Bacterial Staining Research Articles

Characterisation of C‐β‐Cyclodextrin‐Thymol Inclusion Complexes as Delivery Systems for Antibacterial and Antioxidant Applications

ABSTRACTThymol (THY) is a natural antioxidant and antimicrobial; however, its biological activity and application in the food and pharmaceutical fields are limited due to its low water solubility and volatility. In this study, inclusion complexes of cationic‐β‐cyclodextrin‐THY (C‐β‐CD‐THY) were prepared by using the aqueous stirring method. Then UV–Vis spectra, FT‐IR, NMR, DSC, XRD and SEM data were collected to characterise the structure and morphology of the inclusion complexes. Phase solubility experiments showed a better solubilisation effect of C‐β‐CD‐THY than HP‐β‐CD‐THY. At a concentration of 0.64 mmol/L for THY, the DPPH scavenging rate was 60.99% and 61.31% for HP‐β‐CD‐THY and C‐β‐CD‐THY, respectively, whereas that of THY in 10% ethanol was only 43.47%. The bacteriostatic activity was verified using a circle of inhibition and the live/dead bacterial double stain. C‐β‐CD‐THY exhibited better antimicrobial activities against Escherichia coli and Staphylococcus aureus than HP‐β‐CD‐THY. In conclusion, the C‐β‐CD‐THY inclusion complexes have the potential to be applied as an effective bacteriostatic agent for food and pharmaceutical applications.

Virtual Gram staining of label-free bacteria using dark-field microscopy and deep learning.

Gram staining has been a frequently used staining protocol in microbiology. It is vulnerable to staining artifacts due to, e.g., operator errors and chemical variations. Here, we introduce virtual Gram staining of label-free bacteria using a trained neural network that digitally transforms dark-field images of unstained bacteria into their Gram-stained equivalents matching bright-field image contrast. After a one-time training, the virtual Gram staining model processes an axial stack of dark-field microscopy images of label-free bacteria (never seen before) to rapidly generate Gram staining, bypassing several chemical steps involved in the conventional staining process. We demonstrated the success of virtual Gram staining on label-free bacteria samples containing Escherichia coli and Listeria innocua by quantifying the staining accuracy of the model and comparing the chromatic and morphological features of the virtually stained bacteria against their chemically stained counterparts. This virtual bacterial staining framework bypasses the traditional Gram staining protocol and its challenges, including stain standardization, operator errors, and sensitivity to chemical variations.

Training of Microbe Cell Visualization from Fermentation Food at UPT. Integrated Laboratory UHO

Indonesia has diverse local food commodities that are valuable as a national food source. Microbes serve an important part in food processing, but they can also be harmful and damage food products. The aim of this training is to provide students with skills in understanding microbial cell visualization techniques in food fermentation. Tempeh and the probiotic drink Yakult as sources of fungi and bacteria, respectively, were used in this training. There are four steps for this training consisting of preparation, visualization of mold on tempeh, visualization of bacteria on Yakult as well as training assessment. The findings indicate that students can identify the complex morphology of tempeh mold, which consists of aseptate hyphae, spores, and sporangiophores that sustain the sporangium. Moreover, they exhibited a bacil shape as the morphology of bacteria from Yakult under a light microscope with 400x magnification. Bacterial staining is recommended to visualize bacteria more clearly than without staining. This occurs because bacteria are smaller than mold and have a more translucent hue. The findings of the activity assessment revealed that participants were able to follow the instruction well. This is demonstrated by success indicators in displaying mold morphology, which includes hyphae, sporangiophores, sporangia, and spores. Participants were also able to identify the structure of rod-shaped bacterial organisms, known as bacilli.

