Search Results (950)

Transdermal hydrogel films were fabricated from gellan gum, chitosan, and agar–agar, employing glutaraldehyde as a covalent crosslinker. The obtained formulation exhibited structural stability, pH-sensitive swelling, and high biocompatibility without the participation of metal ions. FTIR spectra showed the emergence of a characteristic imine (C=N) vibration near 1630 cm⁻¹, confirming covalent network formation through Schiff-base reactions. SEM imaging revealed a homogeneous porous architecture (45–120 μm) that enhances moisture absorption and molecular diffusion. The swelling ratio reached 410 ± 12% at pH 9.18 and 275 ± 9% at pH 4.01, evidencing pronounced pH responsiveness. Mechanical strength measured 0.82 ± 0.03 MPa with elongation of 42 ± 2%, ensuring flexibility for skin application. The temperature-controlled release of methylene blue achieved 78 ± 4% at 40 °C after 24 h, consistent with diffusion-limited transport. This gellan–chitosan–agar hydrogel network crosslinked with glutaraldehyde represents a stable, pH-responsive, and biocompatible platform suitable for wound care and transdermal drug delivery. Full article

Biodegradable packaging based on starch–polycaprolactone (PCL) composites is a promising route to reduce reliance on petroleum-derived plastics. Here, wheat starches with A- and B-type crystallinity—sourced from Kazakhstani varieties—were dual-modified by electron-beam irradiation followed by acetylation and incorporated into PCL (30–50 wt%) via melt extrusion and compression molding. The resulting films were characterized for morphology, mechanical performance, water-vapor permeability (WVP), thermal behavior, antibacterial activity, and biodegradation under soil and composting conditions. Acetylated A-type starch dispersed more uniformly within the PCL matrix, yielding smoother surfaces, higher tensile strength, and moderate WVP. In contrast, B-type starch produced a more porous microstructure with increased WVP and accelerated mass loss during composting (up to ~45% within 10 days at higher starch loadings). Incorporation of starch slightly decreased thermal stability relative to neat PCL, while agar-diffusion assays against Escherichia coli and Staphylococcus aureus showed loading-dependent inhibition zones, with A-type composites generally outperforming B-type at equivalent contents. Taken together, A-type starch–PCL films are better suited for applications requiring mechanical integrity and controlled moisture transfer, whereas B-type systems favor breathable packaging and rapid compostability. These results clarify how starch crystalline type governs structure–property–degradation relationships in PCL composites and support the targeted design of sustainable packaging materials using regionally available starch resources. Full article

A comparative study was performed between some waste materials to assess their ability to produce natural pigment from Bacillus subtilis KU710517 isolated from the marine sponge Pseudoceratina arabica. Bacillus subtilis KU710517 was able to produce a yellowish-brown pigment with wheat bran and molokhia stems in both water and synthetic media. Some factors affecting the pigment production by Bacillus subtilis KU710517 were studied. The pigments produced had been assessed for their use in dyeing wool fabrics (at a liquor ratio of 50:1 across various pH levels), and the color strength values of samples were examined. The highest color strength value of dyed wool fabrics was obtained when using water containing 6% molokhia stems (K/S 6.98) for 2 days at pH 9. Also, good fastness properties were obtained with molokhia stems. Therefore, the yellowish-brown pigment produced from Bacillus subtilis KU710517 is highly appropriate for dyeing and printing wool textiles and serves as a safe alternative to synthetic dyes that create environmental issues. Moreover, using waste materials and water in the production of dye is an economical and ecofriendly method. HPLC analysis of the pigment produced from molokhia stems in a water medium indicated the presence of rutin and syringic acid, which are responsible for the yellowish-brown color. The antimicrobial properties of the produced pigment were examined with the cup agar diffusion technique. Nutrient agar plates were inoculated with 0.1 mL of 105–106 cells/mL of yeast and bacteria. Czapek-Dox agar plates were heavily inoculated with 0.1 mL (106 cells/mL) of fungal culture. 100 microliters of the dye sample were added to each cup. The pigment showed considerable antimicrobial activity against bacteria, yeast, and fungi and displayed the strongest antimicrobial activity against E. coli (28 mm zone of inhibition). Therefore, the produced pigment can be used in the pharmaceutical field, especially in the dyeing of surgical dressings and clothing. Full article

