Sterilization Efficiency Research Articles

Toluidine blue O photosensitizer combined with caffeic acid improves antibacterial performance by increasing the permeability of cell membrane

Photodynamic therapy has always been an antibacterial tool for solving multi-drug resistant bacteria problem, but the side effects and the low efficiency due to the high aggregation and low solubility of photosensitizers limit its application. Due to the anti-inflammatory effect of caffeic acid, two novel photosensitizers (CA-1-TBO, CA-TBO) were synthesized by conjugating caffeic acid with toluidine blue O (TBO). The structures have been characterized by 1HNMR and high-resolution mass spectrometry. The UV-vis absorption, fluorescence spectra and the octanol-water partition coefficient of two photosensitizers were measured to evaluate their photophysical properties and hydrophilic/hydrophobic properties. Compared with parent TBO, the two modified photosensitizers have shown a higher quantum yield and kinetics constants of singlet oxygen, which has been supported by the simulation results of density functional theory. As drug-resistant representatives of gram-positive and gram-negative bacteria, respectively, S. aureus and P. aeruginosa have been used for in vitro antibacterial experiments. The sterilization efficiencies of the two modified photosensitizers far exceed that of parent TBO. The results of the octanol-water partition coefficient and fluorescence quantification showed that modified photosensitizers CA-1-TBO and CA-TBO could be more accumulated than parent TBO. Based on scanning electron microscopy images, protein gel electrophoresis, and the conductivity of the bacterial solution, the possible mechanism of improved antibacterial photodynamic efficiencies could be induced by membrane permeability due to the caffeic acid effect. The findings demonstrate the significant potential of natural phenolic compounds in the development of photosensitizer molecules with characteristics such as more efficient, biocompatible and less side effects.

Design of bubble-based plasma sterilization system based on freestanding rotary triboelectric nanogenerator

Plasma activated water (PAW) has emerged an appealing strategy for sterilization and disinfectant. However, its rational combination with self-powered system is urgently need to study. In this work, a self-powered plasma sterilization system was proposed based on freestanding rotary triboelectric nanogenerator (FR-TENG). The FR-TENG serves as an efficient energy source to trigger the plasma discharge in the bubble between two electrodes. After clarifying the effect of rotary speed on the output performance of FR-TENG, the influence of composition and velocity of bubble on generation of reactive oxygen species is further investigated. As a result, this bubble-based discharge system with the rational design is able to generate PAW effectively. The generation of different active substances with bactericidal ability was further quantitively studied. Moreover, the analysis of sterilization efficiency and TEM image demonstrate the superior sterilization performance of the bubble-based plasma sterilizer. This study offers a feasible strategy to combine TENG with PAW technology for enhanced sterilization.

H2O2 self-supplying Mo/Fe@CuO2 nanozyme with NIR light enhanced catalytic activity and photothermal synergistic antibacterial application

Nanozymes have drawn increasing attention due to unique enzyme-mimic catalytic activities for the treatment of bacterial infections. Herein, a novel tri-metal nanozyme for synergistic eradication of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was generated by Mo/Fe doped carbon dots (Mo/Fe-CDs) wrapping copper peroxide (CuO2) nanozyme (Mo/Fe@CuO2). Mo/Fe@CuO2 showed near-infrared (NIR) light-enhanced peroxidase-like catalytic activity, and H2O2 self-supply to promote the generation of reactive oxygen species (ROS) for highly efficient antibacterial photothermal therapy. The CuO2 could generate H2O2 in the acidic microenvironment, and Mo/Fe-CDs consequently could convert H2O2 to hydroxyl radicals (·OH), resulting in the improvement of sterilization efficiency. Interestingly, Mo/Fe-CDs could activate the transformation of Cu2+ to Cu+ through the co-catalytic reaction based on the Mo4+/Mo6+ and Fe3+/Fe2+ redox couples, and provided photonic hyperthermia (PTT) to enhance the peroxidase-like activity. Meanwhile, Mo/Fe@CuO2 showed glutathione (GSH) oxidase-like activity, which can achieve the depletion of glutathione (GSH) in bacteria, thus significantly improving the bactericidal effect. The collaborative eradication of bacteria, through innovative metal carbon-based nanozyme technology, provides a powerful and feasible approach to treating bacterial infections that threaten human health.

