Search Results (1,012)

This review explores the biofilm architecture and drug resistance of Enterococcus faecalis in clinical and environmental settings. The biofilm in E. faecalis is a heterogeneous, three-dimensional, mushroom-like or multilayered structure, characteristically forming diplococci or short chains interspersed with water channels for nutrient exchange and waste removal. Exopolysaccharides, proteins, lipids, and extracellular DNA create a protective matrix. Persister cells within the biofilm contribute to antibiotic resistance and survival. The heterogeneous architecture of the E. faecalis biofilm contains both dense clusters and loosely packed regions that vary in thickness, ranging from 10 to 100 µm, depending on the environmental conditions. The pathogenicity of the E. faecalis biofilm is mediated through complex interactions between genes and virulence factors such as DNA release, cytolysin, pili, secreted antigen A, and microbial surface components that recognize adhesive matrix molecules, often involving a key protein called enterococcal surface protein (Esp). Clinically, it is implicated in a range of nosocomial infections, including urinary tract infections, endocarditis, and surgical wound infections. The biofilm serves as a nidus for bacterial dissemination and as a reservoir for antimicrobial resistance. The effectiveness of first-line antibiotics (ampicillin, vancomycin, and aminoglycosides) is diminished due to reduced penetration, altered metabolism, increased tolerance, and intrinsic and acquired resistance. Alternative strategies for biofilm disruption, such as combination therapy (ampicillin with aminoglycosides), as well as newer approaches, including antimicrobial peptides, quorum-sensing inhibitors, and biofilm-disrupting agents (DNase or dispersin B), are also being explored to improve treatment outcomes. Environmentally, E. faecalis biofilms contribute to contamination in water systems, food production facilities, and healthcare environments. They persist in harsh conditions, facilitating the spread of multidrug-resistant strains and increasing the risk of transmission to humans and animals. Therefore, understanding the biofilm architecture and drug resistance is essential for developing effective strategies to mitigate their clinical and environmental impact. Full article

The extensive use of pesticides has significant implications for public health and the environment. Breeding crop plants is the most effective and environmentally friendly approach to improve the plants’ resistance. However, it is time-consuming and costly, and it is sometimes difficult to achieve satisfactory results. Plants induce defense responses to natural elicitors by interpreting multiple genes that encode proteins, including enzymes, secondary metabolites, and pathogenesis-related (PR) proteins. These responses characterize systemic acquired resistance. Humic substances trigger positive local and systemic physiological responses through a complex network of hormone-like signaling pathways and can be used to induce biotic and abiotic stress resistance. This study aimed to assess the effect of humic substances on the activity of phenylalanine ammonia-lyase (PAL), peroxidase (POX), and β-1,3-glucanase (GLU) used as a resistance marker in various plant species, including orange, coffee, sugarcane, soybeans, maize, and tomato. Seedlings were treated with a dilute aqueous suspension of humic substances (4 mM C L⁻¹) as a foliar spray or left untreated (control). Leaf tissues were collected for enzyme assessment two days later. Humic substances significantly promoted the systemic acquired resistance marker activities compared to the control in all independent assays. Overall, all enzymes studied in this work, PAL, GLUC, and POX, showed an increase in activity by 133%, 181%, and 149%, respectively. Among the crops studied, citrus and coffee achieved the highest activity increase in all enzymes, except for POX in coffee, which showed a decrease of 29% compared to the control. GLUC exhibited the highest response to HS treatment, the enzyme most prominently involved in increasing enzymatic activity in all crops. Plants can improve their resistance to pathogens through the exogenous application of HSs as this promotes the activity of enzymes related to plant resistance. Finally, we consider the potential use of humic substances as a natural chemical priming agent to boost plant resistance in agriculture Full article

