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Oral microbiome dysbiosis mediates chronic periodontal disease, gut microbial dysbiosis, and mucosal barrier disfunction that leads to steatohepatitis via the enterohepatic circulation. Improving this dysbiosis towards health may improve liver disease. Treatment with antibiotics and probiotics have been used to modulate the microbial, immunological, and clinical landscape of periodontal disease with some success. The aim of the present investigation was to evaluate the potential for nisin, an antimicrobial peptide produced by Lactococcus lactis, to counteract the periodontitis-associated gut dysbiosis and to modulate the glycolipid-metabolism and inflammation in the liver. Periodontal pathogens, namely Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum, were administrated topically onto the oral cavity to establish polymicrobial periodontal disease in mice. In the context of disease, nisin treatment significantly shifted the microbiome towards a new composition, commensurate with health while preventing the harmful inflammation in the small intestine concomitant with decreased villi structural integrity, and heightened hepatic exposure to bacteria and lipid and malondialdehyde accumulation in the liver. Validation with RNA Seq analyses, confirmed the significant infection-related alteration of several genes involved in mitochondrial dysregulation, oxidative phosphorylation, and metal/iron binding and their restitution following nisin treatment. In support of these in vivo findings indicating that periodontopathogens induce gastrointestinal and liver distant organ lesions, human autopsy specimens demonstrated a correlation between tooth loss and severity of liver disease. Nisin's ability to shift the gut and liver microbiome towards a new state commensurate with health while mitigating enteritis, represents a novel approach to treating NAFLD-steatohepatitis-associated periodontal disease.

Background: Due to the adverse effects of industrial chemicals and their carcinogenicity and toxicity for humans, the debates have increased on using natural preservatives. This study was conducted to investigate the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against Aspergillus flavus in vivo by inoculation in laboratory-manufactured Ras cheese. A novel, safe, and natural approach of nanoprecipitation using acetic acid was employed to prepare nisin nanoparticles. The prepared NPs were characterized using zeta-sizer, FTIR, and transmission electron microscopy (TEM). Furthermore, the cytotoxicity of nisin NPs on Vero cells was assessed. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined in vitro against A. flavus isolates using the agar well-diffusion method. The sensory evaluation of manufactured Ras cheese was conducted over a 60-day storage period. Results: The obtained results showed a strong antifungal activity of nisin NPs (0.0625 mg/mL) against A. flavus strain in comparison with pure nisin (0.5 mg/mL). Notably, the count decreased gradually by time from 2 × 108 at zero time and could not be detected at the 7th week. The count with pure nisin decreased from 2 × 108 at zero time and could not be detected at the 10th week where it’s enough time to produce aflatoxins in cheese. The MICs of nisin and nisin NPs were 0.25 and 0.0313 mg/mL, respectively. Nisin NPs used in our experiment had good biocompatibility and safety for food preservation. Additionally, the sensory parameters of the manufactured Ras cheese inoculated with nisin and nisin NPs were of high overall acceptability (OAA). Conclusions: Overall, the results of this study suggested that adding more concentration (˃0.0625 mg/mL) from nisin nanoparticles during the production of Ras cheese may be a helpful strategy for food preservation against A. flavus in the dairy industry. [ABSTRACT FROM AUTHOR]

ABSTRACT Antimicrobial peptides (AMPs) are renowned for their broad‐spectrum efficacy against viruses, bacteria, and fungi, thereby holding promise for medicinal applications. Nisin, a bacteriocin synthesized by gram‐positive bacteria such as Lactobacillus and Streptococcus, has been used as a food preservative owing to its antimicrobial characteristics for decades. However, recent developments prompt further research on its application as therapeutic interventions, mainly focusing on anticancer activity. In line with this, the present study portrays the effects of nisin on human colorectal cancer cells and the underlying molecular mechanisms. A dose‐dependent decrease in cell viability with increasing concentrations of nisin was determined by the Alamar blue viability assay, which was supported by significant morphological changes in cells. Subsequently, we probed the apoptotic effects of nisin using EtBr/AO staining, confirming the induction of apoptosis upon nisin treatment, which was further confirmed by ELISA analysis. Elevated levels of Caspase 7 indicated increased apoptosis in nisin‐treated cells. As pharmaceutical p53 reactivation is considered as an attractive strategy to combat chemoresistance and adverse effects, the effect of nisin on p53 expression was determined by mRNA analysis. An upregulation in p53 expression in nisin‐treated cells compared to untreated controls suggests that bacterial nisin reactivates mutated p53. To assess cell cycle dynamics, we utilized PI flow cytometry, unveiling a G0/G1 phase arrest in nisin‐treated cells in contrast to untreated controls. In summary, our results strongly advocate the potential of nisin as a compelling candidate for drug development against colorectal cancer. [ABSTRACT FROM AUTHOR]

The major challenge in employing high pressure (HP) at moderate temperature for sterilization is the remarkable resistance of bacterial spores. High isostatic pressure can initiate spore germination, enabling subsequent inactivation under mild conditions. However, not all spores could be triggered to germinate under pressure at temperatures =80°C so far. In this study, germination treatment combinations were evaluated for Bacillus spores involving moderate HP (150 MPa, 37°C, 5 min), very HP (vHP, 550 MPa, 60°C, 2.5 or 9 min), simple and complex nutrient germinants [L-valine, L-alanine, and tryptic soy broth (TSB)], nisin, and incubation at atmospheric pressure (37°C). The most effective combinations for Bacillus subtilis resulted in a reduction of culturable dormant spores by 8 log10 units. The combinations involved nisin, a nutrient germinant (L-valine or TSB), a first vHP treatment (550 MPa, 60°C, 2.5 min), incubation at atmospheric pressure (37°C, 6 h), and a second vHP treatment (550 MPa, 60°C, 2.5 min). Such treatment combination with L-valine reduced Bacillus amyloliquefaciens spores by only 2 log10 units. B. amyloliquefaciens, thus, proved to be substantially more HP-resistant compared to B. subtilis, validating previous studies. Despite combining different germination mechanisms, complete germination could not be achieved for either species. The natural bacteriocin nisin did seemingly not promote HP germination initiation under chosen HP conditions, contrary to previous literature. Nevertheless, nisin might be beneficial to inhibit the growth of HP-germinated or remaining ungerminated spores. Future germination experiments might consider that nisin could not be completely removed from spores by washing, thereby affecting plate count enumeration. IMPORTANCE Extremely resistant spore-forming bacteria are widely distributed in nature. They infiltrate the food chain and processing environments, posing risks of spoilage and food safety. Traditional heat-intensive inactivation methods often negatively affect the product quality. HP germination-inactivation offers a potential solution for better preserving sensitive ingredients while inactivating spores. However, the presence of ungerminated (superdormant) spores hampers the strategy's success and safety. Knowledge of strategies to overcome resistance to HP germination is vital to progress mild spore control technologies. Our study contributes to the evaluation and development of mild preservation processes by evaluating strategies to enhance the HP germination-inactivation efficacy. Mild preservation processes can fulfill the consumers' demand for safe and minimally processed food. [ABSTRACT FROM AUTHOR]

The present work reports the development and validation of a chromosomal expression system in Streptococcus pneumoniae which permits gene expression under the control of Lactococcus lactis lantibiotic nisin. The system is based on the integrative and conjugative element (ICE) Tn5253 of S. pneumoniae capable of site-specific chromosomal integration and conjugal transfer to a variety of bacterial species. We constructed an insertion vector that integrates in Tn5251, an ICE contained in Tn5253, which carries the tetracycline resistance tet(M) gene. The vector contains the nisRK regulatory system operon, the L. lactis nisin inducible promoter PnisA upstream of a multiple cloning site for target DNA insertion, and is flanked by two DNA regions of Tn5251 which drive homologous recombination in ICE Tn5253. For system evaluation, the emm6.1::ha1 fusion gene was cloned and integrated into the chromosome of the Tn5253-carrying pneumococcal strain FR24 by transformation. This gene encodes a fusion protein containing the signal peptide, the 122 N-terminal and the 140 C-terminal aa of the Streptococcus pyogenes M6 surface protein joined to the HA1 subunit of the influenza virus A hemagglutinin. Quantitative RT-PCR analysis carried out on total RNA purified from nisin treated and untreated cultures showed an increase in emm6.1::ha1 transcript copy number with growing nisin concentration. The expression of M6-HA1 protein was detected by Western blot and quantified by Dot blot, while Flow cytometry analysis confirmed the presence on the pneumococcal surface. Recombinant ICE Tn5253::[nisRK]-[emm6.1::ha1] containing the nisin-inducible expression system was successfully transferred by conjugation in different streptococcal species including Streptococcus gordonii, S. pyogenes, Streptococcus agalactiae and Enterococcus faecalis. As for S. pneumoniae, the emm6.1::ha1 transcript copy number and the amount of M6-HA1 protein produced correlated with the nisin concentration used for induction in all investigated bacterial hosts. We demonstrated that this host-vector expression system is stably integrated as a single copy within the bacterial chromosome, is transferable to both transformable and non transformable bacterial species, and allows fine tuning of protein expression modulated by nisin concentration. These characteristics make our system suitable for a wide range of applications including complementation assays, physiological studies, host-pathogen interaction studies. [ABSTRACT FROM AUTHOR]

