Search Results (13,307)

Background/Objectives: Antimicrobial resistance (AMR) in Staphylococcus spp. associated with poultry production is an emerging concern with implications for animal and public health. This study aimed to characterize antimicrobial susceptibility patterns and detect targeted methicillin resistance determinants in Staphylococcus isolates recovered from broiler chickens affected by bacterial chondronecrosis with osteomyelitis (BCO). Methods: A total of 200 bacterial isolates were evaluated, of which 167 were confirmed as Staphylococcus spp. Species identification was performed using presumptive phenotypic characterization followed by 16S rRNA gene sequencing. Antimicrobial susceptibility was assessed using disk diffusion, while presumptive methicillin-resistant phenotypes were evaluated using oxacillin screening and CHROMagar MRSA. Targeted molecular detection of mecA and mecC was performed by PCR. Results: The isolates demonstrated substantial species diversity, with S. aureus as the predominant species. Antimicrobial resistance was mainly observed against β-lactam antibiotics, particularly penicillin (33.5%), whereas high susceptibility was retained for non-β-lactam agents, including ciprofloxacin, tetracycline, trimethoprim–sulfamethoxazole, and azithromycin. A targeted PCR detected mecA in 7.2% of isolates, while mecC was not detected. The detection of mecA in oxacillin-susceptible isolates suggested genotype–phenotype discordance. Conclusions: BCO-associated Staphylococcus spp. from broiler chickens showed diverse species distribution, penicillin-dominant resistance, and targeted mecA detection across multiple species, supporting the use of combined phenotypic and molecular approaches for methicillin resistance surveillance. Full article

High-performance thermal protection materials are urgently required in harsh thermal environments, such as hypersonic vehicles, the thermal runaway of energy batteries and high-temperature equipment. Conventional aerogels only exhibit passive thermal insulation and fail to resist instantaneous high-temperature attack. Herein, a cooling material of ammonium oxalate (AO) was introduced to achieve efficient, active endothermic protection. A cellular isolation effect induced by graphene nanosheets combined with anti-solvent crystallization was adopted to significantly decrease the size of AO crystals by over 93%. Based on superfine morphology and the constructed conduction network, the decomposition rate and heat absorption capacity of obtained graphene-doped AO powders (GdAPs) are improved by 41.2% and 30.4%, respectively. The mechanisms of morphology regulation and enhanced heat absorption are explored specifically in this study. Furthermore, GdAPs are embedded in phenolic resin to prepare thermal protection composite materials. Benefiting from their nearly complete thermal decomposition, GdAPs serve as a sacrificial template to generate discrete micropores in pyrolyzed resin. So, the as-prepared carbon aerogels (CAs) with a regulable microstructure exhibit an extremely low thermal conductivity of 0.056 W/(m·K), which is lower than those of reported CAs with the same density. Based on the above advantages, a synergistic endothermic-insulating thermal protection material is reported for the first time, and its heating rate is only 28.6% of that of commercial silica aerogel under identical high-temperature shock. Therefore, a new accessible strategy is demonstrated to provide high-efficiency thermal protection for resisting both abrupt and prolonged high temperature. Full article

Metronidazole is an antibiotic used to treat Helicobacter pylori, a bacterium responsible for chronic infections in humans that cause gastric inflammation, ulcers, and cancer. However, its long-term administration is limited by toxicity and increased resistance. In the search for more effective agents against H. pylori infection, molecular hybridization has now been applied to the synthesis of the new compound 3. Its structure connects the metronidazole moiety to pectolinarigenin, the latter obtained by acid hydrolysis of glycosylated flavonoids isolated from the plant Linaria reflexa Desf. The NOE effect supported the C-7 functionalization of 3, as evidenced by the energy-minimized DFT-calculated structure. The new molecule enriches the chemical space of known metronidazole–flavonoid analogs, among which the genistein derivative 2 was reported as the most active in inhibiting bacterial strains. The computational analysis of 2 and 3 compared with metronidazole as the reference has provided favorable data for both Absorption, Distribution, Metabolism, and Excretion (ADME) predictions and the probability of anti-H. pylori activity, besides rising docking evaluation on three specific targets and dynamics simulation as inhibitors of the flavodoxin enzyme. The results are promising for further in-depth biological investigation. Full article

