Efficacy and safety of preventing catheter-associated urinary tract infection by inhibiting catheter bacterial biofilm formation: a multicenter randomized controlled trial.

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) remains the most significant challenge among hospital-acquired infections (HAIs), yet still unresolved. The present study aims to evaluate the preventive effectiveness of JUC Spray Dressing (name of U.S. FDA and CE certifications, while the medical device name in China is Long-acting Antimicrobial Material) alone for CAUTI without combining with antibiotics and to evaluate the impact of bacterial biofilm formation on CAUTI results on the inserted catheters of patients. METHODS: In this multicenter, randomized, double-blind study, we enrolled adults who suffered from acute urinary retention (AUR) and required catheterization in 6 hospitals in China. Participants were randomly allocated 1:1 according to a random number table to receive JUC Spray Dressing (JUC group) or normal saline (placebo group). The catheters were pretreated with JUC Spray Dressing or normal saline respectively before catheterization. Urine samples and catheter samples were collected after catheterization by trial staff for further investigation. RESULTS: From April 2012 to April 2020, we enrolled 264 patients and randomly assigned them to the JUC group (n = 132) and the placebo group (n = 132). Clinical symptoms and urine bacterial cultures showed the incidence of CAUTI of the JUC group was significantly lower than the placebo group (P < 0.01). In addition, another 30 patients were enrolled to evaluate the biofilm formation on catheters after catheter insertion in the patients' urethra (10 groups, 3 each). The results of scanning electron microscopy (SEM) showed that bacterial biofilm formed on the 5th day in the placebo group, while no bacterial biofilm formed on the 5th day in the JUC group. In addition, no adverse reactions were reported using JUC Spray Dressing. CONCLUSION: Continued indwelling urinary catheters for 5 days resulted in bacterial biofilm formation, and pretreatment of urethral catheters with JUC Spray Dressing can prevent bacterial biofilm formation by forming a physical antimicrobial film, and significantly reduce the incidence of CAUTI. This is the first report of a study on inhibiting bacterial biofilm formation on the catheters in CAUTI patients.

Key biological processes and essential genes for Proteus mirabilis biofilm development inhibition by protocatechuic acid.

Proteus mirabilis is an opportunistic pathogen linked to human urinary tract infections, and is potentially present as a foodborne pathogen within poultry products, including broiler chickens. This report outlines the inhibitory impacts of protocatechuic acid (PCA) on P. mirabilis isolated from a broiler slaughterhouse in China as well as its biofilm. This investigation encompasses assays related to motility and adhesion, bacterial metabolic activity, extracellular polymer (EPS) production, and scavenging capacity. The findings demonstrated that PCA reduced biofilm formation by 61 %. Transcriptomics findings identified that PCA limited the expression of genes like PstS that promote adhesin formation, rbsA and RcsB that alter bacterial chemotaxis, lipopolysaccharide synthesis genes LpxA and EptB, and cell wall synthesis genes MurF and MrdA, and affects the Regulator of Capsule Synthesis (RCS) two-component modulation system. Weighted gene co-expression network analysis (WGCNA) was conducted to identify the core genes. Furthermore, the binding sites of PCA to cytochrome oxidases cydA and cydB, two subunits of ATP synthase atpI and atpH, and ftsZ, which regulate bacterial division, were predicted via molecular docking. Metabolome analysis determined that PCA critically influenced coenzyme A biosynthesis, nucleotide metabolism, alanine, aspartic acid, and glutamate metabolic pathways of P. mirabilis. Therefore, PCA impacts metabolism within bacteria via various pathways, limiting the levels of extracellular polymer and bacterial viability to hinder biofilm formation. Additionally, we prepared an antibacterial plastic film containing protocatechuic acid using PVA as the monomer and CNC as the reinforcing agent. We examined the mechanical and antibacterial properties of this film. When used to wrap chicken, it reduced the total number of colonies, slowed the deterioration of chicken, and maintained the freshness of chicken. In conclusion, the information outlined in this study complements our comprehension of P. mirabilis inhibition by PCA and provides clues for the reduction of foodborne infections associated with P. mirabilis.

Optimization and characterization of taro starch, nisin, and sodium alginate-based biodegradable films: antimicrobial effect in chicken meat.

