Phaidra - University of Veterinary Medicine Vienna
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Antimicrobial susceptibility profiles of Mycoplasma hyosynoviae strains isolated from five European countries between 2018 and 2023
No full textMycoplasma (M.) hyosynoviae is a facultative pathogen, causing arthritis in finisher pigs world-wide. In the absence of a commercial vaccine improvement of housing conditions and antibiotic therapy are the only options to alleviate the clinical signs. This study aimed to determine antibiotic susceptibility profiles of 106 M. hyosynoviae isolates against ten antibiotics licensed for veterinary use in cases of arthritis. The isolates were collected between 2018 and 2023 from five European countries: Austria (n = 20), Belgium (n = 20), Germany (n = 25), Hungary (n = 21) and Italy (n = 20). The minimal inhibitory concentrations (MIC) were determined by broth micro-dilution assay. The tested isolates were highly susceptible to tiamulin (MIC90 ≤ 0.039 µg/ml), tylvalosin (MIC90 ≤ 0.039 µg/ml) and lincomycin (MIC90 ≤ 0.25 µg/ml). Low concentrations of tylosin (MIC90 0.5 µg/ml) and tilmicosin (MIC90 1 µg/ml) inhibited the growth of the isolates. While moderate minimal inhibitory concentrations were detected for doxycycline (MIC90 0.312 µg/ml), oxytetracycline (MIC90 2 µg/ml), enrofloxacin (MIC90 0.625 µg/ml) and florfenicol (MIC90 2 µg/ml), only high concentrations of tulathromycin (MIC90 64 µg/ml) inhibited the growth of the isolates. Statistical analysis revealed significant differences between countries in case of enrofloxacin, where the Hungarian isolates showed the lowest MIC values, and the German isolates the highest MIC values among the tested countries. Our results show that European M. hyosynoviae isolates are generally susceptible to the tested antibiotics with the exception of tulathromycin. The country specific differences indicate the importance of regular susceptibility testing of isolates on a Pan-European level
Methods to assess on-farm biosecurity in Europe and beyond
No full textThe aim of this study was to identify which biosecurity assessment methods (BAMs) are currently used in practice in animal farms. To address this, a structured questionnaire was developed to gather information such as the animal species, main objectives, type of enforcement, output generated and feedback of the result. In the context of the BETTER Cost Action project, country representatives identified in each of their countries which BAMs were used and completed an online survey. The survey was prepared and translated in 23 languages. Besides a descriptive analysis, clusters of BAMs were determined using a multiple correspondence analysis. Responses, collected between December 2022 and July 2023, included 74 BAMs used in 28 countries. Most of them were used in a single country while three were used in multiple countries. This study provides a comprehensive picture of existing BAMs and insights into their diversity, such as variations in objectives, implementation, evaluators, respondents, feedback, or assessment outputs. Moreover, we identified four BAMs clusters differentiated by their objective, evaluator and type of feedback provided. This study might also represent the basis for future research on strengths and weaknesses of different BAMs
Vector-borne pathogens in dogs from the Republic of Kosovo
No full textCanine vector-borne pathogens (CVBP) are transmitted by arthropod vectors such as ticks, fleas, mosquitoes, and phlebotomine sand flies and are of global veterinary and medical importance. Dogs are important reservoir hosts, which may develop potentially life-threatening clinical signs. The Balkan area harbors diverse vector fauna and associated CVBPs, and data, particularly from the Republic of Kosovo, are scarce. Considering the high number of stray and privately owned dogs primarily kept outside, living in close contact with dogs might promote spillover of zoonotic pathogens to human populations. To combat these diseases, a One Health approach is required. Therefore, our study molecularly analyzed samples of dogs for CVBP.Blood samples of 276 dogs originating from all seven districts of Kosovo collected from 2021 to 2022 were screened using polymerase chain reaction (PCR) and sequencing for a substantial set of pathogens, including Anaplasma spp., Babesia spp., Bartonella spp., Ehrlichia spp., Filarioidea, Hepatozoon spp., Mycoplasma spp., Rickettsia spp., and Trypanosoma spp. Prevalence rates were statistically assessed on the basis of various factors such as sex, breed, age, and district.In total, 150 (54.3%) dogs tested positive for at least one pathogen, comprising eight species of five genera. The most prevalent