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a critical public health threat because infections caused by this pathogen are associated with high morbidity, mortality, and limited effective therapeutic options. Whilst the majority of studies have concentrated on inter-patient bacterial transmission, within-host genomic analysis offers unprecedented resolution for tracking dynamic clone predominance, plasmid rearrangements, and microevolution under clinical selection pressures. Methods and Results: Whole-genome sequencing (WGS) of nine isolates recovered from oral and rectal swabs revealed an exceptional case of CRKP clonal turnover in an intensive care unit (ICU) patient. Three distinct high-risk clones were identified during the 18 days of surveillance: an initial ST101 (Clonal Group (CG) 101) strain (days 1–7) followed by concurrent colonization with ST395 (carrying bla_NDM-5) and ST512 lineages (both CG258, days 11–18). Conclusions: This study describes a rare instance of within-host heterogeneity of CRKP, involving three distinct STs spanning two CGs. Whole-genome analysis revealed potential structural rearrangements of resistance- and virulence-associated plasmids between coexisting lineages. These genomic shifts likely reflect rapid adaptation under the intense selective pressure of broad-spectrum antibiotic therapy, culminating in the persistence of a less virulent yet multidrug-resistant ST512 clone and a favorable clinical outcome with patient recovery. Full article

Combine harvesters are evolving from machines equipped with isolated monitoring devices into distributed sensing platforms for process supervision, machine diagnosis, and adaptive control. This review summarizes representative research on six major sensing tasks in combine harvesters: grain loss, grain breakage, cleaning load, feed rate, grain-bin state, and grain quality. The reviewed studies are compared within a unified engineering framework that considers sensing target, installation position, signal path, disturbance source, calibration transferability, field robustness, and control relevance. Rather than evaluating sensors only as individual devices, this review emphasizes the coupled design of transducers, structural anti-interference measures, sampling paths, signal processing, and field-oriented validation under vibration-dominated and dust-laden harvesting conditions. The analysis shows that loss-rate and feed-rate sensing are currently the most mature and control-relevant categories, whereas breakage-rate, grain-bin, and integrated quality sensing remain constrained by representative sampling, disturbance resistance, and cross-condition generalization. Future progress will depend on multi-sensor fusion, realistic benchmark protocols, crop-aware calibration transfer, and tighter integration among onboard sensing, machine control, and digital harvesting systems. By clarifying the engineering value of these sensing routes, the review also supports loss reduction, quality preservation, labor-saving operation, and more reliable adaptive control in commercial grain harvesting. Full article

Subclinical bovine mastitis (SBM) is an inflammatory condition of the udder that remains a major concern for the dairy industry due to its high incidence and the direct and indirect associated costs. Antibiotics are widely used for prophylaxis and therapy in livestock, especially for SBM. However, overuse and misuse have contributed to the emergence of antimicrobial resistance (AMR), enabling resistant bacteria to enter the food chain and potentially spread to humans. This study aimed to detect antibiotic-resistant Staphylococcus and Streptococcus associated with SBM in dairy cows from Pioter, north-central Ecuador. For this, a commercial screening test, morphological and biochemical assays, standard culture techniques, mass spectrometry, and PCR (polymerase chain reaction) were applied. Among 99 isolates, 77 were Staphylococcus and 22 were Streptococcus. Among the identified Staphylococcus isolates, S. aureus was the predominant species (36.4%). Resistance in Staphylococcus exceeded 70% for fosfomycin and was under 30% for the other antibiotics tested. In Streptococcus, S. uberis predominated (54.5%), with resistance primarily to penicillin and tetracycline (>50%). PCR identified mecA, nuc, and lukSF-PV genes in 7.8%, 29.9%, and 6.5% of Staphylococcus isolates, respectively. In Streptococcus, the ermB and blaZ genes were found in 18.2% and 50% of isolates, respectively. These data provide a baseline on SBM-associated AMR in the study area and highlight the need for ongoing surveillance and improved milking practices to mitigate risks to the dairy sector and public health. Full article

