Research

Funding: Deutsche Forschungsgemeinschaft, 391.868 EUR

Project Details:
Gill diseases seriously affect fish health and have a high negative impact on aquaculture, mainly because of the multifunctional properties of gills in fish physiology. Studies on pathogen related gill diseases are largely hampered by the lack of infection models, which exclusively affect gills. Carp edema virus (CEV), a fish-infecting pox virus, affects predominantly the gills of common carp (Cyprinus carpio). It induces a severe gill disease known as koi sleepy disease (KSD) and is fatal for the majority of infected fish.. Due to its severe effect on gills, the CEV infection causes physiological distress to infected fish and also seems to induce an impairment of the immunity. Interestingly, different strains of common carp show high (Amur carp - AS strain) or low (koi strain) resistance to this virus. Our working hypotheses propose that: (i) differential stress response/stress sensitivity might affect the outcome of KSD in koi and AS strains of carp and (ii) severe impairment of the immune response during KSD may have an impact on the general immunological status of the survivors after CEV infection.
In the present project, we will study the mechanisms underlying the differences in the resistance to CEV between AS and koi carp strains. We will also study how a CEV-induced impairment of immune response influences the susceptibility of carp to other pathogens such as the bacterium Flavobacterium branchiophilum or the viruses cyprinid herpesvirus 3 (CyHV-3) and spring viraemia of carp virus (SVCV). To study the mechanisms of the immunity diminishing we will use a "salt rescue model" which is based on the supplementation of salt (NaCl) into the tank water, which abolishes the impairment of physiology and immune responses in CEV infected fish.
The results of this project will allow us to identify the interplay of stress and immune responses in fish affected by a viral gill disease and its importance for resistance/susceptibility of fish to clinical disease. Finally, the results will allow us to expand our knowledge on important and phylogenetically conserved mechanisms regulating anti-viral immune response. In future, in-depth knowledge of such interactions will help to develop novel strategies for preventing and combating pathogen-induced gill diseases in aquaculture.

Cooperation Partners:

Krakow University, Poland

Funding: AfT e.V. (Akademie für Tiergesundheit), 24.000 EUR

Project Details:
Die Tatsache, einen erfolgreichen Zuchtrüden plötzlich und meist unbemerkt für die Zucht zu verlieren, ist beim Besitzer oftmals mit einer starken emotionalen Belastung, aber auch mit wirtschaftlichen Verlusten verbunden. Zusätzlich dazu stellt es den Tierarzt vor große Probleme: Aufgrund der meist späten Vorstellung des Rüdens ist es äußerst schwierig die auslösende Noxe rückblickend zu identifizieren und eine dementsprechende Behandlung einzuleiten. Azoospermie, das Fehlen von Spermien im Ejakulat, ist mit 34,8% der häufigste Befund bei infertilen, andrologisch geschlechtsgesunden Rüden. Sowohl beim Hund als auch bei anderen Spezies, kommt die testikuläre nicht-obstruktive Form der Azoospermie (NOA) am häufigsten vor. Die Diagnose ist mit hochgradigen histologischen Veränderungen, Infiltration von Immunzellen und dem Arrest der Spermatogenese assoziiert, was auf eine spontane autoimmun-vermittelte Orchitis (AIO) hindeutet. Die Art der beteiligten Immunzellen wurde von der AG identifiziert und die Expression von Entzündungsmarkern näher charakterisiert. Bei bereits eingetretener Infertilität ist von einer schlechten Prognose und irreversiblen Schädigung des Gewebes auszugehen. Eine Möglichkeit der Therapie oder Heilung der Erkrankung besteht bisher nicht. Grundvoraussetzung für die Bildung von gesunden Spermien im Ejakulat ist das Vorhandensein der sogenannten spermatogonial stem cells (SCCs) im Hoden. Diese Stammzellpopulation besitzt einerseits die Fähigkeit zur Selbsterneuerung und produziert andererseits sich differenzierende Tochterzellen. Aktuelle Studien beschäftigen sich mit der Verwendung von SSCs zur Behandlung von Infertilität und Fruchtbarkeitsstörungen in der Humanmedizin. Um diese Erkenntnisse auf der Rüden übertragen zu können, ist ein erster essenzieller Schritt zur Behandlung der AIO die Suche nach SSCs im entzündlich veränderten Hodengewebe.