Bacterial cellulose (BC) hydrogel is a promising skin wound healing biomaterial due to its unique properties, including a moist environment that facilitates tissue healing. To enhance its antimicrobial efficacy, BC dressings were loaded with penicillin and streptomycin. FT-IR analysis confirmed successful drug binding, while SEM revealed a nanofibrous and porous hydrogel structure. In vitro studies using 3T3 mouse fibroblasts demonstrated biocompatibility, and scratch wound assays achieved complete closure across all tested concentrations. Antibacterial activity, assessed via agar diffusion against Pseudomonas aeruginosa and Staphylococcus aureus, showed a concentration-dependent increase in inhibition zones, highlighting the potential of BC-Pen/Strep hydrogels as effective antimicrobial wound dressings. Full article

Background: Antibiotic resistance is spreading, and the effectiveness of the most widely used antibiotics is decreasing. These issues are global health and food safety concerns that require immediate attention. One potential solution is the use of various gemmotherapy extracts (GTEs). However, there is a paucity of studies investigating the presumptive antimicrobial activity of GTEs. Methods: In this comparative study, we are assessing the antimicrobial properties of eight selected GTEs, as well as their polyphenol content and antioxidant activity, against a panel of microorganisms (Gram-positive and Gram-negative bacteria, yeasts, and molds). We are using the agar diffusion method (ADM) and the broth microdilution method (BMD) to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Results: Among the analyzed extracts, dog rose, lingonberry, sea buckthorn, blackthorn, and common grape GTEs showed the highest total phenolic content, antioxidant activity, and the most relevant antimicrobial activity including certain differences with respect to the microbiostatic and/or microbicidal properties. These results demonstrate the relative strength of the antimicrobial effects of specific GTEs against certain microbial species, which could facilitate the use of these GTEs in personalized and/or specific antimicrobial therapies. Full article

Background: The emergence of extended-spectrum β-lactamase (ESBL) producing and colistin-resistant Escherichia coli in retail meat poses a significant public health risk. Method: A total of 180 retail meat samples (chicken parts, internals, processed products; lamb; beef; fish) were purchased from markets and butcher shops across Turkiye. Presumptive ESBL-producing isolates were screened on chromogenic agar and phenotypically confirmed. Species identity was verified by uspA PCR, and resistance genes (blaCTX-M, blaTEM, blaOXA, blaSHV, mcr-1, mcr-2, mcr-3) were analyzed. Colistin MICs were determined by broth microdilution, while antimicrobial susceptibility of ESBL-positive isolates was assessed by disk diffusion. Results: Overall, ESBL-producing E. coli were detected in 21.7% (n = 39) of the 180 meat samples analyzed, with the highest prevalence observed in chicken parts (26/40, 65.0%) and giblets (6/10, 60%). All ESBL-E. coli isolates harbored blaCTX-M, with blaCTX-M-1 identified as the sole variant. The blaTEM gene was detected in 61.5% (24/39) of ESBL-positive E. coli isolates. Colistin resistance was identified in six isolates (15.4%), all of which carried the mcr-1 gene. Additionally, one lamb minced meat isolate harbored the mcr-2 gene. Co-occurrence analysis revealed that the most frequent resistance gene combination among ESBL-producing isolates was blaCTX-M1 + blaTEM, detected predominantly in chicken meat samples, while mcr-1 was observed only in isolates harboring single or limited resistance genes, suggesting a distinct acquisition pattern. Conclusions: A high prevalence of blaCTX-M-1 and the co-occurrence of mcr genes were detected in E. coli isolates from retail meat, particularly poultry. The detection of mcr-1/mcr-2 co-carriage in lamb meat, though rare, highlights the need for broader surveillance. These findings underscore the need for integrated monitoring and prudent antimicrobial use in food animals. The use of antibiotics as growth promoters is prohibited in Türkiye, and therapeutic applications require a veterinary prescription; however, stronger enforcement remains essential to limit the dissemination of multidrug-resistant bacteria in the food chain. Full article