Spectrum of cutaneous manifestations in patients with type 2 diabetes mellitus

Background: Skin disorders, usually neglected and frequently under diagnosed among diabetic patients. These are common complications and encounter a broad spectrum of disorders in diabetes. Aims and Objectives: Present study, aimed to evaluate various cutaneous manifestations among type 2 diabetes mellitus (DM) patients. Materials and Methods: The present study was conducted at Dermatology, Diabetic Clinic of tertiary care centre hospital. After approval from the Institutional Ethics Committee and consent from study subjects, 240 subjects were included. All subjects underwent clinical examination-special emphasis on cutaneous manifestations. Blood samples were collected and used for the estimation of blood glucose, liver function tests and renal function tests, complete blood count, bacterial infections-Gram stain and culture, fungal infections-KOH (potassium hydroxide) mount, Gram stain (for Candida), and culture. Results: Out of 200, 140 (58.4%) were males and 100 (41.6%) were females. The majority of the patients were 5th, 6thand 7th decades. Acrochordons 22 (9.1%) and candidal balanoposthitis 21 (8.7%) were predominantly observed. Fungal, bacterial, and non-infective were 90 (37.5%), 54 (22.5%), and 112 (46.6%), respectively. On bacterial culture, Pyogenic ulcer was observed in 8, furunculosis in 6, etc. KOH mount positive in 22 patients and culture positive was seen in 16 patients. In non-infective dermatoses, Acrochordons were observed in 24 patients. The majority of the patients were on oral hypoglycemic agents. Conclusion: This study’s results showed demographic, social factors, and the prevalence of various dermatological manifestations in type 2 DM patients.

Carrier-free nanomedicine for combined antibacterial therapy through pH-responsive controlled release of sulfadiazine and emodin

To mitigate bacterial drug resistance and enhance antibacterial efficacy in the treatment of bacterial infections, a novel antibacterial self-releasing nanomedicine was developed in this study. The innovative nanodrug integrates the active components of traditional Chinese medicine with antibiotics to circumvent bacterial resistance. Additionally, phenylboronic acid (PBA) was used as a bacterial targeting agent to specifically localize the infection site and regulate drug release. In this system, sulfadiazine (Su), emodin (Em), and PBA were assembled through boron ester bonds and hydrophobic interactions, forming a stable self-delivery nanodrug designated as Su/Em/PBA. Subsequently, the drug release capability was evaluated at pH 5.5 and pH 7.4. Notably, the boronic acid ester bond formed by PBA is pH-responsive, demonstrating a significantly higher release of Su and Em in the acidic microenvironment of bacterial infections (pH 5.5) compared to physiological environment (pH 7.4) (Su: 93.9 % vs. 29.9 %; Em: 81.9 % vs. 16.4 %). This indicated that Su/Em/PBA exhibited an effective drug release capability at the site of bacterial infection. The bactericidal effect was evaluated through in vitro plate staining experiments and live/dead bacterial staining assays. The combination of Su and Em enhanced the antibacterial efficacy of Su/Em/PBA, achieving antibacterial rates of 84.0 % against Staphylococcus aureus (S. aureus) and 88.6 % against Escherichia coli (E. coli), signifying the effective antibacterial properties of Su/Em/PBA. In conclusion, our study presents a straightforward approach to developing antibacterial self-releasing nanomedicine with excellent antibacterial activity, making it a promising candidate for future clinical trials.

Utilization Of Butterfly Pea Flowers (Clioria ternate L.) In Gram Staining Of Staphylococcus aureus and Escherichia coli Bacteria

Introduction : Butterfly pea flower (Clitoria ternatea L.) is one of the most commonly found plants. Butterfly pea flowers contain anthocyanins which are abundant in the flowers and play a role in giving red, violet-blue color to the flowers. Anthocyanins are the main molecules of plant colorants. The potential of anthocyanins in butterfly pea flowers can be used as a natural coloring reagent. Objective : The purpose of this study was to determine whether telang flower extract can be used as a substitute for gentian violet in Gram staining. Method : The research method used is experimental. Result : The results of Gram staining research using original pH butterfly pea flower extract at concentrations of 1:10, 2:10, 3:10, 4:10, and pH 5 butterfly pea flower extract at concentrations of 1:10, 2:10, 3:10, 4:10, 5:10 on Staphylococcus aureus bacteria showed poor bacterial staining results because the bacteria were not purple while the original pH butterfly pea flower extract at a concentration of 5:10 showed good staining results because the bacteria were purple. While in Escherichia coli bacteria, butterfly pea flower extract shows good staining results because the bacteria are red. Conclusion : Data analysis using the Kruskal Wallis test obtained Asymp. Sig (0.000) <0.05, it can be concluded that there is a significant difference in Gram staining using gentian violet and telang flower extract with variations in pH and composition as a substitute for gentian violet.