High performance photothermal carbon nanotubes/nanostructured hydrogel for solar electricity production and solar water sterilization

Solar energy is a promising renewable energy source with the potential to contribute to sustainable development. Efficient photothermal conversion is critical for solar energy acquisition and conversion. Here, carbon nanotubes (CNTs) were gelatinized to obtain the nanostructured CNT/hydrogel, and then highly light-absorbing CNT/n-hydrogels with surface texture were obtained by replicating the micrometer structure from the black silicon (b-Si) surface onto CNT/hydrogels by using a PDMS mold. Through the synergistic effect of both surface texture and nanostructures, it demonstrates high efficiency of solar electricity production and solar sterilization. A small thermoelectric (TE) module with an area of 4 × 4 cm2 is integrated with CNT/n-hydrogel absorber for the investigation of photo-thermoelectric conversion. The output power of the CNT/n-hydrogel TE device is 1.42 W•m−2 under 1 sun. And by connecting four devices in series, it has successfully demonstrated for charging mobile phones under two different solar illuminations. This work provides a cost-effective and easy fabrication method for opening up the hydrogel as a photothermal absorber, which is low-cost, reproducible, high-efficiency solar water sterilization and high photothermal conversion efficiency.

Recent design strategies for boosting chemodynamic therapy of bacterial infections

AbstractThe emergence of drug‐resistant bacteria poses a significant threat to people's lives and health as bacterial infections continue to persist. Currently, antibiotic therapy remains the primary approach for tackling bacterial infections. However, the escalating rates of drug resistance coupled with the lag in the development of novel drugs have led to diminishing effectiveness of conventional treatments. Therefore, the development of nonantibiotic‐dependent therapeutic strategies has become imperative to impede the rise of bacterial resistance. The emergence of chemodynamic therapy (CDT) has opened up a new possibility due to the CDT can convert H2O2 into •OH via Fenton/Fenton‐like reaction for drug‐resistant bacterial treatment. However, the efficacy of CDT is limited by a variety of practical factors. To overcome this limitation, the sterilization efficiency of CDT can be enhanced by introducing the therapeutics with inherent antimicrobial capability. In addition, researchers have explored CDT‐based combined therapies to augment its antimicrobial effects and mitigate its potential toxic side effects toward normal tissues. This review examines the research progress of CDT in the antimicrobial field, explores various strategies to enhance CDT efficacy and presents the synergistic effects of CDT in combination with other modalities. And last, the current challenges faced by CDT and the future research directions are discussed.

Bletilla Striata polysaccharides thermosensitive gel for photothermal treatment of bacterial infection

Skin is the most important defense shield which touched external environment directly. Effectively clearing microbes in infected wound via non-antibiotic therapy is crucial for the promotion of recovery in complex biological environments, and the wound healing is a crucial process after sterilization to avoid superinfection. Herein, a kind of Prussian blue-based photothermal responsive gel, Bletilla striata polysaccharide-mingled, isatin-functionalized Prussian blue gel (PB-ISA/BSP gel) was reported for effective treatment of bacterial infection and wound healing. The introduction of effective components of traditional Chinese medicine (TCM), isatin (ISA), enhanced the efficiency of sterilization synergistically. Furthermore, the process of wound healing was promoted by Bletilla striata polysaccharides (BSP). PB-ISA@BSP had a considerable antibacterial rate with 98.5 % under an 808 nm laser for 10 min in vitro. Besides, PB-ISA/BSP gel showed an effective antibacterial efficacy in vivo and a fast wound healing rate as well. The as-prepared functional particles can invade and destroy bacteria membrane to kill microbes. This work highlights that PB-ISA/BSP gel is a promising antibacterial agent based on synergistically enhanced photothermal effect and wound healing promotion ability and provides inspiration for future therapy based on the synergy between photothermal agent and active components in TCM.

