Search Results (61)

Lipopeptides (LPs) have evolved from naturally occurring compounds to key therapeutic agents against multidrug-resistant (MDR) bacterial infections. However, their expanding clinical use has triggered emerging resistance mechanisms, posing serious challenges to anti-infective therapy. This systematic review outlines the development of LP resistance and highlights innovative strategies to counteract it. To overcome these evolving barriers, the field has transitioned from traditional empirical optimization to multidimensional rational design. Moving beyond conventional structure–activity relationship (SAR)-guided chemical synthesis, current approaches integrate diverse innovative methodologies. Based on these advances, this review provides the first systematic summary of contemporary strategies for developing novel LPs, offering new perspectives and methodological support to combat resistant bacterial infections and accelerate the development of next-generation LP-based therapeutics. Full article

Klebsiella pneumoniae is increasingly reported in canine medicine, with growing attention to multidrug-resistant (MDR) and hypervirulent strains. Although its overall prevalence in dogs appears relatively low, published studies indicate that affected animals may harbor clinically important resistance determinants, including extended-spectrum β-lactamases and, less frequently, carbapenemases. Canine isolates described in the literature also carry virulence-associated traits such as hypermucoviscosity and enhanced iron-acquisition systems, which overlap with features of high-risk human lineages and suggest potential, but largely inferred, interspecies links. These observations highlight the relevance of a One Health perspective and the importance of coordinated surveillance that includes companion animals. This narrative review synthesizes available literature on the epidemiology, clinical presentations, antimicrobial resistance, virulence traits, and molecular characteristics of K. pneumoniae in dogs. We critically evaluate evidence suggesting that dogs may function as reservoirs, sentinels, or amplifiers of MDR strains, particularly in clinical settings or following antimicrobial exposure. In addition, we summarize emerging alternative and adjunctive strategies—such as bacteriophage therapy, antimicrobial peptides, anti-virulence approaches, microbiome-based interventions, as well as strengthened antimicrobial stewardship and infection-control practices—that are under investigation as complements to conventional antibiotics. Overall, published evidence indicates that K. pneumoniae infections in dogs represent an under recognized but potentially important clinical and One Health concern. Continued surveillance, responsible antimicrobial use, and rigorous evaluation of non-antibiotic strategies will be essential to inform future veterinary practice and public health policy. Full article

Non-typhoidal Salmonella (NTS) are globally distributed zoonotic pathogens of major concern within the One Health–One Biofilm framework. Fluoroquinolone-resistant Salmonella strains are included by the World Health Organization (WHO) in the Bacterial Priority Pathogens List as high-risk agents. A key virulence determinant of Salmonella is its ability to form biofilms, which may display multidrug-resistant (MDR) characteristics and contribute to bacterial persistence and treatment failure. Animals, particularly poultry and reptiles, represent important reservoirs of Salmonella, and reptile-associated salmonellosis (RAS) may manifest as extraintestinal infections in humans. In the post-antibiotic era, there is an urgent need to identify effective alternatives to conventional therapies. This review summarizes current knowledge on Salmonella biofilms, with particular attention to their MDR potential, and discusses possible strategies for their prevention and eradication, including specific immunoprophylaxis, bacteriophage therapy, and alternative antimicrobials. The promising antimicrobials include plant-based compounds/extracts, bacteriocins, fatty acids, and synthetic/semi-synthetic substances. The integration of vaccination, phage therapy, and novel anti-biofilm compounds may provide a sustainable alternative to antibiotics in controlling Salmonella infections and aligns with the principles of the One Health approach. Full article

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) and a major contributor to the global antimicrobial resistance crisis. The increasing prevalence of multidrug-resistant (MDR) strains, including expanded-spectrum β-lactamases (ESBL) and carbapenemase-producing isolates, severely limits treatment options. This review provides an overview on the key molecular mechanisms of UPEC antibiotic resistance, such as enzymatic inactivation, target-site mutations, efflux pump activity, and biofilm formation. Beyond conventional antibiotics, special emphasis is placed on phytochemical strategies as promising alternatives. Flavonoids, alkaloids, terpenoids, and essential oils exhibit antibacterial, anti-adhesive, and antibiofilm properties. These natural bioactive compounds modulate motility, suppress fimbrial expression, inhibit quorum sensing, and enhance antibiotic efficacy, acting both as standalone agents and as adjuvants. Current in vitro and in vivo studies highlight the potential of plant-derived compounds and biologically based therapies to combat UPEC. However, challenges related to standardization, bioavailability, and clinical validation remain unresolved. Integrating molecular mechanistic insights with advanced phytochemical research may offers a sustainable and effective strategy for mitigating UPEC antibiotic resistance. Full article

