Search Results (874)

Infectious diseases present a significant global health challenge, further exacerbated by the rising prevalence of antimicrobial resistance and the limited availability of effective antiviral and antimicrobial agents. The Erythrina genus has garnered scientific interest due to its diverse array of bioactive phytoconstituents, with potential therapeutic relevance. This review aims to synthesize and critically assess the existing literature on the antiviral, antibacterial, antifungal, and antiplasmodial properties of Erythrina species. A comprehensive literature search was conducted using PubMed, Scopus, and Google Scholar databases. Relevant studies were identified through keyword searches combining pathogen-specific terms with “Erythrina”. The extracted data were categorized based on the pathogen type and its associated bioactive compounds. Several Erythrina species exhibited substantial antiviral activity against prominent viral pathogens, such as HIV and SARS-CoV-2. Notably, strong antibacterial efficacy was observed against Staphylococcus aureus, including multidrug-resistant strains. Antifungal activity was most pronounced against Candida albicans, while potent antiplasmodial effects were reported against both drug-sensitive and drug-resistant strains of Plasmodium falciparum. These pharmacological effects were predominantly attributed to prenylated flavonoids, isoflavones, pterocarpans, and erythrina-type alkaloids. Further mechanistic studies and in vivo evaluations are essential to fully assess their clinical efficacy and support the development of plant-derived antimicrobial agents. Full article

Background: Antimicrobial resistance (AMR) is a major global health threat, particularly in surgical site infections (SSIs), where multidrug-resistant (MDR) pathogens complicate treatment. Objective: This study aimed to identify antimicrobial resistance genes and assess their prevalence in bacterial species causing SSIs in Lebanon. Materials and Methods: The present research is a multicenter and prospective study that included patients who developed SSIs after surgery in seven hospitals, within the period of January 2024–September 2024. Bacterial isolates from wound swabs or tissue samples were identified using standard microbiological methods. Antimicrobial susceptibility was tested by disk diffusion, and resistance genes were detected by PCR. Data were analyzed using Statistical Package for the Social Sciences (SPSS). Results: Among 6933 surgical patients, 63 developed SSIs (0.91%; 95% CI [0.70–1.15]). Gram-negative bacteria predominated (73%), mainly Escherichia coli and Pseudomonas aeruginosa, while Gram-positive isolates accounted for 27%, mostly Staphylococcus aureus. MDR was observed in 71% of Gram-positive and 61% of Gram-negative isolates. The most frequent genes were mecA in S. aureus (100%) and coagulase-negative staphylococci (83.3%); bla_CTX-M in E. coli, Klebsiella pneumoniae, and Enterobacter cloacae (100%); and bla_NDM in E. cloacae (100%) and Acinetobacter baumannii (60%). bla_KPC was less common, and no isolates carried Imipenemase (IMP), Verona integron-encoded metallo-β-lactamase (VIM), and Oxacillinase-48-like β-lactamase (OXA-48). Conclusions: This study highlights the high prevalence of antibiotic resistance in agents causing SSIs in Lebanese hospitals. Resistance genes, particularly mecA, bla_CTX-M, and blaNDM, were highly prevalent in SSI pathogens, underscoring the urgent need for surveillance and judicious antibiotic use in Lebanese hospitals. Full article

Background/Objectives: Modern healthcare faces a growing burden of antimicrobial resistance, prominently driven by ESKAPE pathogens. These organisms—Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.—are the leading causes of healthcare-associated infections, associated with limited therapeutic options and increased morbidity. Continuous surveillance is crucial for informing empirical therapy and guiding stewardship. Methods: We perform a single-center, seven-year retrospective study (2018–2024) at a 1000-bed tertiary hospital in Warsaw, Poland. Bloodstream isolates of ESKAPE pathogens were identified according to the EUCAST guidelines. Data were analyzed by pathogen, ward, and year of isolation. Results: From 2483 positive blood cultures, 3724 ESKAPE pathogens were recovered. S. aureus and K. pneumoniae predominated, particularly in the Intensive Care Unit and Hematology ward. Resistance analysis revealed persistently high vancomycin resistance in E. faecium, variable but notable methicillin resistance in S. aureus, and frequent ESBL production in K. pneumoniae with an alarming rise in carbapenemase-producing strains, including dual NDM + OXA-48 co-producers. A. baumannii exhibited near-universal multidrug resistance. P. aeruginosa demonstrated lower resistance rates with preserved colistin susceptibility, while Enterobacter spp. remained fully carbapenem-susceptible. Linezolid retained activity against E. faecium, while colistin remained effective against A. baumannii and P. aeruginosa. Modern β-lactam/β-lactamase inhibitor combinations were active against K. pneumoniae. Conclusions: Our findings underscore the critical role of ESKAPE pathogens in bloodstream infections and highlight divergent resistance patterns across species. The emergence of carbapenemase-producing K. pneumoniae and the persistence of multidrug-resistant A. baumannii are of particular concern. Sustained surveillance, robust antimicrobial stewardship, and tailored infection control strategies remained essential to curb the evolving resistance threat in tertiary care settings. Full article