Biodegradable films based on polymers from renewable resources have become a feasible technology to preserve the quality (texture, color, flavor) and safety of food. The addition of antimicrobial agents to films can prevent the growth of pathogenic microorganisms that affect meat and poultry products. In this study, a biodegradable film with sodium alginate (SA), taro starch (MS), and nisin (Nis) was optimized to have high tensile strength (TS), breaking force (BF), and a low water vapor permeability (WVP) using a Box-Behnken response surface design, and its antimicrobial effect was evaluated in relation to its use as a packaging material for chicken meat. The OB was characterized via analysis of its mechanical, physical, and chemical properties; in addition, the total migration of Nis was also analyzed, along with its retention ability, the kinetics of the release of Nis into food simulants, and its antimicrobial activity against Listeria monocytogenes in vitro and on inoculated chicken meat. The resulting optimal OB was produced with 1.9% MS, 1% glycerol (G), and 2,369 IU/mL of Nis, and displayed adequate TS and WVP. The OB significantly reduced the microbial load and helped extend the shelf life of the chicken meat under refrigeration by up to 15 d. Total migration and the kinetics of the release of Nis showed that the OB can be used on hydrophilic and acidic foods, making it a natural alternative for use in food packaging.

Synergistic effect of graphene oxide/zinc oxide nanocomposites on polylactic acid-based active packaging film: Properties, release kinetics and antimicrobial efficiency.

Incorporating two different nanoparticles in nanocomposite films is promising as their synergistic effects could significantly enhance polymer performance. Our previous work conferred the remarkable antimicrobial (AM) properties of the polylactic acid (PLA)-based film using optimal formulations of synergistic graphene oxide (GO)/zinc oxide (ZnO) nanocomposites. This study further explores the release profile of GO/ZnO nanocomposite and their impact on the antimicrobial properties. A fixed 1.11 wt% GO and different ZnO concentrations were well dispersed in the PLA matrix. Increasing ZnO concentrations tended to increase agglomeration, as evident in rougher surfaces. Agglomeration inhibited water penetration, leading to a significant reduction in water permeability (46.3 %), moisture content (31.6 %) but an improvement in Young's Modulus (52.6 %). The overall and specific migration of GO/ZnO nanocomposites was found to be within acceptable limits. It is inferred that the release of Zn2+ ions followed pseudo-Fickian behavior with an initial burst effect. AM film with the highest concentration of ZnO (1.25 wt%) exhibited the highest inhibition rate against Escherichia coli (68.0 %), Bacillus cereus (66.5 %), Saccharomyces cerevisiae (70.9 %). Results suggest that GO/ZnO nanocomposites with optimal ZnO concentrations have the potential to serve as promising antimicrobial food packaging materials, offering enhanced barrier, antimicrobial properties and a controlled release system.

Chitosan-based composite films containing eugenol nanoemulsion, ZnO nanoparticles and Aloe vera gel for active food packaging.

Biopolymer-based food packaging films are gaining increasing popularity, as consumers' demands for sustainable alternatives and environmental concerns associated with synthetic plastic packaging grow. In this research work, chitosan-based active antimicrobial films reinforced with eugenol nanoemulsion (EuNE), Aloe vera gel, and zinc oxide nanoparticles (ZnONPs) were fabricated and characterized for their solubility, microstructure, optical properties, antimicrobial and antioxidant activities. The rate of release of EuNE from the fabricated films was also evaluated to determine active nature of the films. The EuNE droplet size was about 200 nm, and they were uniformly distributed throughout the film matrices. Incorporation of EuNE in chitosan drastically improved UV-light barrier property of the fabricated composite film by 3 to 6 folds, while maintaining their transparency. The XRD spectra of the fabricated films showed good compatibility between the chitosan and the incorporated active agents. The incorporation of ZnONPs significantly improved their antibacterial properties against foodborne bacteria and tensile strength about 2-folds, whereas incorporation of EuNE and AVG improved DPPH scavenging activities of the chitosan film up to 95 %, respectively.

Development of antimicrobial gelatin-ulvan-beeswax composite films: Optimization of formulation using mixture design methodology.

