Conventional Disinfection Research Articles

Exploring Metal Ions as Potential Antimicrobial Agents to Combat Future Drug Resistance in Mycoplasma bovis

The rise in antimicrobial resistance (AMR) in Mycoplasma bovis underscores the urgent need for alternative treatments. This study evaluated the minimal inhibitory concentrations (MICs) of four metal ions (cobalt, copper, silver, and zinc) and colloidal silver against 15 clinical M. bovis isolates, alongside conventional antimicrobials (florfenicol, tetracycline, tulathromycin, and tylosin). Colloidal silver demonstrated the most effective antimicrobial activity, inhibiting 81.25% of isolates at 1.5 mg/L, while silver inhibited 93.7% of isolates at concentrations above 1.5 mg/L. Copper exhibited notable efficacy, inhibiting 37.5% of isolates at 1.5 mg/L, with a small proportion responding at 0.1 mg/L. Cobalt and zinc displayed variable activity, with MIC values ranging from 0.7 to 12.5 mg/L. In contrast, conventional antimicrobials showed limited effectiveness: tetracycline inhibited 31.25% of isolates at ≥16 mg/L, tylosin inhibited 25% at 16 mg/L, and tulathromycin MICs ranged from 0.5 to 8 mg/L. Time–kill assays revealed a reduction in M. bovis viability after eight hours of exposure to silver and colloidal silver, though higher concentrations (4×–8× MIC) were required for complete eradication. These findings highlight the significant potential of colloidal silver and copper as alternatives for treating M. bovis infections and combating AMR. Further research is essential to explore their standalone and synergistic applications for therapeutic use.

Inhibition of Salmonella enterica and Enterohemorrhagic Escherichia coli by Ethanolic Extracts of Pomegranate Peels

This study compared the effect of phenolics extracted from four different types of pomegranate peels for controlling the growth of Salmonella enterica and enterohemorrhagic Escherichia coli. Cells of the two bacterial cultures (5 log CFU/mL) were treated in tryptic soy broth containing 0, 1, or 2% ethanolic extracts of four pomegranate peels for 5, 10, or 24 h at 25 °C. The surviving cells were recovered on a general-purpose agar and a selective medium. The extracts of three products were more effective (p ≤ 0.05) against E. coli than the extract of the remaining product, which had a similar activity to the extracts of two of the products used against S. enterica. Longer treatment time and higher extract concentration resulted in greater pathogen population reductions. The bacterial strains used had varied susceptibility to the extracts. Reductions in cell population positively correlated with the total contents of hydrolyzable tannins in the treatment systems. These findings suggested that ethanolic extracts of evaluated pomegranate peels had inhibitory activities against the two bacterial pathogens. This highlights the potential of pomegranate peels as a promising natural alternative to conventional antimicrobials for controlling foodborne pathogens like S. enterica and E. coli.

Comprehensive management of complex resorptive lesions: Report of two cases

Abstract In the field of endodontics, the management of complex resorptive lesions demands innovative and precise interventions. This report delineates the comprehensive management of two distinct cases, each presenting unique challenges. The first case involved a 23-year-old male with hypothyroidism, presenting with pain and external cervical resorption with internal communication in his lower left front tooth. The case was diagnosed with pulp necrosis and asymptomatic apical periodontitis. The second case involved a 26-year-old female in good health, dissatisfied with the cosmetic appearance, and experiencing occasional pain from a previously treated upper front tooth with concurrent external apical and internal resorption. It was diagnosed as previously treated, with symptomatic apical periodontitis. These cases were notable for their complexity and the tailored approach to diagnosis and treatment, employing advanced techniques and materials, such as bioceramic materials, for optimal outcomes. The first case was approached through conventional endodontic disinfection, flap reflection, and the meticulous external management of the resorptive defect with bioceramic material, followed by restorative procedures. The second case required retreatment, including wide canal management, apex negotiation, and the establishment of an apical plug with bioceramic material, culminating in backfilling with thermoplasticized gutta-percha and subsequent prosthetic rehabilitation. Remarkably, both cases demonstrated successful healing and patient satisfaction at a 6-month follow-up, with radiographs and photographs evidencing the desired clinical outcomes. This report highlights the necessity of adaptability, precision, and the integration of innovative materials and techniques in endodontic practice to effectively address complex resorptive lesions. It underscores the significance of a comprehensive diagnostic and treatment framework that can guide clinical decision-making and enhance procedural outcomes in similar challenging scenarios. It contributes valuable insights and reinforces the imperative of detailed management in endodontic complexities.

