Phaidra - University of Veterinary Medicine Vienna
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Characterisation of Staphylococcus aureus Strains and Their Prophages That Carry Horse-Specific Leukocidin Genes lukP/Q
No full textLeukocidins of Staphylococcus (S.) aureus are bicomponent toxins that form polymeric pores in host leukocyte membranes, leading to cell death and/or triggering apoptosis. Some of these toxin genes are located on prophages and are associated with specific hosts. The genes lukP/Q have been described from equine S. aureus isolates. We examined the genomes, including the lukP/Q prophages, of S. aureus strains belonging to clonal complexes CC1, CC350, CC816, and CC8115. In addition to sequencing, phages were characterised by mitomycin C induction and transmission electron microscopy (TEM). All lukP/Q prophages integrated into the lip2=geh gene, and all included also the gene scn-eq encoding an equine staphylococcal complement inhibitor. The lukP/Q prophages clustered, based on gene content and allelic variants, into three groups. One was found in CC1 and CC97 sequences; one was present mainly in CC350 but also in other lineages (CC1, CC97, CC133, CC398); and a third one was exclusively observed in CC816 and CC8115. Prophages of the latter group additionally included a rare enterotoxin A allele (sea320E). Moreover, a prophage from a CC522 goat isolate was found to harbour lukP. Its lukF component could be regarded as chimaera comprising parts of lukQ and of lukF-P83. A putative kinase gene of 1095 basepairs was found to be associated with equine strains of S. aureus. It was also localised on prophages. However, these prophages were different from the ones that carried lukP/Q, and three different integration sites of kinase-carrying phages were identified. These observations confirmed the presence of prophage-located important virulence-associated genes in equine S. aureus and that certain prophages might determine the host specificity of the staphylococcal strains they reside in
Mastitis has a cumulative and lasting effect on milk yield and lactose content in dairy cows
No full textMilk lactose content (LC) physiologically decreases with parity order in dairy cows, but also after udder health inflammation(s) and in presence of elevated milk SCC in subclinical cases. Therefore, the progressive decrease in milk LC observed along cows\u27 productive life can be attributed to a combination of factors that altogether impair the epithelial integrity, resulting in weaker tight junctions, e.g., physiological aging of epithelium, mechanical epithelial stress due to milking, and experienced clinical or subclinical mastitis. Mastitis is also known to affect the udder synthesis ability, so our intention through this study was to evaluate if there is a cumulative and lasting effect of mammary gland inflammation(s) on milk yield (MY) and LC. For this purpose, we used diagnoses of clinical mastitis and milk data of Austrian Fleckvieh cows to evaluate the effect of cumulative mastitis events on LC and MY. Only mastitis diagnoses recorded by trained veterinarians were used. Finally, we investigated if cumulative mastitis is a heritable trait and whether it is genetically correlated with either LC or MY. Estimates were obtained using univariate and bivariate linear animal models. A significant reduction in LC and MY was observed in cows that suffered from mastitis compared with those that did not experience udder inflammation. The h2 of cumulative mastitis is promising and much greater (0.09) than the h2 of the binary event itself (?0.03). The genetic correlations between cumulative mastitis with LC and MY were negative, suggesting that cows with a great genetic merit for MY and LC are expected to be more resistant to repeated inflammations and less recidivist. When we used number of lifetime SCC peaks (?200,000 or 400,000 cells/mL) to calculate cumulative inflammation events, h2 was even higher (up to 0.38), implying that subclinical mastitis also has a relevant negative impact on both LC and MY. Finally, the present study demonstrated how repeated mastitis events can permanently affect the mammary gland epithelial integrity and synthesis ability, and that the number of cumulative mastitis is a promising phenotype to be used in selection index in combination with other indicator traits toward more resistant and resilient mammary glands
Guinea Pig (Cavia porcellus) Welfare: Associations Between Husbandry Practices, Human-Animal Interactions, and Animal Behaviour