Results:

https://scholar.google.de/scholar?hl=de&as_sdt=0%2C5&as_vis=1&q=Detection+of+spermatogonial+stem+cells+%28SSC%29+in+testicular+tissue+of+dogs+with+spontaneous+immune+mediated+orchitis&btnG=

Funding: Hirsch foundation, 50.000 EUR

Project Details:
Decellularized heart valve tissues can be used to replace a malfunctioning heart valve. This option is particularly suitable for young patients, because decellularized tissues have regeneration potential. We have pioneered in developing methods for dry preservation of mammalian cells and tissues and demonstrated that this can be done using disaccharides such as sucrose or trehalose which can be found at high concentrations in anhydrobiotic organisms that naturally survive drying. Drying of decellularized heart valves may alter the properties of the extracellular matrix and impair their in vivo efficacy. The central aim of this project is to test if sucrose can be used for dry preservation of heart valves so that they can be safely used for transplantation. We already established methods to freeze-dry heart valves, but their storage stability needs to be demonstrated. In this project we plan to evaluate if vacuum-drying, which lacks a damaging freezing step, can be used as an alternative drying method. The second objective is to study the effects of (freeze-)drying on scaffold structure, and matrix biomolecules directly after drying as well during storage under normal (4°C or room temperate) and accelerated aging (37°C/high relative humidity) storage conditions. The general tissue architecture will be studied on hematoxylin-eosin stained tissue sections, whereas Fourier transform infrared spectroscopy (FTIR) will be used to obtain spectral fingerprints of tissues during storage. For the latter principal component analysis of the spectra will be used to evaluate tissue modifications during storage. Furthermore, accumulation of oxidative damage will be determined. We postulate that overall tissue structural appearance, and therewith functionality, are compromised by ice crystals, and that this can be minimized by reducing the tissue water content prior to freezing, or to avoid ice formation by using vacuum drying.

Funding: Drittmittelprojekt, gefördert durch die Fritz-Ahrberg-Stiftung., 95.000 EUR

Project Details:
The preservation of food with chemical or physical methods should reduce the microbial contamination of food and should extend the shelf life of the products in order to minimise the health risk for the consumer. In a previous project at the Institute of Food Quality and Food Safety, the bacteria-reducing effects of Ethyl-Nα-lauryl-L-arginate hydrochloride (LAE) have already been successfully investigated. However, few studies are available that have examined the influence of LAE in combination with a biological preservation method (starter bacteria cultures) on the microbiological contamination with pathogenic and spoilage bacteria as well as on the chemical and sensory quality characteristics of the treated products. These investigations are useful to improve an individual effect by a combined treatment and to check whether these processes change qualitative properties of the food. For this reason, in the present study fresh meat from pigs, cattle and chickens, after inoculation with defined microorganisms, will be individually treated with LAE and starter culture mixtures either alone, or in combination, in order to show the effects of a combined treatment in comparison to the untreated control sample and to the individual treatment. Not only the short-term effects directly after treatment, but also the long-term effects during storage of the products until the usual best-before or use-by date will be investigated.

Funding: Gefördert durch die Fritz-Ahrberg-Stiftung., 35.000 EUR

Project Details:
Raw cured products are popular meat products that often get their color from the addition of nitrite during aging. Here, the nitrite reacts with the myoglobin within the muscles to form red nitrosomyoglobin. In addition, the nitrite is also used to suppress the growth of undesirable microorganisms, particularly Clostridium botulinum and Listeria monocytogenes. However, free nitrite may still be present in the meat product, which can react with amines to form nitroso compounds that are harmful to health.
However, Parma ham has been produced for a long time without the addition of nitrite or nitrate, using only salt. The red color of the ham is due to the formation of zinc protoporphyrin (ZnP), which is increasingly formed during the storage of the ham for up to 15 months. In this process, iron is replaced by zinc in myoglobin, regardless of the microbiological contamination of the meat. In the study, raw hams with and without the addition of nitrite are to be produced from turkey breast muscles and pork hams. At various times over a 15-month period, starting from the raw material, meat texture parameters will be examined and microbial status determined at regular intervals throughout the aging period. After maturing, the hams are sliced, subjected to a two-week storage test, analyzed microbiologically and physicochemically and evaluated with regard to its sensory characteristics. The aim of this research project is to verify the feasibility of the production and to determine the quality of an air-dried raw ham made from turkey or pork without nitrite curing salt in comparison to raw hams containing nitrite.

Funding: Drittmittelprojekt, gefördert durch die Fritz-Ahrberg-Stiftung., 70.000 EUR

Project Details:
The present study is exploring the potential of the cold-plasma-technology for the production of meat products without the addition of nitrite curing salt. PPA (= plama processed air) and PAW (= plasma activated water) are used do generate reactive nitrogen species in meat batter which might induce a reddening effect during the production of cooked sausages. Products generated with this novel technology are analyzed for microbiological, sensory and physicochemical parameters after production and after a storage period.

