Search Results (207)

Endotoxins, lipopolysaccharides released from the outer membrane of Gram-negative bacteria, pose a significant risk in healthcare environments, particularly in Central Sterile Supply Departments (CSSDs), where the delivery of sterile pyrogen-free medical devices is critical for patient safety. Traditional methods for controlling endotoxins in water systems, such as ultraviolet (UV) disinfection, have proven ineffective at reducing endotoxin concentrations to comply with regulatory standards (<0.25 EU/mL). This limitation presents a significant challenge, especially in the context of reverse osmosis (RO) permeate used in CSSDs, where water typically has very low conductivity. Despite the established importance of endotoxin removal, a gap in the literature exists regarding effective chemical-free methods that can meet the stringent endotoxin limits in such low-conductivity environments. This study addresses this gap by evaluating the effectiveness of the eBooster™ electrochemical technology—featuring proprietary electrode materials and a reactor design optimized for potable water—for endotoxin removal from water, specifically under the low-conductivity conditions typical of RO permeate. Laboratory experiments using the B250 reactor achieved >90% endotoxin reduction (from 1.2 EU/mL to <0.1 EU/mL) at flow rates ≤5 L/min and current densities of 0.45–2.7 mA/cm². Additional real-world testing at three hospitals showed that the eBooster™ unit, when installed in the RO tank recirculation loop, consistently reduced endotoxin levels from 0.76 EU/mL (with UV) to <0.05 EU/mL over 24 months of operation, while heterotrophic plate counts dropped from 190 to <1 CFU/100 mL. Statistical analysis confirmed the reproducibility and flow-rate dependence of the removal efficiency. Limitations observed included reduced efficacy at higher flow rates, the need for sufficient residence time, and a temporary performance decline after two years due to a power fault, which was promptly corrected. Compared to earlier approaches, eBooster™ demonstrated superior performance in low-conductivity environments without added chemicals or significant maintenance. These findings highlight the strength and novelty of eBooster™ as a reliable, chemical-free, and maintenance-friendly alternative to traditional UV disinfection systems, offering a promising solution for critical water treatment applications in healthcare environments. Full article

Objectives: Burkholderia cepacia complex (Bcc), a Gram-negative organism, is a well-recognized cause of hospital outbreaks, often linked to a contaminated shared source, such as multidose medications. In this study, we report an outbreak of Bcc infections in a tertiary care hospital, associated with the intrinsic contamination of a prepared solution used in interventional radiology (IR) procedures. Additionally, we provide a detailed explanation of the interventions implemented to control and interrupt the outbreak. Methods: Records from the infection control committee from 1 January 2023 to 31 October 2024 were screened to identify cases with Bcc growth in cultured blood, urine, or respiratory samples. Clinical and laboratory data were collected in March 2025. Bacterial identification was performed using conventional methods and MALDI-TOF (Bruker Daltonics, Bremen, Germany). Controls were matched to cases by ward, date of initial growth, and duration of hospitalization. Demographic and clinical data of these patients were systematically collected and analyzed. Microbiological cultures were obtained from environmental objects of concern and certain medications. Results: A total of 82 Burkholderia species were identified. We enrolled 77 cases and 77 matched controls. The source of contamination was identified in ready-to-use intravenous medications (remifentanil and magnesium preparations) in the IR department. These preparations were compounded in advance by the team and were used repeatedly. Although the outbreak originated from contaminated IV medications used in IR, secondary transmission likely affected 28 non-IR patients via fomites, shared environments, and possible lapses in isolation precautions. The mortality rate among the cases was 16.9%. Infection with Bcc was associated with prolonged intensive care unit stays (p = 0.018) and an extended overall hospitalization duration (p < 0.001); however, it was not associated with increased mortality. The enforcement of contact precautions and comprehensive environmental decontamination successfully reduced the incidence of the Bcc outbreak. No pathogens were detected in cultures obtained after the disinfection. Conclusions: The hospital transmission of Bcc is likely driven by cross-contamination, invasive medical procedures, and the administration of contaminated medications. Implementing stringent infection control measures such as staff retraining, updated policies on medication use, enhanced environmental decontamination, and strict adherence to isolation precautions has proven effective in curbing the spread of virulent and transmissible Bcc. Full article

