Search Results (201)

The efficacy of peracetic acid (0.05%, 0.5%, and 1%), sodium hypochlorite (0.2%, 0.6%, and 1%), and benzalkonium chloride (0.3%, 1.15%, and 2%) was evaluated against Staphylococcus aureus (ATCC 6538), Salmonella enterica serovar Typhimurium, (ATCC 14028), Enterococcus hirae (ATCC 8043), Pseudomonas aeruginosa (ATCC 9027), Escherichia coli (ATCC 9027), and Listeria monocytogenes (ATCC 35152) using stainless steel discs, following European Committee for Standardization (CEN) guidelines. According to CEN, a sanitizer must achieve at least a 5 Log₁₀ CFU reduction to be considered effective. Peracetic acid at 1% demonstrated the highest inactivation capacity, reducing all tested strains by more than 7 Log₁₀ CFU/mL. P. aeruginosa (ATCC 9027) showed high tolerance to sodium hypochlorite and benzalkonium chloride, with reductions below 2 Log₁₀ CFU/mL even at maximum concentrations. Both sodium hypochlorite and benzalkonium chloride, at their highest tested concentrations, effectively inactivated S. aureus, S. typhimurium, E. hirae, L. monocytogenes, and E. coli, achieving reductions greater than 7 Log₁₀ CFU/mL. Overall, sanitizers were effective only at intermediate or maximum concentrations recommended by the manufacturers, suggesting that minimum label concentrations should be avoided to ensure microbiological control. Full article

This study reports the preparation of benzalkonium chloride-modified montmorillonite (MMT-1227) via a wet chemical method and systematically investigates its structural characteristics and antimicrobial/antifungal properties. The modified montmorillonite was comprehensively characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET) surface area analysis. The results confirmed the successful intercalation of benzalkonium chloride into montmorillonite layers, leading to altered surface morphology, increased interlayer spacing, and enhanced hydrophobicity. Antimicrobial assays demonstrated that MMT-1227 exhibits potent activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, with inhibition zone diameters of 15.6 ± 0.2 mm and 17.7 ± 0.2 mm, respectively, and minimum inhibitory concentrations (MIC) of 1 mg/mL and 0.5 mg/mL. When incorporated into latex paint at a mass fraction of 0.3%, MMT-1227 achieved a 99.9% antibacterial rate against both strains after 24 h. Additionally, fungal resistance testing in accordance with GB/T 1741-2020 revealed that the modified paint films completely inhibited the growth of eight common mold strains (e.g., Aspergillus niger, Trichoderma viride), achieving a resistance grade of 0. These findings validate that benzalkonium chloride modification endows montmorillonite with excellent antimicrobial and antifungal properties, highlighting its potential as a high-performance additive for functional coatings and related antimicrobial materials. Full article

Background: Trichosporon spp. are opportunistic fungi, capable of causing infection, especially in critically ill individuals who often use broad-spectrum antibiotics, invasive devices, and have comorbidities. Objectives The aim of this study was to analyze individuals’ clinical characteristics, evaluate tolerance to biocides, as well as biofilm formation and efflux pump activity in isolates of Trichosporon asahii. Methods: Clinical isolates of T. asahii collected between 2020 and 2023 from both hospitalized and non-hospitalized individuals, of both sexes, regardless of age, were tested for tolerance to sodium hypochlorite, hydrogen peroxide, benzalkonium chloride, and ethyl alcohol. Efflux pump activity was also assessed using ethidium bromide, and biofilm formation was measured with the Safranin test. Clinical parameters such as outcomes, source, and length of hospitalization were analyzed through electronic medical records. Results: A total of 37 clinical isolates of T. asahii were identified. Thirty-three (83.8%) isolates were from hospitalized individuals, with 81.82% collected in ICUs, an average hospital stay of 35 days, and a mortality rate of 51.6%. The tested strains displayed the largest mean inhibition zone for 2% sodium hypochlorite, indicating lower tolerance. A high level of efflux pump expression was detected among clinical isolates. Biofilm formation was detected in 25/67.5% of the isolates. Conclusions: These findings highlight the clinical relevance of T. asahii, particularly in critically ill individuals, and underscore the pathogen’s ability to tolerate biocides, express efflux pumps, and form biofilms, all of which may contribute to its persistence and pathogenicity in hospital environments. Enhanced surveillance and effective microbial control measures are essential to mitigate the risks associated with T. asahii infections. Full article