The Biofilm Removal and Bactericidal Effect of an 810-nm High-Power Laser on an Orthodontic Bracket Surface: An In Vitro Study.

Objective: The present study aimed to analyze the biofilm removal and bactericidal effect of laser treatment alone and laser combined with ultrasonic scaling on orthodontic brackets. It also assessed whether the use of a laser can improve the efficiency of biofilm removal and bactericidal effect compared with traditional ultrasonic instrumentation. Background Data: Streptococcus mutans (S. mutans) can lead to white spots and dental caries. Orthodontic brackets make teeth cleaning more difficult, and biofilms or bacteria on the surface of brackets worsen the oral environment, which may cause some oral diseases. Laser can be used for biofilm removal and killing bacteria on the surface of an object through thermal, photochemical, and pressure effects, which is widely used in the treatment of oral diseases. Methods: A total of 600 mandibular incisor brackets were collected for this study. Among these, 320 unused brackets were used for the S. mutans crystal violet assay (n = 160) and for S. mutans live/dead bacterial staining (n = 160). Another 280 brackets, obtained from patients who had undergone therapy for over two years, were used for the mature multispecies biofilms removal assay (n = 120) and multispecies bacterial live/dead bacterial staining (n = 160). Ultrasonic scaling, laser, and laser combined with ultrasonic scaling were applied to the labial surface of brackets covered by S. mutans biofilm or mature multispecies biofilms. Specifically, we used the following three methods: ultrasonic scaling for 10 sec without laser; 810-nm laser (Doctor Smile, Italy, LA5D0 001.1) with 0.3-mm spot size at total 21.2 kJ/cm2 for 10 sec; and 810-nm laser at total 10.6 kJ/cm2 for 5 sec, followed by ultrasonic scaling for 5 sec. The 810-nm diode laser removed biofilms with a power of 1.5 W and a power density of 2.12 kW/cm2. The S. mutans biofilm was examined using crystal violet assay, and scanning electron microscopy (SEM) was used for mature multispecies biofilms to evaluate the effect of the three methods on biofilm removal. Live/dead bacterial staining was used to examine the bactericidal effect on remaining biofilms by confocal laser scanning microscopy (CLSM). Results: For S. mutans biofilm, the optical density (OD) value and live/dead bacterial ratio in the laser and the laser combined with ultrasonic scaling groups were significantly lower than those in the ultrasonic scaling group (p < 0.05); moreover, the OD value and the live/dead bacterial ratio in laser treatment combined with ultrasonic scaling and laser treatment alone showed no significant difference (p > 0.05). For mature multispecies biofilms, the percentage of biofilm coverage after treatment was higher in the laser group than in the ultrasonic scaling group (p < 0.05) and lower in the laser combined with ultrasonic scaling group than in the ultrasonic scaling group (p < 0.05), and live/dead bacterial staining showed that laser treatment alone killed the most bacteria, followed by laser treatment combined with ultrasonic scaling, while ultrasonic scaling alone seldom killed bacteria. Conclusions: Laser treatment alone has a better bactericidal effect and can also remove more S. mutans biofilm than ultrasonic scaling alone, but it fails to remove more mature multispecies biofilms. Laser treatment combined with ultrasonic scaling can remove more S. mutans biofilm and mature multispecies biofilms than ultrasonic scaling alone and also has a better bactericidal effect than ultrasonic scaling alone on a bracket surface.

Evaluation of bacterial anti-adhesion and sustained antimicrobial abilities of chlorhexidine gluconate-loaded phase-transited lysozyme nanoparticle suspension on dentine: An exvivo study.