Ozonation and ozone-based advanced oxidation processes, including ozone/hydrogen peroxide and ozone/ultraviolet irradiation, have been extensively studied for their efficacy in treating wastewater across various industries. While sectors such as pulp and paper, textile, food and beverage, microelectronics, and municipal wastewater have successfully implemented ozone at full scale, others have yet to fully embrace these technologies’ effectiveness. This review article examines recent publications from the past two decades, exploring novel applications of ozone-based technologies in treating wastewater from diverse sectors, including food and beverage, agriculture, aquaculture, textile, pulp and paper, oil and gas, medical and pharmaceutical manufacturing, pesticides, cosmetics, cigarettes, latex, cork manufacturing, semiconductors, and electroplating industries. The review underscores ozone’s broad applicability in degrading recalcitrant synthetic and natural organics, thereby reducing toxicity and enhancing biodegradability in industrial effluents. Additionally, ozone-based treatments prove highly effective in disinfecting pathogenic microorganisms present in these effluents. Continued research and application of these ozonation and ozone-based advanced oxidation processes hold promise for addressing environmental challenges and advancing sustainable wastewater management practices globally. Full article

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen with significant clinical relevance in both human and veterinary medicine. Despite its well-documented role in hospital-acquired infections in human healthcare settings, its persistence and transmission within veterinary clinics remain underexplored. This review highlights the overlooked status of veterinary facilities as environmental reservoirs and amplification points for multidrug-resistant (MDR) P. aeruginosa, emphasizing their relevance to One Health surveillance. We examine the bacterium’s environmental survival strategies, including biofilm formation, resistance to disinfectants, and tolerance to nutrient-poor conditions that facilitate the long-term colonization of moist surfaces, drains, medical equipment, and plumbing systems. Common transmission vectors are identified, including asymptomatic animal carriers, contaminated instruments, and the hands of veterinary staff. The review synthesizes current data on antimicrobial resistance in environmental isolates, revealing frequent expression of efflux pumps and mobile resistance genes, and documents the potential for zoonotic transmission to staff and pet owners. Key gaps in environmental monitoring, infection control protocols, and genomic surveillance are identified, with a call for standardized approaches tailored to the veterinary context. Control strategies, including mechanical biofilm disruption, disinfectant cycling, effluent monitoring, and staff hygiene training, are evaluated for feasibility and impact. The article concludes with a One Health framework outlining cross-species and environmental transmission pathways. It advocates for harmonized surveillance, infrastructure improvements, and intersectoral collaboration to reduce the risk posed by MDR P. aeruginosa within veterinary clinical environments and beyond. By addressing these blind spots, veterinary facilities can become proactive partners in antimicrobial stewardship and global resistance mitigation. Full article

A total of 1.6 million tons of personal protective equipment (PPE) waste has been generated daily since 2019 and this production has not abated since that time. Within PPEs, isolation gowns make up the largest percentage by weight of landfill waste. This study aimed to evaluate the effectiveness of rapid, reproducible disinfection protocols to help facilitate safe reuse and minimize risks from microbial contamination. Disinfection of isolation gowns via fogging with hydrogen peroxide (HP) and hypochlorous acid (HC) were evaluated in the present study compared to standard ethylene oxide (EO) sterilization. This study was conducted at VCA West Coast Specialty and Emergency Animal Hospital in the United States. Ten isolation gowns (control) were cultured on tryptic soy agar contact plates in 10 predetermined areas to determine microbial load and morphology/types on non-sterile gowns before use. Following this, 10 gowns were fogged with 12% HP, and then once drying was complete, they were cultured in the predetermined areas for microbial load and morphology/types. This procedure was repeated with another set of 10 gowns fogged with 500 ppm HC. Lastly, 10 gowns were sterilized with EO using standard protocol and cultures were performed similarly. Median CFU (colony-forming unit) counts at 48 h for control, EO, HP, and HC were 4.5, 0, 0, and 0; at 72 h, they were 107, 0, 0, and 0, respectively. No significant difference was noted between the disinfection groups; post hoc pairwise analysis showed that the CFU counts for the disinfection groups were significantly lower than those for the control. The median percent reduction at 48 h for EO, HP, and HC was 100, 100, and 100; at 72 h, it was 100, 100, and 100, respectively. No significant difference was detected among the groups. The median number of microbe types for control, EO, HP, and HC was 2.5, 0, 0, and 0; there was no difference between the disinfection groups, but the number of microbe types was significantly higher for the control than for the disinfection groups. EO is environmentally toxic, expensive, and carcinogenic; it requires prolonged disinfection cycle times, expensive equipment, and trained personnel. This study suggests that HP and HC provide a cost-effective, relatively nontoxic, environmentally safe, and comparatively short disinfection time option for the disinfection and reuse of isolation gowns that does not require trained personnel or specialized equipment. Full article

