Research

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: Karl-Eibl-Stiftung (Form: Stipendium: 900?/Mo für Doktorand), 18.900 EUR

Project Details:
The aim of the first part of the dissertation project is to establish an innovative technology as a method of separating bull semen. The basis of this technology is the use of microfluidic chips. The second part of the project is to use this technology in genetically valuable breeding bulls whose ejaculates contain less than 70% forward-motility sperm. This technology could also be used to improve the quality of sex sorting of spermcells.

Results:

In this work we used samples with artificially induced damage for establishing protocols for flow cytometric analysis of sperm viability, as well as computer assisted analysis of sperm motility patterns. Moreover, we found that samples previously enriched with damaged sperm were especially useful for testing the effectiveness of different sperm selection procedures.

 

The major aim of this work was to evaluate how microfluidic chips perform in selecting high quality sperm, i.e., in comparison to other techniques such as swim-up and percoll density gradient centrifugation. In addition, we planned to test if sperm selected, using microfluidic chips exhibit better motility behavior, increased fertilization capacity in vitro, and wanted to evaluate the performance with the flow cytometric X/Y-sperm sorting.

 

Both, freshly diluted and cryopreserved sperm were tested also taking into account the variation among individuals. We determined that when using microfluidic sorting and swim-up methods, sperm recovery was low, however, sperm were of superior quality. Sperm recovery was higher after using percoll density gradient centrifugation, but this coincided with the presence of increased numbers of membrane damaged and motile sperm. In addition, the presence of a relatively high ratio of motile sperm in high quality sperm samples exhibited characteristic kinematic parameters including increased movement velocity and linearity; which was maintained when specimens were investigated in viscous media, mimicking oviductal fluid. In our hands, when compared with ordinary processing, remained that the increased sperm quality after microfluidic selection did not result an increased in vitro embryo production. Nonetheless, performing microfluidic sperm selection prior to flow cytometric sorting of X/Y-sperm appeared beneficial; since this improved initial sperm quality to required levels, reduced contents of debris and dead sperm during FACS sorting, and enabled to significantly improve sorting speed and the correctly oriented X-chromosome bearing sperm numbers in the population.

 

In conclusion, the use of microfluidic chips has great potential in reproductive medicine and veterinary assisted reproduction technologies. This is not only beneficial for any easier selection and enrichment of high quality sperm samples, which are more likely to fertilize an oocyte, but as a processing step, also for fulfilling the requirements needed for successful flow cytometric sorting of X/Y chromosome bearing sperm.

The use of microfluidic chips has great potential in reproductive medicine and veterinary assisted reproduction technologies. This is not only beneficial for any easier selection and enrichment of high quality sperm samples, which are more likely to fertilize an oocyte, but as a processing step, also for fulfilling the requirements needed for successful flow cytometric sorting of X/Y chromosome bearing sperm.

https://elib.tiho-hannover.de/receive/tiho_mods_00012249

Cooperation Partners:

Calisici, Oguz, Phytobiotics GmbH

Alkabes, Stephane, Masterrind GmbH Verden

Funding: EU Kommission (Horizon 2020), 3.034.581 EUR

Project Details:
Immunhistochemical and molecular Investigations of hormonal receptors in the puerperal uterus in cattle

Project Details:
The persistence of Actinobacillus pleuropneumoniae (App) on the tonsils facilitates the spread of the pathogen in pig populations. Microbiological-cultural detection of the pathogen from tonsils has proven to be difficult because the diverse commensal colonization by other bacteria (e.g., Streptococcus suis) often overgrows App during culturing. The use of selective media leads to higher sensitivity of bacteriological diagnostics, but nevertheless, the success rate compared to molecular biological tests (PCR) is not satisfactory.
In most cases, acute outbreaks of porcine pleuropneumonia occur in persistently infected pigs under the influence of trigger factors. In vitro, the influence of stress hormones, such as cortisol and catecholamines on the growth behavior of the pathogen will be investigated. Possibly, catecholamines and cortisol can be used under in vitro conditions to improve the growth behavior of A. pleuropneumoniae.

Project Details:
The preventive effect of a prebiotic feed on the occurrence of tail biting in pigs is investigated. Situations in which tail biting occurs are characterized in terms of clinical signs, colostrum supply in the preceding phase of life, and concentration of inflammatory and stress parameters in blood and saliva in the rearing phase. The aim of the study is to clarify whether improved intestinal health through feeding prebiotics has a preventive effect against tail biting and whether the sum of all negative influencing factors including stress experienced since birth, which may be reflected in laboratory diagnostic parameters (acute phase proteins, stress markers), lead to the occurrence of tail biting after a so far undefined threshold has been exceeded.

Cooperation Partners:

Jakob Aundrup, Schweinegesundheitsdienst der Landwirtschaftskammer Niedersachsen

Project Details:
Comparison of different methods for typing of App

Cooperation Partners:

Henning Lindhaus

Funding: Pfizer, 54.000 EUR

Project Details:
Tick-borne encephalitis (TBE) is considered as one of the most important viral tick-borne diseases affecting humans. The disease may cause death or permanent disability due to severe neurological damage. TBE thus represents a considerable public health burden. In recent years, a considerable geographic expansion of TBE has been noted in Germany with the consequence the National Institute of Public Health (Robert-Koch-Institut) declared district in the Northern Germ federal state Lower Saxony as official risk area in the beginning of 2019. However, the usually very small areas of TBE virus circulation (so called natural foci) are still mostly unknown in Northern Germany. This study aims to identify the locations of TBE transmission foci (i.e. the presence of TBE-positive ticks) in Lower Saxony, Northern Germany, by following up on the movement patterns and possible sources of tick exposure of TBE patients. Detection of TBE virus occurrence in Northern Germany will help to prevent clinical cases of disease as it can be expected that public awareness about TBE foci will lead to avoidance of known hot spot areas and increase the people´s willingness to vaccinate.

Results:

Topp, A.-K., Springer, A., Dobler, G., Bestehorn-Willmann, M., Monazahian, M., Strube, C. (2022) New and confirmed foci of tick-borne encephalitis virus (TEBV) in Northern Germany determined by TEBV detection in ticks. Pathogens 11, 126

https://www.mdpi.com/2076-0817/11/2/126

Cooperation Partners:

Dr. M. Monazahian, Niedersächsisches Landesgesundheitsamt, Hannover

Prof. Dr. Gerhard Dobler, Nationales Konsiliarlabor für FSME, München

Funding: QS Fachgesellschaft Geflügel GmbH QS Wissenschaftsfonds, 70.000 EUR

Project Details:
Epidemiological Investigations on outbreaks of Histomonosis in turkey in Germany - these investigattions aim to assess ways of pathogen entrance and conditions fa-vouring disease.

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=