Cancer cells, like yeast, use fermentation despite the presence of oxygen, a phenomenon called aerobic glycolysis. The advantage is that it maintains many C-C bonds of glucose, allowing highly proliferating cells to produce the biomolecules that are necessary for cytokinesis. However, aerobic glycolysis is less energy-efficient than respiration, and it must operate at high frequency and produces large amounts of lactate, which modifies and stimulates DNA repair enzymes via lysine lactylation. This makes cancer cells resistant to radiotherapy, which requires a combination with chemotherapy using drugs that inhibit DNA repair. However, this converts healthy cells to cancer cells, indicating that research is still required regarding the relationship between glycolysis and cancer. Using yeast as a model, we discovered that the glycolytic enzymes TPI and GAPDH (Tpi1p and Tdh1-3p in yeast) interact with the DNA damage-dependent Checkpoint Rad9p (53BP1/BRCA1/MDC1 in humans). We propose that Tpi1p and Tdh1-3p override Rad9p, allowing cells with damaged DNA to proliferate. We isolated tpi and gapdh mutant strains that are deficient in DNA repair. While the tpi mutant strain has lower enzymatic activity, the gapdh mutant strains have normal enzymatic activity, confirming previous reports that GAPDH moonlights in the DNA damage response. Full article

Background/Objectives: Vancomycin-resistant (VRE) and vancomycin-variable (VVE) Enterococcus spp. represent an increasing clinical challenge due to limited treatment options and the potential for undetected dissemination of such resistance genes. Data on Enterococci genomic epidemiology in healthcare settings remain rather limited. Our study aimed to investigate vancomycin resistance determinants in Enterococcus spp., clonal structure, and occurrence of VVE using whole-genome sequencing (WGS) in Latvia. Methods: Clinical isolates collected from hospitalised patients in two tertiary-level hospitals in Latvia (2021–2024) were analysed using WGS following routine laboratory identification. Vancomycin resistance determinants were identified in silico, along with MLST and cgMLST genotyping. Results: Of 532 sequenced isolates, 482 met the quality and inclusion criteria. E. faecalis (56.64%) and E. faecium (40.25%) predominated. Among 125 isolates carrying vancomycin resistance genes, vanB (54.40%) was the most frequent, followed by vanA (38.20%) and vanC (6.40%); vanC was restricted to E. gallinarum and E. casseliflavus. Vancomycin resistance was more prevalent in E. faecium (51.03%) than in E. faecalis (6.59%). cgMLST identified outbreak clusters among E. faecium ST80 and ST78 with complex type-specific resistance patterns and hospital specificity. E. faecalis showed polyclonal endemicity with the vanB gene present in different clades. Three (0.62%) vancomycin-variable E. faecium (VVE) isolates were identified in one hospital, harbouring vanA-type gene clusters comprising vanHAX but lacking the sensory gene vanS and the regulatory gene vanR. Conclusions: The VanB gene predominated in both hospitals, driven by clonal expansion of hospital-adapted E. faecium ST80/ST78, contrasting with earlier vanA predominance in Europe but aligning with recent regional vanB trends. The detection of VVE highlights clinically relevant genotype–phenotype discordance, underscoring the importance of integrating genomic surveillance with routine phenotypic testing to detect cryptic resistance and guide effective antimicrobial therapy. Full article

Introduction: Stenotrophomonas maltophilia (S. maltophilia) has emerged as an important opportunistic pathogen. It is resistant to most available antibiotics due to its intrinsic resistance, leaving only some antibacterial agents as possible therapeutic options, which is further complicated by acquired mechanisms of antimicrobial resistance. This study aimed to provide a comprehensive genomic characterization of clinical S. maltophilia complex (Smc) isolates, focusing on molecular characterization of its resistance and virulence, since studies tackling this are scarce in Oman. Methods: This study is a prospective cross-sectional study, in which a total of 21 clinical isolates of Smc were collected from different clinical samples and further characterized using Whole Genome Sequencing. Results: Besides S. maltophilia, the isolates included S. hibiscicola, S. pavanii, and S. muris for the first time in Oman. All isolates were found to be susceptible to cefiderocol, levofloxacin, and minocycline. Sequence types (STs) were diverse among the isolates, with more than half of the isolates showing new STs with novel alleles. Additionally, blaOXA-2, sul1, and the recently described aac(6′)-Iap and aph(9)-Ic were detected among the isolates. Moreover, virulence-associated genes (smf-1, pilT, pilQ, gpmA, rmlA, spgM, stmPr1, plcN, clpP, and katE) were highly conserved across all isolates. Mobile genetic elements were detected in most of the isolates (76.20%). Conclusions: The collected isolates showed high ST diversity and showed no specific pattern in terms of antibiotic susceptibility and resistance genes. More studies are needed to establish relationships between the different members of the Smc and the different molecular resistome and virulome. Full article