This study aimed to optimize three factors of a non-thermal treatment for a fruit and vegetable (F&V) smoothie: ultrasonication (US) time, US amplitude as a percentage of the maximum one (%maxA), and nisin concentration. When the focus was on minimizing deterioration and maximizing quality immediately after treatment (day 0), the analysis suggested an optimal treatment of 2.4 min of US at 70%maxA and 11.83 mg kg−1 of nisin (opt1). However, when targeting minimal deterioration at advanced storage (day 9), a more intensive treatment of 7.4 min at 74%maxA and 12.5 mg kg−1 of nisin (opt2) was recommended. Both optimal treatments significantly reduced spoilage microorganisms and enzyme activity, increased total phenolic content and antioxidant capacity in the F&V smoothie, while maintaining its physicochemical properties and color. During storage, samples treated with both optimal conditions exhibited enhanced stability, extending the microbiological shelf-life by at least 14 days. Opt2 outperformed opt1, but cost-effectiveness must be weighed due to factors higher intensities. The obtained results lay the foundation for future research and demonstrate the great potential of these combined methods for preserving F&V beverages. [ABSTRACT FROM AUTHOR]

Good hygienic milking practices including the disinfection of the cow teat skin before and after milking aimed at preventing the occurrence of new intramammary infections (IMI) in dairy cows. This practice is generally performed using disinfectants, and in the current context of attention to the emergence of resistances, it is of greatest interest to evaluate alternative solutions that can expand treatment options. We assessed the efficacy of a pre-dipping and a post-dipping product based on the bacteriocin-containing culture of Lactococcus cremoris strain FT27, as compared to commercial disinfectants. FT27 was selected for the bactericidal activity in vitro against food pathogens. In the present study, it also revealed a high bactericidal activity against the main mastitis pathogens, most likely related to Nisin A production, according to genomic and proteomic analysis. The lactococcus-based preparations were applied in two commercial dairy farms in Northern Italy. Overall, 298 dairy cows were enrolled, 141 in the treated group (TR), and 157 in the control group (CTR). The cows were sampled at quarter level every two weeks for 3 months. During the trial, all cows showed a good health status. The hygiene level for udder, flanks and legs was generally good (on average < 3 score); the udder hygiene was significantly worse (P < 0.01) in the CTR group. The teat apex hyperkeratosis was overall low (on average < 2 score). We recorded no significant differences between the two experimental groups in the Somatic Cell Count (SCC) values and the bacteriological results. The overall frequency of new IMI was low, ranging 0.6 − 0.5% for S. aureus in the TR or CTR group respectively, to 2.6–4.4% for NASM. Regarding Str. spp., the new IMI accounted for 1.7% or 1.9% in the TR or CTR group, respectively. Notably, the incidence of S. aureus new IMI did not increase during the study, even though neither of the two herds segregated the positive cows. The non-inferiority test showed that the Lactococcus-based pre- and post-dipping products had an efficacy comparable to proven commercial disinfectants in maintaining udder health and preventing new IMI, thus representing a possible alternative to current teat dip products. [ABSTRACT FROM AUTHOR]

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The accumulation of nisin in the fermentation medium can reduce the process's productivity. This research studied the potential of Nymphaea alba leaf powder (NALP) as a hydrophobic biosorbent for efficient in-situ nisin adsorption from the fermentation medium by docking and experimental analysis. Molecular docking analysis showed that di-galloyl ellagic acid, a phytochemical compound found in N. alba, had the highest affinity towards nisin. Enhancements in nisin adsorption were seen following pre-treatment of NAPL with HCl and MgCl2. A logistic growth model was employed to evaluate the growth dynamics of the biosorption capacity, offering valuable insights for process scalability. Furthermore, optimization through Response Surface Methodology elucidated optimal nisin desorption conditions by Liebig's law of the minimum, which posits that the scarcest resource governs production efficiency. Fourier Transform Infrared (FTIR) spectroscopy pinpointed vital functional groups involved in biosorption. Scanning electron microscopy revealed the changing physical characteristics of the biosorbent after exposure to nisin. The findings designate NALP as a feasible adsorbent for nisin removal from the fermentation broth, thus facilitating its application in the purification of other biotechnological products based on growth and production optimization principles. [ABSTRACT FROM AUTHOR]

AMPs are neutral and small size component of the immune system and showed better activity for the treatment of tuberculosis. The present study aimed to complex nisin with carbohydrate to increase bioavailability and provide site-specific action at lungs via pulmonary route. Nanocomplexes were prepared by kneading method and then adsorbed on lactose for DPI formulation. Nanocomplex of nisin peptide with carbohydrate offered a better effect along with dose reduction was proved by using M. tuberculosis H37Ra (ATCC 25177). Nanocomplex proved to be an alternative delivery to conventional drug therapy for the treatment of tuberculosis. [ABSTRACT FROM AUTHOR]

The demand for wound care is increasing globally and the traditional wound dressings offer limited support to the healing process, failing to meet the requirements of current healthcare system. Drug-controlled release nanotechnology has garnered interest recently in the field of biomedicine. Electrospun nanofibers are considered as an advanced wound dressing due to their unique structure and a biological function similar to the extracellular matrix. In this study, a polycaprolactone (PCL)-polyethylene glycol (PEG) loaded with nisin was developed by electrospinning technique. The fabricated nanofiber was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The degradation index, in vitro release studies, antioxidant activity, and cell cytotoxicity analyses of the nanofibers were also performed. The antibacterial activity of the nanofiber was evaluated against wound causing skin pathogens like Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, and Klebsiella pneumoniae. The FTIR data demonstrate the interactions between PCL, PEG, and nisin. The presence of nisin in the fiber was confirmed by the characteristic bands of nisin at 3398.63, 1643.23, and 1242.17 cm−1. The nanofibers exhibited maximum controlled nisin release of 94.3% at 24 h. The nisin-loaded nanofibers exhibited antibacterial activity against all the indicator organisms used in the study. About 78% viability was observed on nisin-loaded nanofibers during the MTT assay. The results indicated that the fabricated antibacterial nanofiber has the potential for wound healing application and the treatment of bacterial infections in wounds. [ABSTRACT FROM AUTHOR]

As a natural preservative, nisin is widely used in the food industry, while its application in biomedicine is limited due to its susceptibility to interference from external conditions. In this study, a nanoparticle–hydrogel composite system was designed to encapsulate and release nisin. Nisin nanoparticles were identified with a smooth, spherical visual morphology, particle size of 122.72 ± 4.88 nm, polydispersity coefficient of 0.473 ± 0.063, and zeta potential of 23.89 ± 0.37 mV. Based on the sample state and critical properties, three temperature-sensitive hydrogels based on chitosan were ultimately chosen with a rapid gelation time of 112 s, outstanding reticular structure, and optimal swelling ratio of 239.05 ± 7.15%. The composite system exhibited the same antibacterial properties as nisin, demonstrated by the composite system's inhibition zone diameter of 17.06 ± 0.83 mm, compared to 20.20 ± 0.58 mm for nisin, which was attributed to the prolonged release effect of the hydrogel at the appropriate temperature. The composite system also demonstrated good biocompatibility and safety, making it suitable for application as short-term wound dressings in biomedicine due to its low hemolysis rate of less than 2%. In summary, our nanoparticle-based hydrogel composite system offers a novel application form of nisin while ensuring its stability, thereby deepening and broadening the employment of nisin. [ABSTRACT FROM AUTHOR]

Abstract Background Due to the adverse effects of industrial chemicals and their carcinogenicity and toxicity for humans, the debates have increased on using natural preservatives. This study was conducted to investigate the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against Aspergillus flavus in vivo by inoculation in laboratory-manufactured Ras cheese. A novel, safe, and natural approach of nanoprecipitation using acetic acid was employed to prepare nisin nanoparticles. The prepared NPs were characterized using zeta-sizer, FTIR, and transmission electron microscopy (TEM). Furthermore, the cytotoxicity of nisin NPs on Vero cells was assessed. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined in vitro against A. flavus isolates using the agar well-diffusion method. The sensory evaluation of manufactured Ras cheese was conducted over a 60-day storage period. Results The obtained results showed a strong antifungal activity of nisin NPs (0.0625 mg/mL) against A. flavus strain in comparison with pure nisin (0.5 mg/mL). Notably, the count decreased gradually by time from 2 × 108 at zero time and could not be detected at the 7th week. The count with pure nisin decreased from 2 × 108 at zero time and could not be detected at the 10th week where it’s enough time to produce aflatoxins in cheese. The MICs of nisin and nisin NPs were 0.25 and 0.0313 mg/mL, respectively. Nisin NPs used in our experiment had good biocompatibility and safety for food preservation. Additionally, the sensory parameters of the manufactured Ras cheese inoculated with nisin and nisin NPs were of high overall acceptability (OAA). Conclusions Overall, the results of this study suggested that adding more concentration (˃0.0625 mg/mL) from nisin nanoparticles during the production of Ras cheese may be a helpful strategy for food preservation against A. flavus in the dairy industry.