Nanocarrier-Mediated Dermal Drug Delivery System of Antimicrobial Agents for Targeting Skin and Soft Tissue Infections.

Antimicrobial resistance in disease-causing microbes is seen as a severe problem that affects the entire world, makes therapy less effective, and raises mortality rates. Dermal antimicrobial therapy becomes a desirable choice in the management of infectious disorders since the rising resistance to systemic antimicrobial treatment frequently necessitates the use of more toxic drugs. Nanoparticulate systems such as nanobactericides, which have built-in antibacterial activity, and nanocarriers, which function as drug delivery systems for conventional antimicrobials, are just two examples of the treatment methods made feasible by nanotechnology. Silver nanoparticles, zinc oxide nanoparticles, and titanium dioxide nanoparticles are examples of inorganic nanoparticles that are efficient on sensitive and multidrug-resistant bacterial strains both as nanobactericides and nanocarriers. To stop the growth of microorganisms that are resistant to standard antimicrobials, various antimicrobials for dermal application are widely used. This review covers the most prevalent microbes responsible for skin and soft tissue infections, techniques to deliver dermal antimicrobials, topical antimicrobial safety concerns, current issues, challenges, and potential future developments. A thorough and methodical search of databases, such as Google Scholar, PubMed, Science Direct, and others, using specified keyword combinations, such as "antimicrobials," "dermal," "nanocarriers," and numerous others, was used to gather relevant literature for this work.

In Vitro Antimicrobial Efficacy Assessment of Ethanolic, Aqueous, and Dual Solvent Extracts of Mushroom Ganoderma lucidum: Genomic and Morphological Analysis.

Background: Infectious diseases caused by bacteria are life-threating and are among the major causes of death in the world. Antibiotics have offered humans a new approach to infection control. Antibiotics are reckoned as the "magic bullets" for the fight against bacterial infections, therefore increasing life expectancy and decreasing mortality and morbidity. However, the overuse of antibiotics has resulted in the persistent growth of resistant bacterial pathogens. New antimicrobial approaches against resistant pathogens are being examined. Mushrooms seem to be a promising, and possibly more efficient, alternative method to that of conventional antimicrobials. This work aimed to investigate the phytochemical constituents and antimicrobial potential of ethanolic, aqueous, and dual solvent extracts of mushroom Ganoderma lucidum. Methods: The antimicrobial studies were carried out by broth dilution against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The present research work was also carried out to examine genomic changes associated with ethanolic, aqueous, and dual solvent extracts of G. lucidum in S. aureus and E. coli. Results: Our data quantitatively showed that all the extracts of G. lucidum were found to exhibit various degrees of antimicrobial effects against S. aureus and E. coli where the ethanolic extract exhibited the most potent antimicrobial activity. SEM images showed untreated cells with normal cell characteristics while, after treatment with extracts of G. lucidum, cells appeared damaged with irregular cell surfaces and cell wall defacement. The results of HPLC analysis showed that ethanolic and aqueous extract of G. lucidum consisted of beta[1-3] glucans, ganoderic acid, and triterpenoids. Genomic analysis identified selective sweeps in several genes associated with growth, biosynthesis transport, and stress. Conclusions: This study concludes that the extracts of three solvents of G. lucidum have antimicrobial activity against infectious bacteria causing morphological changes and the acquisition of mutations in genes. Therefore, the extracts of G. lucidum may be candidates for preventing infectious diseases in the future. Ganoderma lucidum mushroom is therefore a reliable source of antimicrobial agent that can be used against infectious diseases.

Antimicrobial Peptides: A Promising Alternative to Conventional Antimicrobials for Combating Polymicrobial Biofilms.