Background: Broad-spectrum antibiotics are often used for suspected infections in patients with hematologic malignancies due to the risk of severe infections. Although antibiotic use can lead to antimicrobial resistance and microbiome dysbiosis, the effects of antibiotics on the microbiome and resistome in patients with acute myeloid leukemia (AML) undergoing remission induction chemotherapy (RIC) are not well understood. Methods: Various statistical models were utilized to examine the effects of antibiotic administration on the microbiome and resistome over time, as well as differences in AR-infection (ARI) and colonization (ARC) by important CDC-threats in 119 AML patients. Results: A greater number of unique antibiotic classes administered correlated with a loss of unique antibiotic resistance genes (ARGs) (R = −0.39, p = 0.008). Specifically, although a greater number of oxazolidinone administrations was correlated with a greater loss of diversity (R = −0.58, p < 0.001), each additional day of linezolid reduced the risk of ARC by ~30% (HR: 0.663, p = 0.047) and decreased the odds of acquiring genes predicted to confer macrolide (HR: 0.50, p = 0.026) resistance. Conclusions: The number of antibiotic administrations and the types of antibiotics used can influence the risk of antibiotic resistance gene (ARG) expansion and ARC events in AML patients undergoing RIC. While certain antibiotics may reduce microbial diversity, they are not always linked to an increase in ARGs or ARC events. Full article

In the Chan Buddhism koan (gong’an 公案) tradition, the act of “slaying the snake” functions as a signature gesture imbued with complex, historically layered cultural meanings. Rather than merely examining its motivations, this paper emphasizes tracing the semantic transformations that this motif has undergone across different historical contexts. It argues that “snake-slaying” operated variously as an imperial narrative strategy reinforcing ruling class ideology; as a form of popular resistance by commoners against flood-related disasters; as a dietary practice among aristocrats and literati seeking danyao (elixirs) 丹藥 for reclusion and transcendence; and ultimately, within the Chan tradition, as a method of spiritual cultivation whereby masters sever desires rooted in attachment to both selfhood and the Dharma. More specifically, first, as an imperial narrative logic, snake-slaying embodied exemplary power: both Liu Bang 劉邦 and Guizong 歸宗 enacted this discursive strategy, with Guizong’s legitimacy in slaying the snake deriving from the precedent set by Liu Bang. Second, as a folk strategy of demystification, snake-slaying acquired a moral aura—since the snake was perceived as malevolent force, their slaying appeared righteous and heroic. Finally, as a mode of self-cultivation among the aristocracy, snake-slaying laid the groundwork for its later internalization. In Daoism, slaying the snake was a means of cultivating the body; in Chan Buddhism, the act is elevated to a higher plane—becoming a way of cultivating the mind. This transformation unfolded naturally, as if predestined. In all cases, the internalization of the snake-slaying motif was not an overnight development: the cultural genes that preceded its appearance in the Chan tradition provided the fertile ground for its karmic maturation and discursive proliferation. Full article

The pharmacological treatment of cholangiocarcinoma (CCA) is often hampered by tumor resistance. Improving our understanding of this issue is crucial for developing strategies that can overcome drug refractoriness. We have established and characterized two novel human cell sublines derived from extrahepatic CCA EGI-1 cells that are resistant to cisplatin and 5-fluorouracil (5-FU). Migration and proliferation were analyzed using holographic microscopy. The expression of genes involved in drug uptake and efflux was determined by RT-qPCR. Cross-resistance to commonly used antitumor drugs was assayed using the MTT test. EGI-1 sublines resistant to cisplatin (CR) or 5-FU (FR) exhibited more than a three-fold increase in resistance to cisplatin and 5-FU, respectively, and showed reduced proliferation, migration, and colony-formation rates, along with an altered cell cycle compared to wild-type cells, while retaining tumorigenic capacity. The analysis of the transportome showed downregulation of uptake transporters and upregulation of the export pumps MRP3/4. EGI-1 cells with acquired resistance to 5-FU demonstrated cross-resistance to irinotecan and gemcitabine, while cisplatin-resistant cells showed decreased sensitivity to 5-FU and platinum derivatives. These resistant cell lines offer valuable models for investigating the molecular basis of chemoresistance in CCA, providing a robust platform for the development and evaluation of novel therapeutic strategies. Full article