Thai medicinal flowers, namely Mesua ferrea L. (Bunnak), Mammea siamensis T. Anderson (Saraphi), and Clitoria ternatea (Anchan) have long been valued for their traditional medicinal. This study investigated their phytochemical composition and bioactivities, with a particular focus on antioxidant and antibacterial properties. Methods: Ethanolic flower extracts were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC–MS). Antioxidant activities were determined by DPPH, ABTS, and FRAP assays. Antibacterial activity against Escherichia coli, E. coli O157:H7, Salmonella Typhi, Shigella dysenteriae, and Vibrio cholerae were assessed by agar well diffusion, broth dilution methods, and time–kill assays. Biofilm formation, biofilm disruption, and bacterial adhesion to Caco-2 cells were evaluated. Morphological changes in E. coli O157:H7 were examined using scanning electron microscopy (SEM), and leakage of intracellular contents (DNA, RNA, proteins) were quantified. Results: HPLC analysis revealed the highest level of gallic acid in M. ferrea and quercetin in M. siamensis. LC–MS analysis identified fifteen putative metabolites across the flower extracts, including quercetin, kaempferol, catechin, and luteolin derivatives, with species-specific profiles. C. ternatea extract exhibited the greatest total flavonoid content and antioxidant activity. Among the extracts, M. ferrea exhibited the strongest inhibitory effect, with inhibition zone of 13.00–15.00 mm and MIC/MBC values of 31.25–62.5 mg/mL. All extracts exhibited time-dependent bactericidal activity, significantly inhibited biofilm formation, disrupted established biofilms, and reduced bacterial adhesion to intestinal epithelial cells. SEM revealed membrane disruption in E. coli O157:H7 and leakage of intracellular components. Conclusions: Thai medicinal flower extracts, particularly M. ferrea, possess strong antioxidant and antibacterial activities. Their ability to inhibit biofilm formation, interfere with bacterial adhesion, and disrupt bacterial membranes highlights their potential as natural alternatives for preventing or controlling enteric bacterial infections. Full article

The role of petting zoo animals in the dissemination of disease has been widely studied, yet understanding the potential reservoir of antimicrobial resistance (AMR) in these centres has not been explored in the United Kingdom (UK). To understand the carriage of AMR pathogens within petting zoos, this study aimed to identify AMR in E. coli and Staphylococcus intermedius group (SIG) isolated from faeces and skin, respectively, including selective cultures for ESBL-E. coli and methicillin-resistant staphylococci. Faecal samples and skin swabs were collected from 166 petted mammals across eight UK centres to recover E. coli and coagulase-positive staphylococci (CoPS), respectively, through enrichment culture methods, plating onto non-selective (tryptone bile-x agar, mannitol salt agar) and selective media (ESBL ChromID, mannitol salt agar with 6 mg/L oxacillin). Antimicrobial susceptibility was assessed using Kirby-Bauer disc diffusion, covering eight classes of antimicrobials. Antimicrobial usage records from the past 12-months were obtained from 7/8 centres. Overall, 145/166 faecal samples yielded 223 E. coli isolates, with an overall AMR prevalence of 42.6%. Thirteen E. coli isolates (from 8.5% of animals) were classified as multidrug-resistant. ESBL-producing E. coli were detected in 5/166 faecal samples. From 166 skin swabs, 84 yielded CoPS isolates, with S. aureus (n = 70), SIG (n = 13) and S. hyicus (n = 1) identified. Overall, 25.3% of SIG isolates exhibited resistance to at least one antimicrobial. Antimicrobial usage correlated positively with AMR prevalence for E. coli (p < 0.001), though was not associated with multidrug-resistance. This study demonstrates for the first time the presence of AMR within bacteria isolated from UK petting zoo animals, highlighting this reservoir of AMR bacteria. Full article