Polymicrobial biofilms adhere to surfaces and enhance pathogen resistance to conventional treatments, significantly contributing to chronic infections in the respiratory tract, oral cavity, chronic wounds, and on medical devices. This review examines antimicrobial peptides (AMPs) as a promising alternative to traditional antibiotics for treating biofilm-associated infections. AMPs, which can be produced as part of the innate immune response or synthesized therapeutically, have broad-spectrum antimicrobial activity, often disrupting microbial cell membranes and causing cell death. Many specifically target negatively charged bacterial membranes, unlike host cell membranes. Research shows AMPs effectively inhibit and disrupt polymicrobial biofilms and can enhance conventional antibiotics' efficacy. Preclinical and clinical research is advancing, with animal studies and clinical trials showing promise against multidrug-resistant bacteria and fungi. Numerous patents indicate increasing interest in AMPs. However, challenges such as peptide stability, potential cytotoxicity, and high production costs must be addressed. Ongoing research focuses on optimizing AMP structures, enhancing stability, and developing cost-effective production methods. In summary, AMPs offer a novel approach to combating biofilm-associated infections, with their unique mechanisms and synergistic potential with existing antibiotics positioning them as promising candidates for future treatments.

A EFICÁCIA DA TERAPIA FOTODINÂMICA NO TRATAMENTO ENDODÔNTICO EM DENTES IMATUROS COM DIAGNÓSTICO DE NECROSE PULPAR: RELATO DE CASO CLÍNICO

Photodynamic Therapy (PDT) has been very effective in endodontics due to its benefits in eliminating resistant microorganisms in root canals. Being combined with a photosensitizing agent such as Methylene Blue, enhancing the effect of PDT, complementing conventional disinfection treatments, improving the effectiveness of endodontic treatment. The objective of this study was to report a clinical case on the use of photodynamic therapy in immature teeth with pulp necrosis, emphasizing the procedures performed, clinical and radiographic results obtained, as well as the effectiveness of different methods for disinfecting root canals. Research was carried out in electronic databases: Pubmed and Virtual Health Library from 2018 to 2024. The present work concluded that having knowledge about diagnosis and management in cases of immature teeth with pulp necrosis is extremely important to the dentist so that a good prognosis can be obtained in the treatment and so that the patient has the functionality of their oral environment reestablished.

Clinical characteristics and prognosis of bloodstream infections with carbapenem-resistant Gram-negative organisms in patients with hematological malignancies: A multicenter case-control study in China

To investigate clinical characteristics of hematological malignancy (HM) patients with carbapenem-resistant gram-negative organism (CRO) bloodstream infections (BSI) in China, and to elucidate the prognostic risk factors of CRO BSI. We conducted a multicenter case-control study of 201 HM patients with CRO BSI between 2018-2020. Antimicrobial susceptibility testing and whole genome sequencing were performed for CRO isolates. Independent risk factors for 28-day crude mortality were analyzed using Cox proportional hazards regression models. The subgroups of major species were also evaluated. The pathogens responsible for CRO BSI in HM patients dominated by ST11 CRKP, ST167 CREC and ST463 CRPA. Most isolates produced carbapenemases with KPC and NDM being the main. CRO isolates had resistance rates to conventional antimicrobials ranging from 55%-100% and poor susceptibility to novel antimicrobials related to carbapenemases and species. The 28-day crude mortality was 24.2%. Non-Hodgkin lymphoma, heart disease, blaKPC-2 positive, empirical antibiotic therapy with linezolid, Pitt bacteremia score >3.5 were risk factors for 28-day mortality and appropriate definitive antibiotic therapy, tigecycline-containing therapy and aminoglycoside-containing therapy were protective factors. blaKPC-2 positive in CRKP and ST463 in CRPA were associated with Pitt bacteremia score >3.5. Solid tumor and other site infections before BSI were risk factors for ST463 CRPA BSI and pulmonary infection before BSI was risk factor for KPC-KP BSI. The antimicrobial resistance of CRO isolates for BSI in HM patients is critical. HM patients with CRO BSI should be treated with appropriate definitive antibiotic therapy based on early clarification of pathology and their antimicrobial susceptibility.