Intelligent pulsed ultraviolet c radiation sterilization system: A cleaner solution of raw ready-to-eat aquatic products processing

The sterilization of raw ready-to-eat aquatic products is a crucial method for ensuring their safety for consumption after production. However, achieving intelligent decision-making and higher sterilization efficiency remains a technical challenge. In this paper, an intelligent ultraviolet c radiation (UVC) pulse sterilization system for raw ready-to-eat aquatic products processing lines is presented. The objective of intelligently classifying and grading aquatic products in an automated production line and then sterilizing them is attained. On the basis of the thermal radiation perspective factor method, an irradiation prediction model for the columnar pulsed UVC field is developed, and an automated decision model for the UVC sterilization level is developed in conjunction with the hierarchical analysis method. Automatic control of the UVC lamp is achieved with precision. Using a combination of direct measurements and simulation calculations, the accuracy of the prediction structure is verified. In addition, the system's key model, the UVC intensity decision model, was evaluated, and the results indicated that the decision model had an error rate of 13.3% in the sterilization of raw ready-to-eat aquatic products and that the system's sterilization rate could reach approximately 95%. Additionally, the economics of implementation and overall performance of the sterilization system were evaluated and determined to be effective in reducing spoilage rates and human resource losses, thereby promoting sustainable and clean production in the raw food fish processing industry.

Effect of UV-C LED arrangement on the sterilization of Escherichia coli in planar water disinfection reactors

In this study, a planar UV reactor with five distinct UV-C LED arrangements was proposed to treat drinking water. The particle tracing method combined with computational fluid dynamics were used to simulate water velocity field, microbial trajectory and residence time. The ray tracing method was used to determine the irradiance distribution in water. The simulated variables were then integrated to determine the distribution of fluence in water. Both experimental and theoretical results among the five distinct UV light modules used in this study, turn-enhanced emission exhibited the highest efficiency in sterilizing Escherichia coli owning to the synergic effect of hydrodynamics and UV radiation. Turn-enhanced emission combined with turn-induced secondary flow effectively improved the reactor performance. At a flow rate of 300 mL/min, turn-enhanced emission resulted in an inactivation value of 4.56 log, which was approximately 0.90, 0.82, 0.84, and 2.41 log higher than the values obtained with top, staggered, lined, and side emission, respectively. According to the particle count and cumulative count of the fluid particles, turn-enhanced emission effectively enhanced the UV fluence to which microbes in water were subjected. In conclusion, optimal combinations of LED arrangements and channel configurations effectively improve the sterilization efficiency of UV reactors.

Effect of channel configuration on the water sterilization efficiency of a photoreactor with ultraviolet C light-emitting diodes

This study investigated the effect of flow channel configuration on the water disinfection efficiency of a photoreactor with ultraviolet (UV) C light-emitting diodes (LEDs). The synergistic effect of UV radiation and hydrodynamics on microbial inactivation was analyzed to obtain the UV fluence distribution for five channel configurations. Simulations revealed that the serpentine and spiral configurations led to similar microbial residence times. However, the high mixing efficiency in the serpentine configuration resulted in the efficiency of Escherichia coli inactivation being higher in this configuration than in the spiral configuration. Although the pin configuration achieved the highest average UV fluence of the five channel configurations, the E. coli inactivation value in this configuration was low because approximately 25 % of the microbes received UV fluence of less than 5 mJ/cm2. This study modified the pin configuration, and the results revealed that this configuration effectively increased the UV fluence received by microbes and eliminated low-fluence particles. At a flow rate of 120 mL/min, the average UV fluence in the modified pin configuration was 43 %, 52 %, and 72 % higher than those in the serpentine, spiral, and bioinspired configurations, respectively. Experimental findings indicated that at a maximum flow rate of 160 mL/min, the E. coli inactivation value achieved in the modified pin configuration was 3.3 log, which was approximately 0.4, 1.2, 1.5, and 1.8 log higher than those achieved in the serpentine, spiral, pin, and bioinspired configurations, respectively. The results of this study provide insights regarding enhancement of the UV exposure of microorganisms and can be used as a guideline in flow channel design for water disinfection reactors with UV-C LEDs.