Background: The rapid emergence of antibiotic resistance in Acinetobacter baumannii has led the World Health Organization (WHO) to designate it as a “high priority” pathogen. The emergence of multidrug-resistant (MDR) and pandrug-resistant (PDR) strains poses considerable treatment challenges. As antimicrobial resistance (AMR) escalates toward a post-antibiotic era, innovative therapeutic solutions are urgently needed. Objectives: To clone, over-express, and characterize a novel endolysin, LysTAC1, from Acinetobacter phage TAC1 for its antibacterial efficacy against multidrug-resistant bacteria. Methods: A 24 kDa endolysin featuring a glycoside hydrolase Family 19 chitinase domain was tested against carbapenem-resistant Acinetobacter baumannii clinical isolates and various Escherichia coli strains following outer membrane permeabilization with Ethylenediaminetetraacetic acid (EDTA). Stability assays and molecular docking studies were performed. Results: LysTAC1 demonstrated potent lytic activity against Gram-negative bacteria but showed no activity against Gram-positive bacteria (Staphylococcus aureus ATCC 29213 and Enterococcus gallinarum HCD 28-1). LysTAC1 maintained activity across pH 6–9 and temperatures 4–65 °C, with differential sensitivity to metal ions where K⁺ showed no inhibitory effect at any concentration (0.1–100 mM), and Fe²⁺ was non-inhibitory at lower concentrations (0.1–1 mM), while Mg²⁺ and Ca²⁺ demonstrated concentration-dependent inhibition across the tested range (0.1–100 mM). Molecular docking revealed LysTAC1 interactions with chitinase substrates 4-nitrophenyl N-acetyl-β-D-glucosaminide and 4-nitrophenyl N, N-Diacetyl-β-D-chitobioside, with binding energies of −5.82 and −6.85 kcal/mol, respectively. Conclusions: LysTAC1 shows significant potential as a targeted therapeutic agent against A. baumannii with robust stability under physiological conditions. Full article

Background/Objectives: Bacterial resistance to antimicrobials is a major global health challenge, limiting the effectiveness of conventional therapies and complicating infection control. The aim of this study was to investigate the antibacterial potential of biologically synthesized silver nanoparticles (Bio-AgNP), alone and in combination with ampicillin (AMP) and enrofloxacin (ENRO), against multidrug-resistant (MDR) bacterial isolates of clinical and veterinary relevance. Methods: The antibacterial activity of Bio-AgNP, AMP, and ENRO, alone or in combination, was assessed against reference strains and MDR isolates of Escherichia coli, Salmonella enterica serovar Typhimurium and Enteritidis, and Staphylococcus aureus. Minimum inhibitory concentration (MIC) values were determined, and bacterial tolerance to prolonged antimicrobial exposure was evaluated. Additionally, assays were conducted to explore potential mechanisms of action, including cell membrane permeability and oxidative stress induction. Results: All bacterial strains developed increased MIC values after prolonged exposure to conventional antibiotics, confirming resistance. Only E. coli developed resistance to Bio-AgNP. Notably, the Bio-AgNP + AMP combination effectively restored susceptibility in E. coli, while only S. Enteritidis developed resistance to this combination upon prolonged exposure. The synergistic effect of Bio-AgNP with conventional antibiotics significantly reduced bacterial growth within two hours, compared with longer times observed in monotherapy. Mechanistic analysis suggested that the combinations increased membrane permeability, facilitating antibiotic entry. Conclusions: Bio-AgNPs combined with AMP or ENRO enhanced antibacterial activity and overcame resistance in MDR isolates, representing a promising therapeutic alternative. The biological synthesis of Bio-AgNPs, capped with organic biomolecules, supports their potential as safe adjuvants to conventional antibiotics in combating MDR bacterial infections. Full article