Abstract Good hygienic milking practices including the disinfection of the cow teat skin before and after milking aimed at preventing the occurrence of new intramammary infections (IMI) in dairy cows. This practice is generally performed using disinfectants, and in the current context of attention to the emergence of resistances, it is of greatest interest to evaluate alternative solutions that can expand treatment options. We assessed the efficacy of a pre-dipping and a post-dipping product based on the bacteriocin-containing culture of Lactococcus cremoris strain FT27, as compared to commercial disinfectants. FT27 was selected for the bactericidal activity in vitro against food pathogens. In the present study, it also revealed a high bactericidal activity against the main mastitis pathogens, most likely related to Nisin A production, according to genomic and proteomic analysis. The lactococcus-based preparations were applied in two commercial dairy farms in Northern Italy. Overall, 298 dairy cows were enrolled, 141 in the treated group (TR), and 157 in the control group (CTR). The cows were sampled at quarter level every two weeks for 3 months. During the trial, all cows showed a good health status. The hygiene level for udder, flanks and legs was generally good (on average

Abstract The accumulation of nisin in the fermentation medium can reduce the process's productivity. This research studied the potential of Nymphaea alba leaf powder (NALP) as a hydrophobic biosorbent for efficient in-situ nisin adsorption from the fermentation medium by docking and experimental analysis. Molecular docking analysis showed that di-galloyl ellagic acid, a phytochemical compound found in N. alba, had the highest affinity towards nisin. Enhancements in nisin adsorption were seen following pre-treatment of NAPL with HCl and MgCl2. A logistic growth model was employed to evaluate the growth dynamics of the biosorption capacity, offering valuable insights for process scalability. Furthermore, optimization through Response Surface Methodology elucidated optimal nisin desorption conditions by Liebig's law of the minimum, which posits that the scarcest resource governs production efficiency. Fourier Transform Infrared (FTIR) spectroscopy pinpointed vital functional groups involved in biosorption. Scanning electron microscopy revealed the changing physical characteristics of the biosorbent after exposure to nisin. The findings designate NALP as a feasible adsorbent for nisin removal from the fermentation broth, thus facilitating its application in the purification of other biotechnological products based on growth and production optimization principles.

The use of natural antimicrobial peptides is a viable preservation alternative in the production of safe and good-quality products for consumption. Nanoliposomes containing nisin were prepared by film hydration with phosphatidylcholine (PC) and cholesterol, and coated with the polyelectrolytes (PEs) chitosan, cationic maltodextrin or poly-L-lysine (PLL), and characterized in their physical, thermal, functional and storage stability properties. As results, nisin encapsulation efficiency was around 90% for all formulations. The average diameter varied between 93.2 and 115.8 nm, with an increase in size after incorporation of PE, and the zeta potential ranged from + 11.3 to + 23.9 mV. These physical parameters showed good stability during 60 days of refrigeration (4 °C). The thermal characteristics of the liposomes were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). An improvement in the thermal stability of liposomes coated with PEs was observed. Infrared spectroscopy (FTIR) revealed predominantly PC peaks as the bulk component of the nanostructures, but representative peaks of PEs and nisin suggested their presence on the surface of liposomes. Finally, antimicrobial activity was observed against Gram-positive bacteria (L. monocytogenes, S. aureus, and B. cereus) and Gram-negative bacteria (E. coli and S. enterica), in brain heart infusion (BHI), whole, and skimmed milk agar. The formulations containing PEs and nisin maintained the physical properties and antimicrobial activity after 60 days of storage. Therefore, liposomes coated with cationic PEs have the potential to deliver antimicrobial peptides to reduce undesirable bacteria in foods. [ABSTRACT FROM AUTHOR]

In order to solve the problems of short shelf life of refrigerated Micropterus salmoides and the deterioration of quality during refrigerated storage, three preservatives including trehalose (Tre), ginger extract (GE) and Nisin were selected for single factor experiment. L9(34) orthogonal experiment was used to optimize the ratio of the compound preservative. The total viable count (TVC), pH, total volatile basic nitrogen (TVB-N) content, sensory evaluation, water holding capacity, moisture distribution, texture properties and myofibrillar protein (MP) oxidation stability indexes of Micropterus salmoides during refrigerated storage were measured with the optimal ratio of the compound preservative. The optimal ratio of the compound preservative (3.0% Tre, 0.06% GE and 0.06% Nisin) was obtained by single factor experiment and orthogonal experiment. The results showed that on the 8th day of refrigeration, the logarithm of TVC of control group (CK group) was 6.01, which exceeded the specified limit of spoilage. At the 16th day of storage, the logarithm of TVC of EG2 group was still lower than 6.00, the content of TVB-N was not more than 20 mg/100 g and the pH was less than 7.20. Compared with CK group, free water content in compound preservative groups (EG1 group and EG2 group (that was preferred group)) were significantly decreased, water holding capacity were significantly increased (P

Abstract Objectives The aim of this study was to evaluate the effect of in-vivo produced Nisin which is an antimicrobial peptide (AMP) added to adhesive resin on shear bond strength (SBS) and the adhesive remnant index (ARI) of orthodontic brackets. Methods Bacterial AMP was produced by fermentation and the ideal AMP/Bond concentration and antimicrobial efficacy of the mixture were tested. To evaluate the SBS and ARI scores of AMP-added adhesive resins, 80 maxillary premolar teeth extracted for orthodontic purposes were used and randomly assigned into 2 groups (n = 40). Group 1: Control Group (teeth bonded with standard adhesive resin); Group 2: Experimental Group (teeth bonded with AMP-added adhesive resin). Statistical analysis was performed using the SPSS package program and applying the Mann-Whitney U and Fisher’s exact tests. P

Abstract Background The increase in the resistance of bacterial strains to antibiotics has led to research into the bactericidal potential of non-antibiotic compounds. This study aimed to evaluate in vitro antibacterial/ antibiofilm properties of nisin and selenium encapsulated in thiolated chitosan nanoparticles (N/Se@TCsNPs) against prevalent enteric pathogens including standard isolates of Vibrio (V.) cholerae O1 El Tor ATCC 14,035, Campylobacter (C.) jejuni ATCC 29,428, Salmonella (S.) enterica subsp. enterica ATCC 19,430, Shigella (S.) dysenteriae PTCC 1188, Escherichia (E.) coli O157:H7 ATCC 25,922, Listeria (L.) monocytogenes ATCC 19,115, and Staphylococcus (S.) aureus ATCC 29,733. Methods The synthesis and comprehensive analysis of N/Se@TCsNPs have been completed. Antibacterial and antibiofilm capabilities of N/Se@TCsNPs were evaluated through broth microdilution and crystal violet assays. Furthermore, the study included examining the cytotoxic effects on Caco-2 cells and exploring the immunomodulatory effects of N/Se@TCsNPs. This included assessing the levels of both pro-inflammatory (IL-6 and TNFα) and anti-inflammatory (IL-10 and TGFβ) cytokines and determining the gene expression of TLR2 and TLR4. Results The N/Se@TCsNPs showed an average diameter of 136.26 ± 43.17 nm and a zeta potential of 0.27 ± 0.07 mV. FTIR spectroscopy validated the structural features of N/Se@TCsNPs. Scanning electron microscopy (SEM) images confirmed their spherical shape and uniform distribution. Thermogravimetric Analysis (TGA)/Differential Scanning Calorimetry (DSC) tests demonstrated the thermal stability of N/Se@TCsNPs, showing minimal weight loss of 0.03%±0.06 up to 80 °C. The prepared N/Se@TCsNPs showed a thiol content of 512.66 ± 7.33 µmol/g (p

ABSTRACT: Treatment of subclinical mastitis (SCM) during lactation is rarely recommended due to concerns related to both antimicrobial usage and the costs associated with milk discard. Nisin is a naturally produced antimicrobial peptide with a gram-positive spectrum that, when given to dairy cows, does not require milk discard. We evaluated the economic impact of the treatment of SCM during early lactation using a nisin-based intramammary treatment under different scenarios that included various treatment costs, milk prices, and cure rates. We stochastically simulated the dynamics of SCM detected during the first week of lactation. The net economic impact was expressed in US dollars per case. The probabilities of an event and their related costs were estimated using a model that was based on pathogen-specific assumptions selected from peer-reviewed articles. Nisin cure rates were based on results of pivotal studies included in the US Food and Drug Administration (FDA) approval submission. Based on our model, the average cost of a case of intramammary infection (i.e., only true-positive cases) in early lactation was $170 (90% = $148–$187), whereas the cost of a clinical mastitis case was $521 (90% range = $435–$581). Both estimates varied with etiology, parity, and stage of lactation. When comparing the net cost of SCM cases (i.e., CMT-positive tests) detected during the first week of lactation, nisin treatment generated an average positive economic impact of $19 per CMT-positive case. The use of nisin to treat SCM was beneficial 93% of the time. Based on the sensitivity analysis, treatment would result in an economically beneficial outcome for 95% and 73% of multiparous and primiparous cows, respectively. At the herd level, use of intramammary nisin to treat SCM in cows in early lactation was economically beneficial in most tested scenarios. However, the economic impact was highly influenced by factors such as rate of bacteriological cure, cost of treatment, and parity of the affected animal. These factors should be considered when deciding to use nisin as a treatment for SCM.

Nowadays, due to the environmental problems caused by packaging based on synthetic polymers, the use of producing edible films based on biopolymers like polysaccharides, proteins, and fats has been interested. According to all the useful features of psyllium seed hydrocolloid (PH), the aim of this study was to evaluate the possibility of antimicrobial biodegradable edible film production using pH, glycerol, nisin (0, 5000 and 10000 IU/g) and Ethylenediaminetetraacetic acid (EDTA), (0, 15 and 30 wt%). The diameter of the inhibition zones against pathogenic bacteria on medium surface were measured as antimicrobial activity of films. The results showed that films containing nisin and EDTA significantly inhibition of Staphylococcus aureus) and Salmonella typhimurium growth. With increasing concentration of nisin and EDTA the inhibitory power of film against pathogenic bacteria increased. Maximum inhibition was obtained at 3416.03 IU/g concentration of nisin and highest concentration of EDTA (30%). At the optimal point, the inhibition zone against S. aureus and S. typhimurium was 2.02±0.2 and 2.2±0.3 cm, respectively. Tensile and elongation of optimal film was 13.41 Mpa and 28.51%, respectively. According to results of this study, novel biodegradable antimicrobial PH film could be suggested as meat product packaging.