Cronobacter spp. are opportunistic foodborne pathogens that can cause neonatal meningitis, necrotizing enterocolitis, and sepsis. This study conducted a systematic contamination survey and whole-genome epidemiological analysis of 562 low-water-activity food samples in Hunan Province of China. The results showed an overall Cronobacter spp. detection rate of 41.99% (236/562), with spices exhibiting the highest contamination rate (60.06%), and with high-level contamination samples (>110 MPN/g) concentrated in this category. The 236 isolates comprised 6 species, 120 sequence types, and 39 clonal complexes, with C. sakazakii being the most frequently isolated species (64.83%) and high-risk clones ST4, ST1, ST148, and ST64 prevailing. Multiple virulence genes (TraJ, fur, rcsAB, rpoS) and antimicrobial resistance genes (qnrS1, blaTEM-1, blaCTX-M-55, blaLAP-2, aac(3)-IId, aadA2, tet(A), floR, mcr-9.1, sul2) were detected. Core genome multilocus sequence typing (cgMLST) identified two clustering patterns: Cluster C, whose genetic clustering was consistent with transmission associated with potential common upstream raw materials across different brands and provinces, and Cluster G, whose clustering suggested potential persistent colonization in the production environment across multiple batches of the same brand. This study elucidates the contamination characteristics of Cronobacter spp. in low-water-activity foods from Hunan Province and provides a basis for WGS-based active surveillance and supply chain traceability. Full article

Background/Objectives: Antimicrobial resistance (AMR), driven by high-risk bacterial pathogens, is a major healthcare threat. This scoping review mapped artificial intelligence/machine learning (AI/ML) and computational approaches integrated with whole-genome sequencing (WGS), genomic surveillance, rapid typing, epidemiological data, or clinical metadata for early warning of AMR outbreak clones. Methods: Following PRISMA-ScR guidance and the Population–Concept–Context (PCC) framework, PubMed/MEDLINE, Scopus, and Web of Science were searched for English-language studies published between 2010 and 2026. Eligible studies addressed AI/ML or computational approaches for AMR outbreak detection, clone surveillance, transmission analysis, or infection prevention and control (IPC). Results: Thirty-eight studies were grouped into five domains: genomic surveillance; rapid typing; resistance, risk-factor, and lineage prediction; transmission reconstruction; and IPC-oriented genomic epidemiology. AI/ML supported automation, isolate prioritization, typing triage, prediction, transmission modelling, and electronic health record (EHR)-linked route identification. Conclusions: AI/ML may enhance WGS-based AMR surveillance, but validation, dataset dependence, heterogeneity, and limited IPC outcome reporting remain key gaps. Full article

Pediatric respiratory infections remain among the leading causes of emergency department visits, hospitalization and pediatric intensive care unit (PICU) admission. Although most acute respiratory infections in children are viral, clinical manifestations overlap substantially among viral, bacterial and atypical pathogens, creating diagnostic uncertainty and promoting empirical antimicrobial use. Rapid antigen tests, nucleic acid amplification tests, multiplex respiratory panels and metagenomic sequencing have expanded the ability to detect pathogens within clinically actionable timeframes. However, evidence from pediatric emergency trials indicates that rapid pathogen detection alone does not necessarily reduce antibiotic prescribing or healthcare costs. These findings suggest that the value of rapid diagnostics depends less on analytical breadth than on whether testing is applied to the right child, in the right clinical scenario and within a predefined decision pathway. This narrative review reorganizes the evidence around a scenario-driven top-pathogen framework. Top pathogens are defined as organisms that, in a specific age group, syndrome, season or care setting, have high prevalence, severe disease potential, transmissibility, treatment implications, antimicrobial resistance relevance or infection-control value. We discuss how top-pathogen testing should differ across emergency triage, inpatient ward management, severe pneumonia, PICU care, hospital-acquired pneumonia, ventilator-associated pneumonia and outbreak settings. We further examine the economic mechanisms through which rapid testing may generate value, including reduced unnecessary antibiotics, timely antiviral therapy, optimized isolation, shorter length of stay, reduced repeated testing and prevention of healthcare-associated transmission. Finally, we propose implementation principles centered on diagnostic stewardship, antimicrobial stewardship, local epidemiology and real-world cost-effectiveness evaluation. A scenario-driven top-pathogen strategy may provide a practical bridge between broad syndromic testing and precision infectious disease management in children. Full article