This study explores the development of biocompatible hydrogel dressings incorporating curcumin as an alternative antibacterial agent. In this context, hydrogels were prepared using polyvinyl alcohol, xanthan gum, gelatin, and curcumin as a therapeutic component. FTIR spectroscopy confirmed the successful incorporation of curcumin into the hydrogel matrix, while release profiles demonstrated sustained release. Mechanical testing indicated that xanthan gum reduced elongation and strength in hydrogels, while the combination of xanthan gum and gelatin increased stiffness without loss of elasticity. Curcumin had no major effect on the tensile and rheological properties, preserving the structural integrity of the hydrogels. The hydrogels demonstrated antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus ATCC strains, as well as multidrug methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates. Biocompatibility was confirmed through viability assays with immortalized human keratinocytes (HaCaT) and adult human dermal fibroblasts (HDFa), showing no acute cytotoxic effects after 48 h of exposure. Their effective action against clinically relevant bacteria and high cytocompatibility position these hydrogels as promising candidates for infection management and antibiotic resistance mitigation in wound care applications. Full article

Antimicrobial resistance has emerged as one of the most critical public health challenges of the 21st century, threatening to undermine the foundations of modern medicine. In 2019, bacterial infections accounted for 13.6% of all global deaths, with more than 7.7 million fatalities directly attributable to 33 bacterial pathogens, most prominently Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Resistance mechanisms are multifactorial, encompassing enzymatic degradation, target modification, efflux pump overexpression, reduced membrane permeability, and biofilm formation, often in combination, leading to multidrug-resistant, extensively drug-resistant, and pandrug-resistant phenotypes. Alarmingly, projections estimate that by 2050 AMR could result in over 10 million deaths annually. This comprehensive review synthesizes global epidemiological data, insights into bacterial resistance mechanisms, and emerging therapeutic solutions, including novel antibiotics such as lasso peptides and macrocyclic peptides (e.g., zosurabalpin), naturally derived compounds (e.g., corallopyronin, clovibactin, chlorotonil A), and targeted inhibitors (e.g., Debio 1453 for Neisseria gonorrhoeae). Addressing the AMR crisis requires coordinated international efforts, accelerated drug discovery, and the integration of innovative non-antibiotic approaches to preserve the efficacy of existing therapies and ensure preparedness against future bacterial threats. Full article

Background: Staphylococcus aureus is one of the most prevalent bacteria in skin and soft tissue infections (SSTIs). Multidrug-resistant strain emergence, particularly methicillin-resistant S. aureus (MRSA), highlights the need for alternative treatments. Objectives: This study investigates the antimicrobial properties of olive leaf extract (OLE) and describes an epidemiological profiling of patients with SSTI who may benefit from it. Methods: OLE was tested in two reference strains, methicillin-susceptible S. aureus (MSSA) ATCC 29213 and MRSA ATCC 700699, and in 126 clinical isolates from patients with SSTIs according to Clinical Laboratory Standards Institute guidelines. Results: The minimum bactericidal concentration (MBC) ranged from 3.12% to 6.25% w/v for MSSA and 1.56% to 3.12% for MRSA. The lethal curve showed a reduction of 6 log₁₀CFU/mL after two hours of incubation. Most of the 126 clinical samples (103 MSSA and 23 MRSA) came from skin lesions, surgical wounds, and ulcers. Over 90% of MSSA strains were resistant to less than five antibiotics, while 82% of MRSA strains were resistant to more than six. Penicillins demonstrated the lowest susceptibility rate (19.8%), whereas linezolid, daptomycin, pristinamycin, trimethoprim–sulfamethoxazole, teicoplanin, vancomycin, and OLE exhibited 100% susceptibility. No growth was observed for all clinical strains with OLE at ≥6.25% w/v. Conclusions: The findings suggest that OLE could become a promising alternative treatment for skin infections, particularly in the context of increasing antibiotic resistance. Full article