To evaluate the effect of chlorhexidine gluconate-loaded phase-transited lysozyme (CHG@PTL) coating on inhibiting bacterial adhesion and biofilm formation in an exvivo root canal dentine model. The physicochemical and structural characteristics of CHG@PTL nanoparticle suspension and its coating formed on the dentine surface were analysed by thioflavin T fluorescence assay, transmission electron microscopy and confocal laser scanning microscopy (CLSM). The sustained chlorhexidine release profile of the CHG@PTL coating on the dentine surface was compared with that of the 2% CHG solution. By comparing with phosphate-buffered saline, 1% sodium hypochlorite and 2% CHG solutions, the sustained antibacterial ability of the CHG@PTL coating and its effects on adhesion and biofilm formation of three types of bacteria (E. faecalis, S. mutans, and A. viscous) were analysed in exvivo root canal dentine models using the serial plate transfer test (SPTT) and CLSM with live/dead bacterial staining, respectively. CHG promoted the lysozyme protein to form a higher proportion of β-sheet structure during phase transition. In the CHG@PTL nanoparticle suspension, characteristic drug-loaded nanospheres with a high concentration of CHG molecules inside and an outer PTL nanofilm were observed, and they formed a thinner and tighter coating on the dentine surface. The CHG@PTL coating on the dentine surface showed a significantly higher cumulative release amount of chlorhexidine than that of 2% CHG (p < .05). The results of SPTT showed that the CHG@PTL coating had a longer antibacterial duration than the control groups. After 12 h of incubation, a higher number of bacteria were agglutinated on the CHG@PTL coating surface compared to the control groups (p < .05). After 7 days of incubation, the number of agglutinated bacteria significantly decreased. At two time points, the percentage of dead bacteria on the CHG@PTL coating surface was the highest among all experimental groups based on CLSM observation (over 99.9% for all three bacteria, p < .001). CHG@PTL nanoparticle suspension could form an antimicrobial coating on the surface of dentine with a novel 'agglutinating bacteria and sterilizing' mode.

A new model measuring bacterial phagocytosis and phagolysosomal oxidisation in humans using the intradermal injection of methylene blue-labelled Escherichia coli.

Phagocytosis is an important leucocyte function, however using existing models it cannot be measured in human tissues in vivo. To address this, we characterized a new phagocytosis model using intradermal methylene blue-labelled Escherichia coli injection (MBEC). Methylene blue (MB) is a licensed human medicine and bacterial stain potentially useful for labelling E. coli that are safe for human injection. Ex vivo co-culture of leucocytes with MBEC caused MB to transfer into neutrophils and macrophages by phagocytosis. During this, a 'red shift' in MB fluorescence was shown to be caused by phagolysosomal oxidisation. Hence, MBEC co-culture could be used to measure phagocytosis and phagolysosomal oxidisation in humans, ex vivo. In healthy volunteers, inflammatory exudate sampling using suction blisters 2-24h after intradermal MBEC injection showed that tissue-acquired neutrophils and monocytes contained more MB than their circulating counterparts, whereas blood and inflamed tissue T, B and NK cells were MBlo. This was validated with spectral flow cytometry by visualizing the MB emission spectrum in tissue-acquired neutrophils. Neutrophil MB emission spectra demonstrated more 'red shift' at 24h compared to earlier time-points, in-keeping with progressive phagolysosomal MB oxidisation in neutrophils over time in vivo. This new MBEC model can therefore measure bacterial phagocytosis and phagolysosomal oxidisation in human skin, in vivo. This has a number of important research applications, for example in studying human phagocyte biology, testing novel antimicrobials, and understanding why certain groups such as males, the elderly or those with diabetes, recent surgery or malnutrition are at increased risk of bacterial infection.

Evaluating Bacterial Viability in Faecal Microbiota Transplantation: A Comparative Analysis of InVitro Cultivation and Membrane Integrity Methods.

