Search Results (233)

Museums may acquire archaeological artefacts discovered by non-specialists or amateur archaeologists, holding the potential to promote the safeguarding of cultural heritage by integrating the local community in their activities. However, this also creates an opportunity for the fraudulent sale of modern forgeries presented as archaeological artefacts, resulting in the need for a critical assessment of the artefact’s authenticity prior to acquisition by the museum. In 2019, the regional museum in Cáceres (Spain) was offered the opportunity to acquire a Phoenician-Punic head pendant, allegedly discovered in the vicinity of the city. The artefact’s authenticity was assessed by traditional approaches, including typological analysis and analysis of manufacture technique, which raised doubts about its purported age. VP-SEM-EDS analysis of the chemical composition of the different glass portions comprising the pendant was used for non-invasive determination of glassmaking recipes, enabling the identification of glass components incompatible with known Iron Age glassmaking recipes from the Mediterranean. Further comparison with historical and modern glassmaking recipes allowed for the identification of the artefact as a recent forgery made from glasses employing modern colouring and opacifying techniques. Full article

The genotoxin colibactin, a complex secondary metabolite, targets eukaryotic cell cycle machinery and contributes to neonatal sepsis and meningitis. Avian pathogenic Escherichia coli (APEC) XM, which produces this genotoxin, is an agent of poultry diseases with zoonotic potential. In this study, we confirmed that clbF was necessary for the APEC XM strain to produce colibactin, but it did not affect the growth, adhesion, or invasion of cells. Deletion of clbF substantially diminished both virulence and systemic dissemination, but it also changed the gene expression of the antiserum survival factor, adherence and invasion, iron acquisition genes, and the secretion system. In conclusion, clbF is necessary for the synthesis of the genotoxin colibactin and affects the development of APEC meningitis in mice. Full article

Soil degradation resulting from intensive agricultural practices, the excessive use of agrochemicals, and climate-induced stresses has significantly impaired soil fertility, disrupted microbial diversity, and reduced crop productivity. Plant growth-promoting bacteria (PGPB) represent a sustainable biological approach to restoring degraded soils by modulating plant physiology and soil function through diverse molecular mechanisms. PGPB synthesizes indole-3-acetic acid (IAA) to stimulate root development and nutrient uptake and produce ACC deaminase, which lowers ethylene accumulation under stress, mitigating growth inhibition. They also enhance nutrient availability by releasing phosphate-solubilizing enzymes and siderophores that improve iron acquisition. In parallel, PGPB activates jasmonate and salicylate pathways, priming a systemic resistance to biotic and abiotic stress. Through quorum sensing, biofilm formation, and biosynthetic gene clusters encoding antibiotics, lipopeptides, and VOCs, PGPB strengthen rhizosphere colonization and suppress pathogens. These interactions contribute to microbial community recovery, an improved soil structure, and enhanced nutrient cycling. This review synthesizes current evidence on the molecular and physiological mechanisms by which PGPB enhance soil restoration in degraded agroecosystems, highlighting their role beyond biofertilization as key agents in ecological rehabilitation. It examines advances in nutrient mobilization, stress mitigation, and signaling pathways, based on the literature retrieved from major scientific databases, focusing on studies published in the last decade. Full article

Acinetobacter baumannii has emerged as a major pathogen responsible for healthcare-associated infections, particularly in intensive care units, contributing to significant morbidity and mortality due to its multidrug resistance and ability to persist in clinical environments. This study aimed to investigate the phenotypic and genomic characteristics of all multidrug-resistant A. baumannii isolates collected between January and June 2022 from two tertiary care hospitals in Thessaloniki, Greece. A total of 40 isolates were included. All isolates exhibited resistance to colistin; however, none harbored the mcr-1 to mcr-9 genes, as confirmed by polymerase chain reaction (PCR). PCR-based screening for virulence-associated genes revealed high prevalence rates of basD (100%), pld (95%), csuE (87.5%), and bap (77.5%). In contrast, ompA and pglC were not detected. Twitching motility ranged from 2 to 50 mm, with 25% of the isolates classified as non-motile and 20% as highly motile. Swarming motility was observed in all strains. Additionally, all isolates demonstrated positive α-hemolysis, suggesting a potential virulence mechanism involving tissue damage and iron acquisition. Pulsed-field gel electrophoresis (PFGE) revealed significant genomic diversity among the isolates, indicating a low likelihood of patient-to-patient or clonal transmission within the hospital setting. These findings highlight the complex relationship between antimicrobial resistance and virulence in clinical A. baumannii isolates and emphasize the urgent need for robust infection control strategies and continued microbiological surveillance. Full article