Potential for synergism of sequential UV-NaClO disinfection on ARGs removal in municipal sewage: Effectiveness, kinetics, and mechanisms

Conventional disinfection technologies have limitations in effectively addressing the challenges posed by the emerging pollutant of antibiotic resistance genes (ARGs). To reduce the risk of antibiotic resistance in wastewater treatment plant (WWTP) effluent, this study investigated the effectiveness of ultraviolet (UV) irradiation followed by Sodium hypochlorite (NaClO) (sequential UV-NaClO) disinfection in removing six classes and 18 subtypes of ARGs in the secondary effluent of a municipal WWTP. The study showed that UV disinfection could reduce tetracycline ARGs (TCs-ARGs) subtype tetQ by 0.98 log, while it was ineffective in removing sulfonamide ARGs (SAs-ARGs). NaClO disinfection was very effective in removing ARGs. Increasing the disinfectant dosage is more effective than extending the disinfection time. The highest removal was observed for the SAs-ARGs subtype sul1 with 4.15 log and the β-lactams-ARGs(β-LACs-ARGs) subtype blaCTX-M1 with 3.87 log. Sequential UV-NaClO disinfection has the potential for synergistic effects in disinfection. Sequential UV-NaClO disinfection with a UV dosage of 15 mJ/cm2 and a NaClO dosage of 10 mg/L can effectively remove 1.46 log of the total 18 subtypes of ARGs, which is 0.73 log higher than the removal achieved by standalone UV irradiation at a fluence of 100 mJ/cm2, and equivalent to the results obtained with NaClO disinfection alone at a dose of 30 mg/L. Additionally, sequential UV-NaClO disinfection can reduce the repair efficiency of ARGs. The proposed modified Hom model can be used to analyze the kinetics of sequential UV-NaClO disinfection synergy. Analysis of microbial community structure and co-occurrence of ARGs showed synchronized and consistent removal of ARGs and their potential bacterial hosts. Sequential UV-NaClO disinfection could achieve 99 % removal of more than half of the genera. Overall, our results indicate that sequential disinfection is a promising disinfection technology for disinfecting municipal wastewater and reducing the spread and transfer of ARGs.

Localized heating coupling with radical oxidation eliminating antibiotic resistance genes (ARGs) in interfacial photothermal Fenton-like disinfection process

Conventional oxidative disinfection processes are inefficient in eliminating intracellular antibiotic resistance genes (iARGs) due to the barrier of the cell membrane and the competitive reaction of cellular constituents within antibiotic-resistant bacteria (ARB), resulting in the widespread prevalence of ARGs in recycled water. This study presented the first application of localized heating coupling with advanced oxidation to destroy the resistant Escherichia coli cells and improved subsequent iARGs (blaTEM-1) degradation in a novel photothermal Fenton-like disinfection process. The Fe-Mn@CNT microfiltration membrane, comprising carbon nanotubes wrapped with Fe and Mn nanoparticles (Fe-Mn@CNT), was employed as a nanomaterial for photothermal conversion and H2O2 activation. The highly efficient absorption of full-spectrum photons by CNTs enabled the Fe-Mn@CNT membrane to concentrate light to generate localized intense heat, resulting in the destruction of ARB nearby, and the subsequent release of iARGs. Interfacial heat favored Fe-Mn-induced H2O2 activation, leading to the production of more ·OH, which in turn promoted the oxidation for ARG degradation and ARB cell damage. The results of the acetylcysteine quenching experiments indicated that interfacial heating and radical oxidation-induced accumulation of intracellular reactive oxygen species contributed to the elimination of about 1-log iARGs through direct attack. The integrity of the cell membrane, the morphology of ARB and the variation of i/e ARG copy numbers were observed to reveal that the introduction of interfacial heating aggravated the cell lysis and accelerated the iARGs release, resulting in the inactivation of 7.27-log ARB and the elimination of 4.64-log iARGs and 2.23-log eARGs. Localized heating coupling with ·OH oxidation achieved a 143 % increase in iARGs removal compared to the conventional Fenton-like oxidation. The interfacial photothermal Fenton-like disinfection process exhibited remarkable material stability, robust disinfection performance, and effective suppression of horizontal gene transfer, underscoring its immense potential to mitigate the risk of ARG dissemination in reclaimed water systems.

Eliminating Intracellular MRSA via Mannosylated Lipid-Coated Calcium Phosphate Nanoparticles.

