51 research outputs found
Zum Vorkommen Transmissibler Spongiformer Enzephalopathien und bakterieller ZNS-Infektionen beim Reh-, Rot- und Gamswild in Bayern
About the occurrence of Transmissible Spongiform Encephalopathies and bacterial CNS infections in roe deer, red deer and chamois in Bavaria
Brain samples of 849 wild ruminants (654 roe deer, 189 red deer and 6 chamois) from Bavaria were examined for the occurrence of TSE and encephalopathies caused by bacteria, respectively. For this, the following investigations were carried out:
âą General bacteriological investigation (aerobic incubation on blood, standard I nutrient and Gassner Agar)
âą Detection of Listeria spp. by selective procedures
- Cultural isolation and biochemical identification with the BBL crystal ID system
- Detection of the iap gene using real time PCR (Lightcycler)
âą Detection of PrPres by ELISA technique (BioRad)
âą Histological investigation
- HE staining
- Immunohistochemistry (mAb L42)
Using conventional bacteriological methods, 464 different bacteria were isolated. 229 of them could be differentiated at the genus level and 235 at the species level. Totally, 35 different bacteria species were isolated, most frequently Micrococcus spp., Bacillus spp. and E. coli. Listeria spp. were detected in 55 brain samples (49 from roe deer, 5 from red deer and 1 from chamois). 52 isolates were identified with the BBL crystal ID system as Listeria monocytogenes and 3 as Listeria grayi ssp. murrayi. As the iap gene was detected in all strains, the correctness of the BBL result concerning L. grayi ssp. murrayi must be scrutinised. Analysis of the geographical distribution of the Listeria findings indicate a regional aggregation in Unterfranken (prevalence for roe deer: 17,8 %, versus 6,6 % in Oberbayern-Schwaben, 6,1 in Niederbayern-Oberpfalz and 0 % in Oberfranken-Mittelfranken).
The histological investigation (HE staining) of 87 tissue samples contaminated with encephalitis relevant bacteria showed inflammation of different severity (e. g. perivascular infiltration (n = 26) or (meningo)encephalitis (n = 13)) in 41 cases.
The validation of the ELISA technique for detecting prionprotein from wild ruminants pointed out that the examination of brain of wild ruminants lead to lower extinctions than that of bovine brain samples. Due to the fact that brain homogenate of 2 known CWD positive wapitis showed definite positive results, all samples were analysed with this test: There were no indications for the occurrence of TSE in any sample. In addition, immunohistochemical investigations of 10 % of all samples did not show PrPres.
Due to the large number of samples, the prevalence of TSE can be quoted under 0,5 % for roe deer and under 1,5 % for red deer with a certainty of 95 %.In der vorliegenden Arbeit wurden Hirnproben von 849 WildwiederkĂ€uern (654 vom Reh-, 189 vom Rot- und 6 vom Gamswild) aus ganz Bayern auf TSE bzw. bakterielle Enzephalopathie-Erreger untersucht. Hierzu wurden folgende Untersuchungen duchgefĂŒhrt:
âą Allgemeine bakteriologische Untersuchung (aerobe Anzucht auf Blut-, NĂ€hr- und Gassner-Agar)
âą Selektiver Listeriennachweis
- Kultureller Nachweis; Identifizierung der Isolate mittels BBL-Crystal-System
- Nachweis des iap-Gens mittels Real-Time PCR (Lightcycler)
âą Nachweis von PrPres mittels ELISA (Fa. BioRad)
âą Histologische Untersuchung
- HE-FĂ€rbung
- Immunhistochemie (mAb L42)
Bei der bakteriologischen Untersuchung wurden 464 Bakterienisolate angezĂŒchtet, von denen 229 bis zur Gattungsebene und 235 bis auf die Speziesebene differenziert werden konnten. Insgesamt wurden 35 verschiedene Bakterienspezies isoliert, am hĂ€ufigsten Micrococcus spp., Bacillus spp. und E. coli. Listerien waren in 55 Hirnproben (49 vom Reh-, 5 vom Rot- und 1 vom Gamswild) nachzuweisen. 52 Isolate wurden mittels BBL-Crystal-System als L. monocytogenes identifiziert, 3 als L. grayi ssp. murrayi. Der Nachweis des iap-Gens gelang in allen FĂ€llen, so dass die Richtigkeit des BBL-Resultates bezĂŒglich L. grayi ssp. murrayi hinterfragt werden muss. Die Auswertung der rĂ€umlichen Verteilung der Listeria-Befunde weist auf eine regionale Verdichtung in Unterfranken hin (PrĂ€valenzrate Rehwild: 17,8 % versus 6,6 % in Oberbayern-Schwaben, 6,1 % in Niederbayern-Oberpfalz und 0 % in Oberfranken-Mittelfranken).
