33145 research outputs found
Sort by
Valutatore di Tesi di Dottorato in Veterinary and Animal Science Class XXXVII - Department of Veterinary Medicine and Animal Sciences - Università degli Studi di Milano: 'Extended-spectrum β-lactamase-, AmpC- and carbapenemase-producing bacteria in dogs and cats'
No full textAntimicrobial resistance (AMR) is a critical global health challenge, compromising the efficacy of antibiotics and threatening both human and animal health. The rise of multidrug-resistant (MDR) bacteria compromises the efficacy of treatments for infections in humans and animals, leading to prolonged illnesses, increased mortality, and substantial economic burdens. Companion animals are increasingly recognized as reservoirs and potential sources of antimicrobial-resistant pathogens, contributing to the dissemination of resistance genes across ecosystems and posing a zoonotic risk. Understanding the prevalence, genetic mechanisms, and risk factors associated with AMR in dogs and cats is essential for the development of effective control strategies within a One Health approach. This thesis primarily focused on fecal shedding of extended-spectrum β-lactamase (ESBL)-, AmpC-, and carbapenemase-producing Escherichia coli, considered a key indicator of antimicrobial resistance in bacterial populations. Fecal samples from dogs and cats, including both pets and stray animals were investigated for the presence, genetic determinants, and associated risk factors of these bacteria. An additional investigation focused on dogs with urinary tract infections and analyzed ESBL-, AmpC-, and carbapenemase-producing E. coli as well as Klebsiella pneumoniae, a clinically significant pathogen often linked to resistance to the highest-priority critically important antimicrobials, along with other AMR mechanisms such as biofilm formation in these bacteria isolated from urinary samples. This thesis is based on four studies. The first study focused on cats, which have been studied less frequently than dogs, and investigated the presence of ESBL/AmpC-producing E. coli in both pet and stray cats. Fecal samples from 97 cats revealed that six (6.2%) carried these resistant bacteria. Genetic analysis detected blaCTX-M in all isolates, along with blaTEM (83.3%),blaSHV (16.7%), and chromosomal AmpC over expression (1%). All isolates were multi-drug resistant (MDR). Statistical analysis demonstrated significant associations between ESBL/AmpC carriage and unhealthy status or previous antibiotic therapy, underscoring the potential role of cats as reservoirs for resistant bacteria. The second study focused exclusively on stray cats and included the study of carbapenemase producing E. coli, due to their importance according to the One Health concept. Among the 94 stray cats analyzed, 18 (19.1%) tested positive for ESBL-/AmpC-/carbapenemase-producing E. coli. Notably, besides ESBL-/AmpC-producing E. coli, this study showed the presence of carbapenemase genes blaNDM and blaOXA-48 in seven (7.4%) samples. Among the isolates
analyzed, 17 (94.4%) were identified as MDR. Hospitalization, prior antibiotic treatment, and unhealthy status were identified as significant risk factors. Moreover, ESBL-producing E. coli were detected in healthy stray cats which had not been hospitalized and had likely not been previously treated. Overall results highlight the complex epidemiology of AMR in stray animals suggesting the need for further investigation on the source of infection also focusing on environmental contamination. Carbapenemase-producing E. coli fecal carriage was further investigated in the third study that focused on dogs, in which carbapenemase-producing bacteria were less frequently studied. The fecal carriage of ESBL-/AmpC-/carbapenemase-producing E. coli was detected in 14/100 (14%) dogs, with 92.9% of isolates exhibiting MDR. Genetic analysis identified blaCTX-M in ESBL-producing isolates, blaCMY-2 in AmpC-producing isolates, and blaOXA-48 in
carbapenemase-producing E. coli. Antibiotic treatment was confirmed as a significant risk factor for fecal shedding of these bacteria, emphasizing the need for antimicrobial stewardship in veterinary medicine. The fourth study investigated AMR bacteria in dogs with bacterial urinary tract infections (UTIs) focusing on the detection of ESBL-/AmpC-/carbapenemase-producing E. coli and K. pneumoniae, including evaluation of biofilm production of isolates, a factor that contributes to bacterial persistence and resistance. Among 133 urine samples analyzed, 53 (39.8%) were culture-positive. E. coli was the predominant pathogen (28; 21.1%) and six (4.5%) samples tested positive for K. pneumoniae. ESBL production, driven by blaCTX-M group 1, was detected in 4/34 (11.8%) E. coli/K. pneumoniae isolates and was significantly associated with K. pneumoniae. Furthermore, 11 (32.4%) isolates exhibited MDR. Biofilm formation was observed in 23 (67.6%) isolates, with moderate biofilm production significantly associated with K. pneumoniae. These findings emphasize the need for in vitro susceptibility testing and careful antibiotic use in treating canine UTIs. Overall, these studies underline the critical role of companion animals in the spread of antimicrobial-resistant bacteria. The detection of MDR and carbapenemase-producing E. coli is of concern and reinforces the need for enhanced surveillance programs and antimicrobial stewardship within a One Health framework, evaluating the risk of transmission to humans due to the close interaction of pets with their owners. Addressing AMR in companion animals is essential to safeguard both veterinary and public health, reinforcing the need for a