Polypyrrole hydrogel with near-infrared light-driven nitric oxide release and photothermal activities for rapid synergistic sterilization and infected wound therapy

Developing low-cost and easy-accessible phototherapy agents with a high sterilization efficiency is urgently needed tackling the increasingly dangerous of bacterial infections. Herein, a broad-spectrum antimicrobial agent (i.e., PP-Mo-NO) with near-infrared laser (NIR) driven nitric oxide (NO) release capacity derived from the assemble of a heat-sensitive NO donor (N, N′-di-sec-butyl-N, N′-dinitroso-1, 4-phenylenediamine, BNN6) with freeze-dried three-dimensional polypyrrole hydrogel crosslinked by the sulfonated dimolybdenum-salen (PP-Mo), was synthesized for the rapid and effective eradicating of Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Upon 808 nm laser irradiation, PP-Mo-NO showed not only superb photothermal efficacy (79.88 %), but also precisely controllable NO release capacity, generating oxidative/nitrosative stress. Within 10 mins of irradiation (1.0 W cm−2), PP-Mo-NO with co-amplified photothermal (PTT)/NO synergetic antibacterial activity presented sterilization rates beyond 99.1% against both the E. coli and S. aureus at a relatively low concentration (100 µg mL−1). Meanwhile, in vivo experiments demonstrated the great application potential of PP-Mo-NO which could effectively kill bacteria at the site of infection, and repair the open infectious wounds, thereby accelerating the tissue reconstruction.

Nano zero-valent iron-based fiber electrode for efficient electro-Fenton treatment of pharmaceutical wastewater: Mechanism of degradation and sterilization

In this study, a novel metal–organic framework (MOF) derived fiber electrode (NZVIF-800) was successfully fabricated by a novel electrostatic spinning and pyrolysis procedure. The NZVIF-800 electrode exhibited great catalytic activity in a heterogeneous electro-Fenton (EF) system for organic degradation, in which the secnidazole (SCZ) was completely degraded within 60 min with excellent stability (no significant change after eight cycles). Importantly, the NZVIF-800 electrode was also highly effective for decontaminating actual pharmaceutical wastewater, in which the TOC and COD removal reached 38% and 47%, respectively, after 4 h EF reaction. Based on experimental analysis, microstructure characterization, and theoretical calculations, the detailed reaction mechanism of the NZVIF-800 electrode was revealed. The impressive EF performance was mainly attributed to the in situ generation of active nano-zero-valent iron (NZVI) derived from the MOF pyrolysis and the confinement effect of the encased carbon layer that could effectively inhibit the loss and inactivation of Fe active sites. The degradation pathways of organic pollutants in simulated and real wastewater were proposed in detail. Significantly, the EF system with NZVIF-800 electrode exhibited strong sterilization ability for the wastewater matrix as evidenced by the colony condition, OD600 values, and Illumina MiSeq sequencing platform analysis (up to 95% sterilization efficiency within 4 h), expanding its application scope for actual wastewater treatment.