As the primary biological risk threatening safe dairy production, bovine mastitis control highly relies on environmental disinfection measures. However, the mechanisms by which chemical disinfectants influence host–environment microbial interactions remain unclear. This study systematically investigated the disinfection efficacy and regulatory effects on microbial community composition and diversity of glutaraldehyde-benzalkonium chloride (BAC) and glutaraldehyde-didecyl dimethyl ammonium bromide (DAB) at recommended concentrations (2–5%), using 80 environmental samples from intensive dairy farms in Xinjiang, China. Combining 16S rDNA sequencing with culturomics, the results showed that BAC achieved a disinfection rate of 99.33%, higher than DAB’s 97.87%, and reduced the environment–gut microbiota similarity index by 23.7% via a cationic bacteriostatic film effect. Microbiome analysis revealed that BAC selectively suppressed Fusobacteriota abundance (15.67% reduction) and promoted Bifidobacterium proliferation (7.42% increase), enhancing intestinal mucosal barrier function through butyrate metabolism. In contrast, DAB induced Actinobacteria enrichment in the environment (44.71%), inhibiting pathogen colonization via bioantagonism. BAC’s long-acting bacteriostatic properties significantly reduced disinfection costs and mastitis incidence. This study first elucidated the mechanism by which quaternary ammonium compound (QAC) disinfectants regulate host health through “environment-gut” microbial interactions, providing a critical theoretical basis for developing precision disinfection protocols integrating “cost reduction-efficiency enhancement-risk mitigation.” Full article

Urogenital schistosomiasis, caused by Schistosoma haematobium and transmitted by Bulinus snails, affects approximately 190 million individuals globally and remains a major public health concern. Effective surveillance of snail vectors is critical for disease control, but traditional identification methods are time-intensive and require specialized expertise. Environmental DNA (eDNA) detection using qPCR has emerged as a promising alternative for large-scale vector surveillance. To prevent eDNA degradation, benzalkonium chloride (BAC) has been proposed as a preservative, though its efficacy with schistosomiasis snail vectors has not been evaluated. This study tested the impact of BAC (0.01%) on the stability of Bulinus truncatus eDNA under simulated field conditions. Water samples from aquaria with varying snail densities (0.5–30 snails/L) were stored up to 42 days with BAC. eDNA detection via qPCR and multivariable linear mixed regression analysis revealed that BAC enhanced eDNA stability. eDNA was detectable up to 42 days in samples with ≥1 snail/L and up to 35 days at 0.5 snails/L. Additionally, a positive correlation between snail density and eDNA concentration was observed. These findings support the development of robust eDNA sampling protocols for field surveillance, enabling effective monitoring in remote areas and potentially distinguishing between low- and high-risk schistosomiasis transmission zones. Full article

