Comparison of antibiotic susceptibility profiles and molecular typing patterns of clinical and environmental Salmonella enterica serotype Newport

The genus Salmonella is composed of more than 2,400 serotypes, many of which cause enteric diseases in humans and animals. Several Salmonella serotypes are multidrug resistant, and there is evidence of the clonal spread of these strains from animals to humans. Salmonella enterica serotype Newport is one of the serotypes that increasingly present a multidrug-resistant phenotype. Source tracking and antibiotic resistance testing are important considerations for identifying the outbreak strain. The first goal of this study was to examine the antibiotic susceptibility patterns of clinical and environmental Salmonella Newport isolates from various geographic locations and to compare the discriminatory ability of two DNA fingerprinting techniques. The second goal was to determine whether the antibiotic resistance profiles and typing patterns correlated. Thirty Salmonella Newport isolates, including environmental and human clinical strains, were subjected to pulsed-field gel electrophoresis (PFGE), ribotyping, and antibiotic susceptibility testing. Eighty percent of the isolates showed total or intermediate resistance to one or more drugs; 75% of the isolates were multidrug resistant. Ribotyping with the EcoRI enzyme and PFGE with the XbaI enzyme each divided the isolates into 14 groups. Cluster analysis based on antibiotic susceptibility patterns generated 23 profiles. The susceptible and resistant isolates were not differentiated on the basis of either of the molecular typing techniques. Hence, no correlation was observed between the antibiotic resistance profiles and the DNA subtyping patterns. In conclusion, ribotyping is as discriminatory as PFGE and, when used in combination with antibiotic resistance profiles, provides a powerful tool for the source tracking of Salmonella Newport.     

Protease stability in bovine milk under combined thermal-high hydrostatic pressure treatment

At atmospheric pressure, inactivation of protease from B. subtilis in raw milk and pasteurized milk (with and without homogenization) was studied in a temperature range of 50–80 °C. Thermal inactivation followed a first order kinetic model in the temperature range tested. Temperature dependence of the first order inactivation rate constants could be accurately described by the Arrhenius equation, allowing Ea values to be calculated. Different milk systems did not show differences in enzyme thermo stability.The combined thermal (40, 50 and 60 °C)-high hydrostatic pressure (300–450 and 600 MPa) effect on protease activity was studied. Protease was very resistant to high pressures. Pressure stability was higher in raw milk than in pasteurized milk; homogenization appeared to have a protective effect on the enzyme. The separate effects of pressure and temperature on enzyme inactivation were related to changes in L?-values and milk appearance.A very pronounced antagonistic effect between high temperature and pressure was observed, i.e. at temperatures where thermal inactivation at atmospheric pressure occurs rapidly, application of pressure up to 600 MPa exerted a protective effect.Industrial relevanceHigh hydrostatic pressure (HHP) is an emerging technology that has been successfully applied as a minimal process for a variety of foods. Although the potential for the use of HHP treatment as an alternative method to heat treatment of milk was proposed almost a century ago, the suitability of this innovative technology to extend the shelf-life of milk hinges not only on its ability to inactivate pathogenic vegetative microorganisms but also on its effectiveness to inactivate indigenous and endogenous enzymes. This work examines the combined effects of temperature, pressure and homogenization on the protease (exogenous enzyme from B. subtilis) activity in milk. Inactivation of protease could extend the shelf life of milk.     

A mixed-species microarray for identification of food spoilage bacilli

Failure of food preservation is frequently caused by thermostable spores of members of the Bacillaceae family, which show a wide spectrum of resistance to cleaning and preservation treatments. We constructed and validated a mixed-species genotyping array for 6 Bacillus species, including Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus sporothermodurans, Bacillus cereus and Bacillus coagulans, and 4 Geobacillus species, including Geobacillus stearothermophilus, Geobacillus thermocatenulatus, Geobacillus toebii and Geobacillus sp., in order to track food spoilage isolates from ingredient to product. The discriminating power of the array was evaluated with sets of 42 reference and 20 test strains. Bacterial isolates contain a within-species-conserved core genome comprising 68-88% of the entire genome and a non-conserved accessory genome comprising 7-22%. The majority of the core genome markers do not hybridise between species, thus they allow for efficient discrimination at the species level. The accessory genome array markers provide high-resolution discrimination at the level of individual isolates from a single species. In conclusion, the reported mixed-species microarray contains discriminating markers that allow rapid and cost-effective typing of Bacillus food spoilage bacteria in a wide variety of food products.     