Faecal microbiota transplantation (FMT) is a developing therapy for disorders related to gut dysbiosis. Despite its growing application, standardised protocols for FMT filtrate preparation and quality assessment remain undeveloped. The viability of bacteria in the filtrate is crucial for FMT's efficacy and for validating protocol execution. We compared two methods-in vitro cultivation and membrane integrity assessment-for their accuracy, reproducibility and clinical applicability in measuring bacterial viability in frozen FMT stool filtrate. Bacterial viability in stool filtrate was evaluated using (i) membrane integrity through fluorescent DNA staining with SYTO9 and propidium iodide, followed by flow cytometry and (ii) culturable bacteria counts (colony-forming units, CFU) under aerobic or anaerobic conditions. Using different types of samples (pure bacterial culture, stool of germ-free and conventionally bred mice, native and heat-treated human stool), we refined the bacterial DNA staining protocol integrated with flow cytometry for assessment of bacterial viability in frozen human stool samples. Both the membrane integrity-based and cultivation-based methods exhibited significant variability in bacterial viability across different FMT filtrates, without correlation. The cultivation-based method showed a mean coefficient of variance of 30.3%, ranging from 7.4% to 60.1%. Conversely, the membrane integrity approach yielded more reproducible results, with a mean coefficient of variance for viable cells of 6.4% ranging from 0.2% to 18.2%. Bacterial viability assessment in stool filtrate using the membrane integrity method offers robust and precise data, making it a suitable option for faecal material evaluation in FMT. In contrast, the cultivation-dependent methods produce inconsistent outcomes.

Screening the Subsistence of Bacterial Propagation in Different Units of Tertiary Hospitals in Bangladesh Along with Their Drug Susceptible Pattern

Abstract BACKGROUND: Antibiotic resistance is concerning since it has been associated with higher mortality and healthcare expenditures, especially for patients, physicians, and the healthcare system. In order to address the significant issue of antibiotic-resistant patterns of pathogen, the current research aimed to isolate hospital-acquired bacterial stains from the premises of many private and public medical college hospitals in Dhaka, Bangladesh, India. MATERIALS AND METHODS: To conduct this study, the samples were collected from different units, for example, intensive care unit, general ward, gynecological ward, emergency ward and outdoor unit, employing swab technique method, and transferred aseptically in the Microbiology Laboratory of Stamford University Bangladesh. The drug-resistant profile of the isolates was estimated through the disk-diffusion method. RESULTS: The pattern of resistance of the isolates was clearly evident against seven different antibiotics such as cefexime (5 μg), ciprofloxacin (5 μg), Co-Trimoxazole (25 μg), cefuroxime (30 μg), gentamycin (10 μg), nalidixic acid (30 μg), and Polymyxin B (300 μg). According to our findings, Staphylococcus spp., Escherichia coli, Klebsiella spp., Bacillus anthracis, and Haemophilus influenza showed resistance against all the antibiotics except gentamycin (10 μg). CONCLUSION: The study revealed the multidrug resistance in clinically identified pathogens which is very alarming and could be the prime reason for spading the nosocomial infection.

Veillonella parvula acts as a pathobiont promoting the biofilm virulence and cariogenicity of Streptococcus mutans in adult severe caries.

Adult severe caries (ASC) brings severe oral dysfunction and treatment difficulties to patients, and yet no clear pathogenic mechanism for it has been found. This study is focused on the composition of dental plaque microbiome profiles in order to identify disease-relevant species and to investigate into their interactions with the S. mutans. Samples of dental plaque were collected for metagenomic analysis. The acidification, aciduricity, oxidative stress tolerance, and gtf (glucosyltransferase) gene expression of S. mutans cocultured with V. parvula which was identified as ASC-related dominant bacterium. The biofilm formation and extracellular exopolysaccharide (EPS) synthesis of dual-strain were analyzed with scanning electron microscopy (SEM), crystal violet (CV) staining, live/dead bacterial staining, and confocal laser scanning microscopy (CLSM). Furthermore, rodent model experiments were performed to validate the in vivo cariogenicity of the dual-species biofilm. The most significantly abundant taxon found associated with ASC was V. parvula. In vitro experiments found that V. parvula can effectively promote S. mutans mature biofilm formation with enhanced acid resistance, hydrogen peroxide detoxicity, and biofilm virulence. Rodent model experiments revealed that V. parvula was incapable of causing disease on its own, but it significantly heightened the biofilm virulence of S. mutans when being co-infected and augmented the progression, quantity, and severity of dental caries. Our findings demonstrated that V. parvula may act as a synergistic pathobiont to modulate the metabolic activity, spatial structure, and pathogenicity of biofilms of S. mutans in the context of ASC.IMPORTANCEAdult severe caries (ASC), as a special type of acute caries, is rarely reported and its worthiness of further study is still in dispute. Yet studies on the etiology of severe caries in adults have not found a clear pathogenic mechanism for it. Knowledge of the oral microbiota is important for the treatment of dental caries. We discovered that the interaction between V. parvula and S. mutans augments the severity of dental caries in vivo, suggesting V. parvula may act as a synergistic pathobiont exacerbating biofilm virulence of S. mutans in ASC. Our findings may improve the understanding of ASC pathogenesis and are likely to provide a basis for planning appropriate therapeutic strategies.