No full textResearch on the welfare of pet guinea pigs and connections between their behaviour and husbandry practices is scarce. Through an online survey among 1181 German-speaking guinea pig caretakers, we investigated husbandry practices (including social composition, housing type, free roaming, enrichment, and feeding), human-animal interactions, and guinea pig behaviour. Most participating caretakers seemed attentive to their animals\u27 needs and welfare, as shown by the prevalence of self-built enclosures (42.8%) and fenced floor areas (21.1%), with various enrichment and furnishings, and mostly balanced nutrition. Husbandry practices that can negatively impact welfare, such as individual housing and no constant access to hay, were observed for 7.5% and 0.4% of the animals, respectively. Eating and resting next to conspecifics and locomotor play occurred several times per day in 87.6%, 48.1%, and 19.9% of animals, respectively. Biting, running up and down and bar chewing were rare (several times per day in 0.4%, 2.9%, and 0.7% of animals, respectively). We found significant associations of guinea pig behaviour with human-animal interactions and housing conditions. For instance, affiliative behaviour and locomotor play and use of enrichment were more frequently reported in the case of more frequent positive human-animal interactions and food enrichment. Our results provide additional knowledge to support consultations on behaviour and husbandry practices
Getting used to it? Stress of repeated management procedures in semi-domesticated reindeer
No full textExtensive animal production systems, such as reindeer husbandry may represent a system to further study the context dependence of stress responses and the potential implications for animal welfare as research on food animal stress and welfare has so far primarily focused on animals in intensive animal production systems while animals from extensive production systems, such as reindeer, are yet underrepresented. We investigated short- and longer-term stress responses to repeated herding, handling and restraint and its potential effect on animal welfare in semi-domesticated adult female reindeer (Rangifer tarandus tarandus). We also assessed seasonal differences and the potential effect of the additional stressor of calf removal using serum concentrations of glucocorticoids (cortisol, cortisone and corticosterone), their precursors (11-desoxcortisol, 17-?-hydroxyprogesterone and deoxycorticosterone) and catecholamine metabolites (metanephrine and normetanephrine) in combination with the immunological stress proxy leukocyte coping capacity (LCC) and rectal temperature. Additionally, we assessed the interconnections among different stress indices and their suitability as stress indicators to evaluate handling-induced stress in reindeer, where rectal temperature, other than serum cortisol levels, emerged as a robust and integrative stress parameter.Herding, handling, and restraint elicited a marked and seasonally different short-term stress response with higher stress mediator levels in winter. Further, females who had their calf removed shortly after parturition showed increased stress levels based on LCC. The repeated exposure to the same stressors led to a habituation, with decreasing levels of stress indices to the procedure in both seasons. This outcome implies that reindeer females in the present study were able to cope well with repeated manipulations and that this intensification may not compromise animal welfare. Notably, the traditional stress index body temperature correlated with various stress indices encompassing the HPA axis response (cortisol and corticosterone in summer and additionally cortisone and 11-deoxycortisol in winter), the sympathetic-adrenal-medullary system (metanephrine) as well as the immunological response to stress (LCC), in both seasons.Our results emphasise body (rectal) temperature as a robust and integrative stress parameter in the context of our study. Our findings add to a foundation for evaluating available stress indices in different individual and environmental contexts and may contribute to improved animal management practices aimed at reducing stress levels and enhancing animal welfare
Imaging and outcome correlates of ctDNA methylation markers in prostate cancer: a comparative, cross-sectional [??Ga]Ga-PSMA-11 PET/CT study