Background/Objectives: Non-invasive central nervous system (CNS) therapies are limited by complex mechanisms and the blood–brain barrier, but nasal delivery offers a promising alternative. The study planned to develop a non-invasive in situ intranasal mucoadhesive thermosensitive gel to deliver CNS-active risperidone via nose-to-brain targeting. Risperidone, a second-generation antipsychotic, has shown efficacy in managing both psychotic and mood-related symptoms. The mucoadhesive gel formulations help to prolong the residence time at the nasal absorption site, thereby facilitating the uptake of the drug. Methods: The poloxamer 407 (18.0% w/v), HPMC K100M and K15M (0.3–0.5% w/v), and benzalkonium chloride (0.1% v/v) were used as thermosensitive polymers, a mucoadhesive agent, and a preservative, respectively, for the development of in situ thermosensitive gel. The developed formulations were evaluated for various parameters. Results: The pH, gelation temperature, gelation time, and drug content were found to be 6.20 ± 0.026–6.37 ± 0.015, 34.25 ± 1.10–37.50 ± 1.05 °C, 1.65 ± 0.30–2.50 ± 0.55 min, and 95.58 ± 2.37–98.03 ± 1.68%, respectively. Furthermore, the optimized F3 formulation showed satisfactory gelling capacity (9.52 ± 0.513 h) and an acceptable mucoadhesive strength (1110.65 ± 6.87 dyne/cm²). Diffusion of the drug through the egg membrane depended on the formulation’s viscosity, and the F3 formulation explained the first-order release kinetics, indicating concentration-dependent drug diffusion with n < 0.45 (0.398) value, indicating the Fickian-diffusion (diffusional case I). The pharmacokinetic study was performed with male Wistar albino rats, and the F3 in situ thermosensitive risperidone gel confirmed significantly (p < 0.05) ~5.4 times higher brain AUC_0–∞ when administered intranasally compared to the oral solution. Conclusions: Based on physicochemical, in vitro, and in vivo parameters, it can be concluded that in situ thermosensitive gel is suitable for administration of risperidone through the nasal route and can enhance patient compliance through ease of application and with less repeated administration. Full article

Background/Objectives: The corneal epithelium plays a vital role in maintaining corneal transparency and ocular surface integrity. Chronic topical use of antiglaucoma medications may induce epithelial changes, especially with the concurrent use of multiple agents. This study aimed to evaluate the association between the number and class of antiglaucoma medications and central corneal epithelial thickness (CET), measured using a spectral-domain optical coherence tomography (SD-OCT) device. Methods: This cross-sectional study included 456 eyes from 242 adults (median age 72 years), grouped by the number of antiglaucoma agents used (0–4 medications). All pharmacologically treated participants had received the same regimen for ≥6 months. CET was measured using SD-OCT (SOLIX, Optovue). Generalized estimating equations (GEEs) accounted for inter-eye correlation. Two models were constructed: one evaluating specific medication effects and another assessing CET reduction per additional drug used. Age and sex were included as covariates. Results: CET progressively decreased with the number of medications, ranging from 53 µm in controls to 48 µm with quadruple therapy. Multivariable GEE analysis confirmed a cumulative thinning effect, with each additional medication associated with further CET reduction (β = −2.83 to −9.17 µm, p < 0.001). Latanoprost exerted the most pronounced single-drug effect (β = −3.01 µm, p < 0.001). Age was a modest negative predictor, while sex showed no significant effect. Conclusions: The cumulative number and specific class of antiglaucoma medications have a significant impact on corneal epithelial thickness. These results emphasize the need for vigilant ocular surface evaluation in patients on multi-drug regimens and propose CET as a surrogate marker for the burden of topical therapy. Full article

CO₂-switchable surfactants, applicable for mitigating CO₂ geological storage efficiency challenges, offer promising control over foam stability under reservoir conditions, but their performance under extreme pressure, temperature, and salinity still needs thorough investigation. This study experimentally characterizes the performance of CO₂-switchable surfactants by evaluating their interfacial tension (IFT) reduction, foamability, and foam stability under reservoir-relevant conditions. Six surfactants, including cationic (cetyltrimethylammonium bromide (CTAB) and benzalkonium chloride (BZK)) and nonionic amine-based surfactants (N,N-Dimethyltetradecylamine, N,N-Dimethyldecylamine, and N,N-Dimethylhexylamine), were assessed using synthetic brine mimicking a depleted North Sea oil reservoir. A fractional factorial design was employed to minimize experimental runs while capturing key interactions between surfactant type, temperature, salinity, and divalent ion concentrations. Foam switchability was analyzed by alternating CO₂ and N₂ injections, and interfacial properties were measured to establish correlations between foam generation and IFT. Experimental findings demonstrate that cationic surfactants (BZK and CTAB) exhibit CO₂-switchability and moderate foam stability. Nonionic surfactants show tail length-dependent responsiveness, where D14 demonstrated the highest foamability due to its optimal hydrophilic–hydrophobic balance. IFT measurements revealed that BZK consistently maintained lower IFT values, facilitating stronger foam generation, while CTAB exhibited higher variability. The inverse correlation between IFT and foamability was observed. These insights contribute to the development of tailored surfactants for subsurface CO₂ storage applications, improving foam-based mobility control in CCS projects. Full article