collaborative One Health approach
Malattie dell'apparato locomotore
No full textNel presente capitolo sono considerate solo le principali malattie dell’apparato locomotore, rimandando la trattazione di quelle meno frequenti ai testi specialistici. Di ogni malattia considerata vengono sinteticamente riportati definizione, eziopatogenesi, quadro clinico, diagnosi e terapia, rimandando anche in questo caso il relativo approfondimento ai testi specialistici
Oxidative Stress and Apoptotic Markers in Goats Naturally Infected with Mycobacterium avium subsp. paratuberculosis
Get PDFParatuberculosis, caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a chronic granulomatous enteritis with significant implications for ruminant health, economic productivity, and potential zoonotic risk. This study investigated the expression of biomarkers of oxidative stress and apoptosis in goats naturally infected with MAP, focusing on three biological matrices: serum, intestinal mucosa, and mesenteric lymph nodes. Twenty MAP-positive goats and ten healthy controls were included. Serum and tissue levels of malondialdehyde (MDA), glutathione S-transferase (GST), glutathione peroxidase (GPX), superoxide dismutase (SOD), glutathione reductase (GSR), and caspase-3 were quantitatively assessed using ELISA tests. Gross and histopathological analyses confirmed MAP infection. Infected animals showed significantly elevated serum levels of MDA and caspase-3 (p < 0.001), along with decreased antioxidant enzyme activities (GSR, GST, GPX, SOD). Tissue analysis revealed increased MDA and caspase-3 levels, particularly in the intestinal mucosa compared to mesenteric lymph nodes, suggesting localized oxidative damage and apoptosis. Conversely, antioxidant enzyme activity was higher in mesenteric lymph nodes, indicating a compensatory response and a pronounced involvement of the intestinal tract. These findings demonstrate that MAP infection induces marked oxidative stress and apoptotic processes, especially in the intestinal mucosa. The imbalance between pro-oxidant and antioxidant systems may play a key role in the pathogenesis and chronic progression of the disease. Caspase-3 and MDA, in particular, have been identified as promising diagnostic or prognostic biomarkers for MAP infection. This study highlights the importance of developing improved diagnostic tools and therapeutic strategies targeting oxidative stress pathways in paratuberculosis
Bioformulations based on Trichoderma and Azotobacter consortia modulate composition and improve biological activity of sweet basil (Ocimum basilicum L.) cv. Genovese essential oil
No full textBasil (Ocimum basilicum L.) is widely cultivated for its economic value. Recently, diverse cultivation management practices have emerged to enhance the productivity and quality of plants and their bioactive compounds, including essential oils (EOs). In this study, bioformulations based on Azotobacter chroococcum 76A (76A), Trichoderma afroharzianum T22 (T22), 6-pentyl-α-pyrone (6PP, a lactone produced by Trichoderma), and a biopolymer (BP), were tested on sweet basil cv. Genovese grown in protected cultivation. The effects of the bioformulations on basil EO content, composition, and biological activities were evaluated. The content of EOs from biotreated plants in 6 out of the 9 bioformulations increased up to 0.68 % w/w in the treatment vs. 0.25 % w/w in the control. The bioformulation applications to the plants modified EOs composition, as was demonstrated by GC-MS analysis, particularly regarding eugenol and linalool percentages. All basil EOs inhibited the growth of different bacterial and fungal strains and reduced biofilm production in plate assays, but EOs from plants treated with T22 alone or in combination with 76A showed better performances, e.g. the EO from T22 + 76A treated plants inhibited up to 92.9 % biofilm production in Escherichia coli, demonstrating potential as alternative to synthetical chemical products for disease control applications in agriculture. The ability of EOs to prevent ROS formation and their wound-healing activity in vitro were also examined, with EOs from T22 + 76A treated plants demonstrating the major antioxidant activity. Our findings support the development of innovative formulations based on microbial consortia that can stimulate the production of aromatic and nutraceutical compounds in basil leaves
Black mulberry (Morus nigra L.) prevents deleterious effects of excess glucose in obese C. elegans decreasing lipofuscin accumulation and ROS production