Die histologische Untersuchung (HE-FĂ€rbung) von 87 Proben, bei denen in der bakteriologischen Untersuchung enzephalitisrelevante Keime nachgewiesen wurden, lieĂ in 41 FĂ€llen EntzĂŒndungsgeschehen unterschiedlichen Schweregrades (z. B. perivaskulĂ€re Infiltrationen (n = 26) oder (Meningo-)enzephalitiden (n = 13)) erkennen.
Die Validierungsuntersuchungen zur ĂberprĂŒfung der Tauglichkeit des ELISA-Testes ergaben, dass bei der PrĂŒfung von Hirngewebe von WildwiederkĂ€uern grundsĂ€tzlich niedrigere Extinktionen zu erwarten sind als bei Rinderhirnproben. Da Hirnhomogenat von 2 bekannt CWD-positiven Wapiti-Hirschen zu eindeutig positiven Resultaten fĂŒhrte, wurde das Probenmaterial mit diesem Test untersucht: Es wurden keine Hinweise gefunden, die fĂŒr ein Vorliegen von TSE sprechen. Auch die immunhistochemische Untersuchung von 10 % des Gesamtprobenumfangs ergab keine Anzeichen, die auf das Vorhandensein von PrPres schlieĂen lassen.
Anhand der groĂen Probenanzahl kann deshalb fĂŒr Bayern die Aussage getroffen werden, dass mit 95 %iger Sicherheit die PrĂ€valenzraten beim Rehwild unter 0,5 % und beim Rotwild unter 1,5 % liegen
Distribution of T-2 toxin and HT-2 toxin during experimental feeding of yellow mealworm (Tenebrio molitor)
Within the European Union (EU), edible insects need to be approved as âNovel Foodâ according to Regulation (EU) 2015/2283 and must comply with the requirements of European food law with regard to microbiological and chemical food safety. Substrates used for feeding insects are susceptible to the growth of Fusarium spp. and consequently to contamination with trichothecene mycotoxins. Therefore, the current study aimed to investigate the influence of T-2 and HT-2 toxins on the larval life cycle of yellow mealworm (Tenebrio molitor (L.)) and to study the transfer of T-2, HT-2, T-2 triol and T-2 tetraol in the larvae. In a 4-week feeding study, T. molitor larvae were kept either on naturally (oat flakes moulded with Fusarium sporotrichioides) or artificially contaminated oat flakes, each at two levels (approximately 100 and 250 ÎŒg/kg total T-2 and HT-2). Weight gain and survival rates were monitored, and mycotoxins in the feeding substrates, larvae and residues were determined using LC-MS/MS. Larval development varied between the diets and was 44% higher for larvae fed artificially contaminated diets. However, the artificially contaminated diets had a 16% lower survival rate. No trichothecenes were detected in the surviving larvae after harvest, but T-2 and HT-2 were found both in the dead larvae and in the residues of naturally and artificially contaminated diets
Phenotypic and Genetic Comparison of a PlantâInternalized and an AnimalâIsolated Salmonella Choleraesuis Strain
Contamination of fresh produce with human pathogens poses an important risk for conâ sumers, especially after raw consumption. Moreover, if microorganisms are internalized, no reâ moval by means of further hygienic measures would be possible. Human pathogenic bacteria idenâ tified in these food items are mostly of human or animal origin and an adaptation to this new niche and particularly for internalization would be presumed. This study compares a plantâinternalized and an animalâborne Salmonella enterica subsp. enterica serovar Choleraesuis aiming at the identifiâ cation of adaptation of the plantâinternalized strain to its original environment. For this purpose, a phenotypical characterization by means of growth curves under conditions resembling the indigeâ nous environment from the plantâinternalized strain and further analyses using Pulsedâfield gel electrophoresis and Matrixâassisted laser desorption ionization time of flight spectrometry were asâ sessed. Furthermore, comparative genomic analyses by means of single nucleotide polymorphisms and identification of present/absent genes were performed. Although some phenotypical and geâ netic differences could be found, no signs of a specific adaptation for colonization and internalizaâ tion in plants could be clearly identified. This could suggest that any Salmonella strain could directly settle in this niche without any evolutionary process being necessary. Further comparative analysis including internalized strains would be necessary to assess this question. However, these kinds of strains are not easily available