Background and purpose: Activated textiles have created a new field of application apart from standard textile applications. Novel, functions, for example, antimicrobial properties have been enhanced in textiles. New textile application fields have been recognized for particular areas of healthcare as well as industry, sportswear, and, home textiles. Advances in the field of antibacterial textiles have fascinated enhancing attention because those are a means to solve serious health challenges such as bacterial overgrowth. A lot of research has been done in the field of adding synthetic and toxic materials to fabrics, such as nanosilver triclosan or other metals and organic materials to produce antimicrobial fabrics. These fabrics kill bacteria by binding to intracellular proteins and inactivating these proteins. Also, by using these chemicals, the content of heavy metals in these textiles can be increased. The application of heavy metals in antimicrobial textiles is limited by many environmental tags and standards. Therefore, it is recommended to use natural antimicrobial agents, such as nisin and chitosan to produce environmentally friendly and safe antimicrobial fabrics. Nowadays finishing process with the natural antibacterial agents that protect the environment and human health is gaining importance. Therefore, this study aims to produce fabric coated with chitosan and nisin and to investigate its antimicrobial properties. Materials and methods: In this research, chitosan was used to bind nisin to the surface of polypropylene span band non-woven fabric. The fabric samples were coated with a solution containing chitosan and nisin using a pad-dry-cure method. The appearance, color, and softness of the coated fabrics were compared to the uncoated fabric. The nisin and chitosan binding properties on the fabric were explored by using the Fourier-transform infrared (FTIR (technique. The diffusion method in agar and the standard method (ASTME2149-01) were used to check the antimicrobial properties of fabric samples. The antibacterial effectiveness of fabric samples was tested against common bacteria such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Enterococcus faecalis. After ten washing cycles, the durability of the antimicrobial properties of these fabrics was checked by the method mentioned above. Also, the toxicity of this fabric on fibroblast cells was determined using the MTT colorimetry method after seven days. Results: Fabrics coated with chitosan and nisin do not differ much from the control sample in terms of appearance and softness. The changes observed in the FTIR spectrum, such as the appearance of new absorption peaks and additional peaks associated with peptide bonds, confirm the successful incorporation of nisin and chitosan into the fabric. Antibacterial results have shown that nisin improved the antibacterial effect of coated fabrics versus B. cereus, S. aureus, and P. aeruginosa. The antimicrobial properties of the fabric coated with chitosan-nisin were maintained at some of the efficacy after washing against B. cereus, S. aureus, E. faecalis, L. monocytogenes, E. coli, and P. aeruginosa respectively. Also, the chitosan-nisin coating showed that it did not cause significant toxicity in fibroblast cells even after one week. Conclusion: However, the results showed that the chitosan/nisin coating might be used for medical textiles and antibacterial textiles. It also offers an innovative solution to protect human health and the environment.

Abstract Background Antimicrobial resistance (AMR) is nowadays a major emerging challenge for public health worldwide. The over- and misuse of antibiotics, including those for cell culture, are promoting AMR while also encouraging the research and employment of alternative drugs. The addition of antibiotics to the cell media is strongly recommended in sperm preservation, being gentamicin the most used for boar semen. Because of its continued use, several bacterial strains present in boar semen have developed resistance to this antibiotic. Antimicrobial peptides and proteins (AMPPs) are promising candidates as alternative antibiotics because their mechanism of action is less likely to promote AMR. In the present study, we tested two AMPPs (lysozyme and nisin; 50 and 500 µg/mL) as possible substitutes of gentamicin for boar semen preservation up to 48 h of storage. Results We found that both AMPPs improved sperm plasma membrane and acrosome integrity during semen storage. The highest concentration tested for lysozyme also kept the remaining sperm parameters unaltered, at 48 h of semen storage, and reduced the bacterial load at comparable levels of the samples supplemented with gentamicin (p > 0.05). On the other hand, while nisin (500 µg/mL) reduced the total Enterobacteriaceae counts, it also decreased the rapid and progressive sperm population and the seminal oxidation-reduction potential (p

Background: Nosocomial infections caused by multidrug-resistant Pseudomonas aeruginosa are a considerable public health threat, requiring innovative therapeutic approaches. Objectives: This study explored preconditioning mesenchymal stem cells (MSCs) with the antimicrobial peptide Nisin to enhance their antibacterial properties while maintaining regenerative capacity. Methods: Human MSCs were preconditioned with varying concentrations of Nisin (0.1–1000 IU/mL) to determine an optimal dose. MSCs preconditioned with Nisin were characterized using microscopy, flow cytometry, gene expression analysis, and functional assays. The effects of preconditioning on the viability, phenotype, differentiation capacity, antimicrobial peptide expression, and antibacterial activity of MSCs against Pseudomonas aeruginosa were tested in vitro. The therapeutic efficacy was evaluated by topically applying conditioned media from Nisin-preconditioned versus control MSCs to infected wounds in a rat model, assessing bacterial burden, healing, host response, and survival. Results: An optimal Nisin dose of 500 IU/mL was identified, which increased MSC antibacterial gene expression and secretome activity without compromising viability or stemness. Nisin-preconditioned MSCs showed upregulated expression of LL37 and hepcidin. Conditioned media from Nisin-preconditioned MSCs exhibited about 4-fold more inhibition of P. aeruginosa growth compared to non-preconditioned MSCs. In the wound infection model, the secretome of Nisin-preconditioned MSCs suppressed bacterial load, accelerated wound closure, modulated inflammation, and improved survival compared to standard MSC treatments. Conclusion: This study explores the effect of preconditioning MSCs with the antimicrobial peptide Nisin on enhancing their antibacterial properties while maintaining regenerative capacity. Secreted factors from Nisin-preconditioned MSCs have the potential to attenuate infections and promote healing in vivo. The approach holds translational promise for managing antibiotic-resistant infections and warrants further development. Preconditioned MSCs with Nisin may offer innovative, multifaceted therapies for combating nosocomial pathogens and promoting tissue regeneration.

Introduction: This study was conducted to compare the effects of nisin (NIS) and ionophore antibiotic monensin (MON) on the growth performance, rumen fermentation, nutrient digestion and plasma metabolites of fattening Hu sheep. Methods: Thirty-six male Hu sheep (23.5 ± 1.0 kg) were divided into two blocks based on BW (low BW and high BW). Sheep within each block were then allotted to 9 pens respectively (two sheep/pen). Pens within each block were randomly assigned to one of three dietary treatments: (1) basal diet (CON); (2) basal diet + 40 mg/kg DM of MON; (3) basal diet + 274.5 mg/kg DM of NIS. The study lasted 9 weeks, with the initial 2 weeks for adaptation and the subsequent 7 weeks for treatment. Results: The results showed that both NIS and MON addition had no impacts on average daily gain (ADG), dry matter intake (DMI), and feed conservation rate (G:F) of sheep (p > 0.05). The digestibility of ether extract (EE) was lower in the MONfed and NIS-fed sheep (p < 0.01) than in the CON group, whereas crude protein (CP) digestibility was higher in the MON-fed sheep compared to those fed NIS (p < 0.05). Both NIS and MON supplementation decreased acetate levels and acetate/propionate ratio in the rumen of Hu sheep (p < 0.05). Sheep fed MON exhibited higher total cholesterol concentrations (p < 0.05) compared to the CON and NIS groups. However, there were no significant differences in other plasma metabolites, including blood urea nitrogen (BUN), total bile acid, triglyceride, total protein, albumin, globulin, glucose, etc., among the three groups (p > 0.05). Discussion: In conclusion, dietary addition of NIS and MON altered the rumen fermentation mode by reducing acetate levels, with no discernible effects on the growth performance of the fattening Hu sheep. [ABSTRACT FROM AUTHOR]

In order to solve the problems of short shelf life of refrigerated Micropterus salmoides and the deterioration of quality during refrigerated storage, three preservatives including trehalose (Tre), ginger extract (GE) and Nisin were selected for single factor experiment. L9(34) orthogonal experiment was used to optimize the ratio of the compound preservative. The total viable count (TVC), pH, total volatile basic nitrogen (TVB-N) content, sensory evaluation, water holding capacity, moisture distribution, texture properties and myofibrillar protein (MP) oxidation stability indexes of Micropterus salmoides during refrigerated storage were measured with the optimal ratio of the compound preservative. The optimal ratio of the compound preservative (3.0% Tre, 0.06% GE and 0.06% Nisin) was obtained by single factor experiment and orthogonal experiment. The results showed that on the 8th day of refrigeration, the logarithm of TVC of control group (CK group) was 6.01, which exceeded the specified limit of spoilage. At the 16th day of storage, the logarithm of TVC of EG2 group was still lower than 6.00, the content of TVB-N was not more than 20 mg/100 g and the pH was less than 7.20. Compared with CK group, free water content in compound preservative groups (EG1 group and EG2 group (that was preferred group)) were significantly decreased, water holding capacity were significantly increased (P<0.05), and the hardness, chewiness and sensory scores of Micropterus salmoides were better than CK group. The related indexes of MP oxidation stability showed that the total sulfhydryl content and Ca2+-ATPase activity in compound preservative groups (EG1 group and EG2 group (that was preferred group)) were significantly higher than those in CK group (P<0.05), while the surface hydrophobicity and carbonyl group content were significantly lower than those in CK group (P<0.05), meanwhile, the protective effect of EG2 group on the oxidation stability of MP was better than that of EG1 group. The correlation analysis showed that there was significant correlation (P<0.01) among the indexes of Micropterus salmoides fillets treated with compound preservatives. Comprehensive analysis showed that the quality deterioration of refrigerated Micropterus salmoides could be effectively delayed and the MP oxidation of refrigerated Micropterus salmoides could be significantly inhibited, among which the optimal ratio group (EG2 group) had the best comprehensive effect. This study would provide a theoretical basis for the development and application of water retention and preservation technology for refrigerated Micropterus salmoides. [ABSTRACT FROM AUTHOR]