Methicillin-resistant Staphylococcus aureus (MRSA) within cells proves exceptionally challenging to eradicate using conventional antimicrobials, resulting in recurring infections and heightened resistance. Herein, we reported an innovative mannosylated lipid-coated photodynamic/photothermal calcium phosphate nanoparticle (MAN-LCaP@ICG) for eradicating intracellular MRSA. The MAN-LCaP functioned as the vehicle for drug delivery, exhibiting preferential uptake by macrophages and facilitating the transport of ICG to intracellular pathogens. The MAN units integrated into MAN-LCaP@ICG could promote binding with MAN residuals on macrophage cells, as evidenced by cellular uptake assays using fluorescence microscopy and flow cytometry. Following its targeted accumulation, MAN-LCaP@ICG could enter into the cytoplasm and efficiently eradicate intracellular MRSA by a combination of the lysosome escape capability of CaP and the photodynamic and photothermal therapeutic effects of ICG. Furthermore, MAN-LCaP@ICG could kill MRSA more effectively than LCaP@ICG without MAN units or free ICG in a mouse peritoneal infection model. Therefore, MAN-LCaP@ICG provided a promising direction for human clinical application in combating intracellular infections.

Beyond Antibiotics: What the Future Holds.

The prevalence of multidrug resistance (MDR) and stagnant drug-development pipelines have led to the rapid rise of hard-to-treat antibiotic-resistant bacterial infections. These infectious diseases are no longer just nosocomial but are also becoming community-acquired. The spread of MDR has reached a crisis level that needs immediate attention. The landmark O'Neill report projects that by 2050, mortality rates associated with MDR bacterial infections will surpass mortality rates associated with individuals afflicted with cancer. Since conventional antimicrobials are no longer very reliable, it is of great importance to investigate different strategies to combat these life-threatening infectious diseases. Here, we provide an overview of recent advances in viable alternative treatment strategies mainly targeting a pathogen's virulence capability rather than viability. Topics include small molecule and immune inhibition of virulence factors, quorum sensing (QS) quenching, inhibition of biofilm development, bacteriophage-mediated therapy, and manipulation of an individual's macroflora to combat MDR bacterial infections.

Study on hand disinfection in inpatient geriatric care on the superiority of cold plasma aerosol versus alcohol-based disinfection methods in a parallel group design

The introduction of fundamental hygiene protocols within the healthcare sector during the nineteenth century led to a significant reduction in mortality rates. Contemporary advancements, such as alcohol-based sanitizers, have further enhanced hand hygiene practices. However, these measures are often overlooked in nursing facilities, resulting in low staff compliance rates and increased cross-infection rates. Novel approaches, such as cold plasma hand disinfection, present promising alternatives due to their minimal skin damage and economic benefits. This study aims to compare the disinfectant efficacy of cold plasma aerosol under practical application conditions with an alcoholic hand disinfectant listed by the Association for Applied Hygiene. The microbial count on participants’ hands was measured, with particular attention paid to the spontaneous occurrence of fecal indicators and the presence of potentially infectious bacteria. A t-test for independent samples was conducted to determine whether there was a significant difference between the two cohorts regarding the research question. Statistical analysis revealed that the mean log colony-forming unit (CFU) values were significantly lower in the test cohort using only the cold plasma method for hand disinfection compared to the cohort using conventional alcohol-based hand disinfection. Moreover, it was demonstrated that, unlike alcohol-based hand disinfection, cold plasma application ensures the effective elimination of Staphylococcus aureus. The findings indicate that staff utilizing plasma disinfection have an average bacterial count that is 0.65 log units lower than those who regularly use alcohol-based hand disinfection. In addition to the efficacy of cold plasma disinfection, its superiority over alcohol-based hand disinfection was also established. Beyond offering economic and logistical advantages, cold plasma disinfection provides additional health benefits as it does not induce skin damage, unlike alcohol-based hand disinfection.

Gallium: a decisive "Trojan Horse" against microorganisms.

Controlling multidrug-resistant microorganisms (MRM) has a long history with the extensive and inappropriate use of antibiotics. At the cost of these drugs being scarce, new possibilities have to be explored to inhibit the growth of microorganisms. Thus, metallic compounds have shown to be promising as a viable alternative to contain pathogens resistant to conventional antimicrobials. Gallium (Ga3+) can be highlighted, which is an antimicrobial agent capable of disrupting the essential activities of microorganisms, such as metabolism, cellular respiration and DNA synthesis. It was observed that this occurs due to the similar properties between Ga3+ and iron (Fe3+), which is a fundamental ion for the correct functioning of bacterial activities. The mimetic effect performed by Ga3+ prevents iron transporters from distinguishing both ions and results in the substitution of Fe3+ for Ga3+ and in adverse metabolic disturbances in rapidly growing cells. This review focuses on analyzing the development of research involving Ga3+, elucidating the intracellular incorporation of the "Trojan Horse", summarizing the mechanism of interaction between gallium and iron and comparing the most recent and broad-spectrum studies using gallium-based compounds with antimicrobial scope.

