Search Results (11,868)

The use of untreated livestock manure in urban agriculture sustains soil fertility but risks disseminating antimicrobial resistance (AMR) in resource-limited settings. This study characterized antibiotic-resistant bacteria (ARB) prevalence across manure–soil–vegetable pathways in Blantyre, Malawi. Using a cross-sectional design, we collected 35 samples (poultry/pig manure, farm/home soils, Brassica rapa subsp. chinensis, Brassica rapa, and Amaranthus spp.) from five livestock farms. Microbiological analysis with API 20E identification and disk diffusion testing revealed clear differences in contamination: Escherichia coli dominated pig manure (52%) and farm soil (35%), with detection in vegetables suggesting possible transfer (e.g., 20% in Brassica rapa subsp. chinensis), while Klebsiella pneumoniae contaminated all sample types (peak: 60% vegetables and 67% home soils). All manure isolates exhibited sulfamethoxazole–trimethoprim resistance, with 50% of pig manure E. coli showing cefotaxime resistance. Soil isolates mirrored these patterns (100% ampicillin resistance in K. pneumoniae and 77% cefotaxime resistance in farm soil E. coli). Vegetables displayed severe multidrug resistance (100% E. coli and 80% K. pneumoniae resistant to ≥3 classes), including critical gentamicin resistance (100% E. coli). Composting for ≤6 weeks, as practiced on the studied farms, did not eliminate ARBs, suggesting that longer durations may be needed. Notably, this study provides the first phenotypic evidence of presumptive Pasteurella-like organisms on edible leafy vegetables, specifically 45% in Amaranthus spp. and 6.1% in Brassica rapa, suggesting a potential zoonotic transmission route from livestock farms that requires molecular confirmation. These findings demonstrate manure-amended farms as AMR reservoirs, necessitating extended composting and antibiotic stewardship to mitigate One Health risks. Full article

Exposure to microorganisms can significantly impact well-being and, more importantly, human health. A frequently overlooked aspect of indoor air quality (IAQ) research is the risk posed by harmful biological agents transported through the air in the form of biological aerosols. Given that healthcare facilities create environments with an increased risk of infection transmission, monitoring IAQ and reducing microbiological contamination have become global public health challenges. This paper presents a literature review, focusing on the current state of knowledge regarding microbiological air quality in healthcare settings. The analysis confirms that Escherichia coli and Staphylococcus aureus are among the most prevalent airborne pathogens in healthcare facilities. The review also underlines the necessity for harmonized guidelines and integrated air quality management strategies to reduce microbial contamination effectively. Finally, the review compiles data on microorganism concentration levels and influencing factors. The present study highlights that implementing standardized monitoring and effective air filtration and disinfection methods is essential to improving microbiological air quality and enhancing patient safety. The sources analyzed in this review were collected from databases such as PubMed, ScienceDirect, ResearchGate, and Web of Science, considering only English-language publications. The studies cited were conducted in multiple countries across different regions, providing a comprehensive global perspective on the issue. Full article

Background: Despite the huge burden of deaths associated with or attributable to antimicrobial resistance, studies on sequencing based antimicrobial resistance (AMR) monitoring in Africa are scarce, specifically in the animal sector. Objective and Methods: With a view to deploy rapid AMR monitoring through leveraging advanced technologies, in the current study, nanopore sequencing was performed with 10 E. coli strains isolated from rectal swabs of pigs and poultry layers in Nigeria. Two sequence analysis methods including command line, where bacterial genomes were assembled, and subsequently antimicrobial resistance genes (ARGs) were detected through online databases, and EPI2ME, an integrated cloud-based data analysis platform with MinION, was used to detect ARGs. Results: A total of 95 ARGs were identified and most of the genes are known to be expressed in the chromosome. Interestingly, few genes including qnrS1, qnrS15, qnrS10, kdpE, cmlA1, MIR-14, sul3 and dfrA12 were identified which were previously reported as transferred through MGEs. The antibiotic susceptibility assay determined that the E. coli isolates were resistant to Penicillin (100%), Ciprofloxacin (70%), tetracycline (50%) and Ampicillin (40%). The accuracies of the command line and EPI2ME methods have been found to be 57.14% and 32.14%, respectively, in predicting AMR. Moreover, the analysis methods showed 62.5% agreement in predicting AMR for the E. coli isolates. Conclusions: Considering the multiple advantages of nanopore sequencing, the application of this rapid and field-feasible sequencing technique holds promise for rapid AMR monitoring in LMICs, including Nigeria. However, the development of a robust sequence analysis pipeline and the optimization of the existing analysis tools are crucial to streamline the deployment of nanopore sequencing in LMICs for AMR monitoring both in animal and human sectors. Full article