Chloroplasts, as the organelles primarily responsible for photosynthesis, require a substantial supply of iron ions. Conversely, due to Fe toxicity, the homeostasis of these ions is subject to tight regulation. Permease in chloroplast 1 (PIC1) has been identified as the primary iron importer into chloroplasts. However, previous studies suggested the existence of a distinct pathway for Fe transfer to chloroplasts, likely involving mitoferrin-like 1 (MFL1) protein. In this work, Arabidopsis MFL1 (AtMFL1) and its cucumber homolog (CsMFL1) were characterized using, among others, Arabidopsis protoplasts as well as both yeast and Arabidopsis mutants. Localization of both proteins in chloroplasts has been shown to be mediated via an N-terminal transit peptide. At the gene level, MFL1 expression profiles differed between the model plant and the crop plant under varying Fe availability. The expression of other genes involved in chloroplast Fe homeostasis, including iron acquisition, trafficking, and storage, was affected to some extent in both AtMFL1 knockout and overexpressing plants. Moreover, root growth and photosynthetic parameters changed unfavorably in the mutant lines. The obtained results imply that AtMFL1 and CsMFL1, as putative chloroplast iron transporters, play a role in both iron management and the proper functioning of the plant. Full article

Sternal bursitis is an underexplored lesion in poultry, often overlooked in microbiological diagnostics. In this study, we characterized 36 Escherichia coli isolates recovered from sternal bursitis in broiler chickens, combining phenotypic antimicrobial susceptibility testing, PCR-based screening, and whole genome sequencing (WGS). The genetic analysis revealed a diverse population spanning 15 sequence types, including ST155, ST201, and ST58. Resistance to tetracycline and ciprofloxacin was common, and several isolates carried genes encoding β-lactamases, including blaTEM-1B. Chromosomal mutations associated with quinolone and fosfomycin resistance (e.g., gyrA p.S83L, glpT_E448K) were also identified. WGS revealed a high number of virulence-associated genes per isolate (58–96), notably those linked to adhesion (fim, ecp clusters), secretion systems (T6SS), and iron acquisition (ent, fep, fes), suggesting strong pathogenic potential. Many isolates harbored virulence markers typical of ExPEC/APEC, such as iss, ompT, and traT, even in the absence of multidrug resistance. Our findings suggest that E. coli from sternal bursitis may act as reservoirs of resistance and virulence traits relevant to animal and public health. This highlights the need for including such lesions in genomic surveillance programs and reinforces the importance of integrated One Health approaches. Full article