Project Details:
Different field strains of important, food-associated microorganisms (Listeria monocytogenes, Escherichia coli, Salmonella enterica ssp., Bacillus cereus, Campylobacter jejuni) are chosen. Subsequently, milk of different species (cattle and small ruminants) is inoculated with these germs and heat-treated under subpasteurization (thermization) conditions, which means low temperature treatments for short times. Aim of the study is to investigate the heat damage which is caused to the different microorganisms directly after heat treatment and after a storage period of three days. Additionally, possible matrix effects and strain variances are determined.

Funding: Drittmittelprojekt, gefördert durch Bundesministerium für Bildung und Forschung., 125.591 EUR

Project Details:
In the second funding period of this sub-project within the Pac-Campylobacter consortium, it aims at combining optimized measures in a synergistic large scale arrangement for reducing Campylobacter spp., meeting the requirements of commercial broiler production and livestock farming. This approach focuses on a combined application of different measures in a "One Health" approach along the entire food chain to reduce the public health risk effectively in a sustainable manner and provide practical support for veterinary public health authorities regarding this issue.

Results:

Poster Abstracts:

1. Bogun K, Peh E, Siekmann L, Plötz M, Kittler S; Untersuchungen zur Anwendung ausgewählter Säuren und Pflanzenextrakte sowie deren Kombination als Reduktionsmethode von Campylobacter spp. auf Hähnchenfleisch. 62. Arbeitstagung des Arbeitsgebietes Lebensmittelsicherheit und Verbraucherschutz der DVG, 25. bis 28. Oktober 2022

2. Bogun K, Peh E, Plötz M, Kittler S; Combination of a phage cocktail and an organic acid cocktail to reduce Campylobacter in broiler chickens - Examination of possible synergistic effects. 2nd German Phage Symposium, 23.-24.5.2022 Universität Hohenheim

3. Bogun K, Peh E, Siekmann L, Plötz M, Kittler S; Examination of selected organic acids and plant extracts and their combination as a reduction method against Campylobacter on chicken meat Zoonoses 2022 - International Symposium on Zoonoses Research 05.-07.10.2022 Berlin

Funding: Bundesanstalt für Gewässerkunde (BfG); Projektleitung in der BfG: Dr. Thomas Taupp, Referat U4 Tierökologie, 230.122 EUR

Project Details:
The estuary of the Elbe is exposed to significant anthropogenic activities such as commercial shipping, fishing, deepening and recreational activities. The estuary is the entrance to the Port of Hamburg and the Kiel Canal - the Elbe is thus one of the busiest waterways in Europe.
Despite the strong anthropogenic use, marine top predators from the North Sea regularly enter the Elbe. Rich fishing grounds attract not only porpoises to the port of Hamburg, but also seals use the Elbe and can be seen at low tide on the then exposed tidal flats. However, it is unclear to what extent seals use the tidal Elbe, in which areas they forage, if they exhibit site fidelity and whether there is a regular exchange with animals from the North Sea.
For this reason, up to 10 harbour seals will be briefly caught at various haul-outs in the tidal Elbe, will be checked for their health and subsequently equipped with special bio-telemetry tags ("SMRU GPS Phone Tags"). Since seals spend most of their lives in the water, where it is difficult to observe them, telemetry (recording of behavioral and environmental data using electronic devices) is a very useful method for assessing behavior, habitat use and interactions between the animals and their environment. The tags record the movements and the diving behavior of the animals in detail and then send the data via the local mobile phone network, which enables a live tracking of the seals. The data obtained will give an insight into the space use, the site fidelity and the home ranges, and will also allow an estimate of possible conflicts, e.g. with the shipping traffic in the Elbe.
In addition, in the course of the catches, various samples are to be taken for further analyses (e.g., heavy metal pollution, exposure to organochemical substances and diet analyses).

Results:

Final Report:

Tracking and survey of harbor seals in the Tidal Elbe River.

https://sync.academiccloud.de/index.php/s/l4KcvGJBNRprh4j

Funding: Bundesanstalt für Landwirtschaft und Ernährung, 344.512 EUR

Project Details:
The aim of the project is to establish an innovative husbandry concept within the framework of the model and demonstration project (MuD) in selected practical farms with broiler chicken husbandry, which meets the high demands on animal welfare and the environment. The following approaches are being worked on within the framework of the project:
-Structuring of the fattening house by installing an additional level with a manure belt for species-appropriate resting, drying and removal of manure and an animal-friendly removal of slaughter animals.
-Establishment of activity zones in the barn, providing animals with options for pecking and dust bathing.
Separate-sex fattening by dividing the house lengthwise into two areas with a net/grid.
-Adapted feeding by protein reduction with supplementation of some essential and semi-essential amino acids (Dl-methionine, valine, isoleucine, gycin). This should produce less N-volatile substances, improve the pollutant gas concentrations in the barn and reduce the nutrient loads in the manure.

Cooperation Partners:

Landwirtschaftskammer Niedersachsen

Praxisbetriebe