The use of clinically important antibiotics in U.S. poultry production has decreased drastically over the past decade. They can only be used to treat diseases under the supervision of a veterinarian. Reducing antibiotic use, even for disease treatment, can improve the long-term sustainability of the industry. In the current study, we examined the effect of supplementation of a low dose of trans-cinnamaldehyde (TC; 0.03%), a GRAS-status plant-derived compound, with or without oxytetracycline (OTC; 16 μg/mL), an anti-30S ribosomal subunit targeting antibiotic, on the multidrug-resistant (MDR) S. Heidelberg (SH) in turkey poults. Two independent experiments were conducted (N = 96). In each experiment, 48, straight-run, day-old, commercial Hybrid Converter turkey poults were randomly assigned to 6 treatments of 8 birds each: Negative Control [NC; −SH, −TC, −OTC, −0.06% Miglyol (MIG, emulsifier for TC in water)], Positive Control (PC; +SH, −TC, −OTC, −MIG), MIG Control (MIG; +SH, −TC, −OTC, +MIG), TC Group (TC; +SH, +TC, −OTC, +MIG), OTC group (OTC; +SH, −TC, +OTC, −MIG), and TC+OTC group (TC+OTC; +SH, +TC, +OTC, +MIG). OTC was supplemented from day 1 through drinking water throughout the experiment. The birds in the TC and TC+OTC groups were supplemented with TC in their drinking water for 7 days post-challenge. All birds were challenged on day 7 with 6 log₁₀ CFU of SH/bird via crop gavage. On day 14, all birds were euthanized to collect the cecum, liver, and spleen for pathogen recovery. TC at 0.03% emulsified in MIG was highly effective in reducing MDR SH colonization in turkey poults (p < 0.05) compared to the SH control (>4.5 log₁₀ CFU/g reduction) on day 14. The OTC group reduced the pathogen load by 2.5 log₁₀ CFU/g by day 14. TC enhanced the effect of OTC, reducing pathogen load by ~3.9 log₁₀ CFU/g compared to the SH control after 7 days. TC significantly reduced SH invasion into the liver and spleen compared with the SH control on day 14. The results of the study indicate that TC at 0.03% can augment OTC at 16 μg/mL for the treatment of MDR SH infection in poults and could be an industry-sustainable strategy. Full article

Essential oil-derived compounds such as eugenol, thymol, cinnamaldehyde, and carvacrol exhibit potent antimicrobial and anti-inflammatory properties, making them promising candidates for therapeutic and industrial applications. This review examines the current evidence regarding the mechanisms of action, efficacy, and ability to disrupt quorum sensing and biofilm formation of essential oil-derived compounds against a broad spectrum of Gram-positive and Gram-negative bacteria, including multidrug-resistant (MDR) strains. The anti-inflammatory activity of these compounds is also highlighted, with emphasis on their modulation of key signaling pathways such as nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs), and their ability to downregulate pro-inflammatory cytokines. However, challenges persist, including cytotoxicity at high concentrations, chemical instability, poor water solubility, and variable pharmacokinetics. Advanced delivery systems such as nano encapsulation and synergistic formulations offer potential strategies to overcome these limitations. This review highlights both the therapeutic potential and the current limitations of these natural compounds, emphasizing the need for continued research to translate preclinical findings into clinical applications. Full article