A simple and rapid smartphone-based colorimetric assay for peracetic acid concentration was developed to facilitate point-of-use disinfectant preparations for infection prevention and control. The colorimetric detection was based on the oxidation of N,N-diethyl-phenylenediamine by peracetic acid through an intermediate reaction with potassium iodide, resulting in pink-magenta products. The colorimetric reaction was performed on a 96-well plate; then, the color products were photographed in one image. The color intensity was evaluated to determine the peracetic acid concentration using a custom-built mobile application named Modern Peracetic Acid Analysis. The relative green intensity of the pink-magenta products was directly proportional to the peracetic acid concentration in the range of 0.15 to 3.0 µg/mL. The detection and quantitation limits were 0.11 µg/mL and 0.34 µg/mL, respectively. The approach was successfully applied to determine the peracetic acid concentration in pharmaceutical disinfectant formulations. The results obtained using the proposed approach showed no significant differences from those obtained using acid–base titration at the 95% confidence level. The greenness of the proposed approach was evaluated using the Complementary Green Analytical Procedure Index, Analytical Greenness, and Blue Applicability Grade Index, demonstrating enhanced environmental friendliness and practical advantages, as well as simple, portable instrumentation that is easier to operate than traditional spectrophotometric and titration methods. Furthermore, a sustainability assessment based on the Need, Quality, and Sustainability index underscored its enhanced sustainability. Full article

Background: Liberia is among the 30 countries with a high burden of tuberculosis worldwide. Health sciences students, who are future health professionals, have essential roles in curtailing the spread of TB. This study aims to evaluate the knowledge, attitude, and practice (KAP) of tuberculosis (TB) among health sciences students. Methods: This study used a quantitative cross-sectional design to assess Medical, Pharmacy, and Public Health students at the University of Liberia’s KAP regarding TB using a modified previously used self-administered questionnaire reviewed by subject experts from 1 April 2025 to 23 April 2025. SPSS 26 was used for analysis. Descriptive statistics, Mann–Whitney, Kruskal–Wallis, and multivariate logistic regression tests were used for analysis. Results: In total, 630 students participated, of which 51.7% were females, 83% were aged 24 or above, 81.6% were single, and 96.7% had never smoked. The KAP levels were 65.9%, 97.3%, and 94.8%, respectively. Higher TB knowledge was significantly associated with being enrolled in the Medical program (OR = 2.20, 95% CI: 1.28–3.76, p < 0.05), being in year 4 and 5 (OR = 1.79, 95% CI: 1.09–2.98, p < 0.05; OR = 2.28, 95% CI: 1.08–4.78, p < 0.05), being unemployed (OR = 1.58, 95% CI: 1.09–2.31, p < 0.05), and having personal acquaintance with individuals diagnosed with TB (OR = 1.64, 95% CI: 1.11–2.42, p < 0.05). Conclusions: The knowledge level among students was good. They had a positive attitude, and their practice levels were good. However, gaps remain in understanding latent TB and proper disinfection methods for TB-related materials. Strengthening the health curriculum to address these specific knowledge gaps is recommended to better align students’ knowledge with their attitudes and practices. Full article