Escherichia coli (E. coli) is one of the most common strains that produce Shiga toxin, which can contaminate food and water, causing serious diseases and even endangering life. Therefore, the detection of E. coli is crucial for protecting public health. At present, most traditional methods have disadvantages such as long detection cycles, high cost, and complex operations. This article proposed a novel commercial Rayleigh surface acoustic wave (R-SAW) biosensor for the detection of trace amounts of E. coli, which utilized the coordination reaction between carboxyl (-COOH) groups and aluminum ions (Al³⁺) to form the bio-enhanced probes, enabling the 5-terminal -COOH-modified aptamers to be preferentially enriched and directionally immobilized on the electrode surface. The biosensor could complete the detection within 100 s, with a linear detection range of 10³–10⁸ cells/mL, a limit of detection (LOD) as low as 732 cells/mL, and a selectivity ratio of 3270:1. This article conducted spiked detection on six types of food, indicating that the biosensor had the advantages of rapid speed, high sensitive, wide detection range, low LOD, strong specificity, and low cost, providing an economical and convenient solution for detecting trace amounts of E. coli in food. Full article

Class IId bacteriocins are linear, unmodified antimicrobial peptides produced by Gram-positive bacteria, and often display potent, narrow-spectrum inhibition spectra. Garvicin Q (GarQ) is a class IId bacteriocin produced by the lactic acid bacterium Lactococcus garvieae. It stands out for its unusual broad-spectrum antimicrobial activity against various bacterial species, including Listeria monocytogenes, Pediococcus pentosaceus, Carnobacterium maltaromaticum, Enterococcus faecalis, and Lactococcus spp. Its protein target is the mannose phosphotransferase system (Man-PTS) of susceptible bacterial strains, though little is known about the precise molecular mechanism behind GarQ’s unusual broad spectrum of activity. In this work, ¹³C- and ¹⁵N-labelled GarQ was recombinantly produced using our previously described “sandwiched” protein expression system in Escherichia coli. We also developed a protocol to purify a uniformly labelled sample of the small ubiquitin-like modifier His₆-SUMO, which is produced as a byproduct of the expression procedure. We demonstrated its use as a “free” protein standard for 3D NMR experiment calibrations. The GarQ solution structure was solved using triple-resonance nuclear magnetic resonance (NMR) spectroscopy and was compared with the structures of other Man-PTS-targeting bacteriocins. GarQ adopts a helix–hinge–helix fold, which is contrary to its structural predictions according to AlphaFold 3. Full article

Background: While most Escherichia coli strains are harmless members of the gastrointestinal microbiota, certain pathogenic variants can cause severe intestinal and extraintestinal diseases. A notable outbreak of E. coli O104:H4, involving both enteroaggregative (EAEC) and enterohemorrhagic (EHEC) strains, occurred in Europe, resulting in symptoms ranging from bloody diarrhea to life-threatening colitis and hemolytic uremic syndrome (HUS). Since treatment options remain limited and have changed little over the past 40 years, there is an urgent need for an effective vaccine. Such a vaccine would offer major public health and economic benefits by preventing severe infections and reducing outbreak-related costs. A multiepitope vaccine approach, enabled by advances in immunoinformatics, offers a promising strategy for targeting HUS-causing E. coli (O104:H4 and O157:H7 serotypes) with minimal disruption to normal microbiota. This study aimed to design an immunogenic multiepitope vaccine (MEV) construct using bioinformatics and immunoinformatic tools. Methods and Results: Comparative proteomic analysis identified 672 proteins unique to E. coli O104:H4, excluding proteins shared with the nonpathogenic E. coli K-12-MG1655 strain and those shorter than 100 amino acids. Subcellular localization (P-SORTb) identified 17 extracellular or outer membrane proteins. Four proteins were selected as vaccine candidates based on transmembrane domains (TMHMM), antigenicity (VaxiJen), and conservation among EHEC strains. Epitope prediction revealed ten B-cell, four cytotoxic T-cell, and three helper T-cell epitopes. Four MEVs with different adjuvants were designed and assessed for solubility, stability, and antigenicity. Structural refinement (GALAXY) and docking studies confirmed strong interaction with Toll-Like Receptor 4 (TLR4). In silico immune simulations (C-ImmSim) indicated robust humoral and cellular immune responses. In Conclusions, the proposed MEV construct demonstrated promising immunogenicity and warrants further validation in experimental models. Full article