Cannabinoids from C. sativa L.: Systematic Review on Potential Pharmacological Effects against Infectious Diseases Downstream and Multidrug-Resistant Pathogens

Cannabis sativa L. has garnered attention as a potential source for new antimicrobial agents, particularly due to the increased prevalence of microbial resistance to conventional antimicrobials and the emergence of multidrug-resistant pathogens. This review, conducted according to the PRISMA 2020 statement, systematically analyzed the antimicrobial properties of C. sativa extracts and cannabinoids against various bacteria, fungi, viruses, and parasites. Data were collected from the scientific literature (102 papers) and clinical trials (5 studies) from 2014 to June 2024. Findings revealed that cannabinoids, especially CBD, demonstrate significant antimicrobial activity against Gram-positive bacteria like MRSA, Gram-negative bacteria such as Pseudomonas aeruginosa, various Candida species, SARS-CoV-2, and HIV. Additionally, CBD showed efficacy against parasitic infections like Echinococcus granulosus and Leishmania species. These results suggest that cannabinoids may represent a new class of antimicrobial agents with unique and diverse mechanisms of action, potentially effective in broad-spectrum therapies. This study highlights the urgent need for further research and standardized clinical trials to validate these findings and to develop cannabinoid-based treatments. The antimicrobial properties of C. sativa align with WHO priorities and support global health initiatives, offering promising avenues for addressing antimicrobial resistance and improving public health outcomes.

Plant-derived Bioactive Compounds and Their Mechanistic Roles in Combating Microbial Biofilms

Biofilms are a group of microorganisms that exist on living or non-living surfaces, embedded within extracellular matrices produced by microbial cells. They primarily cause antimicrobial resistance and treatment failure in clinical settings. Biofilms resist conventional antimicrobials because of their polymicrobial nature, ability to evade host immune detection, and increased tolerance to antimicrobial agents. Consequently, considerable attention is given to finding alternative anti-biofilm agents. Medicinal plants contain diverse biologically active compounds reported to possess antimicrobial and anti-biofilm activities. This review elucidates the mechanisms of action of plant-derived bioactive compounds (alkaloids, tannins, indoles, terpenes, and flavonoids) on in vitro microbial biofilms, shedding light on their ability to disrupt and prevent biofilm formation. Additionally, the review emphasizes current and future research directions for these phytochemicals, including synergism with conventional antibiotics and advanced drug delivery systems for treating and eradicating biofilm-associated infections.

Insights into the inhibitory effects of trichloroisocyanuric acid disinfectant on the phototransformation of polypropylene microplastics

The chemical components in the natural aquatic environment have the potential to be involved in phototransformation of microplastics (MPs). Little information is available regarding the mediation effects of artificially introduced chemicals on MP phototransformation, especially those used in aquaculture water that are vulnerable to human interference. Herein, this study investigated the phototransformation process and mechanism of polypropylene microplastic (PP MPs) in presence of trichloroisocyanuric acid (TCCA) disinfectant with unique properties unlike the conventional inorganic chlorine disinfectants. The results showed that the presence of TCCA inhibited the surface photooxidation of PP MPs. Analysis of PP MP surface and reaction filtrate indicated that the inhibitory effects were likely derived from TCCA derivatives and the weakening in promoting effect of polypropylene microplastic-derived dissolved organic matter (PP-DOM) as photolytic byproducts, with the more important role of free chlorine in initial period and that of other chlorine species (i.e., the adsorbed chloride ions (Cl−), newly formed carbon-chlorine (CCl) bonds, chlorinated cyanurates, and chlorinated products) in middle and later period. The study highlights for the first time the important role of chlorine species derived from TCCA in phototransformation process of co-existed PP MPs and proposes a previously unrecognized phototransformation pathway, which will provide a new understanding and knowledge for the environmental behavior of MPs in aquaculture environment.

