Trends in technology, trade and consumption likely to impact on microbial food safety

Current and potential future trends in technology, consumption and trade of food that may impact on food-borne disease are analysed and the key driving factors identified focusing on the European Union and, to a lesser extent, accounting for the United States and global issues. Understanding of factors is developed using system-based methods and their impact is discussed in relation to current events and predictions of future trends. These factors come from a wide range of spheres relevant to food and include political, economic, social, technological, regulatory and environmental drivers. The degree of certainty in assessing the impact of important driving factors is considered in relation to food-borne disease. The most important factors driving an increase in the burden of food-borne disease in the next few decades were found to be the anticipated doubling of the global demand for food and of the international trade in food next to a significantly increased consumption of certain high-value food commodities such as meat and poultry and fresh produce. A less important factor potentially increasing the food-borne disease burden would be the increased demand for convenience foods. Factors that may contribute to a reduction in the food-borne disease burden were identified as the ability of governments around the world to take effective regulatory measures as well as the development and use of new food safety technologies and detection methods. The most important factor in reducing the burden of food-borne disease was identified as our ability to first detect and investigate a food safety issue and then to develop effective control measures. Given the global scale of impact on food safety that current and potentially future trends have, either by potentially increasing or decreasing the food-borne disease burden, it is concluded that a key role is fulfilled by intergovernmental organisations and by international standard setting bodies in coordinating the establishment and rolling-out of effective measures that, on balance, help ensure long-term consumer protection and fair international trade. Keywords: Microbial food safety; Food technology; Globalizatio

Comparing nonsynergy gamma models and interaction models to predict growth of emetic Bacillus cereus for combinations of pH and water activity values

This research aims to test the absence (gamma hypothesis) or occurrence of synergy between two growth-limiting factors, i.e., pH and water activity (aw), using a systematic approach for model selection. In this approach, preset criteria were used to evaluate the performance of models. Such a systematic approach is required to be confident in the correctness of the individual components of the combined (synergy) models. With Bacillus cereus F4810/72 as the test organism, estimated growth boundaries for the aw-lowering solutes NaCl, KCl, and glucose were 1.13 M, 1.13 M, and 1.68 M, respectively. The accompanying aw values were 0.954, 0.956, and 0.961, respectively, indicating that equal aw values result in similar effects on growth. Out of the 12 models evaluated using the preset criteria, the model of J. H. T. Luong (Biotechnol. Bioeng. 27:280–285, 1985) was the best model to describe the effect of aw on growth. This aw model and the previously selected pH model were combined into a gamma model and into two synergy models. None of the three models was able to describe the combined pH and aw conditions sufficiently well to satisfy the preset criteria. The best matches between predicted and experimental data were obtained with the gamma model, followed by the synergy model of Y. Le Marc et al. (Int. J. Food Microbiol. 73:219–237, 2002). No combination of models that was able to predict the impact of both individual and combined hurdles correctly could be found. Consequently, in this case we could not prove the existence of synergy nor falsify the gamma hypothesis

Literary studies on surgical methods of nervetransplantations on horses suffering from hemiplegia laryngis sinistra