No full textTo validate the clinical utility of a previously identified circulating tumor DNA methylation marker (meth-ctDNA) panel for disease detection and survival outcomes, meth-ctDNA markers were compared to PSA levels and PSMA PET/CT findings in men with different stages of prostate cancer (PCa).122 PCa patients who underwent [??Ga]Ga-PSMA-11 PET/CT and plasma sampling (03/2019-08/2021) were analyzed. cfDNA was extracted, and a panel of 8 individual meth-ctDNA markers was queried. PET scans were qualitatively and quantitatively assessed. PSA and meth-ctDNA markers were compared to PET findings, and their relative prognostic value was evaluated.PSA discriminated best between negative and tumor-indicative PET scans in all (AUC 0.77) and hormone-sensitive (hsPC) patients (0.737). In castration-resistant PCa (CRPC), the meth-ctDNA marker KLF8 performed best (AUC 0.824). CHST11 differentiated best between non- and metastatic scans (AUC 0.705) overall, KLF8 best in hsPC and CRPC (AUC 0.662, 0.85). Several meth-ctDNA markers correlated low to moderate with
the tumor volume in all (5/8) and CRPC patients (6/8), while PSA levels correlated moderately to strongly with the tumor volume in all groups (all p?<?0.001). CRPC overall survival was independently associated with LDAH and PSA (p?=?0.0168, p?<?0.001).The studied meth-ctDNA markers are promising for the minimally-invasive detection and prognostication of CRPC but do not allow for clinical characterization of hsPC. Prospective studies are warranted for their use in therapy response and outcome prediction in CRPC and potential incremental value for PCa monitoring in PSA-low settings
Response to high ambient temperatures in short-distance and trans-Saharan migratory species
No full textIn consideration of current global climate change, ecophysiological research on wild birds has increased its emphasis on approaches related to thermal tolerance. Many studies have investigated how desert specialists are adapted physiologically to the hot and xeric conditions they live in. Our aim was to test whether migratory passerines from temperate areas also have physiological adaptations to cope with heat stress and whether such adaptations may be related to habitat or migration distance. Using video recording and flow-through respirometry, we measured temperatures of panting onset (TPANT) of 113 individuals of 14 different species, exposed to increasing ambient temperature. Our study species differed in size, migration type (short-distance migrants vs. trans-Saharan migrants) and habitat preferences (woodland, farmland, reeds). We found that trans-Saharan migrants started panting at higher ambient temperatures (TA) than short-distance migrants of similar size, but no difference between species from different habitats. This finding suggests that migrants facing a desert crossing may have adaptations to decrease the
risk of dehydration while maintaining body temperature below the critical range. According to this, we suggest that there may be selection on traits related to the modulation of respiratory water loss in birds that cross the Sahara Desert during migration. Flexibility in these traits will be of crucial importance in a warmer future
Spoilage characteristics of sous-vide beef caused by Clostridium estertheticum
No full textThe increasing popularity of sous-vide (SV) cooking necessitates research into the microbiological quality, sensory changes, and shelf life of SV products. Studies show that SV cooking significantly reduces the levels of meat microbiota and pathogens, positively affecting the shelf life and safety of SV products. However, the meat spoilage organism Clostridium estertheticum can survive SV cooking as it can produce heat-tolerant spores. Theses spores can germinate and multiply during storage at refrigerated temperatures, leading to spoilage of SV meat. Therefore, the aim of this study was to characterise the spoilage of SV beef caused by C. estertheticum compared to non-SV beef. In addition to the determination of spoilage characteristics, all beef samples were subjected to culture and qPCR analysis to determine the numbers of total bacteria, lactic acid bacteria, Enterobacteriaceae, yeasts, and C. estertheticum. Species identification of the colonies on the culture media was performed using MALDI-TOF MS. The tests were carried out at three different times (three repetitions). A total of 90 beef samples were analysed, of which 54 samples were artificially contaminated with three strains of C. estertheticum and vacuum-packed. Of these, 27 beef samples underwent SV cooking (55 °C, 70 min). After 28 days of storage at 4 °C, the SV beef samples exhibited significantly higher levels of gas and stronger spoilage odour compared to non-SV samples (p < 0.05). While drip loss and pH levels were also higher in SV beef, these were not considered specific spoilage characteristics caused by C. estertheticum. Microbiological and qPCR analyses revealed that all SV beef samples had very low bacterial and yeast counts but very high numbers of C. estertheticum, which strongly correlated with the sensory changes observed. We concluded that SV beef containing C. estertheticum has a shorter shelf life than contaminated non-SV beef. This is the first study to examine the spoilage of SV beef by C. estertheticum. The results may help raise awareness among meat producers and restaurants about the risk of meat losses due to spoilage caused by these bacteria