Aims This study evaluates the antibacterial characteristics and mechanisms of combined tea polyphenols (TPs), Nisin, and ε-polylysine (PL) against Streptococcus canis, Streptococcus minor, Streptococcus mutans , and Actinomyces oris , common zoonotic pathogens in companion animals. Methods and results Pathogenic strains were isolated from feline oral cavities and assessed using minimum inhibitory concentration (MIC) tests, inhibition zone assays, growth kinetics, and biofilm inhibition studies. Among single agents, PL exhibited the lowest MIC values against all four pathogens. TP showed significant resistance against S. minor , and Nisin against S. mutans. The combination treatment (Comb) of TP, Nisin, and PL in a ratio of 13:5:1 demonstrated broad-spectrum antibacterial activity, maintaining low MIC values, forming large inhibition zones, prolonging the bacterial lag phase, reducing growth rates, and inhibiting biofilm formation. RNA sequencing and metabolomic analysis indicated that TP, Nisin, and PL inhibited various membrane-bound carbohydrate-specific transferases through the phosphoenolpyruvate-dependent phosphotransferase system in S. canis , disrupting carbohydrate uptake. They also downregulated glycolysis and the citric acid cycle, inhibiting cellular energy metabolism. Additionally, they modulated the activities of peptidoglycan glycosyltransferases and d -alanyl- d -alanine carboxypeptidase, interfering with peptidoglycan cross-linking and bacterial cell wall stability. Conclusions The Comb therapy significantly enhances antibacterial efficacy by targeting multiple bacterial pathways, offering potential applications in food and pharmaceutical antimicrobials. [ABSTRACT FROM AUTHOR]

Purpose: Nisin is a lantibiotic effective against Gram-positive microorganisms such as Streptococcus mutans. The study aimed to determine the effect of the addition of nisin to high-viscosity glass-ionomer cement (HVGIC) on its antibacterial activity, setting time, surface microhardness, and compressive strength. Methods: 1 and 3% w/w nisin were added to HVGIC before mixing. Unmodified HVGIC was the control. Agar disc diffusion, direct contact test, and scanning electron microscopy (SEM) analysis were used to evaluate antibacterial activity against S. mutans. Setting time, surface microhardness, and compressive strength were measured using Gilmore needle apparatus, digital microhardness tester, and universal testing machine, respectively. Statistical analysis included Student's t test, one-way ANOVA with Tamhane's post hoc test, and repeated-measures ANOVA. Results: As evidenced by the agar disc diffusion (p < 0.001), direct contact tests (p = 0.025), and SEM analysis of the S. mutans cell count and cell surface area (p = 0.049 and 0.003), 3% nisin had the strongest antibacterial activity. There was a dose-dependent increase in setting time (p = 0.005) and surface microhardness (p = 0.006), with no significant difference in compressive strength compared to control. Conclusion: The addition of 3% nisin to HVGIC enhances the antibacterial action against S. mutans and surface microhardness without adversely affecting setting time and compressive strength. [ABSTRACT FROM AUTHOR]

Periodontitis-related oral microbial dysbiosis is thought to contribute to adverse pregnancy outcomes (APOs), infertility, and female reproductive inflammation. Since probiotics can modulate periodontitis and oral microbiome dysbiosis, this study examined the effects of a probiotic bacteriocin, nisin, in modulating the reproductive microbiome and inflammation triggered by periodontitis. A total of 24 eight-week-old BALB/cByJ female mice were randomly divided into four treatment groups (control, infection, nisin, and infection+nisin group), with 6 mice per group. A polymicrobial (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum) mouse model of periodontal disease was used to evaluate the effects of this disease on the female reproductive system, with a focus on the microbiome, local inflammation, and nisin's therapeutic potential in this context. Moreover, 16s RNA sequencing was used to evaluate the changes in the microbiome and RT-PCR was used to evaluate the changes in inflammatory cytokines. Periodontal pathogen DNA was detected in the reproductive organs, and in the heart and aorta at the end of the experimental period, and the DNA was especially elevated in the oral cavity in the infection group. Compared to the control groups, only P. gingivalis was significantly higher in the oral cavity and uterus of the infection groups, and T. forsythia and F. nucleatum were significantly higher in the oral cavity of the infection groups. The infection and nisin treatment group had significantly lower levels of P. gingivalis, T. forsythia, and F. nucleatum in the oral cavity compared with the infection group. Since periodontal pathogen DNA was also detected in the heart and aorta, this suggests potential circulatory system transmission. The polymicrobial infection generally decreased the microbiome diversity in the uterus, which was abrogated by nisin treatment. The polymicrobial infection groups, compared to the control groups, generally had lower Firmicutes and higher Bacteroidota in all the reproductive organs, with similar trends revealed in the heart. However, the nisin treatment group and the infection and nisin group, compared to the control or infection groups, generally had higher Proteobacteria and lower Firmicutes and Bacteroidota in the reproductive organs and the heart. Nisin treatment also altered the microbiome community structure in the reproductive tract to a new state that did not mirror the controls. Periodontal disease, compared to the controls, triggered an increase in inflammatory cytokines (IL-6, TNF-α) in the uterus and oral cavity, which was abrogated by nisin treatment. Polymicrobial periodontal disease alters the reproductive tract's microbial profile, microbiome, and inflammatory status. Nisin modulates the microbial profile and microbiome of the reproductive tract and mitigates the elevated uterine inflammatory cytokines triggered by periodontal disease. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to evaluate the effect of in-vivo produced Nisin which is an antimicrobial peptide (AMP) added to adhesive resin on shear bond strength (SBS) and the adhesive remnant index (ARI) of orthodontic brackets. Methods: Bacterial AMP was produced by fermentation and the ideal AMP/Bond concentration and antimicrobial efficacy of the mixture were tested. To evaluate the SBS and ARI scores of AMP-added adhesive resins, 80 maxillary premolar teeth extracted for orthodontic purposes were used and randomly assigned into 2 groups (n = 40). Group 1: Control Group (teeth bonded with standard adhesive resin); Group 2: Experimental Group (teeth bonded with AMP-added adhesive resin). Statistical analysis was performed using the SPSS package program and applying the Mann-Whitney U and Fisher's exact tests. P < 0.05 was considered as statistically significant. Results: Nisin synthesized in-vivo from Lactococcus lactis (L. lactis) (ATCC 7962) bacteria was provided to form a homogenous solution at an ideal concentration To find the minimum AMP/Bond mixture ratio that showed maximum antimicrobial activity, AMP and Bond mixtures were tested at various concentration levels between 1/160 and 1/2 (AMP/Bond). As a result, the optimum ratio was determined as 1/40. The antimicrobial efficacy of Nisin-added adhesive resin was tested against Streptococcus mutans (S. mutans) (ATCC 35,688) and Lactobacillus strains (cariogenic microorganisms). AMP formed a 2.7 cm diameter zone alone, while 1/40 AMP-bond mixture formed a 1.2 cm diameter zone. SBS values of the teeth bonded with Nisin added adhesive (17.49 ± 5.31) were significantly higher than the control group (14.54 ± 4.96) (P = 0.004). According to the four point scale, Nisin added adhesive provided a higher ARI score in favour of the adhesive and tooth compared to the control group (ARI = 3, n = 20). Conclusions: Nisin produced from L. lactis (ATCC 7962) had greater antimicrobial effects after mixing with adhesive bond against cariogenic microorganisms S. mutans (ATCC 35,688) and Lactobacillus strains. Nisin added adhesive increased shear bond strength (SBS) of orthodontic brackets and ARI scores in favor of adhesive & teeth. Clinical relevance: Clinicians should take into account that using Nisin-added adhesive resin in orthodontic treatments can provide prophylaxis against tooth decay, especially in patients with poor oral hygiene. [ABSTRACT FROM AUTHOR]

Nisin, a thermostable, approved food preservative, has limited therapeutic applications because of its high pH and proteolytic enzyme instability. The unavailability of a rapid, simple method of detection also restricts the research of nisin. The objective of this study was to adapt the simple, rapid protein estimation method of detection for nisin formulation and to formulate and evaluate site-specific nanoformulation for therapeutic applications, viz. colon cancer, and anti-bacterial action. Three nanoformulations of nisin with chitosan, gellan gum, and dextran (ECN, EGN, and EDN) were prepared and characterized in vitro. Among three, EGN was selected as a good formulation based on its size surface charge, morphology, drug loading, and release characteristics. FT-IR and DSC revealed the interaction pattern and stability nature. The stability of nisin in an alkaline environment was confirmed by CD. Its therapeutic applications were proved by efficiency against colon cancer cells evaluated by MTT assay and AO/EB staining using Caco-2 cell lines. The in situ sol–gel mechanism imparted by gellan gum was proved the sole reason for the stability and activity of nisin in EGN at lower GIT. This was confirmed (using rheometer) by shear-thickening characteristics of formulation EGN in simulated colon fluid. The antibacterial activity against Staphylococcus aureus by disk diffusion method was also performed to confirm the retention of antimicrobial activity of nisin in EGN. Hence, gellan gum-nisin colloidal nanoparticles are found good candidates for drug delivery at lower GIT and stabilizing alkaline food materials. [ABSTRACT FROM AUTHOR]