The only biocidal iodine species in topical iodine disinfectants is molecular iodine (I2). I2, a biomolecule, has broad-spectrum antimicrobial activity and does not generate resistance. Physicians, regulatory agencies, and scientists have assumed that I2 is responsible for the skin staining and irritation associated with the clinical use of iodine disinfectants; this assumption is deeply embedded in the medical community but is not supported with empirical data. This study provides the first experimental data that measure the biocompatibility of I2 with human skin. Human skin explants in tissue culture were evaluated at 3, 7, and 24 h after being exposed to I2 (500 to 15,000 ppm). Cell viability was measured relative to phosphate-buffered saline using 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl-tetrazolium bromide (MTT). The biocidal activity of I2 vapor emitted from silicone was demonstrated against bacteria growing on agar to confirm I2 off-gassing from skin was an active biocide. Additionally, statistically significant bacterial reductions with both gas and solution phase I2 were observed in a static and dynamic five-species wound biofilm. The data suggest that high, e.g., 50–5000 ppm, levels of I2 should be incorporated into topical iodine disinfectants instead of the very low (0.2–10 ppm) levels found in 10% povidone iodine products currently in use. Full article

Objective: Current good manufacturing practice (cGMP) guidance for positron emission tomography (PET) drugs has been established in Europe and the United States. In Japan, the Pharmaceuticals and Medical Devices Agency (PMDA) approved the use of radiosynthesizers as medical devices for the in-house manufacturing of PET drugs in hospitals and clinics, regardless of the cGMP environment. Without adequate facilities, equipment, and personnel required by cGMP regulations, the quality assurance (QA) and clinical effectiveness of PET drugs largely depend on the radiosynthesizers themselves. To bridge the gap between radiochemistry standardization and site qualification, the Japanese Society of Nuclear Medicine (JSNM) has issued guidance for the in-house manufacturing of small-scale PET drugs under academic GMP (a-GMP) environments. The goals of cGMP and a-GMP are different: cGMP focuses on process optimization, certification, and commercialization, while a-GMP facilitates the small-scale, in-house production of PET drugs for clinical trials and patient-specific standard of care. Among PET isotopes, N-13 has a short half-life (10 min) and must be synthesized on site. [¹³N]Ammonia ([¹³N]NH₃) is used for myocardial perfusion imaging under the Japan Health Insurance System (JHIS) and was thus selected as a working example for the manufacturing of PET drugs in an a-GMP environment. Methods: A [¹³N]NH₃-radiosynthesizer was installed in a hot cell within an a-GMP-compliant radiopharmacy unit. To comply with a-GMP regulations, the air flow was adjusted through HEPA filters. All cabinets and cells were disinfected to ensure sterility once a month. Standard operating procedures (SOPs) were applied, including analytical methods. Batch records, QA data, and radiation exposure to staff in the synthesis of [¹³N]NH₃ were measured and documented. Results: 2.52 GBq of [¹³N]NH₃ end-of-synthesis (EOS) was obtained in an average of 13.5 min in 15 production runs. The radiochemical purity was more than 99%. Exposure doses were 11 µSv for one production run and 22 µSv for two production runs. The pre-irradiation background dose rate was 0.12 µSv/h. After irradiation, the exposed dosage in the front of the hot cell was 0.15 µSv/h. The leakage dosage measured at the bench was 0.16 µSv/h. The exposure and leakage dosages in the manufacturing of [¹³N]NH₃ were similar to the background level as measured by radiation monitoring systems in an a-GMP environments. All QAs, environmental data, bacteria assays, and particulates met a-GMP compliance standards. Conclusions: In-house a-GMP environments require dedicated radiosynthesizers, documentation for batch records, validation schedules, radiation protection monitoring, air and particulate systems, and accountable personnel. In this study, the in-house manufacturing of [¹³N]NH₃ under a-GMP conditions was successfully demonstrated. These findings support the international harmonization of small-scale PET drug manufacturing in hospitals and clinics for future multi-center clinical trials and the development of a standard of care. Full article