Worldwide, lung cancer is one of the most common cancers, with non-small cell lung cancer (NSCLC) including up to 80–85% of all lung cancer diagnoses. The landscape of NSCLC is characterized by a heterogeneous spectrum of gene alterations, with tyrosine kinase inhibitors (TKIs) and targeted treatments that significantly improve survival outcomes for patients with oncogene-addicted NSCLC, offering superior efficacy, and often favorable safety and tolerability profiles compared to chemotherapy-based treatments. However, the complexity of NSCLC extends to co-occurring genomic alterations or amplifications in tumor suppressors and other oncogenes, such as TP53, STK11, KEAP1, PIK3CA, RB1, and others, that significantly influence disease progression, therapeutic resistance, and clinical outcomes. These co-mutations often contribute to the development of primary and acquired resistance to targeted therapies, complicating decision-making strategies. This review provides a timely and comprehensive synthesis of current insights into co-mutations in NSCLC, with a particular focus on their clinical implications, and offers a novel perspective by integrating recent molecular insights with therapeutic challenges, addressing existing knowledge gaps through a more integrative and clinically oriented analysis of co-mutations. Advances in next-generation sequencing (NGS) and molecular profiling have enabled the identification of these co-alterations, paving the way for more personalized therapeutic approaches. However, challenges remain in interpreting the functional interplay of co-mutations and translating these insights into effective clinical interventions. This review also highlights the significance of co-mutations in shaping NSCLC biology, and discusses their impact on current therapeutic paradigms, emphasizing the need for integrative biomarker-driven approaches to improve outcomes in NSCLC. Full article

Powdery mildew caused by Sphaerotheca fusca poses a significant threat to cucumber (Cucumis sativus L.) production worldwide, underscoring the need for sustainable disease management strategies. This study investigates the potential of L-lysine, abundantly produced by Bacillus subtilis M 320 (BSM320), to prime systemic acquired resistance (SAR) pathways in cucumber plants. Liquid chromatography–mass spectrometry analysis identified L-lysine as the primary bioactive metabolite in the BSM320 culture filtrate. Foliar application of purified L-lysine significantly reduced powdery mildew symptoms, lowering disease severity by up to 92% at concentrations ≥ 2500 mg/L. However, in vitro spore germination assays indicated that L-lysine did not exhibit direct antifungal activity, indicating that its protective effect is likely mediated through the activation of plant immune responses. Quantitative reverse transcription PCR revealed marked upregulation of key defense-related genes encoding pathogenesis-related proteins 1 and 3, lipoxygenase 1 and 23, WRKY transcription factor 20, and L-type lectin receptor kinase 6.1 within 24 h of treatment. Concurrently, salicylic acid (SA) levels increased threefold in lysine-treated plants, confirming the induction of an SA-dependent SAR pathway. These findings highlight L-lysine as a sustainable, residue-free priming agent capable of enhancing broad-spectrum plant immunity, offering a promising approach for amino acid-based crop protection. Full article

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen with significant clinical relevance in both human and veterinary medicine. Despite its well-documented role in hospital-acquired infections in human healthcare settings, its persistence and transmission within veterinary clinics remain underexplored. This review highlights the overlooked status of veterinary facilities as environmental reservoirs and amplification points for multidrug-resistant (MDR) P. aeruginosa, emphasizing their relevance to One Health surveillance. We examine the bacterium’s environmental survival strategies, including biofilm formation, resistance to disinfectants, and tolerance to nutrient-poor conditions that facilitate the long-term colonization of moist surfaces, drains, medical equipment, and plumbing systems. Common transmission vectors are identified, including asymptomatic animal carriers, contaminated instruments, and the hands of veterinary staff. The review synthesizes current data on antimicrobial resistance in environmental isolates, revealing frequent expression of efflux pumps and mobile resistance genes, and documents the potential for zoonotic transmission to staff and pet owners. Key gaps in environmental monitoring, infection control protocols, and genomic surveillance are identified, with a call for standardized approaches tailored to the veterinary context. Control strategies, including mechanical biofilm disruption, disinfectant cycling, effluent monitoring, and staff hygiene training, are evaluated for feasibility and impact. The article concludes with a One Health framework outlining cross-species and environmental transmission pathways. It advocates for harmonized surveillance, infrastructure improvements, and intersectoral collaboration to reduce the risk posed by MDR P. aeruginosa within veterinary clinical environments and beyond. By addressing these blind spots, veterinary facilities can become proactive partners in antimicrobial stewardship and global resistance mitigation. Full article