Rhythmic categories in horse gait kinematics
No full textAnecdotally, horses\u27 gaits sound rhythmic. Are they really? In this study, we quantified the motor rhythmicity of horses across three different gaits (walk, trot, and canter). For the first time, we adopted quantitative tools from bioacoustics and music cognition to quantify locomotor rhythmicity. Specifically, we tested whether kinematics data contained rhythmic categories; these occur when adjacent temporal intervals are categorically, rather than randomly, distributed. We extracted the motion cycle duration (tk) of two ipsilateral hooves from motion data of 13 ridden horses and calculated the ratios from two successive tk values. We tested whether these ratios significantly fell within rhythmic categories and quantified how close they were to small-integer ratios, a rhythmic feature also present in animal vocalizations and human music. We found a strong isochronous pattern-a 1:1 rhythmic ratio, corresponding to the ticking of a clock-in the motion of single limbs for all gaits. We also analyzed the interlimb coordination of the two ipsilateral hooves\u27 impacts to identify differences associated with the biomechanical patterns of the three gaits. We found an interlimb 1:1 rhythmic pattern for trot and 1:3 and 3:1 rhythmic categories for walk and canter. Our findings are a first step toward quantifying rhythmicity in horse locomotion and potentially the resulting rhythmic sounds, with possible implications as tools to
detect gait irregularities. Overall, we show that rhythmic categories are a valuable tool for gait kinematic analysis and that they can be used to quantify temporal patterns in the motor domain
Annual report 2024 / University of Veterinary Medicine Vienna
No full textThe Annual Report gives an overview of academic life at the university, summarising the latest news in research, teaching and the university clinics. This report is available in german and english
An In Vitro Nutritional Evaluation of Mixed Silages of Drought-Impaired Grass and Sugar Beet Pulp With or Without Silage Inoculants
No full textIncreasing droughts adversely affect grasslands, diminishing the availability and quality of forages for ruminants. We have recently shown that mixed ensiling of drought-impaired grass (DIG) with sugar beet pulp (SBP) improved the conservation and feed value of silage. The application of silage additives may further improve the ruminal degradability, which may thereby shape the fermentation and microbiome in the rumen when those silages are tested as part of dairy diets. Therefore, we performed a long-term in vitro nutritional evaluation of diets containing 50% (DM basis) of mixed silages from DIG and SBP, ensiled either with no additive (T_CON) or with anaerobic fungi culture supernatant (25% in DM; T_AF), mixed ruminal fluid (10% in DM; T_RF) or lactic acid bacteria (1% in FM; T_LAB). The data showed a high degradability of all diets (e.g., > 70% for organic matter), though without differences in nutrient degradabilities among treatments (p > 0.05). Fermentation characteristics, such as ruminal pH, short-chain fatty acid profile, and gas production were only marginally affected by the treatments. Isobutyric acid proportion was higher in T_CON than in T_AF (p = 0.01), whereas isovaleric acid proportion was lower in T_LAB than in T_RF (p = 0.01). The analysis of the bacterial community revealed similar diversity and structure across all treatments in both the liquid and solid fraction. Noteworthy, Lactobacillus was among the predominant genera in the liquid fraction, which may have derived from the mixed silages. In conclusion, mixed silages from DIG and SBP as part of a 50% concentrate diet showed high ruminal degradability, but no beneficial impact by the tested silage additives was observed. Hence, under these conditions, their application appears not justified. Our results warrant further in vivo verification, whereby it would be of interest to determine the impact of the applied silage additives in forage-based diets (e.g., > 50% silage in diet DM) in future research