Oat-based complex stimulates skin barrier protein synthesis and reduces skin ageing

Citation: IFSCC Magazine , 11 (2008) (3) 225–229
The dermis is considered a highly dynamic structure that determines the biomechanical properties of the skin. It is composed of two dermal compartments separated by a vascular plexus: the papillary dermis and the reticular dermis. In the last few years, several studies have demonstrated the role of the dermal epidermal junction in the cutaneous ageing process. Recently, teams specialized in the study of the dermal matrix have focused their studies on the superior dermis in close contact with the dermal epidermal junction: the papillary dermis. They defined the role of matrix proteins in this area. Collagens XII and XVI, non-fibrillar collagens specific to the papillary dermis, are responsible for skin deformability and extensibility. Oxytalan fibres are related to elastic properties of the skin. Ubiquitous collagens such as collagens I and VI are associated with the cohesion and the resistance of the dermis. As the papillary dermis is the primary site of intrinsic dermal ageing, we studied expression of these molecules in our own in vitro model of intrinsic ageing of the papillary dermis. The results of this innovative approach confirmed that their expression was reduced. Nevertheless, active molecules may exist in nature that are capable of restoring a normal expression profile of these markers for a cosmetic anti-ageing application.
Keywords:  Anti-ageing, papillary dermis, collagens XVI and XII, oxytalan fibres     

Resistance of Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter jejuni after exposure to repetitive cycles of mild bactericidal treatments

While maintaining nutritional and sensorial attributes of fresh foods mild processing technologies generally deliver microbiologically perishable food products. Currently little information exists on possible increase in the resistance of pathogens after repetitive exposure to mild (sub-lethal) treatments. Multiple strain-cocktails of Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter jejuni were exposed to 20 consecutive cycles of sub-lethal inactivation by three different techniques. Used techniques comprised inactivation with lactic acid (LA), chlorine dioxide (ClO₂) and intense light pulses (ILP). Results showed that the selection of resistant cells was both species and technique dependent. While repetitive cycles of ClO₂ treatment did not result in increased resistance, repetitive inactivation with LA yielded L. monocytogenes culture of higher resistance in comparison to the parental culture. The increased resistance, expressed as decreased level of reduction in bacterial counts in subsequent inactivation cycles, was also observed with ILP for both L. monocytogenes and E. coli O157:H7 strains. Visual trend observations were confirmed through statistical linear regression analysis. No such effects were noted for C. jejuni which became undetectable after first 2–5 cycles. Current findings indicate the ability of foodborne pathogens to adapt to mild bactericidal treatments creating new challenges in risk assessment and more specifically in hazard analysis.     

Ernährung und Klimaschutz: Orientierung für Verbraucher

Zusammenfassung:  Als Ursache der globalen Klima?nderung wird vor allem der Energieverbrauch in Industrie, Haushalten und bei Transporten diskutiert. Erheblichen Anteil haben auch die Klimagase aus der Landwirtschaft und dem Ern?hrungssektor, doch fehlt es hier bislang an klaren Forderungen zu deren Reduzierung. Besondere Dramatik bekommt die Klima?nderung durch die Tatsache, dass historisch vor allem die Industriel?nder dafür verantwortlich sind, die L?nder des Südens aber st?rker beeintr?chtigt werden. Immer mehr landwirtschaftliche Fl?chen dienen nicht mehr direkt der menschlichen Ern?hrung, sondern der Produktion von Tierfutter, Energietr?gern und Rohstoffen – vorwiegend für die reichen Industriel?nder. Der Kampf gegen den Hunger in der Welt wird durch die Klima?nderung mit der Ausweitung von Wüsten und Ernteeinbu?en zus?tzlich erschwert. Deshalb müssen die Emissionen rasch und verbindlich zurückgeführt und die Klima?nderung begrenzt werden – auch im Sektor Landwirtschaft / Ern?hrung. Verbraucher in Deutschland und Europa sind grunds?tzlich über die Klima?nderung sehr besorgt und entsprechend motiviert, etwas für den Klimaschutz zu tun. H?ufig fehlen aber handlungsorientierte und alltagsad?quate Informationen und Empfehlungen. Für den Ern?hrungssektor sollen CO ₂-Labels, Energie- und ?kobilanzen solche Informationen liefern, führen aber oft zu widersprüchlichen Aussagen und tragen daher mehr zur Verwirrung als zur Orientierung der Verbraucher bei. Die Aussagen und Empfehlungen sollten leicht verst?ndlich und attraktiv formuliert sein, um zu motivieren. Sie sollten eine Bandbreite verschiedener Ma?nahmen er?ffnen, um individuelle Vorlieben zu erm?glichen. Und sie sollten eine grunds?tzliche Orientierung geben und dabei vermeintliche Widersprüche im Detail vernachl?ssigen. Zum Füllen dieser Lücke m?chten die Verbraucherzentralen mit der Ausstellung „Klimaschutz schmeckt“ beitragen. Eingegangen: 8. April 2009; angenommen: 14. April 2009     