Shedding of Mycobacterium caprae by wild red deer (Cervus elaphus) in the Bavarian alpine regions, Germany
The number of natural infections with Mycobacterium caprae in wildlife and in cattle in the Bavarian and Austrian alpine regions has increased over the last decade. Red deer (Cervus elaphus) have been recognized as maintenance reservoir; however, the transmission routes of M. caprae among and from naturally infected red deer are unknown. The unexpected high prevalence in some hot spot regions might suggest an effective indirect transmission of infection. Therefore, this study was undertaken to diagnose the occurrence of M. caprae in faeces and secretions of red deer in their natural habitat. A total of 2,806 red deer hunted in this region during 2014â2016 were included in this study. After pathological examination, organs (lymph nodes, lung, heart), excretions and secretions (faeces, urine, saliva and tonsil swabs) were further investigated by qPCR specific for Mycobacterium tuberculosis complex (MTC), M. bovis and M. caprae. Samples tested positive by qPCR were processed for culturing of mycobacteria. In total, 55 (2.0%) animals were confirmed positive for M. caprae by pathological examination, PCR and culturing of the affected organ material. With the exception of one sample, all of the secretion and excretion samples were negative for mycobacteria of the Mycobacterium tuberculosis complex (MTC). From one red deer, M. caprae could be isolated from the heart sac as well as from the faeces. Wholeâgenome sequencing confirmed that both strains were clonally related. This is the first confirmation that M. caprae can be shed with the faeces of a naturally infected red deer. However, further studies focusing on a higher number of infected animals, sample standardization and coordinated multiple sampling are necessary to improve the understanding of transmission routes under natural conditions
PrĂ€valenz von Hilfsschleimbeuteln (Bursae auxiliares) und Klauenverletzungen bei Mastschweinen zum Schlachtzeitpunkt â Ergebnisse einer Studie an vier Schlachthöfen
The formation of auxiliary bursae is not part of the embryonal development but occurs as a pathologic reaction to a trauma, especially when exposed parts of the extremities are mechanically stressed. Among other reasons the keeping of pigs on artificial flooring and in particular the use of fully slatted flooring surfaces plays an important role.In a study at four abattoirs in Southern Germany we investigated the prevalence of auxiliary bursae in fattening pigs at the time of delivery and during meat inspection. For that purpose classification criteria were developed to record and graduate the occurrence and type of severity of bursae. Animals without appearance of bursae were graded 0, while animals with bursae being lightly, moderately or severely pronounced were graded 1, 2 and 3 respectively. 91.2% of 9 2 randomly selected finishers from conventional keeping showed prevalence of grade 1 to 3 bursae (grade 1: 7.7%; grade 2: 3. %; grade 3: 0.7 %), only 2.2% of these pigs were not affected (grade 0). In addition, claw injuries were detected in 26.5% of another group of 00 randomly selected fattening pigs.The prevalence of auxiliary bursae in a control group, consisting of 52 animals from organic production, was only 13.2%. In this group, the detected bursae were less pronounced (grade 1) and no claw injuries appeared.The high prevalence of technopathies such as auxiliary bursae and claw injuries in fattening pigs from conventional production points to the need for action regarding animal welfare and are relevant for operative selfmonitoring measurements based on the German animal protection law (§ 11). Information on the origin of the animals, i. e. on farms, was not