Highly efficient and broad-spectrum antibacterial carbon dots combat antibiotic resistance

Bacterial infections have become a major global public health issue, particularly with the emergence of multidrug-resistant strains. Therefore, developing non-antibiotic antimicrobial agents is crucial for treating drug-resistant bacterial infections. Building on previous research into natural products as novel antibacterial agents, this study synthesized curcumin-derived carbon dots using curcumin and ethylenediamine as raw materials through a hydrothermal method. The resulting carbon dots not only improved the water solubility and stability of curcumin but also exhibited highly efficient broad-spectrum antibacterial activity. Detailed investigations into the antibacterial performance and mechanisms of the carbon dots were conducted through experiments such as minimum inhibitory concentration (MIC) determination, live/dead bacterial staining, morphological studies, nucleic acid concentration detection, and reactive oxygen species (ROS) detection. The results indicated that the carbon dots significantly damaged the structural integrity of bacteria and generated large amounts of ROS. They exhibited remarkable antibacterial effects against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, and effectively inhibited drug-resistant MRSA. Their antibacterial efficacy was notably superior to that of broad-spectrum antibiotics such as chloramphenicol and Sulfadiazine. This study highlights the potential application of curcumin-derived carbon dots in combating bacterial infections and provides valuable insights for developing novel antibacterial agents derived from natural products.

Enhanced Antibacterial Activity of Carbon Dots: A Hybrid Approach with Levofloxacin, Curcumin, and Tea Polyphenols

Bacterial infections and their increasing resistance to antibiotics pose a significant challenge in medical treatment. This study presents the synthesis and characterization of novel carbon dots (CDs) using levofloxacin (Lf), curcumin (Cur), and tea polyphenols (TP) through a facile hydrothermal method. The synthesized curcumin-tea polyphenol@carbon dots (Cur-TP@CDs) and levofloxacin-tea polyphenol@carbon dots (Lf-TP@CDs) were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, confirming their unique structural and chemical properties. Cur-TP@CDs exhibited an average particle size of 1.32 nanometers (nm), while Lf-TP@CDs averaged 1.58 nm. Both types demonstrated significant antibacterial activity, with Lf-TP@CDs showing superior effectiveness against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in broth dilution and disc diffusion assays. Biofilm inhibition assays revealed a significant reduction in biofilm formation at higher concentrations. The ultraviolet-visible (UV-vis) and photoluminescence (PL) spectral analyses indicated efficient photon emission, and electron paramagnetic resonance (EPR) analysis showed increased singlet oxygen generation, enhancing bactericidal effects. Live and dead bacterial staining followed by scanning electron microscopy (SEM) analysis confirmed dose-dependent bacterial cell damage and morphological deformities. These findings suggest that Cur-TP@CDs and Lf-TP@CDs are promising antibacterial agents, potentially offering a novel approach to combat antibiotic-resistant bacterial infections.