Background: Treatment of metastatic cancer remains a challenge, because cancer cells acquire resistance even to the most contemporary therapies. This study analyzed the role of the phosphoprotein Stathmin 1 (STMN1) in regulating cancer cell growth and metastatic potential. Methods: Public datasets with metastatic castration-resistant prostate cancer (mCRPC) and breast cancer (BC) were analyzed to determine the interrelationship between STMN1, hepatocyte growth factor (HGF) and MET proto-oncogene (MET) expression, overall survival, and response to chemotherapy. Site-directed mutagenesis, cell cycle analysis, proliferation, and migration and invasion assays determined the impact of STMN1 phosphorylation on proliferation and metastatic potential. Results: Increased STMN1 associates with HGF and MET gene expression in mCRPC, and taxane chemotherapy further increases HGF expression. STMN1 and HGF are highest, and overall survival is poorest in mCRPC in the liver compared to other sites, implying the metastatic site influences their expression levels and potentially the pattern of metastatic spread. Increased STMN1 and MET also predict taxane responsiveness in BC patients. Analysis of STMN1 serine (S)16, 25, 38, and 63 determined that total (t) STMN1 and STMN1 S16 phosphorylation (pSTMN1^S16) are co-regulated by HGF/MET during cell cycle progression, pSTMN1^S16 alone can promote cell proliferation, and pSTMN1^S16 shortens the cell cycle similar to HGF treatment, while STMN1^S16 dephosphorylation lengthens the cell cycle to arrest cell growth in G2/M, similar to HGF plus the MET inhibitor AMG337. Importantly, STMN1^S16 does not promote metastasis. Conclusions: Selectively inhibiting STMN1^S16 phosphorylation may provide an alternative strategy for inhibiting MET-mediated cell growth to eliminate metastatic cancer cells and inhibit further metastasis. Full article

Nucleobase and nucleoside analogs are critical components of antimetabolite chemotherapy treatments used to disrupt DNA replication and induce apoptosis in rapidly proliferating cancer cells. However, the development of resistance to these agents remains a major clinical challenge. This review explores the epigenetic mechanisms that contribute to acquired chemoresistance, focusing on DNA methylation, histone modifications, and non-coding RNAs (ncRNAs). These epigenetic alterations regulate key processes such as DNA repair, drug metabolism, cell transport, and autophagy, enabling cancer cells to survive and resist therapeutic pressure. We highlight how dysregulation of DNA methyltransferases (DNMTs) and histone acetyltransferases (HATs) modulates expression of transporters (e.g., hENT1, ABCB1), DNA repair enzymes (e.g., Polβ, BRCA1/2), and autophagy-related genes (e.g., CSNK2A1, BNIP3). Furthermore, emerging roles for long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in regulating nucleoside export and DNA damage response pathways underscore their relevance as therapeutic targets. The interplay of these epigenetic modifications drives resistance to agents such as gemcitabine and 5-fluorouracil across multiple tumor types. We also discuss recent progress in therapeutic interventions, including DNMT and HDAC inhibitors, RNA-based therapeutics, and CRISPR-based epigenome editing. Full article