Solar driven photocatalytic disinfection by Z-scheme heterojunction of In2O3/g-C3N4: Performance, mechanism and application

To realize an efficient solar disinfection, Z-scheme In2O3/g-C3N4 heterojunctions were prepared and its performances were investigated. The In2O3/g-C3N4 exhibits a wide light response range and a low carrier recombination rate. Due to the transfer of electron (e-) and hole (h+) between In2O3 and g-C3N4, the generations of superoxide (O2•-) and hydroxyl radicals (HO•) were enhanced. O2•−, HO• and h+ played important roles for disinfection. Approximately 106 CFU/mL E. coli were inactivated within 90 min. In addition to cell membrane lysis, DNA was degraded. In2O3/g-C3N4 still revealed high sterilization efficiencies under natural sunlight or for actual wastewater treatment. Although humic acid and inorganic anions (Cl‾ < NO3‾ < SO42‾ < H2PO4‾ < HCO3‾) inhibited the disinfection, detection limit (DL, about 5.8-log removal) can be achieved. Furthermore, DL still could be achieved and the In2O3/g-C3N4 structure remained intact after 5 cycles. This study provides novel guidance for solar-driven water purification.

Germicidal effect of intense pulsed light on Pseudomonas aeruginosa in food processing.

Pseudomonas aeruginosa (P. aeruginosa) can cause serious infections in many parts of the body and is also an underestimated foodborne pathogen. Intense pulsed light sterilization is recognized for its high sterilization efficiency, flexible and safe operation and ease of installation on production lines, which makes up for the shortcomings of several other physical sterilization technologies. This experiment studied the killing efficiency of different capacitances (650 μF, 470 μF, and 220 μF) of intense pulsed light on foodborne pathogenic microorganisms P. aeruginosa in the models of liquid food models, 96-well cell plates, and polycarbonate membrane models at room temperature (25°C) and refrigerated (4°C) environments to provide data to support the application of IPL sterilization devices in food processing. The IPL was very effective in killing P. aeruginosa in the planktonic state as well as in the early and mature biofilm states, meeting target kill rates of 100%, 99.99%, and 94.33% for a given number of exposures. The biofilms formed in the polycarbonate membrane model and the 96-well plate model were more resistant to killing compared to the planktonic state. To achieve the same bactericidal effect, the number of flashes increased with decreasing capacitance. The bactericidal effect of IPL on P. aeruginosa was significantly influenced by the state of the bacterium. The larger the capacitance the higher the number of pulses and the better the sterilization effect on P. aeruginosa.

畜禽舍空间相控分裂导线复合除尘杀菌装置设计研究

Livestock scale breeding is the inevitable trend of future livestock and poultry husbandry. Closed breeding requires excellent environment and livestock and poultry housings contain a lot of dust, pathogenic microorganisms and harmful gases, affecting the health of livestock and poultry and breeding personnel. Most of the common sterilization and dust collection devices for livestock and poultry housings on the market are too high energy consumption, and easy to cause secondary pollution. Therefore, an environmental purification device was designed to absorb dust in the air and kill harmful bacteria by using high voltage pulsed electric field. The device was designed using phase control principle and bundled conductor. COMSOL Multiphysics software was used to simulate the layout of single conductor, twin bundled conductor and quad bundled conductor. It was found that when the conductor was designed as twin bundled conductor or quad bundled conductor, the gradient distribution of spatial electric field intensity was more uniform and the downward trend of electric field was slower, which could effectively improve the dust collection and sterilization efficiency of the device. At the same time, a variety of electric field environments can be set up by using phase difference to meet different environmental requirements of livestock and poultry. The compound dust collection and sterilization device with phase-controlled bundled conductor for livestock and poultry housing space includes high voltage pulse generator, bundled conductor, high voltage special timer, insulator and other parts, which can effectively reduce the dust content in the air, the concentration of pathogenic bacteria, harmful gases, etc. after assembly test and can also reduce the humidity in the livestock and poultry housings.