A new generation of antimicrobial film was developed by incorporation of ulvan extracted from Ulva intestinalis into gelatin from common carp scale and its water sensitivity was reduced with addition of beeswax. Optimum composition of gelatin (0-100%w/w), ulvan (0-100%w/w) and beeswax (0-10%w/w) for achieving composite films with minimum water solubility (S) and water vapor permeability (WVP) and maximum tensile strength (TS), elongation at break point (EAB) and antibacterial effect on E. coli (EC) were investigated using mixture design methodology. Both pure gelatin and ulvan films and their composites had relatively good mechanical and optical properties. Addition of ulvan to gelatin produced composite films with good antibacterial properties but water resistance of all the films was weak. Addition of beeswax up to ∼5 % improved the water resistance and mechanical properties of the films without jeopardizing their antibacterial properties. The final optimum formulation with a desirability of 0.709 was achieved as 52.18 % of gelatin, 40.83 % of ulvan and 6.97 % of beeswax resulting in a minimum possible S (40 %) and WVP (1.86 10-10 g/ms Pa) and maximum possible TS (6.23 MPa) and EAB (89 %) with good EC (7.66 mm). Finally, good mechanical, thermal and microstructural properties of the optimum composite film was confirmed. Altogether, a combination of ulvan and beeswax can be a promising solution for development of gelatin films with both antimicrobial properties and lower water sensitivity.

Antimicrobial Activity of Chitosan/Gelatin/Poly(vinyl alcohol) Ternary Blend Film Incorporated with Duchesnea indica Extract in Strawberry Applications.

Chitosan (CTS)/gelatin (GEL)/poly(vinyl alcohol) (PVA)-based composite films with different concentrations of Duchesnea indica extract (DIE) (6.25 and 25 mg/mL), an antimicrobial agent, were manufactured using a casting technique. Results indicated that elongation at break decreased as DIE was added at higher concentrations. Composite films showed no significant differences in thickness, tensile strength, and water vapor permeability. Scanning electron microscopy images revealed that DIE was successfully incorporated into film matrices to interact with polymers. The addition of DIE to the film inhibited the growth of S. aureus by up to 4.9 log CFU/mL. The inhibitory effect on S. aureus using DIE-incorporated coating applied to strawberries was greatest at room temperature storage for 24 h only when it was coated twice or more. The maximum inhibition in strawberries was 2.5 log CFU/g when they were coated twice and 3.2 log CFU/g when they were coated three times. The results of this study suggest that DIE could be used as a natural antimicrobial agent, and DIE-integrated CTS/GEL/PVA films or coatings have potential as a food packaging alternative for preventing foodborne pathogen contamination.

Transparent, Robust, and Photochemical Antibacterial Surface Based on Hydrogen Bonding between a Si-Al and Cationic Dye.

Healthcare-associated infections can occur and spread through direct contact with contaminated fomites in a hospital, such as mobile phones, tablets, computer keyboards, doorknobs, and other surfaces. Herein, this study shows a transparent, robust, and visible light-activated antibacterial surface based on hydrogen bonds between a transparent silica-alumina (Si-Al) sol-gel and a visible light-activated photosensitizer, such as crystal violet (CV). The study of the bonding mechanisms revealed that hydrogen bonding predominantly occurs between the N of CV and Al-OH. Apart from CV, Si-Al can be combined with a variety of dyes, highlighting its potential for wide application. The Si-Al@CV film selectively generates singlet oxygen using ambient visible light, triggering potent photochemical antibacterial performance against Gram-positive and Gram-negative bacteria. Additionally, the Si-Al@CV film is stable even after mechanical stability tests such as tape adhesion, scratch, bending, and water immersion. In vitro cytotoxicity tests using C2C12 myoblast cells showed that the Si-Al@CV film is a biocompatible material. This work suggests a new approach for designing a transparent and robust touchscreen surface with photochemical antibacterial capability against healthcare-associated infections.

Biocidal Coatings from Complexes of Carboxylated Latex Particles and a Linear Cationic Polymer.

A linear polycation, poly(diallyldimethylammonium chloride), electrostatically interacts with anionic latex particles from a carboxylated butadiene-styrene copolymer in aqueous solution thus forming an interpolyelectrolyte complex. A mutual neutralization of oppositely charged latex and polycation groups occurs at W = latex/polycation = 50 w/w ratio. At W = 27, an ultimate polycation adsorption is reached, resulting in the formation of positive polycomplex particles, while at W ˂ 27, two-component systems are formed composed of positive polycomplex particles and free polycation. A film created from the W = 12 formulation shows a high toxicity to Gram-positive and Gram-negative bacteria and yeast. Repeated washing the film leads to partial removal of polycation and a 50% decrease in the activity of the film only towards Gram-negative Pseudomonas aeruginosa. The results indicate the potential for use of the mixed polymer formulations for the fabrication of antimicrobial films and coatings.