Guanidine disinfectants are cationic polymers recognized for their effective sterilization properties and their ability to prevent bacterial resistance. As a result, they are widely utilized in medical, healthcare, household, and animal husbandry settings. However, the bactericidal effects and mechanisms of guanidine in marine aquaculture systems remain unclear due to the polymeric nature of guanidine ions and the complexity of marine environments. The inhibitory effects and bactericidal mechanisms of polyhexamethylene biguanide (PHMB) on key pathogens and probiotics are examined in this study. It was shown that PHMB had inhibitory effects on Vibrio parahaemolyticus (VP), Photobacterium damselae subsp. damselae (PDD), Bacillus subtilis (BS), Escherichia coli (EPEC), and Staphylococcus aureus (SAU), with minimum inhibitory concentrations (MICs) ranging from 3.91 to 125.0 µg/mL, and minimum bactericidal concentrations (MBCs) from 15.63 to 250.0 µg/mL. A stronger bactericidal effect of PHMB on marine bacteria compared to EPEC and SAU was exhibited. It was shown in ion interference experiments that the addition of calcium ions reduced the bactericidal effectiveness of PHMB against VP and PDD by 87.73% and 53.35%, respectively. At a PHMB concentration of 62.50 µg/mL, minor changes in cell surface potential energy (CSPE) were exhibited by Gram-positive bacteria (SAU and BS), while more significant alterations were shown by Gram-negative pathogens. It was revealed by propidium iodide staining and scanning electron microscopy (SEM) analysis that the bacterial cell membrane was directly disrupted by PHMB. DNA and RNA release analysis further revealed that following PHMB treatment, changes in membrane permeability were exhibited by Gram-negative pathogens, with a significant increase in extracellular DNA content as PHMB concentration increased. No such effect was observed in Gram-positive bacteria. Additional evidence was provided by the findings that PHMB effectively inhibits bacterial pathogens in mariculture systems, with a significantly stronger inhibitory effect on Gram-negative pathogens than on Gram-positive bacteria. These results indicated that PHMB could serve as a new antimicrobial agent in mariculture. Full article

Background: Shigella flexneri is a major cause of shigellosis in developing regions and is known to cause outbreaks in institutional settings. Transmission occurs via the fecal–oral route. It invades intestinal epithelial cells, causing diarrhea, systemic symptoms, and complications such as hemolytic uremic syndrome. This study aimed to characterize the clinical presentation, administered treatment, infection outcomes, and infection control measures during a local S. flexneri outbreak at a rehabilitation center. Methods: This case series at King Saud University Medical City (Oct–Dec 2024) investigated S. flexneri infections from a rehabilitation center. Stool and blood samples were cultured and analyzed using microbiological methods. Molecular studies were used to verify the genetic linkage between the isolates and to study their virulence genes. Results: Four cases of S. flexneri were included, involving patients with various comorbidities, residing in a rehabilitation center, and presenting with symptoms like fever and diarrhea. Laboratory investigations revealed leukocytosis, electrolyte imbalances, and elevated inflammatory markers. Imaging studies showed findings consistent with colitis in two cases. Patients were managed with IV fluids and targeted antibiotics, leading to symptom resolution. Molecular studies confirmed the genetic relatedness between the S. flexneri isolates, with virulence genes indicating cellular invasion and inflammation as primary drivers of disease severity. Outbreak management comprised contact isolation, environmental disinfection, and education. Conclusions: S. flexneri outbreaks in long-term care facilities pose challenges among bedbound patients. Diapers may facilitate transmission, and infections may cause severe complications. Robust infection control, identifying outbreak sources, and strengthening prevention strategies are essential to protect vulnerable populations. Full article

This study investigates the AI-assisted analyses of radiation disinfection effects on the mechanical properties of recycled date kernel powder–epoxy composites for medical applications, utilizing Euclidean distances and the k-nearest neighbor (KNN) algorithm. Tensile and compression tests were conducted on twenty specimens following ASTM standards, with the data analyzed using a t-test to evaluate the impact of the UVC disinfection process on the material’s mechanical properties. The application of AI through the KNN algorithm successfully identified the three most representative curves out of five for both tensile and compression tests. This targeted curve selection minimized variability and focused on the most relevant data, enhancing the reliability of the analysis. Following the application of UVC and AI, tensile tests showed a 20–30% increase in ultimate stress. Similarly, compression tests revealed a 25% increase in transition stress, an 18–22% improvement in ultimate stress, and approximately a 12% rise in fracture stress. This research underscores the potential of combining AI, sustainable materials, and UVC technology to develop advanced composites for medical applications. The proposed methodology offers a robust framework for evaluating material performance while promoting the creation of eco-friendly, high-performance materials that meet the stringent standards of medical use. Full article