Recently, the search for new antimicrobial compounds, including the secondary metabolites of basidiomycetes, has become increasingly important. Representatives of this division of higher fungi have high biosynthetic abilities, which contributes to their use as producers. In this work, extracts of culture liquids and submerged mycelia from 18 strains representing three different orders of basidiomycetes were studied. For this purpose, the submerged cultivation of strains, extraction of biological material, and evaluation of the extract’s antimicrobial activity using the agar well diffusion method were carried out. The minimum inhibitory concentration was determined for extracts with strong activity. The most promising ones were analyzed using HPLC-MS. As a result, it was found that 16 strains contained antimicrobial metabolites. Thus, the strains selected for further work were Hericium corraloides 4, which showed not only the antibacterial but also antifungal activity of cultural liquid and submerged mycelia extracts, and Fomitopsis betulina 3, Fomitopsis pinicola 2, Hericium erinaceus 1, and Laetiporus sulphureus 4, whose cultural liquid extracts exhibited high antibacterial activity against Gram-positive and Gram-negative test cultures. For these strains, metabolic profiles were obtained using the method HPLC-MS. Using this method, two metabolites were preliminary identified: hericerin in H. erinaceus 1 and sulfureuine H in L. sulphureus 4. Full article

Background/Objectives: Fungal colonization and biofilm formation on intrauterine device (IUD) strings are known to contribute to recurrent infections and decreased contraceptive efficacy. This study aims to develop a novel approach to prevent Candida reservoir and biofilm formation on IUD strings, thereby lowering the risk of IUD-associated vulvovaginal candidiasis (VVC). Methods: Cervicovaginal samples were collected from human cervix using a sterile cytobrush, avoiding microbial contamination. Cytological examination using the Papanicolaou method was performed to detect the presence of Candida. The antifungal effect of the essential oils (EOs) was determined by broth dilution and disk diffusion methods. Antifungal and biofilm inhibitory effects of Thymus zygis (Tz) EO-coated IUD strings were determined by agar diffusion and crystal violet binding assays, while fungal growth on the coated strings was assessed using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) analysis. Results: Tz EO exhibited significantly lower minimum inhibitory concentration (MIC ≤ 0.06 µL/mL) and minimum fungicidal concentration (MFC = 0.24 µL/mL) values compared to Melaleuca alternifolia (Ma) EO (MIC > 0.24 µL/mL, MFC = 1.95 µL/mL), along with larger zones of inhibition (ZOI) against both Candida albicans (110.0 ± 6.0 mm vs. 91.3 ± 7.0 mm) and Candida glabrata (84.0 ± 13.1 mm vs. 50.0 ± 9.2 mm), indicating a stronger antifungal potential. On IUD strings coated with 4% (40 μL/g) Tz EO in hypromellose ointment, the biofilm formation of both C. albicans and C. glabrata strains was inhibited by 58.9% and 66.7%, respectively, as confirmed by SEM and EDX. Conclusions: Tz EO-coated IUD strings effectively inhibit Candida growth, suggesting a promising natural strategy to reduce recurrent IUD-associated fungal infections. However, before these results can be translated to clinical practice, additional research is needed. Future investigations may encompass an extended number of Candida isolates, stability and release studies of the EO in relation to the formulation, toxicity to vaginal mucosa, epithelial cells and sperm motility, and the effect on vaginal microbiotia. Full article

This research prepared and characterised novel mixed coordination complexes derived from escitalopram with eugenol and curcumin to form (L₁) and (L₂), respectively. The complexes were prepared via Williamson ether synthesis and analysed by FTIR, UV–Vis, ¹H-NMR spectroscopy, elemental analysis, molar conductivity, and magnetic susceptibility. The results confirmed their octahedral geometries. Magnetic investigation reported high-spin configurations for Mn(II), Co(II), and Ni(II) complexes, whereas Cu(II) exhibited a distorted octahedral arrangement with characteristic d–d transitions. In addition, the calculation of Density functional theory (DFT) provided more insight into the detailed structural and electronic properties of the new ligand and its complexes. Antimicrobial compounds were evaluated against Escherichia coli, Staphylococcus aureus, and Candida albicans through the agar well diffusion method. The reported results revealed that Cobalt complexes showed antimicrobial activity followed by Copper (Cu), Nickel (Ni) and Manganese(Mn) complexes, respectively, due to an increase in Co-lipophilicity, which leads to improved diffusion through microbial cell membranes. The research findings confirmed that escitalopram-based mixed ligands coordinate with transition metals and could have significant biological applications. Full article