Cationic Cu(I)-covalent organic framework as self-enhanced synergetic Photothermal/Phtodynamic/Cationic/Enzymatic antibacterial agent

Combination therapy, functioned by the integration of two or more therapies, simultaneously, into one platform, have gained wide popularity to combat antibiotic-resistant bacteria in both the clinical trials and fundamental researches. Here, a multifunctional cationic Cu(I)-covalent organic framework (COF), denoted as HLVCu, which could realize the joint action of photothermal/photodynamic/cationic/enzymatic therapies was facilely fabricated as an antimicrobial therapy platform. This material enables an amplified synergistic therapeutic effects to combat bacteria. The intrinsic photothermal activity could enhance the enzymatic activity, which is closely related to temperature to effectively catalyze the generation of toxic hydroxyl radical (•OH) from low concentration H2O2 to synergize with photothermal therapy. The positive charged skeleton structure allows the material to interact better with the bacterial membrane, which could decrease the diffusion distance of reactive oxygen species (ROS), realizing the quickly and effectively killing of bacteria. Under the laser irradiation, the present HLV-Cu could act as a broad-spectrum antibacterial agent, delivering an extremely high sterilization efficiency of 100% towards the gram positive (S. aureus) and gram negative (E. coli) model microorganisms, simultaneously, at a low dose of agents. Altogether, this work offers a new and safe antibiotic-free treatment option for high-efficiency combination antimicrobial therapy.

Effect of Humidity on the Inactivation of Bacillus Subtilis Spore by Non-thermal Atmospheric Air Plasma

Objective: If a medical device is not properly disinfected, it will pose a potential danger to patients. Spore is an experimental strain to verify the effect of disinfection on medical devices. It has a complex structure and is somewhat resistant to conventional disinfection techniques. Based on the advantages of simple structure and abundant reactive oxygen and nitrogen species (RONS), surface dielectric barrier discharge (SDBD) has been used to deal with inactivate spores, which provided experimental support for the application of sterilization spores in medical devices. Methods: The sterilization efficiency of the plasma was evaluated by calculating the number of viable colonies on Tryptose Soya Agar. RONS including ozone, nitrogen oxides and other reactive species produced in SDBD were measured by ozone analyzer, Fourier infrared spectrometer and chemical probes, respectively. Ultraviolet-visible spectrophotometer was used to determine the concentration of protein and nucleic acid. Results: After 20min of SDBD treatment, the number of inactivated spores could reach more than 4 log at high humidity (&gt;6g/m3), while the spores were hardly inactivated at low humidity (&lt;6g/m3). Ozone production was inhibited with increasing humidity while OH radicals and peroxynitrous acid increased with increasing humidity. The optical density values of protein and nucleic acid released from spores treated with SDBD was detected and a strong correlation was found with the spore inactivation trend. The protein shell and membrane structure of the spores were destroyed by SDBD, and more leakage and destruction of proteins and nucleic acids in the spores were obtained under the high humidity. Conclusion: With the increase of air humidity (from 0.15g/m3 to 70.16g/m3), stable SDBD is obtained showing a typical filamentous discharge pattern. Compared with low humidity, high humidity is more favorable to SDBD inactivation of spores.

Real-Time Monitoring of H2O2 Sterilization on Individual Bacillus atrophaeus Spores by Optical Sensing with Trapping Raman Spectroscopy

Hydrogen peroxide (H2O2), a strong oxidizer, is a commonly used sterilization agent employed during aseptic food processing and medical applications. To assess the sterilization efficiency with H2O2, bacterial spores are common microbial systems due to their remarkable robustness against a wide variety of decontamination strategies. Despite their widespread use, there is, however, only little information about the detailed time-resolved mechanism underlying the oxidative spore death by H2O2. In this work, we investigate chemical and morphological changes of individual Bacillus atrophaeus spores undergoing oxidative damage using optical sensing with trapping Raman microscopy in real-time. The time-resolved experiments reveal that spore death involves two distinct phases: (i) an initial phase dominated by the fast release of dipicolinic acid (DPA), a major spore biomarker, which indicates the rupture of the spore’s core; and (ii) the oxidation of the remaining spore material resulting in the subsequent fragmentation of the spores’ coat. Simultaneous observation of the spore morphology by optical microscopy corroborates these mechanisms. The dependence of the onset of DPA release and the time constant of spore fragmentation on H2O2 shows that the formation of reactive oxygen species from H2O2 is the rate-limiting factor of oxidative spore death.