The continuous advancement of medical technologies and the increasing demand for high-performance medical devices have driven the search for innovative solutions in biomaterials engineering. However, ensuring the sterility of polymeric biomaterials while maintaining their mechanical integrity remains a significant challenge. This research examines how steam sterilization impacts the mechanical properties of four polymeric biomaterials frequently utilized in medical applications: MED610, PEEK, PET-G HT100, and RGD720. Samples were produced using additive manufacturing (AM), specifically Material Jetting (MJT) and Material Extrusion (MEX) processes, and exposed to steam sterilization at 121 °C and 134 °C. A comprehensive verification process was conducted to ensure the effectiveness of sterilization, including pre-sterilization cleaning, disinfection procedures, and the use of process indicators such as the Bowie–Dick test. Mechanical evaluation included bending tests and Rockwell hardness measurements to assess changes in structural integrity and mechanical strength after sterilization. The results revealed that, while some materials exhibited significant alterations in mechanical properties, others demonstrated high resistance to thermal and humidity exposure during sterilization. These findings provide critical insights into the selection and optimization of polymeric biomaterials for sterilizable medical applications, ensuring their durability and safety in clinical use. Full article

This study investigated the presence of antibiotic-resistance genes in drinking water consumed by the university community in the Peruvian Amazon. Water samples were collected from three primary sources: inflow from the distribution network, a storage cistern, and an underground intake. Conventional PCR was employed to detect genes associated with resistance to erythromycin (ermC), ampicillin (amp), ciprofloxacin (QEP), multidrug resistance (marA), and specific multidrug resistance in E. coli (qEmarA). Physicochemical analysis revealed compliance with most regulatory standards; however, groundwater samples showed lead concentrations exceeding legal limits (0.72 mg/L) and lacked residual chlorine. All sampling points tested positive for the evaluated resistance genes, demonstrating the widespread dissemination of resistance factors in drinking water. Contrary to initial expectations, resistance genes were also prevalent in treated sources. These findings reveal a critical public health risk for the university community, emphasising the need for effective disinfection systems and robust monitoring protocols to ensure water safety. The presence of these resistance genes in water is a critical public health concern as it can facilitate the spread of resistant bacteria, reducing the effectiveness of medical treatments and increasing the risk of infections that are difficult to control. Full article

Dental infections can disrupt root development in immature permanent teeth, making traditional endodontic treatment challenging. Apexogenesis, a regenerative approach that promotes natural root development, offers a potential solution. However, issues related to disinfection and material biocompatibility still remain. The objective of this study was to evaluate the synergistic antimicrobial and antibiofilm properties of double and triple antibiotic combinations against common oral pathogens, and to incorporate the most effective combination into a thermosensitive hydrogel, to develop an alternative intracanal medication. Antibiotics were tested alone and in combination in planktonic and biofilm conditions of oral bacteria and Candida albicans. The antibiotic combinations with potential antimicrobial synergy were tested on Enterococcus faecalis biofilms in radicular dentin by confocal microscopy. Metronidazole (ME), ciprofloxacin (CI), and fosfomycin (FO) were incorporated into poly(N-vinylcaprolactam) (PNVCL) hydrogels, and their antibiofilm activity was compared to PNVCL hydrogels containing chlorhexidine (CHX) or calcium hydroxide (CH). The cytotoxicity of the hydrogels was assessed on MDPC-23 odontoblast-like cells using metiltetrazolium assays. A statistical analysis was performed using ANOVA followed by Tukey’s test (p < 0.05). The combination of ME + CI + FO showed superior antibiofilm effects in mono- and dual-species biofilms and on biofilms inside dentinal tubules, comparable to CHX. PNVCL hydrogels with ME + CI + FO significantly reduced E. faecalis biofilms in dentinal tubules, exhibiting a higher efficacy than PNVCL + CH. Cytotoxicity tests revealed minimal effects on cell viability for both PNVCL hydrogels with and without antibiotics. In conclusion, ME + CI + FO showed potent antimicrobial synergy and, when loaded in thermosensitive PNVCL hydrogel, demonstrated significant antibiofilm activity and low cytotoxicity. These findings emphasize the potential of this formulation as an effective and biocompatible endodontic medication, especially for the treatment of immature permanent teeth. Full article