This study evaluated the antibacterial efficacy and growth-promoting potential of Moringa oleifera and Thymus vulgaris methanolic extracts in broiler chickens challenged with Escherichia coli O78. In vitro antibacterial screening using agar well diffusion and disc diffusion assays revealed that ciprofloxacin exhibited the strongest inhibitory effect, followed by tetracycline and enrofloxacin, whereas among plant extracts, T. vulgaris was more effective than M. oleifera. The optimal combination (M100T150; 100 mg M. oleifera + 150 mg T. vulgaris) produced the largest inhibition zones against E. coli strains. For the in vivo trial, 540 Ross-308 broiler chicks were distributed into six treatment groups in a completely randomized design and reared for 42 days. Parameters assessed included growth performance, carcass traits, gut pH, ileal microbial counts, and intestinal histomorphology. Results showed that E. coli challenge significantly reduced feed intake, weight gain, carcass yield, and villus integrity while increasing FCR and E. coli counts (p < 0.05). Addition of plant extracts, particularly M100T150, significantly improved weight gain, FCR, Broiler Performance Efficiency Factor (BPEF), and Broiler Farm Economy Index (BFEI) compared to the positive control (p < 0.05). Extracts reduced duodenal and jejunal pH (p < 0.001), suppressed E. coli counts (p = 0.003), and enhanced Lactobacillus populations (p = 0.0004). Histological analysis revealed that extract-supplemented groups had greater villus height and surface area with shallower crypts than the positive control, indicating restoration of gut integrity. These findings suggest that methanolic extracts of M. oleifera and T. vulgaris, particularly in combination, can serve as natural alternatives to antibiotics in broiler production under pathogenic challenge. Full article

Background: Urinary tract infections (UTIs) are among the most common hospital- and community-acquired infections, creating a substantial healthcare burden due to recurrence, complications, and rising antimicrobial resistance. Accurate diagnosis and timely antimicrobial therapy are essential. This study aimed to identify trends in the etiology, treatment, and resistance patterns of UTIs through a retrospective analysis of urine isolates processed at the Laboratory of Microbiology at University Hospital St. George in Plovdiv, the largest tertiary care and reference microbiology center in Bulgaria, between 2017 and 2022. Materials and Methods: A retrospective single-center study was performed at the hospital’s Microbiology Laboratory. During the study period, 74,417 urine samples from 25,087 hospitalized patients were screened with the HB&L UROQUATTRO system. Positive specimens were cultured on blood agar, Eosin-Methylene Blue, and chromogenic media. Identification was performed using biochemical assays, MALDI-TOF MS, and the Vitek 2 Compact system. Antimicrobial susceptibility testing included disk diffusion, MIC determination, broth microdilution (for colistin), and Vitek 2 Compact, interpreted according to EUCAST standards. Descriptive analysis and temporal resistance trends were evaluated with regression models, and interrupted time-series analysis was applied to assess COVID-19-related effects. Results: Out of 10,177 isolates, Gram-negative bacteria predominated (73%), with Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis as the leading pathogens. Among Gram-positives, Enterococcus faecalis was the most frequent. In the post-COVID-19 period, ESBL production increased in E. coli (34–38%), K. pneumoniae (66–77%), and P. mirabilis (13.5–24%). Carbapenem resistance rose in K. pneumoniae (to 40.6%) and P. aeruginosa (to 24%), while none was detected in E. coli. Colistin resistance increased in K. pneumoniae but remained absent in E. coli and P. aeruginosa. High-level aminoglycoside resistance in E. faecalis was stable (~70%), and vancomycin resistance in E. faecium rose from 4.6% to 8.9%. Conclusions: Both community- and hospital-acquired UTIs in Southeastern Bulgaria are increasingly linked to multidrug-resistant pathogens, particularly ESBL-producing and carbapenem-resistant Enterobacterales. Findings from the region’s largest referral center highlight the urgent need for continuous surveillance, rational antibiotic use, and novel therapeutic approaches. Full article