Chitosan is a natural biopolymer with intrinsic antimicrobial properties and strong metal ion chelating properties, making it an ideal matrix for the development of bioactive composites. In this study, silver and copper nanoparticles were synthesized using laser ablation in liquid (LAL) by the ablation of metallic targets into commercial chitosan (Cs) and chitosan produced from Hermetia illucens pupal exuviae (CsE) solutions, avoiding the use of chemical precursors or stabilizing agents. The nanocomposites obtained were characterized by UV–vis spectroscopy, TEM microscopy and FTIR spectroscopy in order to evaluate the size of the nanoparticles and the interactions between the polymer and metal nanoparticles. Antibacterial tests demonstrated the efficacy of Ag-based composites with a minimum inhibitory concentration (MIC) of 0.006 g/L, and Cu-based composites with a MIC of 0.003 g/L against both Escherichia coli and Micrococcus flavus. While the silver composites show antibacterial activity in both colloidal and film forms, the copper composites present antibacterial activity only in colloidal form. Swelling tests indicated that all films maintained a high water absorption capacity, with a swelling index over 200%, unaffected by nanoparticle integration. The results highlight the potential of LAL-synthesized metal–chitosan composites, particularly those based on insect chitosan, as sustainable and effective antimicrobial materials for biomedical and environmental applications. Full article

Grouper (Epinephelus sp.) is one of the most economically important aquaculture species in China and Southeast Asian countries. Nervous necrosis virus (NNV) infection causes significant mortality in grouper aquaculture. Detection of anti-NNV antibodies using the ELISA method has been reported as effective in preventing vertical transmission of NNV in sea bass and flounder. In this study, IgM antibodies were purified from the serum of groupers and subsequently used to immunize rabbits to obtain a secondary antibody. Additionally, the NNV capsid protein (CP) was cloned, over-expressed, and purified in Escherichia coli. Consequently, an ELISA method was developed to detect NNV-specific antibodies in groupers by utilizing purified recombinant NNV capsid protein (CP) and horseradish peroxidase (HRP)-labeled rabbit anti-grouper antibody. This ELISA system was applied in three asymptomatic grouper hatcheries in China, revealing significant variations in antibody levels. Our ELISA method can effectively detect NNV-specific antibodies and is simpler than other methods, making it suitable for subsequent large-scale applications in grouper. Full article

Salicornia europaea L. is a spontaneous halophytic plant, widespread in coastal environments, recognized for its high polyphenol content and bioactivities. In this study, a sustainable extraction strategy was developed by coupling natural deep eutectic solvents (NADESs) with ultrasound-assisted extraction (UAE) to recover bioactive compounds from autochthonous S. europaea collected in the Apulia region of southern Italy. Sixty-one NADES combinations were screened using COSMOtherm software, based on the predicted solubility of isorhamnetin, the major flavonol in Salicornia spp, to identify optimal hydrogen-bond donor (HBD) and acceptor (HBA) pairs. Six selected and prepared NADESs (B:CA, B:Suc, ChCl:U, ChCl:Xil, CA:Glc and Pro:MA) were used to extract S. europaea, and the resulting extracts were evaluated for total phenolic content (TPC), antioxidant capacity (DPPH, ABTS, FRAP) and antibacterial activity against four ATCC bacterial strains (Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus). Among the tested extracts, Pro:MA exhibited the highest TPC (6.79 mg GAE/g) and interesting antioxidant activity (DPPH IC₅₀ = 0.09 mg GAE/g; ABTS = 8.12 mg TE/g; FRAP = 2.41 mg TE/g). In the antibacterial assays, the Pro:MA extract demonstrated the highest activity, with minimum inhibitory concentrations (MICs) ranging from 0.1% to 0.4% v/v and minimum bactericidal concentrations (MBCs) from 0.2% to 0.8% v/v. In addition, the Pro:MA extract maintained TPC stability over a 90-day storage period. These findings support the NADES-UAE system as a green and efficient approach for the recovery of bioactive compounds and for the valorization of halophyte plants, such as S. europaea, with promising ready-to-use applications in the food, pharmaceutical and cosmeceutical sectors. Full article