Background: The emergence of livestock-associated antimicrobial-resistant staphylococci, particularly non-aureus staphylococci, has become a major public health problem requiring immediate global attention. Methods: In this study, 92 Staphylococcus borealis isolates from 20 different pig farms in Korea were examined to determine the following: (1) antimicrobial-resistance (AMR) profiles of the isolates, (2) prevalence of methicillin resistance and staphylococcal cassette chromosome methicillin resistance gene (SCCmec) types, (3) occurrence of chloramphenicol–florfenicol resistance gene (cfr)-mediated oxazolidinone resistance, and (4) genomic characteristics of cfr-positive methicillin-resistant S. borealis (MRSB) via whole-genome sequence (WGS) analysis. Results: The overall rate of S. borealis isolation was 9.1% (92 isolates/1009 swabs), and 34.8% (32/92) of the isolates were MRSB. Surprisingly, all 32 MRSB isolates carried SCCmec V for methicillin resistance, and 31/32 MRSB isolates displayed multidrug-resistance phenotypes. Although 22 cfr-positive S. borealis isolates (20 MRSB and two methicillin-susceptible S. borealis) were identified, most of the isolates were susceptible to linezolid because they carried the 35-bp insertion sequence in the cfr promoter. Moreover, WGS analyses suggested horizontal transmission of SCCmec V and cfr-containing plasmids among different staphylococci species, including Staphylococcus aureus, S. epidermidis, and S. borealis. Conclusions: To the best of our knowledge, this study is the first to describe the AMR characteristics of livestock-associated S. borealis isolates, particularly the high prevalence of SCCmec V and cfr. Collectively, these results suggest that S. borealis is a crucial reservoir of AMR genes on pig farms in Korea. Full article

Lop Nur, an extremely arid environment, harbors unique microbial resources and represents a potential reservoir for novel bioactive substances. With antibiotic resistance becoming an increasing global concern, the resistance traits of microorganisms in extreme habitats and their potential association with antibacterial activity remain poorly understood. This study aimed to investigate the diversity of soil microorganisms in Lop Nur, their resistance to norfloxacin, kanamycin, and amoxicillin, and their inhibitory activity against common pathogenic bacteria, thereby providing a scientific basis for the discovery of new antibacterial candidates. Surface soils from three sampling points in Lop Nur were inoculated onto Gao’s No.1 and LB media supplemented with different antibiotic regimens (single, pairwise, and triple combinations). Isolates were identified by 16S rRNA gene sequencing, their antibiotic resistance was assessed using the disk diffusion method, and antibacterial activity was evaluated using the agar well diffusion method. A total of 120 microorganisms were isolated, belonging to six phyla and nine genera, including 10 potential new species. The control group yielded the highest diversity (35 strains), whereas only 4 strains were recovered under triple-antibiotic treatment, demonstrating the strong selective effect of antibiotic stress. Resistance profiling showed that 88.14% of strains were resistant to amoxicillin, 64.71% to norfloxacin, and 60.68% to kanamycin, with multidrug resistance being widespread. Eleven strains exhibited antibacterial activity against five pathogens, including Staphylococcus aureus (maximum inhibition zone 53.51 mm), and nine of these strains also displayed antibiotic resistance, suggesting a potential association between resistance and antibacterial activity. Microorganisms isolated from Lop Nur displayed extensive resistance and notable antibacterial activity. Antibiotic stress strongly influenced the cultivable microbial isolates, facilitating the recovery of resistant strains with antibacterial potential. These findings provide a valuable reference for exploring microbial resources in extreme environments and highlight the potential link between antibiotic resistance and antibacterial activity. Full article