Herein, we describe the synthesis and characterisation of four new supramolecular cobalt conjugates of antimicrobial peptides functionalised with terpyridine ligands (L). Peptides were chosen based on the well-established arginine-tryptophan (RW)3 motif, with terpyridine-derivatized lysine (Lys(tpy)) added to the sequence, or replacing tryptophan residues. Self-assembly of the antimicrobial peptides with Co(BF4)2·6H2O formed exclusively CoL2 dimers (for peptides with one tpy ligand each) and Co2L4 metallo-macrocycles (for peptides with two tpy ligands for each peptide), which could be 'locked' by oxidation of Co(+II) to Co(+III) with ammonium ceric nitrate. The Co-peptide complexes were characterised by mass spectrometry and in solution by NMR spectroscopy, including 2D diffusion ordered NMR spectroscopy (DOSY) which confirmed the proposed stoichiometries. The antimicrobial activity of the novel peptides and their metallo-supramolecular assemblies was investigated by determination of their minimal inhibitory concentration (MIC) against a panel of Gram-positive and Gram-negative bacteria. Complexation with cobalt increases the activity of the peptides in almost every case. Most of the new metal–peptide conjugates showed good activity against Gram-positive bacteria, including a multi-resistant S. aureus strain and the opportunistic pathogenic yeast C. albicans (down to 7 μmol l−1 for the most active Co2L4 derivate), a value that is increased five-fold compared to the lysine-derivatized peptide ligand alone. Interestingly, conjugates of the CoL2 type also showed decent activity against Gram-negative bacteria including the WHO-flagged problematic A. baumannii strain (down to 18 μmol l−1 for the most active derivative). [ABSTRACT FROM AUTHOR]

Background: The increase in the resistance of bacterial strains to antibiotics has led to research into the bactericidal potential of non-antibiotic compounds. This study aimed to evaluate in vitro antibacterial/ antibiofilm properties of nisin and selenium encapsulated in thiolated chitosan nanoparticles (N/Se@TCsNPs) against prevalent enteric pathogens including standard isolates of Vibrio (V.) cholerae O1 El Tor ATCC 14,035, Campylobacter (C.) jejuni ATCC 29,428, Salmonella (S.) enterica subsp. enterica ATCC 19,430, Shigella (S.) dysenteriae PTCC 1188, Escherichia (E.) coli O157:H7 ATCC 25,922, Listeria (L.) monocytogenes ATCC 19,115, and Staphylococcus (S.) aureus ATCC 29,733. Methods: The synthesis and comprehensive analysis of N/Se@TCsNPs have been completed. Antibacterial and antibiofilm capabilities of N/Se@TCsNPs were evaluated through broth microdilution and crystal violet assays. Furthermore, the study included examining the cytotoxic effects on Caco-2 cells and exploring the immunomodulatory effects of N/Se@TCsNPs. This included assessing the levels of both pro-inflammatory (IL-6 and TNFα) and anti-inflammatory (IL-10 and TGFβ) cytokines and determining the gene expression of TLR2 and TLR4. Results: The N/Se@TCsNPs showed an average diameter of 136.26 ± 43.17 nm and a zeta potential of 0.27 ± 0.07 mV. FTIR spectroscopy validated the structural features of N/Se@TCsNPs. Scanning electron microscopy (SEM) images confirmed their spherical shape and uniform distribution. Thermogravimetric Analysis (TGA)/Differential Scanning Calorimetry (DSC) tests demonstrated the thermal stability of N/Se@TCsNPs, showing minimal weight loss of 0.03%±0.06 up to 80 °C. The prepared N/Se@TCsNPs showed a thiol content of 512.66 ± 7.33 µmol/g (p < 0.05), an encapsulation efficiency (EE) of 69.83%±0.04 (p ≤ 0.001), and a drug release rate of 74.32%±3.45 at pH = 7.2 (p ≤ 0.004). The synthesized nanostructure demonstrated potent antibacterial activity against various isolates, with effective concentrations ranging from 1.5 ± 0.08 to 25 ± 4.04 mg/mL. The ability of N/Se@TCsNPs to reduce bacterial adhesion and internalization in Caco-2 cells underscored their antibiofilm properties (p ≤ 0.0001). Immunological studies indicated that treatment with N/Se@TCsNPs led to decreased levels of inflammatory cytokines IL-6 (14.33 ± 2.33 pg/mL) and TNFα (25 ± 0.5 pg/mL) (p ≤ 0.0001), alongside increased levels of anti-inflammatory cytokines IL-10 (46.00 ± 0.57 pg/mL) and TGFβ (42.58 ± 2.10 pg/mL) in infected Caco-2 cells (p ≤ 0.0001). Moreover, N/Se@TCsNPs significantly reduced the expression of TLR2 (0.22 ± 0.09) and TLR4 (0.16 ± 0.05) (p < 0.0001). Conclusion: In conclusion, N/Se@TCsNPs exhibited significant antibacterial/antibiofilm/anti-attachment/immunomodulatory effectiveness against selected Gram-positive and Gram-negative enteric pathogens. However, additional ex-vivo and in-vivo investigations are needed to fully assess the performance of nanostructured N/Se@TCsNPs. [ABSTRACT FROM AUTHOR]

Cheese is a food in which toxic concentrations of biogenic amines (BA) may be reached, mainly as a consequence of the decarboxylation of determined amino acids by certain lactic acid bacteria (LAB). To maintain the food safety of cheese, environmentally friendly strategies are needed that specifically prevent the growth of BA-producing LAB and the accumulation of BA. The bacteriocins produced by LAB are natural compounds with great potential as food biopreservatives. This work examines the antimicrobial potential of 7 bacteriocin-containing, cell-free supernatants (CFS: coagulin A-CFS, enterocin A-CFS, enterocin P-CFS, lacticin 481-CFS, nisin A-CFS, nisin Z-CFS and plantaricin A-CFS) produced by LAB against 48 strains of the LAB species largely responsible for the accumulation of the most important BA in cheese, that is, histamine, tyramine, and putrescine. Susceptibility to the different CFS was strain-dependent. The histamine-producing species with the broadest sensitivity spectrum were Lentilactobacillus parabuchneri (the species mainly responsible for the accumulation of histamine in cheese) and Pediococcus parvulus. The tyramine-producing species with the broadest sensitivity spectrum was Enterococcus faecium , and Enterococcus faecalis and Enterococcus hirae were among the most sensitive putrescine producers. Nisin A-CFS was active against 31 of the 48 BA-producing strains (the broadest antimicrobial spectrum recorded). Moreover, commercial nisin A prevented biofilm formation by 67% of the BA-producing, biofilm-forming LAB strains. These findings underscore the potential of bacteriocins in the control of BA-producing LAB and support the use of nisin A as a food-grade biopreservative for keeping BA-producing LAB in check and reducing BA accumulation in cheese. [ABSTRACT FROM AUTHOR]

Treatment of subclinical mastitis (SCM) during lactation is rarely recommended due to concerns related to both antimicrobial usage and the costs associated with milk discard. Nisin is a naturally produced antimicrobial peptide with a gram-positive spectrum that, when given to dairy cows, does not require milk discard. We evaluated the economic impact of the treatment of SCM during early lactation using a nisin-based intramammary treatment under different scenarios that included various treatment costs, milk prices, and cure rates. We stochastically simulated the dynamics of SCM detected during the first week of lactation. The net economic impact was expressed in US dollars per case. The probabilities of an event and their related costs were estimated using a model that was based on pathogen-specific assumptions selected from peer-reviewed articles. Nisin cure rates were based on results of pivotal studies included in the US Food and Drug Administration (FDA) approval submission. Based on our model, the average cost of a case of intramammary infection (i.e., only true-positive cases) in early lactation was $170 (90% = $148–$187), whereas the cost of a clinical mastitis case was $521 (90% range = $435–$581). Both estimates varied with etiology, parity, and stage of lactation. When comparing the net cost of SCM cases (i.e., CMT-positive tests) detected during the first week of lactation, nisin treatment generated an average positive economic impact of $19 per CMT-positive case. The use of nisin to treat SCM was beneficial 93% of the time. Based on the sensitivity analysis, treatment would result in an economically beneficial outcome for 95% and 73% of multiparous and primiparous cows, respectively. At the herd level, use of intramammary nisin to treat SCM in cows in early lactation was economically beneficial in most tested scenarios. However, the economic impact was highly influenced by factors such as rate of bacteriological cure, cost of treatment, and parity of the affected animal. These factors should be considered when deciding to use nisin as a treatment for SCM. [ABSTRACT FROM AUTHOR]

Summary: Characterisation of bacterial communities in multispecies biofilm can aid the search for prevention and control strategies. This study evaluated the influence of nisin and quorum quenching compound furanone on the diversity of biofilm formed from raw milk. Stainless steel coupons were immersed in raw milk containing either nisin or furanone. Biofilm DNA was extracted, followed by metataxonomic analyses. Chao‐1 richness, Simpson, and Shannon diversity indexes fluctuated over the 10‐day period in the control biofilm. However, both nisin and furanone led to a decrease in the Chao‐1 index of the biofilm microbiota and small fluctuation in the Simpson and Shannon diversity indexes without altering the number of sessile cells. Gammaproteobacteria, recognised contaminants of significance in milk, was the dominant class in all biofilms. Addition of nisin or furanone to the raw milk altered the microbial community of the biofilm, resulting particularly in the abundance of the genera Acinetobacter, Lactococcus, and Serratia. [ABSTRACT FROM AUTHOR]