Titanium and its alloys are widely used in orthopedics because of their excellent mechanical properties and biocompatibility; however, their bioinert surface results in sluggish osseointegration and renders implants susceptible to bacterial infection. This study innovatively constructed a “CHP-Ti-MAO” composite coating, which aims to simultaneously improve early osseointegration and antibacterial performance. CHP micron coatings coated with hydroxyapatite (HA) and curcumin (Cur) at different PLGA concentrations (50%, 100%, and 150%) were deposited on the basis of calcium–phosphorus ceramic coatings prepared by micro-arc oxidation (MAO) following the emulsification-solvent volatilization method. It was found that increasing the concentration of PLGA can increase the particle size of the coating, enhance the hydrophilicity, and significantly improve the sustained release performance of the drug. Among them, the 100% PLGA concentration group performed the best: the drug-release half-life reached 75 h, and the corrosion current density was the lowest (9.5 × 10⁻⁹ A/cm²), showing the best corrosion resistance. This group of coatings has a strong and long-term antibacterial effect on Escherichia coli, with an antibacterial rate of more than 95% at 24 h and more than 99% by day 17. The hemolysis rate of all coatings was lower than 5%, indicating good biocompatibility. This study confirmed that 100% CHP-Ti-MAO composite coating successfully solved the limitations of excessive pore size and insufficient antibacterial persistence of an MAO layer and also had excellent slow-release, corrosion resistance, and high-efficiency antibacterial capabilities, which provided an important basis for the development of a new generation of multifunctional titanium-based implants. Full article

In this work, polypropylene (PP) melt-blown nonwoven fabric was used as a raw material, which was plasma-treated and grafted with HBP/Ag nanoparticle (NP) solution. The surface wettability, surface morphology, and surface element composition after the treatment were evaluated through a contact angle test, field emission scanning electron microscopy (FE-SEM), energy-dispersive spectrometer (EDS), and Fourier transform infrared spectroscopy (FTIR), respectively. The antibacterial activity of PP fabrics treated with Ag NPs against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was measured. SEM and EDS results showed that Ag NPs were evenly dispersed on the surface of the PP fabrics. The PP fabrics treated with Ag NPs exhibited excellent antibacterial performance. Full article

The present study investigates the antimicrobial, antioxidant, and in vitro antidiabetic potential of cold infusions prepared from different parts of the Greek carob tree (Ceratonia siliqua L.), which is a xerophytic species. Carob samples, including green and ripe pods and leaves, were collected from an urban area of Attica, Greece, and extracted using food-grade solvents (water and a water–ethanol mixture, 90:10, v/v). The extracts were evaluated for antibacterial activity against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538 using automated turbidometry. In addition, total phenolic content and antioxidant and antiradical activities were determined via spectrophotometry; the phenolic profile was analyzed using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QToF-MS), and α-amylase inhibitory activity was assessed through an in vitro assay. All extracts exhibited statistically significant (p < 0.05) bacteriostatic effects, with green pods and leaves showing the highest activity. Ripe pods demonstrated the most potent α-amylase inhibition (up to 96.43%), especially when extracted with water–ethanol mixture (90:10, v/v). Liquid chromatography coupled with tandem quadrupole/time-of-flight mass spectrometry (LC-QToF-MS) analysis revealed a rich phenolic profile across all samples. While carob leaves showed no α-amylase inhibition, their phenolic profile suggests other potential health-related bioactivities. These findings support the development of carob-based functional food products and highlight the nutritional and pharmaceutical potential of this resilient Mediterranean crop. Full article