available throughout the study because of privacy reasons. In order to investigate causal factors for the development of auxiliary bursae and claw injuries beyond the keeping of animals on fully slatted floors, a study on risk factors is necessary. Our data demonstrate that collection of animal welfare data collected at slaughter is needed as a base for veterinary guidance and onfarm interventions aiming to improve animal health and welfare standards.Akzessorische Bursen, sogenannte Hilfsschleimbeutel, sind embryonal nicht vorgebildet, sondern entstehen als pathologische Reaktion, insbesondere bei erhöhten mechanischen Beanspruchungen exponierter Stellen. FĂŒr die Entstehung werden u. a. Spaltenböden ohne Einstreu verantwortlich gemacht. In der vorliegenden Studie wurde das Auftreten von Hilfsschleimbeuteln an den GliedmaĂen von Schlachtschweinen bei Anlieferung an vier sĂŒddeutschen Schlachthöfen und bei der Fleischuntersuchung erfasst. Dazu wurde zunĂ€chst ein Boniturschema entwickelt, mit dem Tiere ohne sichtbares Auftreten von Bursen (Grad 0) von Tieren mit Bursen unterschiedlich starker AusprĂ€gung differenziert werden konnten (Grad 1, 2 und 3: gering-, mittel- bzw. hochgradige VerĂ€nderungen). Bei insgesamt 9 2 randomisiert ausgewĂ€hlten Masthybriden aus konventioneller Haltung traten Bursen mit einer PrĂ€valenz von 91,2 % auf, wobei alle drei Schweregrade vertreten waren: 7,7 % (Grad 1), 3, % (Grad 2) und 0,7 % (Grad 3). Nur bei 2,2 % der Tiere wurden unauffĂ€llige GliedmaĂe (Grad 0) bonitiert. Parallel dazu wurden bei 26,5 % von 00 zufĂ€llig ausgewĂ€hlten Tieren aus konventioneller Haltung Klauenverletzungen festgestellt. Bei 52 Kontrolltieren aus ökologischer Haltung auf Betonboden mit Stroh und Auslauf traten akzessorische Bursen nur als geringgradige VerĂ€nderung (Grad 1) bei 13,2 % der Schweine auf.Die AuffĂ€lligkeiten an den GliedmaĂen von Mastschweinen aus konventioneller Haltung zeigen einen tiergesundheitsrelevanten Handlungsbedarf auf. Die festgestellten VerĂ€nderungen sind geeignete Tierschutzindikatoren, die nach § 11 des Tierschutzgesetzes fĂŒr Eigenkontrollen bei der Nutztierhaltung erhoben und bewertet werden sollen. Da Herkunftsdaten der Tiere aus datenschutzrechtlichen GrĂŒnden nicht zur VerfĂŒgung standen, sollte ĂŒber eine Risiko-Faktoren-Analyse geklĂ€rt werden, welche kausalen Faktoren neben der Haltung auf Spaltenböden ursĂ€chlich an der Entstehung der Technopathien beteiligt sind. Die Erfassung und Nutzung der am Schlachthof gewonnenen, tierwohlrelevanten Daten sind Grundlage fĂŒr eine tierĂ€rztliche Interventionsmöglichkeit auf Betriebsebene mit dem Ziel einer Verbesserung der Tiergesundheit
Corrigendum: Structural Influence on the Dominance of Virus-Specific CD4 T Cell Epitopes in Zika Virus Infection
Zika virus (ZIKV) has recently caused explosive outbreaks in Pacific islands, South- and Central America. Like with other flaviviruses, protective immunity is strongly dependent on potently neutralizing antibodies (Abs) directed against the viral envelope protein E. Such Ab formation is promoted by CD4 T cells through direct interaction with B cells that present epitopes derived from E or other structural proteins of the virus. Here, we examined the extent and epitope dominance of CD4 T cell responses to capsid (C) and envelope proteins in Zika patients. All patients developed ZIKV-specific CD4 T cell responses, with substantial contributions of C and E. In both proteins, immunodominant epitopes clustered at sites that are structurally conserved among flaviviruses but have highly variable sequences, suggesting a strong impact of protein structural features on immunodominant CD4 T cell responses. Our data are particularly relevant for designing flavivirus vaccines and their evaluation in T cell assays and provide insights into the importance of viral protein structure for epitope selection and antigenicity.(VLID)470226
A HeatâActivated DrugâDelivery Platform Based on Phosphatidylâ(oligo)âglycerol Nanocarrier for Effective Cancer Treatment