The Energy Efficiency of Microwave Sterilization of Medical Waste According to the Characteristics of the Heating Element

The Energy Efficiency of Microwave Sterilization of Medical Waste According to the Characteristics of the Heating Element

Effect of radiation sterilization on the ability to induce adipose regeneration in vivo in decellularized adipose-derived matrix.

Decellularized adipose-derived matrix (DAM), a biological scaffold that can induce adipose regeneration. The balance between its sterilization efficiency and its ability to maintain in situ adipose regeneration should be considered in terminal sterilization. The purpose of this study was to investigate the effects of radiation sterilization of cobalt-60 (60 Co)with different doses on adipogenesis induced by different forms of DAM, so as to reduce radiation dose under the premise of safe and effective sterilization and ensure adipogenesis induced by DAM in vivo. High dose (25kGy) and low dose (5kGy) radiation were used to sterilize freeze-dried and wet DAM, respectively. The sterilization efficiency, macro and micro characteristics, mechanical and mechanical properties of DAM were compared, and then implanted into the immunocompromised mice to evaluate the adipose regeneration. Under the two radiation doses, no microbial growth was found in the freeze-dried and wet DAM sterility tests, and no significant changes were observed in the macro and micro structures. In terms of mechanical properties, the elastic modulus of high dose freeze-dried DAM decreased significantly (p<0.001). In vivo animal experiments, the freeze-dried DAM irradiated with high dose almost completely lost its function of adipogenesis in vivo. Although the wet DAM irradiated with high dose could induce fat regeneration in the early stage, the adipocyte deformation and atrophy appeared in the later stage. The freeze-dried and wet DAM after low dose irradiation was similar to the wet DAM without irradiation in the blank control, which could maintain excellent adipogenic and angiogenic functions in vivo. High dose 60 Co irradiation can completely destroy the ability of freeze-dried DAM to induce adipose regeneration in situ, while low dose irradiation (5kGy) can effectively sterilize the DAM without damaging in vivo induced adipose regeneration. Radiation has more damage to freeze-dried DAM than wet DAM in adipogenesis properties.

Epidemiological characteristics of SHV, cmlv, and FosA6-producing carbapenem-resistant Klebsiella pneumoniae based on whole genome sequences in Jiangsu, China.

Carbapenem-resistant Klebsiella pneumoniae (CRKP), particularly those with high virulence, cause invasive disease in clinical settings. An epidemiological investigation was conducted on the evolution, virulence, and antimicrobial resistance of CRKP isolates in two tertiary teaching hospitals in Jiangsu, China from November 2020 to December 2021. There were 31 different CRKP strains discovered. We performed whole genome sequencing (WGS) on 13 SHV, cmlv, and FosA6-producing CRKP to reveal molecular characteristics. Five ST15/ST11 isolates had CRISPR-Cas systems. By conjugation tests, KPC-2 can be transmitted horizontally to E. coil. A conjugative pHN7A8-related multi-resistance plasmid (KPC-2, blaCTX-M-65, blaTEM-1, fosA3, catII, and rmtB) was first discovered in CRKP clinical isolates. Using bacteriological testing, a serum killing assay, and an infection model with Galleria mellonella, three ST11-K64 KPC-2 generating carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) were identified. These strains harbored a virulent plasmid and an IncFII-family pKPC/pHN7A8 conjugative plasmid, which led to hypervirulence and resistance. One of these CR-hvKPs, which co-harbored KPC-2, NDM-6, SHV-182, SHV-64, and blaCTX-M-122 genes, was first discovered. Importantly, this CR-hvKP strain also produced biofilm and had non-inferior fitness. The widespread use of ceftazidime/avibactam might provide this CR-hvKP with a selective advantage; hence, immediate action is required to stop its dissemination. Another important finding is the novel ST6136 in K. pneumoniae. Finally, the sterilization efficiency rates of Fe2C nanoparticles in CRKP were more than 98%. Furthermore, our novel antibacterial Fe2C nanoparticles may also provide a therapeutic strategy for infections.