Acinetobacter baumannii is listed by the World Health Organization as an emerging bacterial priority pathogen, the prevalence and multidrug resistance of which have been increasing. This functional genomics study aimed to understand the drug-resistance mechanisms of an extensively drug-resistant (XDR) A. baumannii strain (IRMCBCU95U) isolated from a transtracheal aspirate sample from a female patient with end-stage renal disease in Saudi Arabia. The whole genome of IRMCBCU95U (4.3 Mbp) was sequenced using Oxford Nanopore long-read sequencing to identify and compare the antibiotic-resistance profile and genomic features of A. baumannii IRMCBCU95U. The antibiogram of A. baumannii IRMCBCU95U revealed resistance to multiple antibiotics, including cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem and piperacillin/tazobactam. A comparative genomic analysis between IRMCBCU95U and A. baumannii K09-14 and ATCC 19606 identified significant genetic heterogeneity and mosaicism among the strains. This analysis also demonstrated the hybrid nature of the genome of IRMCBCU95U and indicates that horizontal gene transfer may have occurred between these strains. The IRMCBCU95U genome has a diverse range of genes associated with antimicrobial resistance and mobile genetic elements (ISAba1 and IS26) associated with the spread of multidrug resistance. The presence of virulence-associated genes that are linked to iron acquisition, motility and transcriptional regulation confirmed that IRMCBCU95U is a priority human pathogen. The plasmid fragment IncFIB(pNDM-Mar) observed in the strain is homologous to the plasmid in Klebsiella pneumoniae (439 bp; similarity: 99.09%), which supports its antimicrobial resistance. From these observations, it can be concluded that the clinical A. baumannii IRMCBCU95U isolate is an emerging extensively drug-resistant human pathogen with a novel combination of resistance genes and a plasmid fragment. The complex resistome of IRMCBCU95U highlights the urgent need for genomic surveillance in hospital settings in Saudi Arabia to fight against the spread of extensively drug-resistant A. baumannii. Full article

Arbuscular mycorrhizal fungi (AMF) symbiosis has great potential in improving grapevine performance and reducing external input dependency in viticulture. However, the precise, strain-specific impacts of different AMF species on ‘Summer Black’ grapevine cuttings across multiple physiological and morphological dimensions remain underexplored. To address this, we conducted a controlled greenhouse pot experiment, systematically evaluating four different AMF species (Diversispora versiformis, Diversispora spurca, Funneliformis mosseae, and Paraglomus occultum) on ‘Summer Black’ grapevine cuttings. All AMF treatments successfully established root colonization, with F. mosseae achieving the highest infection rate. In detail, F. mosseae notably enhanced total root length, root surface area, and volume, while D. versiformis specifically improved primary adventitious and 2nd-order lateral root numbers. Phosphorus (P) uptake in both leaves and roots was significantly elevated across all AMF treatments, with F. mosseae leading to a 42% increase in leaf P content. Furthermore, AMF inoculation generally enhanced the activities of catalase, superoxide dismutase, and peroxidase, along with soluble protein and soluble sugar contents in leaves and roots. Photosynthetic parameters, including net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr), were dramatically increased in AMF-colonized cutting seedlings. Whereas, P. occultum exhibited inhibitory effects on several growth metrics, such as shoot length, leaf and root biomass, and adventitious lateral root numbers, and decreased the contents of Nitrogen (N), potassium (K), magnesium (Mg), and iron (Fe) in both leaves and roots. These findings conclusively demonstrate that AMF symbiosis optimizes root morphology, enhances nutrient acquisition, and boosts photosynthetic efficiency and stress resilience, thus providing valuable insights for developing targeted bio-fertilization strategies in sustainable viticulture. Full article

Strain 53B2 was isolated from a commercial maize (Zea mays L.) field located in the Yaqui Valley, Mexico. Its draft genome comprises 5,844,085 bp, with a G + C content of 37.5%, an N50 of 602,122 bp, an L50 of 4, and a total of 129 contigs. Genome-based taxonomic affiliation showed this strain belonged to Priestia megaterium. Genome annotation revealed 6394 coding DNA sequences (CDSs), organized into 332 subsystems. Among these, several CDSs were associated with traits relevant to plant growth promotion, including categories such as iron acquisition and metabolism (40 CDSs) and secondary metabolism (6 CDSs), among others. In vitro metabolic assays supported genomic predictions, confirming the strain’s ability to produce IAA, solubilize phosphate, and tolerate abiotic stress. Additionally, greenhouse trials demonstrated that inoculation with Priestia megaterium 53B2 significantly enhanced plant growth parameters (p ≤ 0.05) versus uninoculated control: stem height increased by 22.8%, root length by 35.7%, stem and root fresh weights by 39.6% and 66.1%, and stem and root dry weights by 33.7% and 44.7%, respectively. This first report on the beneficial potential of Priestia megaterium 53B2 highlights its potential as a sustainable bioinoculant for maize cultivation. Full article