The potential of cancer drugs is not fully exploited due to low tumor uptake and occurrence of systemic side effects, limiting maximum tolerated dose. Actively targeted nanocarriers improve efficacy while minimizing offâtarget toxicity. Herein, it is the first time a drugâdelivery platform for heatâtriggered intravascular drug release is described, based on synthetic phosphatidylâ(oligo)âglycerols from organic synthesis to preclinical investigation in feline patients. For the nanocarrier formulated doxorubicin (DOX), superior tumor drug delivery and antitumor activity compared with free DOX, conventional liposomal DOX (Caelyx), and temperatureâsensitive lysolipidâcontaining DOXâliposomes in rat sarcoma are demonstrated. In a comparative oncological study with neoadjuvant treatment of feline sarcoma, a metabolic response determined with 18âFâFDGâpositron emission tomography/magnetic resonance imaging (PET/MRI) and histopathological response after tumor resection are significantly better compared with free DOX, potentially by overcoming drug resistance based on improved intratumoral drug distribution. This novel drugâdelivery platform has great potential for the treatment of locally advanced tumors in humans
Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments
Background: The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. Methods: We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. Results: During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks and their hosts and hence the transmission likelihood.[br/] Conclusions: Diluting effects of more diverse habitat patches would pose another reason to maintain or restore high biodiversity in forest patches of rural landscapes. We suggest classifying habitat patches by their regulating services as dilution and amplification habitat, which predominantly either decrease or increase B. burgdorferi prevalence at local and landscape scale and hence LB risk. Particular emphasis on promoting LB-diluting properties should be put on the management of those habitats that are frequently used by humans. In the light of these findings, climate change may be of little concern for LB risk at local scales, but this should be evaluated further
Differentiation of S. chartarum (Ehrenb.) S. Hughes Chemotypes A and S via FT-IR Spectroscopy
Stachybotrys (S.) chartarum is a cellulolytic mould with the ability to produce highly cytotoxic macrocyclic trichothecenes. Two chemotypes are defined according to their ability to produce either atranones or satratoxins. S. chartarum has been well known as the causative agent of the lethal disease stachybotryotoxicosis in horses. Further investigations revealed that this disease is strictly correlated with the presence of macrocyclic trichothecenes. Furthermore, their occurrence in water-damaged buildings has been linked to adverse health effects such as the sick building syndrome. As the chemotypes cannot be characterized via phenotypic criteria, different methods such as PCR, MALDI-TOF MS, LC-MS/MS, thin-layer chromatography and cytotoxicity assays have been used so far. Fourier-transform-infrared spectroscopy (FT-IR) is commonly used for the differentiation of bacteria and yeasts, but this technique is also applicable to filamentous fungi. Hence, this study aimed at evaluating to which extent a reliable differentiation of S. chartarum chemotypes A and S is possible. Besides, another objective was to verify if the recently introduced third genotype of S. chartarum can be identified. Therefore, 28 strains including the two chemotypes and the third genotype H were cultivated on malt extract agar (MEA) and potato dextrose agar in three biological replicates. Each sample was applied to FT-IR measurements on day 7, 14 and 21 of cultivation. In this study, we achieved a distinction of the chemotypes A and S via FT-IR spectroscopy after incubation for 7~days on MEA. In terms of genotype differentiation, the PCR detecting satratoxin- and atranone-gene clusters remained the only applicable method
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