Alternative strategies for controlling Staphylococcus aureus and other pathogens have been continuously investigated, with nisin, a bacteriocin widely used in the food industry as a biopreservative, gaining increasing attention. In addition to its antimicrobial properties, bacteriocins have significant effects on genome functionality even at inhibitory concentrations. This study investigated the impact of subinhibitory concentrations of nisin on S. aureus. Culturing in the presence of 0.625 μmol l−1 nisin, led to the increased relative expression of hla, saeR , and sarA , genes associated with virulence while expression of the sea gene, encoding staphylococcal enterotoxin A (SEA), decreased. In an in vivo experiment, Galleria mellonella larvae inoculated with S. aureus cultured in the presence of nisin exhibited 97% mortality at 72 h post-infection, compared to over 40% of larvae mortality in larvae infected with S. aureus. A comprehensive understanding of the effect of nisin on the transcriptional response of virulence genes and the impact of these changes on the virulence of S. aureus can contribute to assessing the application of this bacteriocin in food and medical contexts. [ABSTRACT FROM AUTHOR]

Various strategies have been researched to enhance the susceptibility of biofilms, given their tolerance to antibiotics. This study evaluated the effect of the anti-microbial peptide nisin in association with antibiotics used in regenerative endodontics, exploring different treatment times and biofilm growth conditions. A mixture of 10 bacterial species was cultivated on dentin specimens anaerobically for 21 days. Biofilms were treated with 1 mL of high-purity nisin Z (nisin ZP, 200 μg/mL) and a triple antibiotic mixture (TAP: ciprofloxacin + metronidazole + minocycline, 5 mg/mL), alone or in combination. The effectiveness of antimicrobial agents was assessed after 1 and 7 days. During the 7-day period, biofilms were treated under 2 conditions: a single dose in a nutrient-depleted setting (ie, no replenishment of growth medium) and multiple doses in a nutrient-rich environment (ie, renewal of medium and antimicrobial agents every 48 h). After treatments, biofilm cells were dispersed, and total colony-forming units were counted. After 1 d-treatment, nisin ZP + TAP resulted in 2-log cell reduction compared to TAP alone (P <.05). After 7 d-treatment with a single dose, nisin ZP + TAP and TAP reduced bacteria to nonculturable levels (P <.05), whereas repeated antimicrobial doses did not eliminate bacteria in a nutrient-rich environment. No bacterial reduction was observed with nisin ZP alone in any treatment time. The additional use of nisin improved the TAP activity only after a short exposure time. Longer exposure to TAP or nisin + TAP in a nutrient-deprived environment effectively eliminated biofilms. [ABSTRACT FROM AUTHOR]

Bacteriocins is the name given to products of the secondary metabolism of many bacterial genera that must display antimicrobial activity. Although there are several bacteriocins described today, it has not been possible to reach a consensus on the method of classification for these biomolecules. In addition, many of them are not yet authorized for therapeutic use against multi-drug-resistant microorganisms due to possible toxic effects. However, recent research has achieved considerable progress in the understanding, classification, and elucidation of their mechanisms of action against microorganisms, which are of medical and biotechnological interest. Therefore, in more current times, protocols are already being conducted for their optimal use, in the hopes of solving multiple health and food conservation problems. This review aims to synthetize the information available nowadays regarding bacteriocins, and their classification, while also providing an insight into the future possibilities of their usage for both the pharmaceutical, food, and biotechnological industry. [ABSTRACT FROM AUTHOR]

Replacing of sodium nitrite from meat processing is a new promising advance in clean label meat products. The current article explored the positive effects of total replacement of sodium nitrite with a combined antimicrobial and antioxidant mixture comprised of 400 ppm nisin (N), 25 ppm Nano sized zinc oxide (Z), 1% chitosan (C) and 1% roselle extract (R) on proximate and fatty acid composition, cooking loss, color analysis and sensory profile of beef sausage. Four types of beef sausage were prepared as following: NT sausage samples as control positive group containing 120 ppm sodium nitrite, NCR samples (400 ppm N, 1% C and 1% R), ZCR (25 ppm Z, 1% C and 1% R) and NZCR samples containing (400 ppm N, 25 ppm Z, 1% C 5and 1% R). The outcomes of the study displayed that there was no significant difference (P > 0.01) in proximate composition of control (NT) and reformulated (NCR, ZCR and NZCR) samples. Concerning fatty acid profiling, saturated (SFA) and monounsaturated fatty acids (MUFA) were the predominant portions in all sausage types and oleic acid was the prevalent one, moreover, reformulated sausages exhibited lower SFA and higher MUFA and PUFA improving fat quality of reformulated beef sausage. A significant difference in cooking loss percentage was observed in NZCR sausage samples compared to other sausages. Noteworthy, cooked reformulated sausages kept their red color after cooking and their a* values were close to those of NT. Sensory assessment (odor, taste and overall acceptance) of reformulated sausages were higher than NT especially for NZCR that recorded the highest scores. Overall, our findings established that combination of antimicrobials (nisin and Nano sized ZnO), antioxidant (chitosan) along with Roselle extract (for red color enhancement) could be potentially applied as a possible nitrite replacer to produce healthier product free from sodium nitrite. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial resistance (AMR) is nowadays a major emerging challenge for public health worldwide. The over- and misuse of antibiotics, including those for cell culture, are promoting AMR while also encouraging the research and employment of alternative drugs. The addition of antibiotics to the cell media is strongly recommended in sperm preservation, being gentamicin the most used for boar semen. Because of its continued use, several bacterial strains present in boar semen have developed resistance to this antibiotic. Antimicrobial peptides and proteins (AMPPs) are promising candidates as alternative antibiotics because their mechanism of action is less likely to promote AMR. In the present study, we tested two AMPPs (lysozyme and nisin; 50 and 500 µg/mL) as possible substitutes of gentamicin for boar semen preservation up to 48 h of storage. Results: We found that both AMPPs improved sperm plasma membrane and acrosome integrity during semen storage. The highest concentration tested for lysozyme also kept the remaining sperm parameters unaltered, at 48 h of semen storage, and reduced the bacterial load at comparable levels of the samples supplemented with gentamicin (p > 0.05). On the other hand, while nisin (500 µg/mL) reduced the total Enterobacteriaceae counts, it also decreased the rapid and progressive sperm population and the seminal oxidation-reduction potential (p < 0.05). Conclusions: The protective effect of lysozyme on sperm function together with its antimicrobial activity and inborn presence in body fluids, including semen and cervical mucus, makes this enzyme a promising antimicrobial agent for boar semen preservation. [ABSTRACT FROM AUTHOR]

Phage-encoded endolysins have emerged as a potential substitute to conventional antibiotics due to their exceptional benefits including host specificity, rapid host killing, least risk of resistance. In addition to their antibacterial potency and biofilm eradication properties, endolysins are reported to exhibit synergism with other antimicrobial agents. In this study, the synergistic potency of endolysins was dissected with antimicrobial peptides to enhance their therapeutic effectiveness. Recombinantly expressed and purified bacteriophage endolysin [T7 endolysin (T7L); and T4 endolysin (T4L)] proteins have been used to evaluate the broad-spectrum antibacterial efficacy using different bacterial strains. Antibacterial/biofilm eradication studies were performed in combination with different antimicrobial peptides (AMPs) such as colistin, nisin, and polymyxin B (PMB) to assess the endolysin’s antimicrobial efficacy and their synergy with AMPs. In combination with T7L, polymyxin B and colistin effectively eradicated the biofilm of Pseudomonas aeruginosa and exhibited a synergistic effect. Further, a combination of T4L and nisin displayed a synergistic effect against Staphylococcus aureus biofilms. In summary, the obtained results endorse the theme of combinational therapy consisting of endolysins and AMPs as an effective remedy against the drug-resistant bacterial biofilms that are a serious concern in healthcare settings. [ABSTRACT FROM AUTHOR]

This study aimed to optimize the formulation of chitosan -caffeic acid nanogel containing Shirazi thyme (Zataria multiflora) essential oil (ZEO) and nisin. The independent variables (the concentration of chitosan nanogel, Shirazi -thyme, and nisin) were optimized based on the highest zeta potential and encapsulation efficiency, besides the lowest particle size and IC50(DPPH) values. The results of The Box -Behnken experimental design and Stepwise -response surface model showed the optimal nanogel formulation was as follows: chitosan concentration= 0.4 g; ZEO= 157.1 ppm and nisin= 10.1 ppm. The particle size, zeta -potential, antioxidant activity, and encapsulation efficiency of the optimal chitosan -ZEO - nisin nanogel were 411.39±18.11 nm, 32.90±1.10 mV, 0.79±0.06 mg.mL - 1, 71.06 - 82.69% respectively. Moreover, the addition of optimized nanogel to the Iranian white cheese formulation showed that the treated cheese samples with ZEO and nisin (free or encapsulated in chitosan nanogel) improved the microbial quality of chess. The antimicrobial activity of the ZEO and nisin encapsulated in chitosan - caffeic acid nanogel was higher than a free form of ZEO -nisin. The Coliforms population of cheeses treated with sodium nitrate and chitosan nanogel containing ZEO -nisin was acceptable during 60 days of storage. During the storage period, the most changes in the color and texture (hardness) of the cheese samples were related to the control sample, and the least change was obtained for samples treated with sodium -nitrate and chitosan nanogel (P < 0.05). Also, the sensory quality of the sample containing ZEO and nisin was acceptable for the sensory evaluator. The sample containing chitosan nanogel received an acceptable sensory score (>3) during 60 days of storage. In general, the potential of the nanogel in increasing the shelf-life of Iranian white cheese was comparable with sodium nitrate. [ABSTRACT FROM AUTHOR]