No full textBlack mulberries have been traditionally used as antidiabetic agents and are a source of nutrients and phenolic compounds, particularly anthocyanins. The objective of this work is to determine if Morus nigra berries could prevent metabolic and obesity-related disorders using in vitro systems and in vivo alternative models such as C. elegans. An aqueous solvent-free extract from Morus nigra fruits rich in phenolic compounds like chlorogenic acid, hyperoside, rutin and cyanidin 3-glucoside was evaluated in the C. elegans obese model subjected to high glucose concentrations evaluating different parameters such as lipid droplets, lipofuscin accumulation and ROS production. The capacity of the extract to inhibit advance glycation end products and free radicals as well as pancreatic lipase and α-amylase was also evaluated in vitro. The black mulberry extract showed a significant capacity to inhibit the accumulation of lipid droplets, reducing by 50.40 % the fat deposits. The extract was able to reverse the deleterious effects of excess glucose in C. elegans enhancing stress resistance, preventing the accumulation of lipofuscin, and decreasing the ROS production. The anti-glycation and antioxidant effects in vitro were higher than the reference substances aminoguanidine and quercetin respectively. Morus nigra was also able to inhibit the pancreatic enzymes α-amylase and lipase and could be considered an interesting traditional food ingredient in the prevention of certain metabolic diseases
Ultrasound Assisted Extraction (UAE) versus traditional Soxhlet apparatus for the obtention of polyphenols, carotenoids and tocopherols from Tagetes erecta L. flowers
No full textBACKGROUND: Tagetes erecta L., commonly known as American marigold, serves as a food plant used for the extraction of carotenoids such as lutein, employed both as culinary ingredient in certain dishes and for its ornamental and medicinal applications. Two extraction techniques, Soxhlet and ultrasound-assisted extraction (UAE), were used on two cultivars (yellow and orange) of T. erecta. Polyphenols were quantified using HPLC-tandem mass spectrometry, whereas carotenoids and tocopherols were determined using HPLC-diode array detection. Biological activity for antioxidant and antiglycation properties was carried out. RESULTS: The best extraction yield was obtained for UAE (7.51% and 6.83% for yellow and orange flowers), corresponding with the largest amounts of polyphenols quantified. The highest content of tocopherols was obtained in the yellow cultivar extracted by Soxhlet (6499.3 ± 21.2 and 4671.0 ± 92.9 mg kg−1 dry extract for α- and γ-tocopherol). The antioxidant potential resulted higher in the orange Soxhlet extract, whereas the yellow Soxhlet extract displayed the best antiglycation activity (median 50% inhibitory concentration of 25.3 ± 3.3 μg mL−1). CONCLUSION: Both extraction techniques showed interesting results in terms of bioactivity and compounds obtention
Anticancer potential of copper(i) complexes based on isopropyl ester derivatives of bis(pyrazol-1-yl)acetate ligands
No full textIn this paper, the isopropyl ester derivatives LOiPr and L2OiPr of bis(pyrazol-1-yl)acetic acid and bis(3,5-dimethyl-pyrazol-1-yl)acetic acid were used as chelators for the preparation of new Cu(i) phosphane complexes 1-4. They were synthesized by the reaction of [Cu(CH3CN)4]PF6 and triphenylphosphine or 1,3,5-triaza-7-phosphaadamantane with LOiPr and L2OiPr ligands, in acetonitrile or acetonitrile/methanol solution. The authenticity of the compounds was confirmed by CHN analysis, 1H-, 13C- and 31P-NMR, FT-IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). Furthermore, the electronic and molecular structures of the selected Cu(i) coordination compound 3 were investigated by synchrotron radiation-induced X-ray photoelectron spectroscopy (SR-XPS), and the local structure around the copper ion site was studied combining X-ray absorption fine structure (XAFS) spectroscopy techniques and DFT modelling. Triphenylphosphine as a coligand confers to [Cu(LOiPr)(PPh3)]PF6 (1) and [Cu(L2OiPr)(PPh3)]PF6 (3) a significant antitumor activity in 3D spheroidal models of human colon cancer cells. Investigations focused on the mechanism of action evidenced protein disulfide-isomerase (PDI) as an innovative molecular target for this class of phosphane copper(i) complexes. By hampering PDI activity, copper(i) complexes were able to cause an imbalance in cancer cell redox homeostasis thus leading to cancer cell death - a non-apoptotic programmed cell death
Event log extraction methodology for ethereum applications
No full textThe adoption of smart contracts in decentralized blockchain-based applications enables reliable and certified audits. These audits allow the extraction of valuable information from blockchains, which can be used to reconstruct the execution of the application and facilitate advanced analyses. One of the most commonly used techniques in this context is process mining, which leverages event logs to trace and accurately represent the process execution of applications. However, extracting execution data from blockchains poses significant challenges, and the current methodologies developed have some limitations. Most approaches are tailored to specific use cases, requiring that analysis techniques are defined during the smart contract’s development. Other techniques are applied a posteriori, relying on blockchain events that often lack a standardized format. This absence of standardization requires complex processing steps to correlate logs with the executed actions and such approaches are not universally applicable to all smart contracts on the blockchain, further limiting their scope. Lastly, none of the existing techniques can extract information from event logs embedded in internal transactions of smart contracts.