pathogens detected were Candidatus Mycoplasma haematoparvum (55; 19.9%), Hepatozoon canis (52; 18.8%), and Mycoplasma haemocanis (49; 17.8%). We also detected double (32; 11.6%) and triple (5; 1.8%) infections, with the latter involving combinations of Mycoplasma spp., Dirofilaria repens, Dirofilaria immitis, H. canis, or Babesia vulpes. In addition, prevalence rates were calculated and mapped by district. Of all included factors, significant prevalence differences were found for purebred/mixed breed dogs as well as between age groups.This study provides the first comprehensive polymerase chain reaction (PCR)-based screening and detection of vector-borne pathogens in dogs from Kosovo and highlights the circulation of pathogens with high veterinary importance and zoonotic potential
Silver and Zinc Oxide Nanoparticles for Effective Aquaculture Wastewater Treatment
No full textThis study explores the use of silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs), either singly or in combination, for the nanoremediation of aquaculture wastewater. Aquaculture wastewater was treated with varying doses of Ag NPs and ZnO NPs across the following six groups: Group 1 (0.05 mg Ag NPs/L), Group 2 (1 mg ZnO NPs/L), Group 3 (0.05 mg Ag NPs/L + 1 mg ZnO NPs/L), Group 4 (0.025 Ag NPs/L + 0.5 mg ZnO NPs/L), Group 5 (0.1 mg Ag NPs/L + 2 mg ZnO NPs/L), and a control group. Water quality, microbial loads and nanomaterial concentrations were assessed over ten days. Transmission electron microscopy (TEM) showed average particle sizes of 102.5 nm for Ag NPs and 110.27 nm for ZnO NPs. The removal efficiencies of NH4-N were over 98% across treatment groups. In addition, COD removal efficiencies were 33.33%, 68.82%, 49.59%, 61.49%, and 37.65%. The log-reductions in aerobic plate counts for the nanoparticle-treated wastewater were 1.191, 1.947, 1.133, 1.071, and 0.087, compared to a reduction of 0.911 in untreated wastewater. Silver concentrations ranged from 0.0079 to 0.0192 mg/L, while zinc concentrations ranged from 0.3040 to 0.9740 mg/L, indicating that ZnO-NPs represent a sustainable treatment method for aquaculture wastewater
Intervention strategies for methicillin-resistant Staphylococcus aureus control in pig farming: a comprehensive review
No full textMethicillin-resistant Staphylococcus aureus (MRSA) poses a serious public health threat due to its zoonotic potential and resistance to several antibiotic classes. Pig farming is recognized as a key reservoir for livestock-associated MRSA, necessitating effective intervention strategies to mitigate its prevalence. The objective of this narrative review was to summarize the current knowledge on the approaches to control MRSA on pig farms. The review process involved a comprehensive search across three electronic databases focusing on studies from 2000 to 2024 in both English and German.The review covers intervention measures including reduced antimicrobial use, cleaning and disinfection, air filtration, and bacteriophage application. Key findings indicate that, while interventions such as cleaning and disinfection and air filtration, can effectively reduce environmental MRSA loads, these measures are often insufficient for long-term control due to frequent recontamination, especially restocking with MRSA-positive animals. Eradication was shown to be effective in low-prevalence regions such as Norway, however, logistical and ethical challenges limit its feasibility in areas with high MRSA prevalence. Additional interventions, such as reduced antimicrobial use and sow washing, provided inconsistent results.Overall, the findings highlight the need for a multifaceted approach, combining several interventions tailored to regional MRSA prevalence, farm management practices, and available resources. Such an integrated strategy is essential for sustainable MRSA control in pig farming, thereby supporting the global One Health initiative aimed at mitigating antimicrobial resistance
Impact of positive end-expiratory pressure and recruitment maneuver on healthy lungs in dogs assessed by functional and anatomical monitoring methods
No full textIntroduction: Atelectasis is a common occurrence during anesthesia, and positive end-expiratory pressure (PEEP) ventilation and recruitment maneuvers (RM) can be used to mitigate this. However, both techniques may be associated with side effects in healthy lungs, and close monitoring is indicated. This study aimed to evaluate the effects of PEEP and RM in healthy dogs and to compare functional lung monitoring methods by electrical impedance tomography (EIT), volumetric capnography (VCap), and blood gas analysis with the gold-standard anatomical monitoring provided by computed tomography (CT).