P. aeruginosa strain NL201 was cultured from an urban water drain in a populated subway underpass as an environmental isolate for the ST111 global high-risk P. aeruginosa clone. In addition to carrying generally present intrinsic P. aeruginosa antibiotic resistance genes, this serotype O4 isolate also carries a set of additional acquired resistance determinants, including aadA2, bla_OXA-10, sul1, and an aac(6′)-Ib family gene. The NL201 isolate features the bla_PDC-3 allele, which was found to confer significantly higher catalytic efficiency against cefepime and imipenem compared to bla_PDC-1, as well as the potent P. aeruginosa virulence factors exoS, exoT, and algD. Serotype O4 isolates of the ST111 global high-risk P. aeruginosa clone have been reported from clinical samples in Canada and the USA, human stool samples in France, and environmental samples (such as cosmetic, hospital drains, and urban water drain) from various European countries. These observations underscore the effective dissemination of the ST111 global high-risk P. aeruginosa clone between different hosts, environments, and habitats, and they warrant targeted investigations from a One Health perspective on the possible routes of its spread and molecular evolution. Full article

Multidrug resistance (MDR) significantly contributes to colon cancer recurrence, making it essential to understand its molecular basis for improved therapies. This study aimed to identify genes and pathways involved in resistance to standard chemotherapeutics by comparing transcriptome profiles of sensitive and paclitaxel-induced MDR colonospheres. Cell viability and growth were assessed following treatment with 5-fluorouracil, oxaliplatin, irinotecan, bevacizumab, and cetuximab. Drug concentrations in culture media posttreatment were measured using high-performance liquid chromatography (HPLC). RNA sequencing (RNA-seq) of untreated sensitive and resistant colonospheres identified differentially expressed genes linked to baseline resistance. Our results confirmed cross-resistance in the resistant model, showing highest oxaliplatin tolerance may involve mechanisms beyond efflux. Transcriptome analysis highlighted upregulation of PIGR and activation of the ribosomal signaling pathway as potential resistance mediators. Notably, AKR1B10, a gene linked to chemotherapeutic detoxification, was overexpressed, whereas genes related to adhesion and membrane transport were downregulated. The overexpression of ribosomal protein genes suggests ribosome biogenesis plays a key role in acquired resistance. These findings suggest that targeting ribosome biogenesis and specific deregulated genes such as PIGR and AKR1B10 may offer promising strategies to overcome MDR in colon cancer. Full article

The intersection of microbial food safety and antimicrobial resistance (AMR) represents a mounting global threat with profound implications for public health, food safety, and sustainable development. This review explores the complex pathways through which foodborne pathogens—such as Salmonella spp., Escherichia coli (E. coli), Listeria monocytogenes (L. monocytogenes), and Campylobacter spp.—acquire and disseminate resistance within human, animal, and environmental ecosystems. Emphasizing a One Health framework, we examine the drivers of AMR across sectors, including the misuse of antibiotics in agriculture, aquaculture, and clinical settings, and assess the role of environmental reservoirs in sustaining and amplifying resistance genes. We further discuss the evolution of surveillance systems, regulatory policies, and antimicrobial stewardship programs (ASPs) designed to mitigate resistance across the food chain. Innovations in next-generation sequencing, metagenomics, and targeted therapeutics such as bacteriophage therapy, antimicrobial peptides (AMPs), and CRISPR-based interventions offer promising alternatives to conventional antibiotics. However, the translation of these advances into practice remains uneven, particularly in low- and middle-income countries (LMICs) facing significant barriers to diagnostic access, laboratory capacity, and equitable treatment availability. Our analysis underscores the urgent need for integrated, cross-sectoral action—anchored in science, policy, and education—to curb the global spread of AMR. Strengthening surveillance, investing in research, promoting responsible antimicrobial use, and fostering global collaboration are essential to preserving the efficacy of existing treatments and ensuring the microbiological safety of food systems worldwide. Full article