Resistance to conventional anti-tumor drugs is one of the significant challenges in oncology, responsible for treatment failure and patient death. Introduction of the targeted drugs (e.g., small molecule tyrosine kinase inhibitors (TKIs) and monoclonal antibodies) in cancer therapy significantly improved overall survival (OS) and progression-free survival (PFS) rates for selected groups of cancer patients and delayed the progression of advanced forms of human malignancies. However, the development of secondary resistance to the targeted drugs remains an unbeatable obstacle to a successful outcome in the long run, thereby making prognosis unfavorable for cancer patients with advanced, recurrent, and metastatic forms of disease. The review focuses on several mechanisms that regulate cancer resistance to conventional chemotherapies. This includes the upregulation of main types of ABC transporters (e.g., ABCB1, ABCC1, and ABCG2), which provides the efflux of chemotherapeutic agents from cancer cells. Additionally, the activation of diverse DNA damage repair (DDR) pathways, epithelial-to-mesenchymal transition (EMT), and the population of cancer stem cells (CSCs) are also discussed in detail, thereby illustrating the diverse molecular mechanisms of cancer sensitivity to chemotherapies. Recently, several TKIs, including those that were initially developed to specifically target FGFR and VEGFR pathways, have also been reported to exhibit “off-target” effects by interacting with ABC transporters and inhibiting their function. This, in turn, illustrates their potency in retaining chemotherapeutic agents within cancer cells and possessing a chemosensitizing function. Of note, FGFR and VEGFR inhibitors may behave as inhibitors or substrates of ABC transporters, depending on the expression of specific pumps and affinity for them, concentrations, and types of co-administered agents, thereby disclosing the complexity of this scenario. Additionally, the aforementioned RTKI can interfere with the other molecular mechanisms regulating tumor sensitivity to conventional chemotherapies, including the regulation of diverse DDR pathways, EMT, and the population of CSCs. Thereby, the aforementioned “off-target” functions of FGFR and VEGFR inhibitors can open novel approaches towards anti-cancer therapies and strategies aimed at counteracting cancer multidrug resistance (MDR), which is important especially as second- or third-line treatments in patients who have progressed on modern chemotherapeutic regimens. Notably, the strategy of using TKIs to potentiate the clinical efficacy of chemotherapies can extend beyond inhibitors of FGFR and VEGFR signaling pathways, thereby providing a rationale for repurposing existing TKIs as an attractive therapeutic approach to overcome cancer chemoresistance. Full article

Chronic myeloid leukemia (CML) is a blood disorder caused by a genetic alteration that creates the BCR-ABL fusion gene, leading to continuous activation of cell growth signals and uncontrolled proliferation of the blood cells. Imatinib (IMA) resistance remains a major obstacle in CML treatment. Integrins, particularly integrin α2 (ITGA2), have been associated with cancer progression and drug resistance. In the current study, we investigated the role of ITGA2 in IMA resistance using IMA-sensitive K562 (K562S) and IMA-resistant K562 (K562R) cells. Our findings showed that ITGA2 is overexpressed in K562R cells and ITGA2 inhibitor E7820 (2.5 µM) treatment significantly decreased cell viability and induced apoptosis in both sensitive and resistant cells. Combination treatment with E7820 and imatinib enhanced pro-apoptotic gene expression (BAX, BIM) and decreased anti-apoptotic BCL2 levels in imatinib-resistant K562R cells. Flow cytometry confirmed ITGA2 inhibition at the protein level, and rhodamine assays revealed reduced MDR1 activity in treated cells. These results demonstrate that targeting ITGA2 may overcome imatinib resistance and offer a novel therapeutic strategy for CML. Full article

Nosocomial infections caused by ESKAPE pathogens represent a significant burden to global health. These pathogens may exhibit multidrug resistance (MDR) mechanisms, of which mechanisms such as efflux pumps and biofilm formation are gaining significant importance. Multidrug resistance mechanisms in ESKAPE pathogens have led to an increase in the effective costs in health care and a higher risk of mortality in hospitalized patients. These pathogens utilize antimicrobial efflux pump mechanisms and bacterial biofilm-forming capabilities to escape the bactericidal action of antimicrobials. ESKAPE bacteria forming colonies demonstrate increased expression of efflux pump-encoding genes. Efflux pumps not only expel antimicrobial agents but also contribute to biofilm formation by bacteria through (1) transport of molecules and transcription factors involved in biofilm quorum sensing, (2) bacterial fimbriae structure transport for biofilm adhesion to surfaces, and (3) regulation of a transmembrane gradient to survive the difficult conditions of biofilm microenvironments. The synergistic role of these mechanisms complicates treatment outcomes. Given the mechanistic link between biofilms and efflux pumps, therapeutic strategies should focus on targeting anti-biofilm mechanisms alongside efflux pump inactivation with efflux pump inhibitors. This review explores the molecular interplay between efflux pumps and biofilm formation, emphasizing potential therapeutic strategies such as efflux pump inhibitors (EPIs) and biofilm-targeting agents. Full article