Methods and materials: Nine healthy Beagle dogs underwent anesthesia and mechanical ventilation three times. After 35 min using zero end-expiratory pressure (ZEEP), CT images, VCap, EIT measurements, and arterial blood gas samples were taken. Thereafter, either (1) ZEEP was continued, (2) PEEP initiated or (3) an RM was performed followed by PEEP. Ten minutes after changing the ventilation mode all measurements were repeated. Only one ventilation mode was employed during each anesthesia.
Results: During RM, we found a significant increase in the percentage of overaerated lung (Vhyper) (p < 0.001), while the amount of normally aerated lung (Vnormal), poorly aerated lung and non-aerated lung decreased (p ≤ 0.001). VCap showed an increase in airway dead space (VDaw/VT) (p = 0.002), and a decrease in alveolar dead space (VDalv/VTalv). For PEEP, an increase in airway dead space (p = 0.003) was found. For both groups, the amount of carbon dioxide exhaled per breath (VTCO2,br) decreased (p = 0.001), and EIT showed a shift of the center of ventilation to the dependent lung areas (p = 0.021 and p = 0.046, respectively). Oxygenation was superior in RM compared to ZEEP (p = 0.033). The arterial partial pressure of carbon dioxide decreased in RM (p = 0.012). Positive associations were found between Vhyper and VDaw/VT (p = 0.004), Vhyper and VDaw/VT (p = 0.004), Vhyper and Vnormal with VTCO2,br (p = 0.002 for both). Negative associations were found between Vhyper and VDalv/VTalv (p = 0.004) and non-dependent silent spaces (p = 0.050), and Vnormal with oxygenation (p = 0.030).
Conclusion: While RM may be effective in improving gas exchange, it appears to be not benign in healthy lungs, and PEEP might be the preferable strategy to avoid lung collapse during anesthesia. Functional monitoring – EIT, VCap, blood gas analysis – does not detect changes corresponding to anatomical findings on CT
Resolving complexity: identification of altersetin and toxin mixtures responsible for the immunomodulatory, antiestrogenic and genotoxic potential of a complex Alternaria mycotoxin extract
No full textAlternaria mycotoxins may pose significant risks to human health due to their diverse spectrum of adverse effects and frequent occurrences in food. A previous study demonstrated the immunosuppressive, antiestrogenic, and genotoxic potential of a complex Alternaria mycotoxin extract (CE). The present study aimed to elucidate specific Alternaria mycotoxins or combinations thereof responsible for toxicity. Following toxicity-guided fractionation of the CE, a multiparametric panel of assays was applied to assess different endpoints. These included immunomodulatory effects (NF-?B reporter gene assay in THP1-Lucia™ monocytes), estrogenicity/antiestrogenicity (alkaline phosphatase assay in Ishikawa cells) and genotoxicity (?H2AX and alkaline comet assays in HepG2 cells). LC-MS/MS analysis revealed prominent mycotoxins in the active fractions, with altersetin (AST) identified as a novel key compound exhibiting immunoinhibitory (?2 ?M) and antiestrogenic (?5 ?M) properties in vitro. Additionally, while specific mycotoxin combinations explained the toxicity of active fractions, some effects remained unexplained, suggesting the presence of unidentified bioactive substances. This study underscores the significance of AST and specific toxin mixtures as major contributors to CE toxicity. Further, it highlights the importance of considering combinatory effects in risk assessment of Alternaria mycotoxins as well as further investigation of unknown Alternaria metabolites, which may pose additional health risks
The role of microRNA in the regulation of hepatic metabolism and energy-expensive processes in the hibernating dormouse
No full textThe garden dormouse (Eliomys quercinus) is a fat-storing mammal that undergoes annual periods of hibernation to mitigate the effects of food scarcity, low ambient temperatures, and reduced photoperiod that characterize winter. Like other hibernating species, this animal suppresses its metabolic rate by downregulating nonessential genes and processes in order to prolong available energy stores and limit waste accumulation throughout the season. MicroRNAs (miRNAs) are short, single-stranded, noncoding RNAs that bind to mRNA and mediate post-transcriptional suppression, making miRNA ideal for modulating widespread changes in gene expression, including global downregulation typified by metabolic rate depression. Using next-generation