Background/Objectives: Periradicular disease is largely microbial in origin. Even gutta-percha (GP) cones manufactured under aseptic conditions can acquire contaminants during handling or storage, undermining otherwise adequate canal preparation. To assess residual antimicrobial activity on GP cones after brief exposure to five endodontic disinfectants: sodium hypochlorite (NaOCl) 1%, 2.5%, 5.25%; chlorhexidine (CHX) 2%; and glutaraldehyde 2% against Enterococcus faecalis and Candida albicans. Methods: Standardized GP cones were dipped for 5–120 s, blotted on neutralizing gauze, and placed on agar inoculated with either organism. Using an agar diffusion approach, inhibition-zone diameters were recorded at 0, 24, and 48 h. Data were summarized using descriptive statistics (means, standard deviations, and 95% confidence intervals) for each disinfectant–dip-time combination. Results: By 24 h, inhibition zones were observed for most disinfectants; for C. albicans, glutaraldehyde 2% showed no measurable effect. At later time points, performance depended on both disinfectant and contact time. For E. faecalis, NaOCl 2.5% and 5.25% yielded the largest zones at 48 h (20–21 mm at 120 s), whereas NaOCl 1% was smaller (10 mm) and glutaraldehyde 2% modest (9 mm). For C. albicans, NaOCl 2.5% and CHX 2% were most effective at 48 h (17–19 mm at 120 s); NaOCl 5.25% was intermediate, NaOCl 1% weak, and glutaraldehyde 2% showed no measurable antifungal effect. Longer immersions (≥45 s) consistently increased inhibition zone diameters. Conclusions: Residual antimicrobial activity on GP cones depends on both the agent and the immersion time. For E. faecalis, higher concentration NaOCl produced the largest zones at short contact time, whereas for C. albicans, CHX 2% and NaOCl 2.5% provided the most reliable carryover. Selecting an appropriate concentration and allowing sufficient dip time may reduce reinfection risk at obturation. Full article

Bacillus cereus sensu lato is widespread and causes significant food spoilage that alters the flavour and structure of milk. The present study investigated the prevalence, enterotoxigenic genes, and resistant profiles of B. cereus strains isolated from raw milk of Bos taurus in South Africa (the Eastern Cape Province). One thousand four hundred samples were obtained from commercial dairy farms and were evaluated for the presence of B. cereus using B. cereus selective agar, and genomic DNA was isolated from B. cereus colonies with specific characteristics. PCR was used to evaluate the presence of enterotoxigenic genes, and antibacterial susceptibility was carried out using the Kirby-Bauer Disc diffusion method. The result revealed that B. cereus was detected in 250 raw milk samples. In addition, 67.2% of the isolates grew when incubated at 4 °C. Among the enterotoxigenic genes studied, ces showed the highest occurrence (88.8%), but hblABC (0%) did not demonstrate amplification from any isolate. Our analysis found two significant patterns (III and V): nheABC-entFM (27.2% and 24.4%) and the ces gene. Total (100%) sensitivity was observed for six of the twelve antibiotics tested, while organisms showed complete resistance to penicillin and rifampicin. This study marks the initial documentation of B. cereus and its enterotoxigenic genes in Bos taurus raw milk sourced from the Eastern Cape Province, South Africa. Enterotoxin FM should be considered the second most crucial enterotoxin, after non-hemolytic enterotoxin, and should be included in the molecular approach used to classify pathogenic B. cereus in nutrimental products. These findings underscore the urgent need for public health awareness, particularly in rural communities where raw milk consumption is prevalent. The high prevalence of antibiotic resistance and toxigenic strains of B. cereus calls for improved milk pasteurization practices to mitigate the risk of foodborne illness. Full article