Anthracyclines have been clinically well established in cancer chemotherapy for decades. The main limitations of this drug class are the development of resistance and severe side effects. In the present investigation, we analyzed 30 anthracyclines in a panel of 59 cell lines of the National Cancer Institute, USA. The log₁₀IC₅₀ values varied from −10.49 M (3′-deamino-3′-(4″-(3″-cyano)morpholinyl)-doxorubicin, 1) to −4.93 M (N,N-dibenzyldaunorubicin hydrochloride, 30). Multidrug-resistant NCI-ADR-Res ovarian cancer cells revealed a high degree of resistance to established anthracyclines (between 18-fold to idarubicin (4) and 166-fold to doxorubicin (13) compared to parental, drug-sensitive OVCAR8 cells). The resistant cells displayed only low degrees of resistance (1- to 5-fold) to four other anthracyclines (7, 18, 28, 30) and were even hypersensitive (collaterally sensitive) to two compounds (1, 26). Live cell time-lapse microscopy proved the cross-resistance of the three chosen anthracyclines (4, 7, 9) on sensitive CCRF/CEM and multidrug-resistant CEM/ADR5000 cells. Structure–activity relationships showed that the presence of tertiary amino functions is helpful in avoiding resistance, while primary amines rather increased resistance development. An α-aminonitrile function as in compound 1 was favorable. Investigating the mRNA expression of 49 ATP-binding cassette (ABC) transporter genes showed that ABCB1/MDR1 encoding P-glycoprotein was the most important one for acquired and inherent resistance to anthracyclines. Molecular docking demonstrated that all anthracyclines bound to the same binding domain at the inner efflux channel side of P-glycoprotein with high binding affinities. Kaplan–Meier statistics of RNA sequencing data of more than 8000 tumor biopsies of TCGA database revealed that out of 23 tumor entities high ABCB1 expression was significantly correlated with worse survival times for acute myeloid leukemia, multiple myeloma, and hepatocellular carcinoma patients. This indicates that ABCB1 may serve as a prognostic marker in anthracycline-based chemotherapy regimens in these tumor types and a target for the development of novel anthracycline derivatives. Full article

Klebsiella pneumoniae is a major public health concern due to its role in Gram-negative bacteremia, which leads to high mortality and increased healthcare costs. This study characterizes phenotypic and genomic features of K. pneumoniae isolates from clinical samples in Karachi, Pakistan. Among 507 isolates, 213 (42%) were carbapenem-resistant based on disk diffusion and MIC testing. Urine (29.7%) and blood (28.3%) were the most common sources, with infections predominantly affecting males (64.7%) and individuals aged 50–70 years. Colistin was the only antibiotic showing consistent activity against these isolates. The whole-genome sequencing of 24 carbapenem-resistant K. pneumoniae (CR-KP) isolates revealed bla_NDM-5 (45.8%) as the dominant carbapenemase gene, followed by bla_NDM-1 (12.5%) and bla_OXA-232 (54.2%). Other detected bla_OXA variants included bla_OXA-1, bla_OXA-4, bla_OXA-10, and bla_OXA-18. The predominant beta-lactamase gene was bla_CTX-M-15 (91.6%), followed by bla_CTX-M-163, bla_CTX-M-186, and bla_CTX-M-194. Sequence types ST147, ST231, ST29, and ST11 were associated with resistance. Plasmid profiling revealed IncR (61.5%), IncL (15.4%), and IncC (7.7%) as common plasmid types. Importantly, resistance was driven not only by acquired genes but also by chromosomal mutations. Porin mutations in OmpK36 and OmpK37 (e.g., P170M, I128M, N230G, A217S) reduced drug influx, while acrR and ramR mutations (e.g., P161R, G164A, P157*) led to efflux pump overexpression, enhancing resistance to fluoroquinolones and tigecycline. These findings highlight a complex resistance landscape driven by diverse carbapenemases and ESBLs, underlining the urgent need for robust antimicrobial stewardship and surveillance strategies. Full article