Background: Multidrug-resistant tuberculosis (MDR-TB) remains a significant public health threat in Central Asia, where rising resistance to first-line anti-TB drugs challenges control efforts. As of 2024, the World Health Organization (WHO) reports that over 2.5% of new TB cases and 18% of previously treated cases are resistant to first-line TB drugs worldwide. Objectives: This integrative review synthesizes current evidence on MDR-TB in Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, with a focus on infection control, diagnostic advancements, and evolving treatment strategies. Methods: A comprehensive literature search was conducted across five electronic databases: PubMed, Scopus, Web of Science, Embase, World Health Organization (WHO) Global Tuberculosis Database, and ClinicalTrials.gov. A total of 29 articles from Central Asian countries met the inclusion criteria. Results: Four main themes were identified: “genetic variability and resistance patterns of MDR-TB strains”; “barriers to effective treatment”; “diagnostic tools”, and “infection control strategies”. Conclusions: This review underscores the importance of comprehensive, multifactorial approaches in addressing drug-resistant TB in the region. The implementation of early diagnosis and all-oral treatment regimens has improved adherence in recent studies. Full article

The growing prevalence of bacterial infections and the alarming rise of antimicrobial resistance (AMR) have driven the need for innovative antimicrobial coatings for medical implants and biomaterials. However, implant surface properties, such as roughness, chemistry, and reactivity, critically influence biological interactions and must be engineered to ensure biocompatibility, corrosion resistance, and sustained antibacterial activity. This review evaluates three principal categories of antimicrobial agents utilized in surface functionalization: metal/metaloxide nanoparticles, antibiotics, and phytochemical compounds. Metal/metaloxide-based coatings, especially those incorporating silver (Ag), zinc oxide (ZnO), and copper oxide (CuO), offer broad-spectrum antimicrobial efficacy through mechanisms such as reactive oxygen species (ROS) generation and bacterial membrane disruption, with a reduced risk of resistance development. Antibiotic-based coatings enable localized drug delivery but often face limitations related to burst release, cytotoxicity, and diminishing effectiveness against multidrug-resistant (MDR) strains. In contrast, phytochemical-derived coatings—using bioactive plant compounds such as curcumin, eugenol, and quercetin—present a promising, biocompatible, and sustainable alternative. These agents not only exhibit antimicrobial properties but also provide anti-inflammatory, antioxidant, and osteogenic benefits, making them multifunctional tools for implant surface modification. The integration of these antimicrobial strategies aims to reduce bacterial adhesion, inhibit biofilm formation, and enhance tissue regeneration. By leveraging the synergistic effects of metal/metaloxide nanoparticles, antibiotics, and phytochemicals, next-generation implant coatings hold the potential to significantly improve infection control and clinical outcomes in implant-based therapies. Full article

The increasing prevalence of multidrug-resistant (MDR) bacterial infections necessitates the exploration of alternative antimicrobial strategies, with phage therapy emerging as a viable option. However, the effectiveness of naturally occurring phages can be significantly limited by bacterial defense systems that include adsorption blocking, restriction–modification, CRISPR-Cas immunity, abortive infection, and NAD+ depletion defense systems. This review examines these bacterial defenses and their implications for phage therapy, while highlighting the potential of phages’ bioengineering to overcome these barriers. By leveraging synthetic biology, genetically engineered phages can be tailored to evade bacterial immunity through such modifications as receptor-binding protein engineering, anti-CRISPR gene incorporation, methylation pattern alterations, and enzymatic degradation of bacterial protective barriers. “Armed phages”, enhanced with antimicrobial peptides, CRISPR-based genome-editing tools, or immune-modulating factors, offer a novel therapeutic avenue. Clinical trials of bioengineered phages, currently SNIPR001 and LBP-EC01, showcase their potential to safely and effectively combat MDR infections. SNIPR001 has completed a Phase I clinical trial evaluating safety in healthy volunteers, while LBP-EC01 is in Phase II trials assessing its performance in the treatment of Escherichia coli-induced urinary tract infections in patients with a history of drug-resistant infections. As “armed phages” progress toward clinical application, they hold great promise for precision-targeted antimicrobial therapies and represent a critical innovation in addressing the global antibiotic resistance crisis. Full article