In this study, a historically significant journal subject to fungal colonization was used as a case study for experimenting with a fumigation treatment using essential oils. The experiments were carried out both in vitro and in vivo directly on the artifact. Post-treatment monitoring showed that the succession of two fumigation treatments (alternately using rosemary and lavender oil) resulted in the complete disinfection of the first and second populations detected on the substrate. The latter was identified as Trichoderma longibrachiatum, a human pathogenic species, which was found to be sensitive to various concentrations of rosemary essential oil (1.2% v/v) and lavender essential oil (0.4% v/v), while it was not contained by the standard biocide based on benzalkonium chloride. The results obtained allowed the proposal of an application protocol for the fumigation of paper items that need to undergo biocidal treatment, which consists of alternating essential oils to increase the action spectrum of the natural substances and implementing a rotation principle to prevent the development of bio-resistances. Full article

Background/Objectives: Dry eye disease (DED), also known as “keratoconjunctivitis sicca”, is a common chronic ocular surface disease accompanied by inflammation and diminished tear production. Bovine Lactoferrin (BLF), a multi-functional iron-binding glycoprotein found in tears, decreased significantly in patients with DED, used for the treatment of dry eye, conjunctivitis, and ocular inflammation. BLF has limited therapeutic efficacy due to poor ocular bioavailability. Methods: This study developed and optimized a BLF-loaded nanosuspension (BLF-NS) using the Box–Behnken Design (BBD). Optimized BLF-NS was then incorporated with polyvinyl pyrrolidone (PVP) and hydroxypropyl methyl cellulose (HPMC) dissolving microneedles (MNs). The formulations were characterized by Scanning and transmission microscopy, DSC, FTIR, ex vivo studies in corneal tissue from sheep and tested for its antibacterial and antifungal efficacy against Methicillin-Resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, and Aspergillus niger, respectively. Moreover, they were tested for their Benzalkonium chloride (BCL) dry eye in a rabbit model. Results: The optimized nanosuspension showed a vesicle size of (215 ± 0.45) nm, a Z.P (zeta potential) of (−28 ± 0.34) mV, and an Entrapment Efficiency (EE%) of (90 ± 0.66) %. The MNs were fabricated using a ratio of biodegradable polymers, PVP/HPMC. The resulting BLF-NS-MNs exhibited sharp pyramidal geometry with high mechanical strength, ensuring ocular insertion. In vitro release showed 95% lactoferrin release over 24 h, while ex vivo permeation achieved 93% trans-corneal delivery. In vivo, BLF-NS-MNs significantly reduced pro-inflammatory cytokines (TNF-α, IL-6, MMP-9, IL-1β, MCP-1) and upregulated antioxidant and anti-inflammatory genes (PPARA, SOD 1), restoring their levels to near-normal (p < 0.001). Conclusions: The nanosuspension combined with MNs has shown higher ocular tolerance against DED ensured by the Draize and Schirmer Tear Test. Full article