Tough, antibacterial fish scale gelatin/chitosan film with excellent water vapor and UV-blocking performance comprising liquefied chitin and silica sol.

Developing biodegradable, and non-toxic materials to replace petrochemical polymers is important. Herein, the waste fish scale-derived gelatin was chosen to prepare an environmental-friendly film. While the natural product of fish scale gelatin (FSG) films has the weakness of low humidity stability, poor antibacterial activity, poor mechanical strength, and weak UV absorption. Hence, a novel multifunctional and mechanically robust FSG-based composite is proposed using chitosan (CTS) as the crosslinking matrix, liquefied chitin product (LCP), and silica sol as the functional fillers. The thermal decomposition kinetics and pyrolysis analysis show that the functional filling components were compatible with the FSG/CTS-based macromolecule matrix. The incorporation of LCP significantly improved the film's flexibility, antibacterial capacity, and UV absorption. The addition of the silica sol also increased the mechanical strength and water tolerance with decreased water vapor permeability (WVP). The increasing apparent activation energy (Ea) along with pyrolysis reactions could correlate well with the composite film's progressive crosslinks. This study demonstrated a renewable FSG/CTS/LCP/Si composite film with a much-improved property that could have potential applications in film-based packaging.

Easy Fabrication of a Polymeric Transparent Sheet to Combat Microbial Infection.

Surges in infectious diseases and their transmission in households and commercial and healthcare settings have increased the use of polymeric materials as protective covers. Despite ongoing efforts, conventional polymeric materials still pose the threat of surface-associated transmission of pathogens due to the fact that they lack antimicrobial properties. Here, we have developed an easy-to-fabricate polymeric sheet [quaternary polymeric transparent sheet (QPTS)] that shows an excellent antimicrobial property and is also transparent in nature, increasing its practical applications in a wide range of surfaces. The sheet was fabricated by combining cationic amphiphilic water-soluble polyethylenimine derivative (QPEINH-C6) and poly(vinyl alcohol) (PVA). The optimum composition (QPTS-3) exhibited a complete reduction of bacterial and fungal infection (∼3-4 log reduction) within 15 min. QPTS-3 also exhibited activity against antibiotic-insusceptible metabolically inactive bacterial cells. The sheet prevented the growth of MRSA biofilm even after 72 h of incubation, which was confirmed through electron microscopy on the QPTS sheet. Most importantly, ∼99.9% of the influenza viral load was reduced completely within 30 min of exposure of the sheet. Apart from the antimicrobial property, the sheet successfully retained its transparency (∼88%) and maintained a significant mechanical strength (∼15 N), highlighting its potential applications in commercial and healthcare settings.

Preparation and characterization of chitosan-based antimicrobial films containing encapsulated lemon essential oil by ionic gelation and cranberry juice.

Research about biodegradable antimicrobial films continues to receive a lot of attention due to the plastic pollution crisis and the need for environment-friendly and safe food products. In this study, we developed chitosan-based antimicrobial films using a combination of encapsulated lemon essential oil (LEO) by ionic gelation and cranberry juice and evaluated the performance of the films. Our results indicated that the incorporation of LEO microspheres and cranberry juice into the chitosan films improved the UV barrier and thermal properties as well as antioxidant activity of the films. The increase in antioxidants was consistent with the chemical components in LEO and cranberry juice as determined by GC-MS; some of which possess antioxidant properties. Furthermore, following antimicrobial activity test, considerable inhibition halo of 11 and 20 mm were observed respectively against fungi Candida albicans and Penicillium roqueforti, particularly in presence of the film containing both LEO microspheres and cranberry juice.

Active Flexible Films for Food Packaging: A Review.

Active food packaging is a dynamic area where the scientific community and industry have been trying to find new strategies to produce innovative packaging that is economically viable and compatible with conventional production processes. The materials used to develop active packaging can be organized into scavenging and emitting materials, and based on organic and inorganic materials. However, the incorporation of these materials in polymer-based flexible packaging is not always straightforward. The challenges to be faced are mainly related to active agents' sensitivity to high temperatures or difficulties in dispersing them in the high viscosity polymer matrix. This review provides an overview of methodologies and processes used in the production of active packaging, particularly for the production of active flexible films at the industrial level. The direct incorporation of active agents in polymer films is presented, focusing on the processing conditions and their effect on the active agent, and final application of the packaging material. Moreover, the incorporation of active agents by coating technologies and supercritical impregnation are presented. Finally, the use of carriers to help the incorporation of active agents and several methodologies is discussed. This review aims to guide academic and industrial researchers in the development of active flexible packaging, namely in the selection of the materials, methodologies, and process conditions.