This study aimed to develop innovative functional gummy candies enriched with protein hydrolysates derived from porcine liver, enhancing their antioxidant and antimicrobial properties. First, the overall consumer acceptability (OA) was assessed to determine the most suitable combination of gummy matrix components. Selected combinations were then analyzed for antioxidant activity (ABTS•+, DPPH•), antimicrobial effects, microbiological safety, and physicochemical characteristics. The incorporation of liver hydrolysates significantly increased antioxidant capacity. The highest activity was observed in sample GC5Pa24Ag, hydrolyzed with papain for 24 h and formulated with agar, showing ABTS•+ and DPPH• scavenging activities of (67.6 ± 0.98 µmol/g) and (49.14 ± 1.00%), respectively (p ≤ 0.05). Pepsin hydrolyzed samples (GC2Pe3Gl, GC2Pe6Gl, GC2Pe24Gl) exhibited significantly larger inhibition zones against Listeria monocytogenes ATCC 13932, Escherichia coli ATCC 25922, and Salmonella enterica subsp. enterica serovar Typhimurium ATCC 14028 compared to the control (p < 0.05). Among all, GC5Pa24Ag demonstrated the broadest antimicrobial activity, with a 29.0 ± 0.2 mm inhibition zone against all tested pathogens. These findings suggest that porcine liver hydrolysates can be successfully incorporated into confectionery products to create functional gummies with potential health benefits, offering antioxidant protection and antimicrobial effects in a consumer-friendly form. Full article

Dehydroshikimate (DHS) dehydratase (DSD) catalyzes the conversion of DHS into 3,4-dihydroxybenzoic acid (3,4-DHBA), a compound with promising applications across various industries. The DSD from Podospora anserina (DSD_Pa) was characterized and its catalytic properties were compared with those of previously investigated enzymes, AsbF (Bacillus thuringiensis), Qa-4 (Neurospora crassa), and QsuB (Corynebacterium glutamicum), both in vitro and in vivo using tube fermentation. Escherichia coli and C. glutamicum were used as platforms to construct model 3,4-DHBA producers. To increase DHS availability in both hosts, shikimate dehydrogenase AroE was inactivated, and the plasmid pVS7-aroG4, encoding 3-deoxy-D-arabinoheptulosonate 7-phosphate synthase (E. coli), was introduced. In E. coli, heterologous 3,4-DHBA synthesis was achieved through chromosomal integration of dsd genes. The fungal genes were codon-optimized for this bacterium. The same genes were cloned into the pVK9 vector and introduced into C. glutamicum, where 3,4-DHBA degradation was disrupted (ΔpcaHG). AsbF (k_cat ~ 1 s⁻¹) showed poor 3,4-DHBA accumulation in both hosts (1–1.5 g/L). The enzymes with better catalytic characteristics, QsuB (k_cat ~ 60 s⁻¹), DSD_Pa (k_cat ~ 125 s⁻¹), and Qa-4 (k_cat ~ 220 s⁻¹), provided 5 g/L 3,4-DHBA in E. coli and 3 g/L 3,4-DHBA in C. glutamicum, except for Qa-4. The low production (~1.5 g/L) observed for Qa-4 in C. glutamicum might be attributed to a non-optimal nucleotide sequence rich in codons rare for C. glutamicum. Full article

Water quality monitoring is a key requirement for fulfilling various national environmental policies, but with many competing needs and limited resources, data collected can suffer from both spatial and temporal deficiencies. Modelling offers the potential to substitute estimated values into observational gaps, but model validation often requires the very data that are lacking. In this paper we present the results of a pilot study to investigate spatial and temporal issues around the monitoring of faecal indicator bacteria (Escherichia coli) in rivers of the Taw and Torridge catchments in the UK. Statistical analysis of in situ measurements versus simulated data from the catchment models reveals similar seasonal associations between riverine bacterial counts and rainfall patterns. Furthermore, spatial apportionment of livestock to better reflect land use was found to be important in the models, especially in upstream reaches of the catchments. In conclusion, successful monitoring of faecal bacteria levels in UK rivers requires risk-based monitoring (sufficient to identify possible seasonal trends) and informed spatial consideration of sampling sites. Catchment models can be useful aids for directing and augmenting such monitoring programmes, but these models should undergo rigorous validation, particularly in upper catchment areas, to ensure correct model response to changes in land use and/or climate. Full article