The effect of sub-inhibitory doses of three disinfectants, sodium hypochlorite (SHY), peracetic acid (PAA), and benzalkonium chloride (BZK), on the resistance to biocides and antibiotics of five strains of Listeria monocytogenes was determined. The minimum inhibitory concentration (MIC) of these chemicals ranged (ppm) between 3533.3 ± 28.9 and 3783.3 ± 28.9 for SHY, between 1000.0 ± 25.0 and 1050.0 ± 25.0 for PAA, and between 1.3 ± 0.6 and 4.3 ± 0.6 for BZK. The minimum bactericidal concentration (ppm) was between 3683.3 ± 57.7 and 3983.3 ± 28.9 for SHY, between 1050.0 ± 25.0 and 1250.0 ± 25.0 for PAA, and between 1.7 ± 1.2 and 4.7 ± 1.2 for BZK. Exposure of the strains to increasing sub-inhibitory concentrations of the biocides caused adaptation and cross-adaptation to these substances, markedly so in the case of BZK, relative to which some strains saw their MIC value increase up to 5.2 times after being exposed to low doses of this disinfectant. After exposure to biocides, changes in the resistance to antibiotics of the strains were also observed. In some cases, strains moved from a category of susceptible or of reduced susceptibility to resistant, especially when exposure was to SHY. These findings suggest a need to avoid the application of sublethal concentrations of disinfectants in both the food industry and the healthcare system. Full article

Background/Objectives: Latanoprost is a leading active pharmaceutical ingredient belonging to the synthetic prostaglandin F2α analogs, widely used as a first-line treatment for open-angle glaucoma and increased intraocular pressure. This study addresses the critical need for an accurate and precise chromatographic method that is capable of simultaneously quantifying latanoprost and six latanoprost-related substances in antiglaucoma eye drops. This will be crucial for patient safety and treatment efficacy. This method enables the separation of latanoprost isomers, (15S)-latanoprost, latanoprost enantiomer, and 5,6-trans latanoprost from latanoprost signal. Furthermore, it is specific for the well-known latanoprost degradants—the major latanoprost acid and the minor 15-ketolatanoprost—as well as synthetic derivatives, such as triphenylphosphine oxide (TPPO) and propan-2-yl 5-(diphenylphosphoryl)pentanoate (IDPP). Using forced degradation studies using high temperatures, UV light, alkalis, acids, and oxidizing agents, the degradation profiles of the drugs were characterized and the method’s stability-indicating power was confirmed. Methods: Separation was achieved on a stationary combined system comprising chiral and cyano columns. Reverse-phase gradient elution and UV 210 nm detection were employed. The novel method was validated according to the European Medicines Agency International Council for Harmonisation Q2 Validation of analytical procedures—Scientific guideline. Results: The method was shown to be linear in the range of 40–60 µg/mL for latanoprost and 0.05–2.77 µg/mL for related substances, confirmed by a correlation coefficient of r = 0.999. Recoveries for latanoprost were obtained within the range of 98.0–102.0% for assays and 90.0–110.0% for impurities. The detection and quantification limits for latanoprost were 0.025 µg/mL and 0.35 µg/mL, respectively. Conclusions: The analytical procedure developed is adequately sensitive, precise, and accurate compared to existing methods. The method can be reliably used to control the critical quality attributes of low-dose latanoprost products, ensuring their required high pharmaceutical quality, which translates into improvements in patient care. This advancement holds significant implications for enhancing the therapeutic management of glaucoma, ensuring drug safety and efficacy. Full article