Evaluation of the Antimicrobial, Thermal, Mechanical, and Barrier Properties of Corn Starch-Chitosan Biodegradable Films Reinforced with Cellulose Nanocrystals.

Packaging materials play an essential role in the preservation and marketing of food and other products. To improve their conservation capacity, antimicrobial agents that inhibit bacterial growth are used. Biopolymers such as starch and chitosan are a sustainable alternative for the generation of films for packaging that can also serve as a support for preservatives and antimicrobial agents. These substances can replace packaging of synthetic origin and maintain good functional properties to ensure the quality of food products. Films based on a mixture of corn starch and chitosan were developed by the casting method and the effect of incorporating cellulose nanocrystals (CNC) at different concentrations (0 to 10% w/w) was studied. The effect of the incorporation of CNC on the rheological, mechanical, thermal and barrier properties, as well as the antimicrobial activity of nanocomposite films, was evaluated. A significant modification of the functional and antimicrobial properties of the starch-chitosan films was observed with an increase in the concentration of nanomaterials. The films with CNC in a range of 0.5 to 5% presented the best performance. In line with the physicochemical characteristics which are desired in antimicrobial materials, this study can serve as a guide for the development this type of packaging for food use.

Sodium alginate/gum arabic/glycerol multicomponent edible films loaded with natamycin: Study on physicochemical, antibacterial, and sweet potatoes preservation properties.

Sweet potato (Ipomonea batatas Lam) is easily damaged due to its thin skin, which is limited in shelf life and causes enormous economic losses in the food industry. A new type of safe, non-toxic, and edible antibacterial functional film was developed with sodium alginate (2.5 %), gum arabic (1 %), glycerol (2 %), and natamycin as an antimicrobial agent in this study. The physical and antibacterial properties of films, such as thickness, chromaticity, water vapor permeability, tensile strength, and elongation at break, were studied. Furthermore, the antibacterial film was applied in the preservation of sweet potatoes. The results showed that natamycin emulsion had good compatibility with sodium alginate. Besides reducing the transparency of the composite membrane, the mechanical properties, barrier properties, and thermal stability of the composite film were significantly enhanced by the addition of natamycin prepared by a pH-cycle method. When the concentration of natamycin in the membrane solution reached 40 µg/mL or more, the antibacterial film had a noticeable inhibitory effect on the growth of molds, and yeasts, significantly enhancing the bacteriostatic effect of the base film. During the sweet potatoes storage, the water content, total starch content, Vc content, and flavonoid glycoside content of sweet potato showed a downward trend. However, the treatment of antibacterial film containing natamycin could slow down the physiological and quality changes of sweet potatoes during conventional storage, and the sweet potatoes still had good processing quality after 120 days of storage.

Development and characterization of levan/pullulan/chitosan edible films enriched with ε-polylysine for active food packaging.

The levan/pullulan/chitosan edible films, enriched with ε-polylysine, as an antimicrobial agent, were successfully fabricated by the casting method, and their applicability for food packaging was systematically evaluated by several analytical techniques. An increase in the levan/pullulan ratios (ranged from 0:6 to 3:3) in the films showed a decreased water solubility (from 72.21% to 26.64%) and oxygen permeability (from 48.75 × 10-2 g·mm·m-2·d-1·kPa-1 to 4.45 × 10-2 g·mm·m-2·d-1·kPa-1), and increased elongation at break (from 10.92% to 46.61%). All the films showed a strong inhibitory effect on two typical food-borne pathogens and good biodegradability in the soil. These films were employed as edible coatings on strawberries, and the storage stability was investigated by means of physical and biochemical parameters. Compared to control, the weight loss, firmness, and total soluble solids of the coated strawberries showed a downward trend. Overall, these findings suggest that the developed edible films could be a potential approach for sustainable active food packaging.

Antimicrobial starch/poly(butylene adipate-co-terephthalate) nanocomposite films loaded with a combination of silver and zinc oxide nanoparticles for food packaging.