sequencing, we analyzed an RNA-seq dataset to determine which miRNAs are differentially regulated during hibernation in the dormouse liver. We found that the expression of 19 miRNAs was altered during hibernation; however, only one major miRNA (miR-34a-5p) remained significantly downregulated after correcting for false discovery rate. Gene Ontology, KEGG Pathway Analysis, and DIANA-miRPath predicted that energy metabolism, nuclear-related functions such as histone binding, chromatin- and chromosomal binding, and the cell cycle are processes that may be differentially regulated during hibernation due to miRNA regulation. Taken together, our data suggest that miRNA influence appears to be strongly directed toward suppressing energy-intensive processes in the nucleus hence contributing to extend the animal\u27s endogenous fuel reserves for the duration of hibernation
The cytotoxic and hemolytic potential of karmitoxin from Karlodinium armiger and how it interacts with sterols
No full textKarmitoxin, produced by Karlodinium armiger, is structurally related to karlotoxin and amphidinols, two potent ichthyotoxic hemolysins with high affinity for sterols. Given these structural similarities, karmitoxin is believed to exhibit comparable toxic effects. Cytotoxicity was assessed in the fish gill cell line RTgill-W1 and the human epithelial colon cell line HCEC-1CT. The hemolytic potential with and without added sterols was tested on fish erythrocytes to investigate possible impacts of toxin-sterol interactions. Sterol interactions were further evaluated using surface plasmon resonance. A 3-h incubation returned an EC50 of 111 and 175 nM in RTgill-W1 and in HCEC-1CT cells, respectively. Lactate dehydrogenase (LDH) release increased with toxin concentration, reaching 11 % in the fish and 40 % in the human cell line. Extended exposure (24 h) increased the toxicity in RTgill-W1 cells (EC50 74 nM, 40 % LDH release). In parallel, hemolytic potential of karmitoxin was confirmed, as well as its interaction with free sterols. Interaction kinetics revealed complex stabilities with kd(s-1) constants of 1.13 × 10-2 (cholesterol), 5.48 × 10-3 (epicholesterol), and 4.72 × 10-3 (ergosterol). Interaction with cholesterol followed the single-exponential model well, while data indicated more complex binding with epicholesterol and ergosterol. Altering the RTgill-W1 cholesterol content did not impact cytotoxicity at the tested concentration. Overall, karmitoxin showed potent cytotoxic and hemolytic properties in human and fish models. Complex formation with sterols may play a role in membrane targeting, yet cellular cholesterol quantity might not affect cytotoxicity
Impact of a two-stage rumen cannulation on the health and rumen function of six lactating dairy cows
No full textObjective
To determine the impact of a two-stage rumen cannulation on the health and rumen function of lactating dairy cows.
Study design
Experimental study.
Animals
Six lactating Holstein cows.
Methods
We performed a two-stage rumen cannulation in six Holstein cows that were 49 ± 11 days in milk. The following clinical health parameters and digestion-associated variables were analyzed on seven measurement days, from before the first surgery until 28 days after the second surgery: body temperature, heart rate, respiratory rate, pain score, rumen fill score, fecal score, wet sieving, auscultation and palpation of the rumen, bodyweight, body condition score, and activity.
Results
The pain score of the cows was constantly zero. Similarly, the body temperature and respiratory rate remained within physiological ranges, whereas the heart rate was slightly higher immediately after the second surgery. No differences were observed in rumen fill (2.00–2.67; p = .10) and fecal consistency scores (2.17–2.67; p = .42). The fecal particle size distribution showed negligible differences. The cows lost approximately 43 kg of bodyweight during the experiment (p < .01), which was reflected in a 0.5-point body condition score loss (p < .01).
Conclusion
A temporary minimal negative effect of a two-stage rumenostomy on the health and body condition of early lactating Holstein cows was observed, whereas digestion was unaffected. Considering the limited sample size, further studies are required to substantiate these findings.
Clinical significance
Given that animals are appropriately medically managed, experimental rumenostomy of lactating dairy cows may not compromise their health or rumen function