This study aimed to investigate the molecular basis of high-level tetracycline resistance to tetracycline antibiotics in Aeromonas hydrophila isolated from fish farming. Comparative genomic analysis of the tetracycline-sensitive strain NJ-35 and the tetracycline-resistant strain AH823 revealed that the tetracycline repressor gene tetR in AH823 had undergone base mutations, resulting in premature translational termination. The tetR gene in NJ-35 was inhibited using a plasmid-based antisense RNA strategy, and the knockdown efficiency was confirmed by RT-qPCR. The resulting tetR antisense RNA-expressing strain, AHtetR-as, exhibited significantly increased resistance to tetracycline antibiotics (minocycline, tetracycline, and doxycycline), but did not affect biofilm formation or hemolysis. Moreover, tetR knockdown in NJ-35 was associated with increased efflux activity and reduced intracellular doxycycline accumulation. Transcriptomic analysis revealed that genes encoding the 30S ribosomal subunit proteins showed a differential expression pattern, with rpsO upregulated and rpsD and rpsP downregulated. These findings suggest that tetR contributes to tetracycline resistance in A. hydrophila and is associated with broad transcriptional changes related to cellular transport and ribosomal function. Full article

Malassezia are commensal lipid dependent yeasts which can cause opportunistic skin infection. Topical imidazole antifungals such as clotrimazole and ketoconazole are the frontline treatment. However, the tendency of fungal infections to recur, combined with the emergence of multi-azole-resistant Malassezia isolates means that many patients have used these antifungal treatments repeatedly or for extended durations with limited efficacy. While the impact of single azole treatments has been studied, the ability of specific azoles to induce cross-resistance is unclear. Understanding the effect of prior exposure of one treatment on susceptibility to other antifungals is important in the selection of the appropriate treatment to avoid driving the evolution of greater resistance. We previously identified drug transporters from the ATP-Binding Cassette (ABC) and Major Facilitator Superfamily (MFS) to be upregulated on extended exposure to clotrimazole. In this study, we investigated the effect of extended clotrimazole, ketoconazole and fluconazole exposure on antifungal cross-resistance profiles and examined the expression of the MFS transporters OPT1 and FLR1 in resistance emergence. We observed that treatment with clotrimazole was associated with increased cross-resistance to other antifungals. Ketoconazole treatment caused elevated MICs in all tested antifungals that did not decrease after drug removal. These findings advance our understanding of fungal adaptive resistance mechanisms and inform improved antifungal strategies to mitigate resistance development. Full article

As part of efforts to identify genes associated with Trichomonas vaginalis resistance to 5-nitroimidazole drugs, thirty cryopreserved T. vaginalis isolates were revived and grown using Diamond’s TYM medium. Minimum lethal concentrations (MLCs) for metronidazole (MTZ), tinidazole (TDZ), and secnidazole (SEC) were determined using a drug susceptibility assay. Transcriptome profiling was performed for 15 MTZ-sensitive (MTZ-S, MLC < 50 µg/mL) and 15 MTZ-resistant (MTZ-R, MLC ≥ 50 µg/mL) isolates using next-generation RNA sequencing. Bioinformatics analyses identified differentially expressed genes (DEGs). Among the MTZ-R isolates, six exhibited low MLCs of 50 µg/mL, five had intermediate MLCs between 100 and 200 µg/mL, and four had high MLCs ≥ 400 µg/mL. Differential gene expression analysis identified 28, 140, and 73 significantly altered genes in low-, intermediate-, and high-level MTZ resistance groups, respectively, with predominantly upregulated expression patterns. The SEC-resistant (SEC-R) isolates exhibited 136 differentially expressed genes, whereas the TDZ-resistant (TDZ-R) isolates showed minimal transcriptional changes. Focused analyses of iron transport pathways revealed reduced expression of ZIP-family iron import genes, particularly TvZIP4 (TVAG_273550), the strongest predictor of resistance in elastic-net modeling (AUC = 0.795). Resistant isolates also demonstrated coordinated upregulation of iron–sulfur cluster assembly and hydrogenosomal protein-import pathways. Weighted gene co-expression network analysis (WGCNA) identified multiple resistance-associated transcriptional modules correlated with MTZ and SEC MLCs. A comparative transcriptomic–proteomic analysis revealed concordant upregulation of iron–sulfur cluster machinery but discordant regulation of hydrogenosomal cargo proteins, likely supporting a post-transcriptional restriction model. These findings provide a broader mechanistic framework for understanding 5-nitroimidazole resistance in T. vaginalis and identifying candidate biomarkers and pathways that may support future therapeutic and diagnostic development. Full article