Antimicrobial starch/PBAT films with the combination of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) were prepared by extrusion blowing. SEM demonstrated the relatively homogeneous distribution of nanoparticles on the fracture surfaces of the nanocomposite films. The incorporation of nanoparticles improved mechanical and barrier properties of the film. The UV-vis spectroscopy revealed that the SP-ZnO(1) film had the highest UV-absorbance. The inhibition effects of the nanocomposite films against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria were observed. The antimicrobial efficiency of SP-Ag(0.8)-ZnO(0.2) and SP-Ag(0.6)-ZnO(0.4) films reached more than 95% within 3 h of contact. The combination of AgNPs and ZnONPs into starch/PBAT blends showed synergistic effects on improving material properties and antimicrobial efficiency of the films. Furthermore, preliminary packaging studies on peaches and nectarines revealed that the antimicrobial films inhibited spoilage of fresh produce and extended their shelf life compared with commercial LDPE packaging films.

Production of Fungal Nanochitosan Using High-Pressure Water Jet System for Biomedical Applications.

In this present work, fungal nanochitosans, with very interesting particle size distribution of 22 µm, were efficiently generated in high-yield production using a high-pressure water jet system (Star Burst System, Sugino, Japan) after 10 passes of mechanical treatment under high pressure. The specific characterization of fungal chitosan nanofibers suspensions in water revealed a high viscosity of 1450 mPa.s and an estimated transparency of 43.5% after 10 passes of fibrillation mechanical treatment. The mechanical characterization of fungal nanochitosan (NC) film are very interesting for medical applications with a Young's modulus (E), a tensile strength (TS), and elongation at break (e%) estimated at 2950 MPa, 50.5 MPa, and 5.5%, respectively. Furthermore, we exhibited that the fungal nanochitosan (NC) film presented very good long-term antioxidant effect (reached 82.4% after 96 h of contact with DPPH radical solution) and very interesting antimicrobial activity when the nanochitosan (NC) fibers are mainly activated as NC-NH3+ form at the surface of the film with 45% reduction and 75% reduction observed for S. aureus (Gram-positive) and E. coli (Gram-negative), respectively, after 6 h of treatment. These promising antimicrobial and antioxidant activities indicated the high potential of valorization toward biomedical applications.

Starch/PBAT blown antimicrobial films based on the synergistic effects of two commercial antimicrobial peptides.

In this study, starch/PBAT antimicrobial film, based on the synergistic effects of two commercial antimicrobial peptides, was fabricated by blown extrusion. The blends with nisin exhibited higher storage modulus and complex viscosity than those with ε-polylysine hydrochloride (ε-PL) alone. ATR-FTIR spectra revealed that new intermolecular hydrogen bonds were formed among starch, nisin, and ε-PL. XRD results indicated that antimicrobial peptides facilitated the destruction of the original crystalline structure of starch. Combination of ε-PL and nisin enhanced tensile strength, flexibility, moisture permeability, and oxygen barrier property of the films with more homogeneous morphology. SP-PN1/2 film (1% ε-PL + 2% nisin) exhibited over 90% inhibition rates against Staphylococcus aureus and Escherichia coli, and prolonged the shelf life of fresh peaches. The antimicrobial film with nisin and ε-PL showed high safety, cost-effectiveness, consumer acceptability, and thus it had a good application prospect in the food packaging field.

Antimicrobial and indicator properties of edible film containing clove bud oil-loaded chitosan capsules and red cabbage for fish preservation.

For safe preservation and consumption of fish, freshness monitoring and antimicrobial control is crucial. Edible films comprising natural antimicrobial and spoilage indicator agents represent a convenient method for such preservation. Edible chitosan-based films were prepared using red cabbage (RC) and clove bud oil (CBO)-loaded chitosan/carrageenan capsules as spoilage indicator and antimicrobial agents, respectively. CBO-loaded capsules were prepared by the ionic gelation of chitosan and carrageenan. Films containing CBO capsules exhibited significantly higher antimicrobial activity than films containing non-encapsulated free CBO, as confirmed by minimum inhibitory concentration and time-kill assays. The highest antimicrobial activity was observed in the largest capsules (1.7 µm). After incubation for 48 h, the pH of fish peptone agar containing Pseudomonas fluorescens increased from approximately 6.0 to 9.0, and a color change from purple to deep blue was clearly observed during the growth of fish-spoiling bacteria. Thus, our results suggested that edible films containing CBO-loaded capsules and RC showed the potential to inhibit microbial growth in fish and to visibly indicate fish freshness.