Algae have great therapeutic value and have attracted a great deal of attention due to the abundance of bioactive compounds they contain, which may be the key to fighting diseases of various origins, such as skin cancer, breast cancer, or osteosarcoma. In this regard, global trends indicate that cancer is likely to become the leading cause of death and the main obstacle to increased life expectancy in the 21st century, which is related to multiple factors, including the various effects of climate change, which will continue to cause afflictions to human health. Then, excess exposure to ultraviolet radiation (UVR) causes damage to DNA, proteins, enzymes, and various cellular structures and leads to the development of cancer, premature aging of the skin (wrinkles, dryness, dilation of blood vessels, and loss of collagen and elastin), or alterations of the immune system. In addition, multidrug resistance (MDR) is characterized by the overexpression of efflux pumps, such as P-glycoprotein or P-gp, that expel chemotherapeutic drugs out of the cancer cell being the main obstacle to their efficacy. Some molecules inhibit efflux pumps when co-administered with antineoplastic agents, such as glycolipids. Mycosporin-like amino acids and glycolipids isolated from Sargassum have shown an important role as potential anticancer agents. The results show that glycolipids and mycosporin-like amino acids present in brown algae of the genus Sargassum exhibit cytotoxic effects on different types of cancer, such as breast cancer, leukemia, and osteosarcoma, which is a key criterion to be considered as a natural anti-cancer strategy; but, more in-depth in vitro studies are needed to represent them at the in vivo level, as well as their validation in preclinical assays. Full article

Pseudomonas aeruginosa is one of world’s most threatening bacteria. In addition to the emerging prevalence of multi-drug resistant (MDR) strains, the bacterium also possesses a wide variety of virulence traits that worsen the course of the infections. Particularly, its ability to form biofilms that protect colonies from antimicrobial agents is a major cause of chronic and hard-to-treat infections in immune-compromised patients. This protective barrier also ensures cell growth on abiotic surfaces and thus enables bacterial survival on medical devices. Hence, as the WHO alerted to the need to develop new treatments, the use of anti-biofilm agents (ABAs) appeared as a promising approach. Given the selection pressure imposed by conventional antibiotics, a new therapeutic strategy has emerged that aims at reducing bacterial virulence without inhibiting cell growth. So-called anti-virulence agents (AVAs) would then restore the efficacy of conventional antibiotics (ATBs) or potentiate the effectiveness of the immune system. The last decade has seen the development of ABAs as AVAs against P. aeruginosa. This review aims to highlight the design strategy and critical features of these molecules to pave the way for further discoveries of highly potent compounds. Full article

Multidrug-resistant tuberculosis (MDR-TB) poses a significant global health threat, especially when it involves the central nervous system (CNS). Tuberculous meningitis (TBM), a severe manifestation of TB, is linked to high mortality rates and long-term neurological complications, further exacerbated by drug resistance and immune evasion mechanisms employed by Mycobacterium tuberculosis (Mtb). Although pulmonary TB remains the primary focus of research, MDR-TBM introduces unique challenges in diagnosis, treatment, and patient outcomes. The effectiveness of current treatments is frequently compromised by poor CNS penetration of anti-TB drugs and the necessity for prolonged therapy, which often involves considerable toxicity. This review explores the potential of cytokine-based adjunct immunotherapies for MDR-TBM, addressing the challenges of balancing pro-inflammatory and anti-inflammatory signals within the CNS. A central focus is the prospective role of glutathione, not only in reducing oxidative stress but also in enhancing host immune defenses against Mtb’s immune evasion strategies. Furthermore, the development of vaccines aimed at upregulating glutathione synthesis in macrophages represents a promising strategy to bolster the immune response and improve treatment outcomes. By integrating glutathione and innovative vaccine approaches into MDR-TBM management, this review proposes a comprehensive strategy that targets Mtb directly while supporting immune modulation, with the potential to enhance patient outcomes and reduce treatment related adverse effects. We underscore the urgent need for further research into adjunctive therapies and immunomodulatory strategies to more effectively combat MDR-TBM. Full article