States (EU candidate countries, member countries of the European Free Trade Association (EFTA) and third countries from outside Europe) the opportunity to participate in these studies. The objective of the studies is to test the ability of the participating laboratories to detect Salmonella at different contamination levels in the various matrices. In addition a comparison is made between the prescribed method of the food and animal feed studies (ISO 6579: RVS and MKTTn) and the prescribed method of the veterinary studies (annex D of ISO 6579: MSRV).This article describes the performance of the individual laboratories in the interlaboratory comparison studies as organised by the EURL for Salmonella in the period 2004-2010.The performance of the majority of the NRLs improved during the course of the studies. Overall the NRL laboratories performed well and were able to detect Salmonella in the different tested matrices. After improvement of the samples, it was possible to define criteria for good performance in the studies organised since 2006. In the eight interlaboratory comparison studies organised in the period 2006–2010, 15 laboratories found in total 19 deviations of which eight concerned a false positive blank result. The other deviations concerned sensitivity problems (false negative results). After checking and improving several technical aspects, the underperforming participating laboratories were able to improve their performance in a follow-up study.     

Monitoring of rotavirus infection in a paediatric hospital by RNA electrophoresis

During the spring of 1987 and the autumn of 1988, stool specimens were collected from infants and young children in the paediatric unit at H. F. Verwoerd Hospital, Pretoria, and examined for the presence of rotaviruses to assess the potential for hospital-acquired infection in the paediatric wards. Stool samples were also collected from children admitted to the hospital for causes unrelated to gastro-enteritis to investigate the possible asymptomatic carriage of rotavirus in this population. Hospital-acquired rotavirus infection was determined in only 9% of cases. Very little asymptomatic carriage of the virus was identified. Electrophoretic analysis of the rotavirus strains showed that the majority of the infections (20 of 42) were associated with a particular strain with a long RNA profile, while 7 minor strains co-circulated (5 with a long electrophoretype and 2 with a short one). An apparent small outbreak of nosocomial infection with a single strain was observed to occur in one of the paediatric wards during the spring and early summer.     

Backward masking performance during and after manic episodes.

In a longitudinal design, 16 inpatients with bipolar mood disorder and 16 normal control participants were administered measures of backward masking. Bipolar inpatients were assessed while actively manic and again following manic episode. Clinical state was determined from ratings on an expanded version of the Brief Psychiatric Rating Scale. Two backward masking paradigms were used: (a) a staircase method, which yielded a critical interstimulus interval, and (b) set interstimulus intervals, which provided a masking function. Bipolar patients performed significantly worse than the normal controls at both sessions, but the Group?×?Session interaction was nonsignificant with both masking procedures. The masking performance deficit for the manic patients was not related to the presence of psychotic symptoms but seemed to be partially associated with lithium treatment. The results indicate that the impaired masking performance of manic patients is not strictly limited to the period of the manic episode. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigation of particle flattening behaviour and bonding mechanisms of APS sprayed coatings on magnesium alloys

Magnesium alloys are promising alternatives to other lightweight materials due to their high specific strength and stiffness. However, the use of magnesium alloys is limited by their poor wear behaviour and low corrosion resistance for many industrial applications. The thermal spray technology offers a wide range of possibilities to improve the surface properties of Mg-based components. In this study, three different coating materials, namely Al, NiAl5 and Al₂O₃, were applied on AZ91 and AE42 substrates using the atmospheric plasma spray technology. The investigation was focused on the bonding strength of the coatings and the related bonding mechanisms. For a better understanding of the bonding mechanisms, the flattening behaviour of the spray particles was investigated in correlation with the substrate pre-heating temperature. It was found that NiAl5-particles could well melt the substrate at the surface and deformed it locally; Al-particles did the same but to a lower extent. The dominating bonding mechanism for NiAl5-coatings could be attributed to a metallurgical bonding. For Al-coatings, this mechanism played a more important role once the substrate pre-heating temperature was increased. Al₂O₃ particles in contrast, were less able to deform the substrate in spite of their higher thermal load and the mechanical anchoring remained the main bonding mechanism. The thermo physical properties of the Mg substrate showed also to have an influence on the adhesion of the coatings.     

Predialysis volume overload and patient‐reported sleep duration and quality in patients receiving hemodialysis

Introduction: Previous studies of patients with end‐stage renal disease have examined the role of fluid shifts on apnea‐hypopnea episodes, but the association between volume overload and patient‐reported sleep quality or duration has not been well‐established. Methods: We studied the association between predialysis bioimpedance spectroscopy‐derived volume estimates and self‐reported sleep quality and duration in 638 patients in the United States Renal Data System ACTIVE/ADIPOSE study receiving hemodialysis from 2009 to 2011. We used questionnaires to assess self‐reported sleep duration and quality. We used relative hydration status (fluid overload/extracellular water; FO/ECW) as the primary predictor and examined associations with hours of sleep duration using linear regression. We used multivariable ordinal logistic regression to determine the association between categories of relative hydration status (normal hydration [FO/ECW < 6.8%], mild overhydration [FO/ECW 6.8%–15%], and hyperhydration [FO/ECW > 15%]) and four levels of difficulty with falling asleep, waking, and returning to sleep. Findings: Higher relative hydration status was associated with fewer hours of sleep (?0.31 hours per 10%, 95% confidence interval (CI) ?0.49 to ?0.13). Compared to the normal hydration group, there was a statistically significant association between higher relative hydration status category and more frequent nighttime waking (OR: mild overhydration 1.92 [95% CI 1.23–2.99], hyperhydration 1.87 [95% CI 1.16–2.99]), a trend toward more difficulty returning to sleep (OR: mild overhydration 1.46 [95% CI 0.94–2.27], hyperhydration 1.52 [95% CI 0.95–2.43]), and no association between relative hydration category and difficulty falling asleep. Discussion: Hydration status was associated with self‐reported sleep duration in patients on dialysis. Future studies should prospectively examine the effects of optimizing fluid status on sleep duration and quality.     