Curcumin-mediated photodynamic disinfection strategy with specific spectral range for mucoid Pseudomonas Aeruginosa from hospital water

BackgroundHospital water systems represent critical environments for the transmission of pathogens, including multidrug-resistant strains like mucoid Pseudomonas aeruginosa (M-PA). Conventional disinfection methods often struggle to eradicate these pathogens effectively, highlighting the need for innovative approaches. ObjectiveThis study aimed to develop an enhanced photodynamic disinfection strategy targeting M-PA from hospital water systems, using curcumin-mediated photodynamic inactivation (PDI) with specific spectral range. MethodsAn M-PA strain isolated from hospital water was subjected to photodynamic treatment using curcumin as the photosensitizer. The efficacy of different wavelengths of light and varying concentrations of curcumin, with and without Tris-EDTA adjuvants, was evaluated through bacterial enumeration, ROS level measurements, transcriptome analysis, and assessment of virulence factors and biofilm formation. In vivo experiments utilizing a DSS-induced colitis mouse model assessed the protective effects of the photodynamic treatment against M-PA infection. ResultsOur findings demonstrated that the combination of curcumin-mediated PDI with specific spectral range effectively reduced M-PA counts in water, particularly when supplemented with Tris-EDTA. Transcriptome analysis revealed significant downregulation of virulence-related genes under sublethal photodynamic conditions. Furthermore, photodynamic treatment inhibited pyocyanin production and biofilm formation in M-PA, highlighting its potential to disrupt pathogenicity mechanisms. In vivo experiments showed that PDI attenuated M-PA-induced colitis in mice, indicating its protective efficacy. ConclusionThis study presents a promising photodynamic disinfection strategy for combating M-PA from hospital water. By optimizing curcumin-mediated PDI with specific spectral range and adjuvants, our approach demonstrates substantial efficacy in reducing bacterial counts, inhibiting virulence factors, and preventing M-PA-associated colitis.

Catalyst-free regeneration of plasma-activated water via ultrasonic cavitation: Removing aggregation concealment of antibiotic-resistant bacteria with enhanced wastewater sustainability

Aggregation is a crucial factor in bacterial biofilm formation, and comprehending its properties is vital for managing waterborne antibiotic-resistant bacteria. In this study, we examined Methicillin-resistant Staphylococcus aureus (MRSA) cell aggregation under varying conditions and assessed the inactivation efficiency of a novel disinfection method, micro-nano bubbles plasma-activated water via ultrasonic stirring cavitation (MPAW-US), on aggregated MRSA cells. Aggregation efficiency increased over time and at low salt concentrations but diminished at higher concentrations. Elevated MRSA cell aggregation in actual water samples represented significant real-life biohazard risks. Unlike conventional disinfection, MPAW-US treatment exhibited minimal change in the inactivation rate constant despite protective outer layers. Enhanced inactivation efficiency results from the synergistic effects of increased intracellular oxidative stress damage and extracellular substance disruption, triggered by ultrasound-activated micro-nano bubbles that improve PAW reactivity and applicability. This approach neither induced MRSA cross-resistance to unfavorable conditions nor increased toxicity or regrowth potential of aggregative MRSA, utilizing ATP levels as potential regrowth capability indicators. Ultimately, this energy-efficient disinfection technology functions effectively across diverse temperature ranges, showcasing exceptional sterilization and nutritional bean sprout production after cyclic filtering, thereby promoting wastewater sustainability amidst carbon emission concerns.

Recent Developments in the Application of Filamentous Fungus Aspergillus oryzae in Ruminant Feed.

The resource-intensive nature of the ruminant farming sector, which has been exacerbated by population growth and increasing pressure to reduce feed antibiotics and growth promoters, has sparked interest in looking for sustainable alternative feed sources to enhance ruminant production efficiency. Edible filamentous fungi, rich in macronutrients like proteins, offer promise in reducing the reliance on conventional protein sources and antimicrobials to improve feed quality and animal performance. The inclusion of single-cell proteins, particularly filamentous fungi, in ruminant feed has long been of scientific and industrial interest. This review focuses on the potential application of the extensively studied Aspergillus oryzae and its fermentation extracts in ruminant nutrition. It provides an overview of conventional ruminant feed ingredients, supplements, and efficiency. Additionally, this review analyzes the re-utilization of organic residues for A. oryzae cultivation and examines the effects of adding fungal extracts to ruminant feed on ruminal digestibility and animal performance, all within a circular bioeconomy framework.