Antimicrobial resistance (AMR) in livestock production systems has emerged as a major global health concern, threatening not only animal welfare and agricultural productivity but also food safety and public health. The widespread, and often poorly regulated, use of antimicrobials for growth promotion, prophylaxis, and metaphylaxis has accelerated the emergence and dissemination of resistant bacteria and resistance genes. These elements circulate across interconnected animal, environmental, and human ecosystems, driven by mobile genetic elements and amplified through the food production chain. It is estimated that more than two-thirds of medically important antimicrobials are used in animals, and AMR could cause millions of human deaths annually by mid-century if unchecked. In some livestock systems, multidrug-resistant E. coli prevalence already exceeds half of isolates, particularly in poultry and swine in low- and middle-income countries (LMICs). This narrative review provides a comprehensive overview of the molecular epidemiology, ecological drivers, and One Health implications of AMR in food-producing animals. We highlight key zoonotic and foodborne bacterial pathogens—including Escherichia coli, Salmonella enterica, and Staphylococcus aureus—as well as underappreciated reservoirs in commensal microbiota and livestock environments. Diagnostic platforms spanning phenotypic assays, PCR, MALDI-TOF MS, whole-genome sequencing, and CRISPR-based tools are examined for their roles in AMR detection, surveillance, and resistance gene characterization. We also evaluate current antimicrobial stewardship practices, global and regional surveillance initiatives, and policy frameworks, identifying critical implementation gaps, especially in low- and middle-income countries. Emerging sectors such as aquaculture and insect farming are considered for their potential role as future AMR hotspots. Finally, we outline future directions including real-time genomic surveillance, AI-assisted resistance prediction, and integrated One Health data platforms as essential innovations to combat AMR. Mitigating the threat of AMR in animal agriculture will require coordinated scientific, regulatory, and cross-sectoral responses to ensure the long-term efficacy of antimicrobial agents for both human and veterinary medicine. Full article

Background: Staphylococcus aureus is a major zoonotic and foodborne pathogen with substantial One Health implications, yet its prevalence, resistance, and virulence potential within the aquaculture sector in Nigeria remains poorly characterized. Objectives: To supplement existing information, this current study investigated the prevalence, clonal distribution, antimicrobial resistance, and virulence gene profiles of S. aureus isolates from fish, fish water, and occupationally exposed fish handlers in Anambra State, Southeast Nigeria. Methods: A total of 607 samples—comprising 465 surface swabs from raw and processed fish, 36 fish water samples, and 106 nasal swabs from fish handlers—were processed using selective culture, biochemical tests, antimicrobial susceptibility testing, DNA microarray analysis, spa typing, and SCCmec typing. Results: S. aureus was recovered from 16.5% (100/607) of the samples. Fourteen (14%) isolates were methicillin-resistant (MRSA), harboring mecA and SCCmec types IV and V, with a combined MRSA prevalence of 2.3%. Multidrug resistance was observed in 52.2% of isolates (mean Multiple Antimicrobial Resistance index: 0.23), with 19 resistance genes spanning nine antimicrobial classes—including heavy metal and biocide resistance. Twenty-eight spa types across 13 clonal complexes (CCs) were identified, with CC1, CC5, and CC8 predominating. The detection of shared spa types between fish and handlers indicates potential cross-contamination. Detected virulence genes included those for accessory gene regulators (agrI-IV), Pantone–Valentine leucocidin (lukFS-PV), toxic shock syndrome (tsst-1), hemolysins (hla, hlb, hld/hlIII, hlgA), biofilm formation (icaA, icaD), immune evasion (chp, scn, sak), enterotoxins (sea, seb, sec, sed, egc, and others), exfoliative toxins (etA, etB), epidermal cells differentiation (edinA, edinB), and capsular types (cap5, cap8). Conclusions: This study reveals that the aquaculture sector in Southeast Nigeria serves as a significant reservoir of genetically diverse, multidrug-resistant S. aureus strains with robust virulence profiles. These findings highlight the necessity of integrated One Health surveillance and targeted interventions addressing antimicrobial use and hygiene practices within aquatic food systems. Full article