Helicobacter pylori is a Gram-negative bacterium that infects almost half of the global population and is linked to gastric conditions like peptic ulcers and gastric cancer, as well as other diseases such as neurological disorders, cardiovascular problems, and iron deficiency anemia. Its survival in the acidic stomach environment is due to virulence factors like urease, flagella, and adhesion proteins (BabA, SabA). Current treatments involve a combination of antibiotics (clarithromycin, metronidazole, amoxicillin, tetracycline) and proton pump inhibitors, but increasing antibiotic resistance, especially to clarithromycin and metronidazole, poses a major challenge. Resistance mechanisms include mutations in drug targets, efflux pump overexpression, and enzymatic degradation of antibiotics. This has prompted exploration of alternative therapies targeting bacterial processes like urease activity, biofilm formation, and metabolic pathways (energy production, amino acid synthesis, iron acquisition). Natural compounds, such as chitosan and plant extracts, show promise in combating H. pylori growth and virulence. Vaccine development is also ongoing, with DNA vaccines showing potential for broad immune responses. However, no vaccine is yet close to widespread clinical use. Full article

Bats serve as key ecological reservoirs of diverse microbial communities, including emerging viruses and antibiotic resistance genes. This study investigates the intestinal microbiota of two insectivorous bat species, Nyctalus noctula and Vespertilio murinus, at the Rostov Bat Rehabilitation Center in Southern Russia using whole metagenome shotgun sequencing. We analyzed taxonomic composition, functional pathways, antibiotic resistance genes, and virulence factors. Densoviruses, especially those closely related to Parus major densovirus, were the most dominant viral sequences identified. Metagenome-assembled densovirus genomes showed high sequence similarity with structural variations and clustered phylogenomically with viruses from mealworms and birds, reflecting both dietary origins and the potential for vertebrate infection. Functional profiling revealed microbial pathways associated with cell wall biosynthesis, energy metabolism, and biofilm formation. A total of 510 antibiotic resistance genes, representing 142 unique types, mainly efflux pumps and β-lactamases, were identified. Additionally, 870 virulence factor genes were detected, with a conserved set of iron acquisition systems and stress response regulators across all samples. These findings highlight the ecological complexity of bat-associated microbiota and viromes and suggest that synanthropic bats may contribute to the circulation of insect-associated viruses and antimicrobial resistance in urban settings. Full article

This study explored the biosynthetic mechanisms and structural diversity of pyoverdines (PVDs) produced by Pseudomonas fulva. Genomic analysis using antiSMASH identified the PVD biosynthetic gene cluster, although the C-terminal peptide sequence could not be predicted. Subsequent liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis revealed the full peptide structure, including modified residues, such as N-acetylhydroxyornithine and cyclohydroxyornithine, and confirmed the presence of several PVD isoforms with different chromophore side chains. Comparative LC-MS analysis across Pseudomonas species demonstrated that P. fulva produces unique PVD molecular mass patterns. The bioinformatic and structural modeling of non-ribosomal peptide synthetase PvdL open reading frame 3 revealed that the A2 and A3 adenylation domains are lysine selective. Although their sequences differ from known lysine-specific signatures, AlphaFold3-based structural prediction revealed conserved substrate-binding configurations, suggesting that similar substrate-binding features may have arisen independently. Notably, Thr²⁹⁷, a unique residue in the non-ribosomal code, likely plays a key role in lysine recognition. The high degree of sequence similarity between the A2 and A3 domains may reflect domain duplication and could be involved in the diversification of the PVD structure. Further functional and ecological studies are required to assess the physiological significance of P. fulva PVDs in microbial iron acquisition. Full article