Bio‐Extract Mediated Synthesis of Y/Fe2O3 Nanoparticles Using Adenanthera pavonina L. and Their Photocatalytic and Antibacterial Activities

AbstractThe present study uses Adenanthera pavonina L. plant extract to synthesize Y/Fe2O3 nanoparticles in a sustainable and efficient manner. Several physicochemical investigations were performed on the synthesized Y/Fe2O3 to evaluate its structure and morphological characteristics. The high crystallinity of Fe2O3 and decreased crystal size of Y/Fe2O3 were revealed by the XRD study. The formulated Y/Fe2O3 was spherical in shape. Y/Fe2O3 has shown potential photocatalytic activity in the degradation of congo red and brilliant green dyes in the presence of visible light. Degradation efficiency is higher than 90% for both dyes. In addition, the antibacterial activity of Y/Fe2O3 was measured against pathogenic strains of Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Proteus mirabilis, Pseudomonas putida, Shigella dysenteriae, and Staphylococcus aureus. Y/Fe2O3 showed promising antibacterial activity against all microorganisms. Micrococcus luteus showed a higher zone of inhibition (equal to 35 mm in diameter) than other microorganisms using Y/Fe2O3. Thus, it is established that the green synthesized Y/Fe2O3 nanoparticles are active catalysts for the photocatalytic degradation of hazardous dyes and have antibacterial properties against different bacterial stains.

Novel [plant essential oils@γ-CD MOF]/ZIF-8 strategy to remove bacteria and dye from bacterial staining wastewater

A novel MOF-on-MOF ([plant essential oils@γ-CD MOF]/ZIF-8) strategy was established in this work, in which a cyclodextrin metal–organic framework (γ-CD MOF) loaded with plant essential oils (cinnamon and oregano oils, COEO) was combined with zeolitic imidazolate framework (ZIF-8) to produce ([COEO@γ-CD MOF]/ZIF-8) for the removal of bacteria and dyes from bacterial staining wastewater. Adsorption isotherm and kinetic studies showed that [COEO@γ-CD MOF]/ZIF-8 could adsorb methylene blue (MB) by monolayer chemisorption with a Qmax of 111.6 mg/g. No bacterial colonies grew on plates treated with [COEO@γ-CD MOF]/ZIF-8, and scanning electron microscope (SEM) images showed a disruption of E. coli and S. aureus structures. This work offers a simple and green method for treating bacterial staining wastewater in microbiology labs.

Benzothiazole-based Schiff base for sensing Ca2+ ions: Synthesis, DFT studies, toxicity evaluation in zebrafish embryo and in silico analysis of MMP-9 inhibition

A new heterocyclic Schiff base, 2-(2-benzo(d)thiazol-2yl)hydrazono)methyl)phenol (BTAZ) synthesized from 2-hydrazinobenzothaizole and salicyclaldehyde was characterized by spectral, mass and single crystal XRD data and subjected to sense Ca2+ ions in methanol–water mixture (1:1, v/v) using UV–visible absorption and fluorescence emission spectral studies. The probe BTAZ showed specific detection of Ca2+ ions in a solution containing various metal ions with a detection limit as low as 5.1 × 10−6 M via photo-induced electron transfer (PET) pathway. The binding stoichiometry between BTAZ and Ca2+ was determined to be 2:1 by Job’s plot method. The stoichiometry and optical properties of both BTAZ and BTAZ-Ca2+ complex showed good correlation with theoretical results based on DFT and TD-DFT calculations. The pharmacological evaluation of the probe BTAZ against bacterial and fungal stains also demonstrated its notable efficacy to control their growth in vitro along with anti-oxidant capabilities. Further, toxicity assay of the probe BTAZ against zebrafish embryo did demonstrate that it is non-toxic to the test model in vivo. Ability of the probe BTAZ to inhibit matrix metalloproteinase-9 (MMP-9) enzyme was analyzed in detail using in silico experiments.

In-situ synthesis and evaluation of anti-bacterial efficacy and angiogenesis of curcumin encapsulated lipogel dermal patch for wound healing applications

The development of synthetic hydrogels as a dermal patch offers unique advantage of providing moist environment around the wound site. The incorporation of curcumin in hydrogel plays a significant role in the healing process of chronic wounds. The present investigation aims to develop nano-formulated curcumin-fused lipogel to impart the dual advantages of sustained drug release and enhanced wound healing ability. The wound healing behaviour of the prepared lipogel has been assessed through series of techniques namely DPPH assay and bacterial inhibitory efficacy through the Kirby Bauer assay against E. coli and S. aureus. Further, the promotion of angiogenesis has been determined through an in-ovo CAM assay. The results obtained from the investigation revealed the enhanced solubility of curcumin in liposome formulation. Moreover, the encapsulation of curcumin in liposomes facilitated prolonged drug release and better antibacterial efficacy against the tested bacterial stains. The developed hydrogel also displayed good adhesion and water retention ability, which is an important prerequisite for better wound healing ability.