Background: Intravascular catheters (ICs) are critical medical devices but require frequent replacement due to the risk of bacterial colonization, which can lead to bloodstream infections. This process causes patient discomfort and incurs significant health and economic costs. Aim: To evaluate the inhibitory activity of natural extracts as potential IC coatings to prevent colonization by methicillin-resistant Staphylococcus aureus (MRSA). Methods: Thirty-six clinical MRSA isolates, obtained from ICs using the Maki technique, were tested. Three natural extracts were evaluated: garlic extract enriched in thiosulfinates (allicin: 7 mg/g), grape extract enriched in proanthocyanidins (92% proanthocyanidins), and propolis extract. Chlorhexidine gluconate (CHG) served as the bactericidal control. The minimum inhibitory concentration (MIC) was determined using the broth microdilution technique with optical density measurements and resazurin-based viability confirmation. The minimum bactericidal concentration (MBC) was assessed from viable cells in wells exceeding the MIC. Results: All tested extracts exhibited bacteriostatic activity against MRSA isolates. The grape extract demonstrated the lowest MIC₉₀ (3.125 mg/mL), followed by propolis extract (MIC₉₀ = 12.5 mg/mL) and garlic extract (MIC₉₀ = 50 mg/mL). Only the propolis extract showed bactericidal activity (MBC = 25 mg/mL). While CHG outperformed the natural extracts, their activity against MRSA suggests potential clinical utility. Conclusion: The natural extracts studied display promising bacteriostatic activity against MRSA isolates from ICs, with propolis extract additionally showing bactericidal effects. Although less potent than CHG, these extracts offer a potential alternative for combating multidrug-resistant pathogens in clinical settings, warranting further investigation for use as IC coatings. Full article

Micro-organisms are abundant in nature and can also be found in hospital settings, causing high rates of infections. This study aimed to identify bacteria isolated from a veterinary hospital, as well as to perform antimicrobial susceptibility testing using the disk diffusion method (Kirby–Bauer), biofilm production tests using 96-well polystyrene microtiter plates and crystal violet dye, and genetic analysis of the ica operon of Staphylococcus isolates. Three collections were made from eleven surfaces and objects in the hospital’s non-critical areas (general areas) and critical areas (surgical center), totaling thirty-three samples. A total of 66 different bacterial isolates were obtained, with 77% (51/66) Gram-positive and 23% (29/66) Gram-negative. Resistance profiles were found for multidrug-resistance (MDR), methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), and other unidentified species of methicillin-resistant coagulase-negative (MRCNS) and extended-spectrum beta-lactamase (ESBL), as well as biofilm production rates of 57% (38/66) of the isolates. Analysis of the operon genes for Staphylococcus sp. showed divergence in some samples when compared to the phenotypic test performed. In summary, there is a high presence of micro-organisms with resistance and virulence factors spread throughout the various areas of the veterinary hospital. Full article

The search for novel natural resources, such as extracts from algae and plant for use as reductants and capping agents for the synthesis of nanoparticles, may be appealing to medicine and nanotechnology. This study aimed to use Malva parviflora fruit extract as a novel source for the green synthesis of silver nanoparticles (AgNPs) and to evaluate their characterization. The results of biosynthesized AgNP characterization using multiple techniques, such as UV–Vis spectroscopy, scanning electron microscopy (SEM), FTIR analysis, and zeta potential (ZP), demonstrated that M. parviflora AgNPs exhibit a peak at 477 nm; possess needle-like and nanorod morphology with diameters ranging from 156.08 to 258.41 nm; contain –OH, C=O, C-C stretching from phenyl groups, and carbohydrates, pyranoid ring, and amide functional groups; and have a zeta potential of −21.2 mV. Moreover, the antibacterial activity of the M. parviflora AgNPs was assessed against two multidrug-resistant strains, including Staphylococcus aureus MRSA and Escherichia coli ESBL, with inhibition zones of 20.33 ± 0.88 mm and 13.33 ± 0.33 mm, respectively. The minimum bactericidal concentration (MBC) was 1.56 µg/mL for both. SEM revealed structural damage to the treated bacterial cells, and RAPD-PCR confirmed these genetic alterations. Additionally, M. parviflora AgNPs showed antioxidant activity (IC₅₀ = 0.68 mg/mL), 69% protein denaturation inhibition, and cytotoxic effects on MCF-7 breast cancer cells at concentrations above 100 µg/mL. These findings suggest that M. parviflora-based AgNPs are safe and effective for antimicrobial and biomedical applications, such as coatings for implanted medical devices, to prevent biofilm formation and facilitate drug delivery. Full article