Antimicrobial resistance is spreading rapidly throughout the world. The food chain can be one of the routes of transmission for microorganisms containing drug-resistance genes and thus serve as a channel for their transmission. Environmental stress and methods of preventing the spread of microorganisms trigger adaptive responses in bacterial cells. The aim of the present study was to determine the effect of the stress induced by sub-inhibitory concentrations (SICs) of cadmium chloride and benzalkonium chloride on antibiotic resistance and the expression of selected virulence factors in Staphylococcus isolates from food. The study was conducted on strains of the species S. epidermidis, S. heamolyticus, S. saprophyticus, and S. aureus. The values of the minimum inhibitory concentration against erythromycin, tetracycline, and oxacillin were determined before and after the incubation of the tested strains under stress conditions. The ability to form biofilm and slime production was also investigated. The expression levels of the genes responsible for antibiotic resistance (blaZ, tetK, tetM, ermB, and mecA) and virulence (eno) were conducted using Real-Time PCR. The MIC values of the antibiotics tested against the strains analyzed were found to be elevated in the presence of SICs of benzalkonium chloride and cadmium chloride. Furthermore, the intensity of biofilm production was also increased. SICs of benzalkonium chloride induced the expression of the tetM, tetK, mecA, and blaZ genes in 75%, 66.6%, 33.3%, and 40% of the isolates tested, respectively. Similar treatment with cadmium chloride induced the expression of the same genes in 75%, 100%, 66.6%, and 40% of the strains. In both cases, the expression of the ermB gene was reduced in 100% of the isolates. The eno gene was found to be overexpressed in 66.6% of the strains following benzalkonium chloride stress, and in 100% of the strains following cadmium chloride stress. These findings suggest that in Staphylococcus spp. strains, changes in the expression of the genes encoding antibiotic resistance and virulence factors may occur in response to the applied stress factors. The results indicate the possibility of selecting more resistant and virulent strains due to the use of too low concentrations of disinfectants, which emphasizes the need to use appropriate inhibitory doses of disinfectants in the food industry. Full article

Salmonella is one of the most significant zoonotic and foodborne pathogens, and it is the leading cause of bacterial diarrhea. In this study, 156 retail meat samples were collected from three supermarkets and one local wet market in Sichuan, China, including 96 chicken samples and 60 pork samples. The prevalence of Salmonella in these samples was analyzed, and 91 samples (58.33%) tested positive, with 60 (62.5%) positive chicken samples and 31 (51.67%) positive pork samples. From these positive samples, 190 Salmonella isolates were confirmed by double PCR. Subsequent serotyping identified nine serovars, with the predominant ones being S. London (58.94%), S. Typhimurium (12.58%), and S. Enteritidis (10.60%). Antibiotic susceptibility test revealed that 168 isolates (88.42%) were resistant to at least one antibiotic, and 150 isolates (78.95%) were resistant to three or more antibiotics. The highest resistance rates were observed for ampicillin (83.16%), followed by tetracycline (76.31%) and trimethoprim/sulfamethoxazole (67.37%). In the disinfectant susceptibility test, Salmonella isolates exhibited higher resistance rates to benzalkonium bromide (100%) and benzalkonium chloride (97.37%), while showing a lower resistance rate to potassium monopersulfate triple salt (33.6%). These findings highlight the high prevalence of Salmonella and its significant resistance to antibiotics and disinfectants, indicating that effective measures must be implemented to ensure the microbiological safety of retail meat. Full article

Background: Bitot’s spots, defined as white foamy triangular or round-shaped spots with the base located at the temporal limbus and the apex towards the lateral canthus, were initially associated with vitamin A deficiency (VAD). More recently, Bitot’s spots were also described in patients with normal vitamin A levels, associated with aniridia, dry-eye syndrome and post-thermal or chemical injury, as well as the usage of benzalkonium chloride (BAK) eyedrops. The aim of this article is to present the management of Bitot-like spots in a patient with congenital aniridia. Methods: An 8-year-old female patient with type 1 congenital aniridia, glaucoma, cataract, strabismus, congenital nistagmus and aniridia-associated keratopathy presented with changes in conjunctival appearance. The ophthalmological examination revealed Bitot-like spots with a foamy appearance, triangular shape, temporal location and proximity to the limbus. Further investigations were required in order to identify the cause of Bitot-like spots. Vitamin D deficiency, dry-eye syndrome, birch and Phleum genus pollen allergy were diagnosed. The patient underwent oral medication with vitamin D and topical treatment with steroids eye solution, preservative-free artificial tears and vitamin A ointment. Results: After three months of treatment, we observed the disappearance of the Bitot-like spots. Conclusions: Congenital aniridia, but also its complications such as glaucoma, dry-eye syndrome and the use of benzalkonium chloride topical medication, increases the risk of Bitot-like spots. Full article