Wachstum der Weltbevölkerung und nachhaltige Tragfähigkeit

Das globale Wachstum der Weltbev?lkerung und die Folgen der zunehmenden Verst?dterung lassen angesichts der weltweiten Verbreitung von Armut und Unterern?hrung die Frage nach den künftigen Grenzen der agraren Tragf?higkeit der Erde aufkommen. Das von den UN-Modellrechnungen, die in der vorliegenden Ver?ffentlichung im überblick vorgestellt werden, vorausberechnete weitere Bev?lkerungswachstum und der Fl?chenverbrauch durch die zunehmende Verst?dterung und Industrialisierung lassen die pro Kopf der Weltbev?lkerung für die Nahrungsmittelproduktion verfügbare Anbaufl?che bis zur Jahrhundertmitte deutlich schrumpfen. Hinzu kommen die gegenw?rtig nur schwer absehbaren Auswirkungen von Bodendegradation und Klimawandel auf die Produktion von Nahrungsmitteln. Ob es hinsichtlich der Tragf?higkeit eine mehr als theoretische Grenze für die Zahl an Menschen gibt, die auf der Erde unter optimalen Bedingungen ern?hrt werden k?nnen, ist umstritten. Trotz eines Rückgangs an agrarer Nutzfl?che pro Kopf geht die FAO in ihrer Prognose aktuell davon aus, dass das globale Angebot an Kalorien pro Kopf der Weltbev?lkerung bis 2030 gesteigert und die Anzahl von Unterern?hrung betroffener Menschen deutlich reduziert werden kann. Unter dem Aspekt der Nachhaltigkeit ist die Produktion von Nahrungsmitteln aber vor allem im Kontext der aktuellen Produktionsbedingungen und der Konkurrenz zu anderen Konsumbereichen zu betrachten und diesbezüglich ist nach Berechnungen des Global Footprint Networks, die hier herangezogen werden, bereits in den 1980er Jahren die Biokapazit?t der Erde für eine nachhaltige Entwicklung überschritten worden. Setzt sich die derzeitige Entwicklung fort, wird unter Einbeziehung des von der UN angenommenen globalen Bev?lkerungswachstums die Biokapazit?t der Erde bis 2050 um mehr als das Doppelte überschritten werden. Eingegangen: 9. Januar 2009; angenommen: 16. Januar 2009 http://www.bib-demographie.de     

Effect of race on peer ratings in an industrial situation.

Examined the effect of race on the peer ratings of 43 black and 50 white industrial employees recently exposed to a foreman-training program which included intensive human relations training. Contrary to previous studies, no race effect was found. In addition, almost all the requirements for convergent and discriminant validity between the races were met. Possible explanations for these results and implications for the use of peer ratings in integrated settings are discussed. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vitamins in brewing: effects of post‐fermentation treatments and exposure and maturation on the thiamine and riboflavin vitamer content of beer

Post‐fermentation processes and maturation are important steps in beer production as they help to shape the organoleptic properties and stabilize the final product. Brewers can use a variety of processing aids (e.g. isinglass, PVPP, etc.) and processes (e.g. pasteurization, bottle conditioning, etc.) to achieve a desired final product with a desirable shelf life; however, these processes can have detrimental effects on the vitamin content of the beer. This research found that heat treatments have a marked influence on the decrease in the thiamine diphosphate vitamer, while PVPP and silica treatments have a greater influence on the decrease in riboflavin vitamers. Refrigeration, filtration or centrifugation have no, or only very limited, influence on thiamine or riboflavin vitamers, while application of isinglass, bentonite, tannic acid and SO₂ causes a decrease in both thiamine and riboflavin vitamers. Storage of beer at refrigerated temperatures appears to provide protection against significant degradation of both thiamine and riboflavin vitamers; however, storage of filtered beer at elevated temperatures shows a decrease in thiamine diphosphate and riboflavin. Storage of bottle‐conditioned beer at elevated temperatures shows a marked decrease in yeast viability, accompanied by a decrease in thiamine diphosphate and free riboflavin, and a marked increase in free thiamine. These findings provide an insight into the reason why there is a significant variation in the vitamer content of beers, even within a single beer style. Copyright © 2016 The Institute of Brewing & Distilling