To address these limitations, we propose EveLog an application-agnostic methodology that can be applied to any EVM-compatible application without predefined constraints. Its primary goal is to extract information from smart contracts, capturing both public and internal transactions, and organising the results into a structured XES event log. The EveLog methodology consists of five key steps: (i) extraction of data from smart contract transactions, (ii) decoding raw data, (iii) selection of sorting criteria, (iv) construction of traces, and (v) generation of the XES event log. EveLog has been implemented in a client–server application and tested on existing solutions, specifically the CryptoKitties application, a blockchain-based game on the Ethereum blockchain. The study was conducted using 12,996 blocks, including over 8,000 real transactions from the Ethereum mainnet
Uncovering drivers of epiphytic cryptogam diversity in forest ecosystems through a functional trait approach
No full textForest biodiversity, including often-overlooked cryptogams, such as epiphytic
lichens, bryophytes, free-living algae, and fungi, underpins the fundamental
processes that sustain ecosystem functions. In the face of growing climatic and
habitat-related changes, it is crucial to understand how shifts in environmental
conditions affect biological communities and, in turn, reshape ecosystem
functions. Achieving this requires insight into the drivers of spatial and temporal
variation in both taxonomic and functional diversity. In our study, we employ a
trait-based framework to quantify taxonomic richness and functional diversity of
epiphytic non-vascular communities across ten forest sites in the Italian ICP
Forests Level II network, representing nemoral, boreal, and Mediterranean forest
types. We investigate biotic traits of recorded taxa (growth form, thallus colour,
secondary metabolite profile, reproductive strategy, and thermal- and
water-related traits) and relate them with key environmental predictors
(macroclimatic variables, sub-canopy microclimate, and stand structure). In
addition, with particular focus on symbiotic organisms, we examine both spatial
patterns and temporal trends in lichen diversity and identify their key drivers
based on data obtained by repeated surveys conducted within the period 2005 –
2024. More than 200 lichen taxa have been recorded and analysed using alpha
and beta diversity metrics. This integrative approach clarifies how cryptogam
communities respond to environmental variation and provides a scientific basis
for conservation planning aimed at sustaining ecosystem services under ongoing
global chang
Innovazione urbana tra tecnologie, clima e impatto sociale / Urban innovation between technologies, climate and social impact
No full textSince their inception, complex programmes1 have inherently interwoven scientific research and practical operational impacts. In particular, the scientific disciplinary sector of Architectural Technology has contributed to the development, implementation, and updating of regulations and the constructional and procedural elements about the execution of public investment programmes to enhance community services (Tartaglia et al., 2022). These technical-scientific support experiences are currently exploring fields of inquiry that transcend the purely physical/formal aspects, venturing into realms more closely associated with Environmental Design. The latter pays particular attention to the intangible aspects of the project (climate-environmental and socio-economic sustainability). As Eduardo Vittoria states, this approach rethinks the project from an «environmental perspective, where the environment, a constructive element of cities [...] is not only reducible to biophysical aspects but is a richly composite system in which, alongside the biosphere, there is also the socio-technosphere» (Vittoria, 2004). Simultaneously, public intervention programmes themselves are evolving. They no longer focus solely on enclosed and circumscribed spaces but aim to encompass the entire urban domain without distinction between open and closed spaces. The trend is thus to promote complex and integrated urban regeneration programmes that aim to revitalise significant parts of the city through comprehensive public interest interventions