A long-term seal- and cod-liver-oil supplementation in hypercholesterolemic subjects

In this long-term study, we wanted to explore the effect of dietary supplementation of seal oil (SO) as compared cod-liver oil (CLO) on subjects with moderate hypercholesterolemia. The test parameters included fatty acid composition in serum, blood lipids, platelet aggregation, and the activity of blood monocytes. After a run-in period of 6 mon, 120 clinically healthy hypercholesterolemic (7.0–9.5 mmol/L; 270–366 mg/dL) subjects were randomly selected to consume either 15 mL of SO or CLO daily for 14 mon followed by a 4-mon wash-out period. A third group was not given any dietary supplement (control). Consumption of marine oils (SO and CLO) changed the fatty acid composition of serum significantly. Maximal levels were achieved after 10 mon. No further changes were seen after 14 mon. A wash-out period of 4 mon hardly altered the level of n−3 fatty acids in serum. Addition of SO gave 30% higher level of eicosapentaenoic acid, as compared to CLO. Subjects taking SO or CLO had lower whole-blood platelet aggregation than the control group. Neither SO nor CLO had any effects on the levels of serum total cholesterol, high-density lipoprotein cholesterol, postprandial triacylglycerol, apolipoproteins A1 and B100, lipoprotein (a), monocyte function expressed as monocyte-derived tissue factor expression, and tumor necrosis factor.     

Dynamic mechanical and thermal properties of fire-retardant polypropylene

A study of the effect of a series of fire retardants and antimony oxide upon the dynamic mechanical and thermal properties of polypropylene suggests three categories. (1) “Inert Fillers”—These raise the elastis modulus and the heat distortion temperature of polypropylene without shifting its glass transition temperature. The melting point of polypropylene is only depressed by 1–3°C, the heat of fusion and the percentage of crystallinity of polypropylene in these composites is ～10 percent lower at additive concentrations of ～30 percent. Very poor interaction exists between the additive and the thermo-plastic which apparently exist in two separate phases. (2) “Chain Stiffener”—These raise the elastic modulus (～25 percent) and the glass transition (～11°C) for polypropylene; the melting point of polypropylene in the composite is lowered by ～6°C indicative of good interaction between the additive and polypropylene. (3) “Plasticizer”—These lower the room temperature elastic modulus (～20 percent) and the glass transition temperature (～11°C) of polypropylene; the melting point of polypropylene in the composite is depressed by ～10°C indicating good interaction. The efficacy of the “plasticizer” and “chain stiffener” are attributed partially to melting of polypropylene at the processing temperature.     

Fatty acid composition of danish margarines and shortenings,with special emphasis ontrans fatty acids

Trans fatty acids from hydrogenated vegetable and marine oils could be as hypercholesterolemic and atherogenic as saturated fatty acids. Hence, it is important to know the fatty acid composition in major food contributors, e.g., margarines and shortenings. In 1992 margarines were examined, and in 1995 brands covering the entire Danish market were examined. Significant amounts oftrans-18∶1 were found only in hard margarines (mean: 4.2±2.8%) and shortenings (mean: 6.8 ±3.1%), whereas the semisoft and soft margarines contained substantially lesstrans-18∶1 in 1995 than in 1992. Where marine oils had been used to a larger degree the meantrans-monoenoic content was about 15%, of which close to 50% was made up of long-chain (C₂₀ and C₂₂)trans fatty acids. A note-worthy decrease in the content oftrans-18∶1 had occurred for the semisoft margarines, from 9.8±6.1% in 1992 to 1.2±2.2% in 1995. Calculated from sales figures, the supply oftrans-18∶1 plus saturated fatty acids from margarines had decreased over this three-year period by 1.4 g/day, which has been replaced bycis monounsaturated and polyunsaturated fatty acids.     

In vitro evaluation of the microbial contamination on new toothbrushes: a preliminary study

Objective: The presence and survival of microorganisms on toothbrush bristles might play a role on the etiology of oral infections. The aim of this in vitro study was to evaluate the presence of bacterial contamination on new toothbrushes before oral contact. Materials and methods: Forty toothbrushes from five different manufacturers were used in this experimental study. Each manufacturer was divided according to conventional local of obtaining: industry, drugstore, market, and perfumery. The toothbrush heads were completely immersed into tubes containing 5.0 mL of sterile peptonated water (dilution 1:10). A group of eight tubes containing the sterile solution was used as control. After 21 days of anaerobic incubation, occurrence of contamination was visually evaluated and confirmed by light microscopy. Results: Bacterial growth in the medium, indicative of bristles contamination, was found in a total of 19 out of 40 samples (47.5%) evaluated: 6 out of 14 samples (42.85%) from industry group, 4 out of 8 samples (50.0%) from drugstore, 5 out of 10 samples (50.0%) from market, and 4 out of 8 samples (50.0%) from perfumery. Only the toothbrushes with bristles coated with chlorhexidine did not show contamination. The Gram‐negative sporulating bacilli were the most prevalent form recovered. Conclusions: Except for chlorhexidine group, bacterial growth was observed in all groups evaluated irrespective local of obtaining. Microsc. Res. Tech., 2012. © 2011 Wiley Periodicals, Inc.