A Four-Year Trend of Ceftriaxone Resistance and Associated Risk Factors Among Different Clinical Samples in Wad Medani, Sudan: A Cross-Sectional Retrospective Study.

Introduction In sub-Saharan Africa, including Sudan, there is commonly no local data on the bacterial profile or antibiotic resistance pattern. Therefore, to bridge these gaps, this study aimed to evaluate ceftriaxone resistance patterns and associated risk factors among different clinical samples. Methods This study was a laboratory-based, retrospective,cross-sectional study. All clinical specimens were obtained from patients at Wad Medani and examined at the Pathology Center for Diagnosis and Research, Faculty of Medicine, University of Gezira, Sudan, from January 2020 to October 2023. Results Overall, 1784 specimens exhibited bacterial growth over four years. Of these, 1260 (70.6%) were females. Approximately one-third of the 588 (33%) studied patients were aged 30 to 44 years. Of the studied samples, 1108 (62.1%) were urine, and 465 (26.1%) were wound swabs. Staphylococcus aureus(697, 39.1%) and Escherichia coli(656, 36.8%) were the most frequently encountered bacteria. Generally, ceftriaxone resistance has been evaluated in 150 positive culture samples. The overall ceftriaxone resistance rate was 106 (70.7%). The greatest proportion of ceftriaxone resistance was observed in 4/4 (100%) of Klebsiella spp. and 66/82 (80.5%)of E. coli strains. The type of isolate (95% Cl, p-value; 0.006) and type of bacterial stain (95% Cl, p-value0.013) have been significantly associated with ceftriaxone resistance, in which Gram-negative bacteria had a greater resistance rate of 98/132 (74.2%)than Gram-positive bacteria 8/18 (44.4%). Conclusions This study revealed a high rate of ceftriaxone resistance. The most resistant bacteria were Klebsiella spp. and E. coli. The type of isolate and bacterial stain were significantly associated with ceftriaxone resistance. Therefore, hospitals should immediately and significantly modify their antibiotic prescription policy to give doctors a consistent strategy for the rational, safe, and effective administration of antibiotics.

A New Nanoplatform Under NIR Released ROS Enhanced Photodynamic Therapy and Low Temperature Photothermal Therapy for Antibacterial and Wound Repair.

Skin injury, often caused by physical or medical mishaps, presents a significant challenge as wound healing is critical to restore skin integrity and tissue function. However, external factors such as infection and inflammation can hinder wound healing, highlighting the importance of developing biomaterials with antibiotic and wound healing properties to treat infections and inflammation. In this study, a novel photothermal nanomaterial (MMPI) was synthesized for infected wound healing by loading indocyanine green (ICG) on magnesium-incorporated mesoporous bioactive glass (Mg-MBG) and coating its surface with polydopamine (PDA). In this study, Mg-MBG and MMPI was synthesized via the sol-gel method and characterized it using various techniques such as scanning electron microscopy (SEM), the energy dispersive X-ray spectrometry (EDS) system and X-ray diffraction (XRD). The cytocompatibility of MMPI was evaluated by confocal laser scanning microscopy (CLSM), CCK8 assay, live/dead staining and F-actin staining of the cytoskeleton. The antibacterial efficiency was assessed using bacterial dead-acting staining, spread plate method (SPM) and TEM. The impact of MMPI on macrophage polarization was initially evaluated through flow cytometry, qPCR and ELISA. Additionally, an in vivo experiment was performed on a mouse model with skin excision infected. Histological analysis and RNA-seq analysis were utilized to analyze the in vivo wound healing and immunomodulation effect. Collectively, the new photothermal and photodynamic nanomaterial (MMPI) can achieve low-temperature antibacterial activity while accelerating wound healing, holds broad application prospects.