The current study aims to co‐encapsulate Shirazi thyme (Zataria multiflora) essential oil (ZEO) and nisin into chitosan nanogel as an antimicrobial and antioxidant agent to enhance the shelf‐life of cheese. Chitosan‐caffeic acid (CS‐CA) nanogel was produced to co‐encapsulate Zataria multiflora essential oil and nisin. This nanogel was characterized by dynamic light scattering (DLS), Fourier Transform Infrared (FTIR) spectroscopic analysis, X‐ray diffraction (XRD) analysis, and scanning electron microscopy (SEM) images. The effect of free (TFZN) and encapsulated ZEO‐nisin in chitosan nanogel (TCZN) on the chemical and microbiological properties of Iranian white cheese was assessed. The particle size, polydispersity index value (PDI), zeta potential, antioxidant activity, and encapsulation efficiency of the optimal chitosan‐ZEO‐nisin nanogel were 421.6 nm, 0.343, 34.0 mV, 71.06%–82.69%, and 41.3 ± 0.5%, 0.79 ± 0.06 mg/mL. respectively. FTIR and XRD approved ZEO and nisin entrapment within chitosan nanogel. The chitosan nanogel showed a highly porous surface with an irregular shape. The bioactive compounds of ZEO and nisin decreased the pH changes in cheese. On the 60th day of storage, the acidity of treated samples was significantly lower than that of control. Although the lowest anisidine index value was observed in samples treated with sodium nitrate (NaNO3) (TS), there was no significant difference between this sample and TCZN. The lowest microbial population was observed in TCZN and TS. After 60 days of ripening, Coliforms were not detected in the culture medium of TCZN and TS. The results can contribute to the development of a natural preservative with the potential for application in the dairy industry. [ABSTRACT FROM AUTHOR]

Background and purpose: Activated textiles have created a new field of application apart from standard textile applications. Novel, functions, for example, antimicrobial properties have been enhanced in textiles. New textile application fields have been recognized for particular areas of healthcare as well as industry, sportswear, and, home textiles. Advances in the field of antibacterial textiles have fascinated enhancing attention because those are a means to solve serious health challenges such as bacterial overgrowth. A lot of research has been done in the field of adding synthetic and toxic materials to fabrics, such as nanosilver triclosan or other metals and organic materials to produce antimicrobial fabrics. These fabrics kill bacteria by binding to intracellular proteins and inactivating these proteins. Also, by using these chemicals, the content of heavy metals in these textiles can be increased. The application of heavy metals in antimicrobial textiles is limited by many environmental tags and standards. Therefore, it is recommended to use natural antimicrobial agents, such as nisin and chitosan to produce environmentally friendly and safe antimicrobial fabrics. Nowadays finishing process with the natural antibacterial agents that protect the environment and human health is gaining importance. Therefore, this study aims to produce fabric coated with chitosan and nisin and to investigate its antimicrobial properties. Materials and methods: In this research, chitosan was used to bind nisin to the surface of polypropylene span band non-woven fabric. The fabric samples were coated with a solution containing chitosan and nisin using a pad-dry-cure method. The appearance, color, and softness of the coated fabrics were compared to the uncoated fabric. The nisin and chitosan binding properties on the fabric were explored by using the Fouriertransform infrared (FTIR( technique. The diffusion method in agar and the standard method (ASTME2149-01) were used to check the antimicrobial properties of fabric samples. The antibacterial effectiveness of fabric samples was tested against common bacteria such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Enterococcus faecalis. After ten washing cycles, the durability of the antimicrobial properties of these fabrics was checked by the method mentioned above. Also, the toxicity of this fabric on fibroblast cells was determined using the MTT colorimetry method after seven days. Results: Fabrics coated with chitosan and nisin do not differ much from the control sample in terms of appearance and softness. The changes observed in the FTIR spectrum, such as the appearance of new absorption peaks and additional peaks associated with peptide bonds, confirm the successful incorporation of nisin and chitosan into the fabric. Antibacterial results have shown that nisin improved the antibacterial effect of coated fabrics versus B. cereus, S. aureus, and P. aeruginosa. The antimicrobial properties of the fabric coated with chitosan-nisin were maintained at some of the efficacy after washing against B. cereus, S. aureus, E. faecalis, L. monocytogenes, E. coli, and P. aeruginosa respectively. Also, the chitosan-nisin coating showed that it did not cause significant toxicity in fibroblast cells even after one week. Conclusion: However, the results showed that the chitosan/nisin coating might be used for medical textiles and antibacterial textiles. It also offers an innovative solution to protect human health and the environment [ABSTRACT FROM AUTHOR]

Nisin is a bacteriocin produced by Lactococcus lactis and it is generally recognised as safe by the U.S. Food and Drug Administration. The study aimed to determine the presence of nisin-resistant Staphylococcus , Enterococcus, and Listeria spp. in 157 raw milk and 125 cheese samples. As a result of the isolation procedure, a total of 282 bacterial strains were isolated. 83/282 strains showed resistance to 300 ppm nisin concentration and they were identified by 16S rRNA sequencing. The two most common species were Enterococcus faecalis and Staphylococcus aureus. In both raw milk and cheese samples, nisin-resistant Listeria could not be detected. Generally, enterococci (59/65) showed higher biofilm formation ability than staphylococci (13/18). 38% (25/65) of enterococci and 88% (16/18) of staphylococci were determined to have protease activity in at least one of Skim Milk Agar, Casein Agar, or Milk Agar. In addition, the most common antibiotic resistance in nisin-resistant enterococci was against chloramphenicol. This study revealed that nisin-resistant staphylococci and enterococci are present in raw milk and cheese. In addition, the presence of some virulence factors such as biofilm production, protease activity, and antibiotic resistance in resistant isolates needs to be drawn attention to. Consumption of nisin-resistant microorganisms with virulence factors through food is a food safety risk. [ABSTRACT FROM AUTHOR]

As a natural cationic peptide, Nisin is capable of widely inhibiting the growth of Gram-positive bacteria. However, it also has drawbacks such as its antimicrobial activity being susceptible to environmental factors. Nano-encapsulation can improve the defects of nisin in food applications. In this study, nisin-loaded egg white protein nanoparticles (AH-NEn) were prepared in fixed ultrasound-mediated under pH 3.0 and 90 °C. Compared with the controls, AH-NEn exhibited smaller particle size (112.5 ± 2.85 nm), smaller PDI (0.25 ± 0.01), larger Zeta potential (24 ± 1.18 mV), and higher encapsulation efficiency (91.82%) and loading capacity (45.91%). The turbidity and Fourier transform infrared spectroscopy (FTIR) results indicated that there are other non-covalent bonding interactions between the molecules of AH-NEn besides the electrostatic forces, which accounts for the fact that it is structurally more stable than the controls. In addition, by the results of fluorescence intensity, differential scanning calorimetry (DSC), and X-ray diffraction (XRD), it was shown that thermal induction could improve the solubility, heat resistance, and encapsulation of nisin in the samples. In terms of antimicrobial function, acid–heat induction did not recede the antimicrobial activity of nisin encapsulated in egg white protein (EWP). Compared with free nisin, the loss rate of bactericidal activity of AH-NEn was reduced by 75.0% and 14.0% following treatment with trypsin or a thermal treatment at 90 °C for 30 min, respectively. [ABSTRACT FROM AUTHOR]

Nisin is used as a natural food preservative because of its broad-spectrum antimicrobial activity against Gram-positive bacteria. However, free nisin is susceptible to various factors that reduce its antimicrobial activity. Milk protein, a protein derived from milk, has self-assembly properties and is a good carrier of bioactive substances. In this study, lactoferrin–nisin nanoparticles (L-N), bovine serum albumin–nisin nanoparticles (B-N), and casein–nisin nanoparticles (C-N) were successfully prepared by a self-assembly technique, and then their properties were investigated. The studies revealed that lactoferrin (LF) and nisin formed L-N mainly through hydrophobic interactions and hydrogen bonding, and L-N had the best performance. The small particle size (29.83 ± 2.42 nm), dense reticular structure, and good thermal stability, storage stability, and emulsification of L-N laid a certain foundation for its application in food. Further bacteriostatic studies showed that L-N enhanced the bacteriostatic activity of nisin, with prominent inhibitory properties against Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus, which mainly disrupted the cell membrane of the bacteria. The above results broaden our understanding of milk protein–nisin nanoparticles, while the excellent antibacterial activity of L-N makes it promising for application as a novel food preservative, which will help to improve the bioavailability of nisin in food systems. [ABSTRACT FROM AUTHOR]

Aims: This study investigates the activity of the broad-spectrum bacteriocin nisin against a large panel of Gram-negative bacterial isolates, including relevant plant, animal, and human pathogens. The aim is to generate supportive evidence towards the use/inclusion of bacteriocin-based therapeutics and open avenues for their continued development. Methods and Results: Nisin inhibitory activity was screened against a panel of 575 strains of Gram-negative bacteria, encompassing 17 genera. Nisin inhibition was observed in 309 out of 575 strains, challenging the prevailing belief that nisin lacks effectiveness against Gram-negative bacteria. The genera Acinetobacter, Helicobacter, Erwinia, and Xanthomonas exhibited particularly high nisin sensitivity. Conclusions: The findings of this study highlight the promising potential of nisin as a therapeutic agent for several key Gram-negative plant, animal, and human pathogens. These results challenge the prevailing notion that nisin is less effective or ineffective against Gram-negative pathogens when compared to Gram-positive pathogens and support future pursuits of nisin as a complementary therapy to existing antibiotics. Significance and Impact of Study: This research supports further exploration of nisin as a promising therapeutic agent for numerous human, animal, and plant health applications, offering a complementary tool for infection control in the face of multidrug-resistant bacteria. [ABSTRACT FROM AUTHOR]