This article considers the impact of self-sufficiency in basic raw materials on the level of systematic risk, required return and capitalization on the example of Russian ferrous metallurgy companies. The methods applied include classical approaches to determining beta coefficient, required return and capitalization, as well as correlation–regression analysis performed in the Python programming language (version 3.0, libraries: Numpy, Pandas, Matplotlib, Datetime, Statistics, Scipy, Bambi). The study revealed an inverse relationship between the self-sufficiency of ferrous metallurgy companies in iron ore and coking coal and their systematic risk. That was confirmed by the developed regression model. The presence of this dependence directly indicates the need to consider self-sufficiency when assessing a company’s required return and capitalization. The acquisition of the Tikhov coal mine by PJSC Magnitogorsk Iron and Steel Works (MMK) led to an increase in capitalization not only due to additional profit from the new asset, but also due to a decrease in the required return caused by the growth of the company’s self-sufficiency in coking coal. The proposed approach contributes to a more accurate assessment of the company’s capitalization and creates additional incentives for vertical integration transactions. Full article

Neonatal Meningitis-causing Escherichia coli (NMEC) is the leading cause of neonatal meningitis and exhibits remarkable adaptability to diverse host environments. Understanding its transcriptional responses across different host niches is crucial for deciphering pathogenesis and identifying potential therapeutic targets. We performed a comparative transcriptomic analysis of NMEC RS218, the prototype strain of NMEC, under four distinct host-mimicking conditions: colonic fluid (CF), serum (S), human brain endothelial cells (HBECs), and cerebrospinal fluid (CSF). Differential gene expression analysis was conducted to assess metabolic shifts, virulence factor regulation, and niche-specific adaptation strategies, in which RS218 demonstrated niche-specific transcriptional reprogramming. In CF, genes associated with biofilm formation, motility, efflux pumps, and cell division regulation were upregulated, aiding gut colonization. The serum environment triggered the expression of siderophore-mediated iron acquisition, enterobactin biosynthesis, and heme utilization genes, facilitating immune evasion and bacterial persistence. In HBECs, NMEC upregulated genes linked to nucleoside metabolism, membrane remodeling, pilus organization, and blood–brain barrier (BBB) traversal. In CSF, genes related to oxidative stress resistance, chemotaxis, DNA repair, biofilm formation, and amino acid biosynthesis were enriched, reflecting NMEC’s adaptive mechanisms for survival under nutrient-depleted conditions. Energy-intensive pathways were consistently downregulated across all niches, highlighting the need for an energy conservation strategy. This study provides novel insights into NMEC’s adaptive strategies across different host environments, emphasizing its metabolic flexibility, virulence regulation, and immune evasion mechanisms, offering potential targets for therapeutic intervention. Full article

Vibrio harveyi is a significant pathogen in marine aquaculture, causing vibriosis in various marine species. This study presents a comparative genomic analysis of two V. harveyi strains, N8T11 and 45T2, which exhibit differing virulence profiles. Virulence assays revealed that N8T11 caused 92% mortality in infected fish, while 45T2 resulted in 0% mortality. Whole-genome sequencing revealed that strain N8T11 harbors five plasmids (pN8T11a, pN8T11b, pN8T11c, pN8T11d and pN8T11e) absent in 45T2, encoding genes potentially linked to virulence, such as siderophore-mediated iron acquisition and stress response mechanisms. Pan-genome analysis highlighted substantial genomic plasticity within V. harveyi, with mobile genetic elements, including plasmids and prophages, contributing to horizontal gene transfer. Conjugation experiments demonstrated that all five N8T11 plasmids can transfer to 45T2 with efficiencies up to 87%, with pN8T11b remaining stable across multiple subcultures, enabling the dissemination of virulence-associated genes. These findings suggest that plasmid-mediated gene transfer plays a role in the virulence variability observed between V. harveyi strains. This study contributes to understanding the genomic factors underlying pathogenicity in V. harveyi and provides insights for future research aimed at controlling vibriosis in aquaculture. Full article