Titelblatt, Inhaltsverzeichnis, Lebenslauf 1\. Einleitung 2.1 Schrifttum Teil 1 2.2 Schrifttum Teil 2 2.3 Schrifttum Teil 3 3\. Diskussion 4\. Schlussfolgerungen 5\. Zusammenfassung 6\. Summary LiteraturverzeichnisNach einer Darstellung von Anatomie und Innervation des Kehlkopfes des Pferdes, wird eine Literaturübersicht über den Erhalt und die Aussagekraft klinischer sowie pathologisch-anatomischer Befunde, sowohl des Nervus laryngeus recurrens als auch des Musculus cricoarytaenoideus dorsalis, beim Vorliegen einer Hemiplegia laryngis sinistra des Pferdes gegeben. Eine Erläuterung pathophysiologischer Vorgänge bei der Denervation und Reinnervation von Skelettmuskulatur, dem Wegfall von Faktoren zur Hemmung der Axoneinsprossung, dem Vorhandensein von Axonwachstumsfaktoren, der Ergänzung und/oder gegenseitigen Behinderung von Nerven bei der Reinnervation, schließt sich an. Die strukturellen Voraussetzungen für eine Reinnervation von Muskulatur werden berücksichtigt, wobei das Augenmerk auf die geschädigte Kehlkopfmuskulatur gelenkt wird. Eigenschaften eines geeigneten Donornerven und zu erwartende Reinnervationserfolge unterschiedlich stark atrophierter Muskulatur werden aufgezeigt. Eine Reihe von Operationen zur Reinnervation der Kehlkopfmuskulatur bei Mensch, Hund und Pferd, wie sie in der Literatur zu finden sind, werden chronologisch aufgeführt. Es wird hierbei zwischen einfachen Nervennähten, Nervenimplantationen und Nerv- Muskelteilchenverpflanzungen unterschieden. Abschließend wird die Eignung des Musculus omohyoideus als Donormuskel für eine Nerv-Muskelteilchenverpflanzung auf den Musculus cricoarytaenoideus dorsalis erörtert. Die Eignung verschiedener Nerven für eine physiologische Wiederherstellung der Kehlkopffunktion, durch die Methode der operativen Nervenverpflanzung beim Vorliegen einer Hemiplegia laryngis sinistra des Pferdes, kann aufgrund der bearbeiteten Literatur eingeschätzt werden. Eine Nerv-Muskelteilchenverpflanzung oder auch eine Nervenimplantation der ventralen Endäste des ersten oder mit Einschränkungen auch des zweiten Halsnerven kommen aus anatomisch-chirurgischer Sicht für eine Reinnervation des Musculus cricoarytaenoideus dorsalis sinister beim Pferd in Frage.After describing the anatomy and innervation of a horses` larynx, a review of availability and meaning fullness of clinical and pathological-anatomic results concerning the nervus laryngeus recurrens and the musculus cricoarytaenoideus dorsalis in case of a horses` Hemiplegia laryngis sinistra is given. An explanation of pathophysiological events in denervation and reinnervation of sceletal muscles, ending of axon-sprouting-inhibitor-factor, axon- sprouting-factor, addition and/or hindrance of nerves among each other during reinnervation follows. The structural pre-condition for a reinnervation of muscles will be thought of while the focus will be on damaged muscles of the larynx. Characteristics of a matching donor and expected success in reinnervation of atrophical muscles are presented. A series of surgical techniques to reinnervert the muscles of the larynx of man, dog and horse, as found in literature, is chroniced. Thereby we differenciate between simple sutures, nervimplantations and nerve-muscle- pedicle-grafts. Closing the literary studies is a discussion of the suitability of the musculus omohyoideus as a donor for a nerve-muscle-pedicle-graft procedure on the musculus cricoarytenoideus dorsalis. The suitability of different nerves for a physiological regeneration of a horses`larynx functions through surgical procedures means can be judged. A nerve-muscle-pedicle-graft or a nervimplantation of the ventral branches of the first, or with restrictions the second cervical nerves, are suitable for a horse from an anatomic-surgical point of view, considering the reinnervation of the musculus cricoarytaenoideus dorsalis

Factors influencing the accuracy of the plating method used to enumerate low numbers of viable micro-organisms in food

This study aims to assess several factors that influence the accuracy of the plate count technique to estimate low numbers of micro-organisms in liquid and solid food. Concentrations around 10 CFU/mL or 100 CFU/g in the original sample, which can still be enumerated with the plate count technique, are considered as low numbers. The impact of low plate counts, technical errors, heterogeneity of contamination and singular versus duplicate plating were studied. Batches of liquid and powdered milk were artificially contaminated with various amounts of Cronobacter sakazakii strain ATCC 29544 to create batches with accurately known levels of contamination. After thoroughly mixing, these batches were extensively sampled and plated in duplicate. The coefficient of variation (CV) was calculated for samples from both batches of liquid and powdered product as a measure of the dispersion within the samples. The impact of technical errors and low plate counts were determined theoretically, experimentally, as well as with Monte Carlo simulations. CV-values for samples of liquid milk batches were found to be similar to their theoretical CV-values established by assuming Poisson distribution of the plate counts. However, CV-values of samples of powdered milk batches were approximately five times higher than their theoretical CV-values. In particular, powdered milk samples with low numbers of Cronobacter spp. showed much more dispersion than expected which was likely due to heterogeneity. The impact of technical errors was found to be less prominent than that of low plate counts or of heterogeneity. Considering the impact of low plate counts on accuracy, it would be advisable to keep to a lower limit for plate counts of 25 colonies/plate rather than to the currently advocated 10 colonies/plate. For a powdered product with a heterogeneous contamination, it is more accurate to use 10 plates for 10 individual samples than to use the same 10 plates for 5 samples plated in duplicat