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Graphical abstract Highlights • Lipophilics and antibacterial effect of three Portuguese Salix spp. barks are studied. • S. atrocinerea and S. fragilis barks show higher long aliphatic aldehydes contents. • Piceol is only detected in S. atrocinerea and S. fragilis barks. • S. viminalis bark presents the highest pentacyclic triterpenes and sterols contents. • The highest E. coli inhibitory effect is exhibited by S. viminalis bark extracts. Abstract Salix (Salicaceae) species bark extracts are traditionally consumed due to their anti-inflammatory and analgesic benefits, mainly attributed to phenolic compounds. However, this biomass could be further exploited calling upon other extractive components, namely the lipophilic fraction. Hence, the present study highlights, for the first time, the chemical characterisation and the inhibitory effect of S. viminalis L., S. atrocinerea Brot. and S. fragilis L. bark lipophilic dichloromethane extracts against the Gram-negative bacterium Escherichia coli. Gas chromatography-mass spectrometry allowed the identification and quantification of 63 compounds, from which 36 were reported for the first time in these Salix species, namely 15 aromatic compounds, 4 fatty acids, 4 long chain aliphatic alcohols, 1 diterpene, 4 pentacyclic triterpenes, 4 tocopherols, 3 long chain aliphatic aldehydes and 1 sterol. Long chain aliphatic aldehydes represent the prevalent family, with triacontanal as the major component in S. fragilis L. and S. atrocinerea Brot. barks. Additionally, β -sitosterol was the major component identified in S. viminalis L. bark lipophilic extract, followed by lupeol. This last extract exhibited the highest inhibitory effect against E. coli viability, being probably related with these bioactive components. In contrast, aromatic compounds were detected at high abundances in S. atrocinerea Brot. and S. fragilis L. barks, with piceol as the predominant component. These findings can contribute to valorise bark of the three endogenous Portuguese Salix species, based on their chemical composition and biological properties. [ABSTRACT FROM AUTHOR]

Phytotoxins produced by marine microalgae, such as paralytic shellfish toxins (PSTs), can accumulate in bivalve molluscs, representing a human health concern due to the life-threatening symptoms they cause. To avoid the commercialization of contaminated bivalves, monitoring programs were established in the EU. The purpose of this work is the implementation of a PST transforming enzyme—carbamoylase—in an impedimetric test for rapid simultaneous detection of several carbamate and N-sulfocarbamoyl PSTs. Carbamoylase hydrolyses carbamate and sulfocarbamoyl toxins, which may account for up to 90% of bivalve toxicity related to PSTs. Conformational changes of carbamoylase accompanying enzymatic reactions were probed by Fourier transform mid-infrared spectroscopy (FT-MIR) and electrochemical impedance spectroscopy (EIS). Furthermore, a combination of EIS with a metal electrode and a carbamoylase-based assay was employed to harness changes in the enzyme conformation and adsorption on the electrode surface during the enzymatic reaction as an analytical signal. After optimization of the working conditions, the developed impedimetric e-tongue could quantify N-sulfocarbamoyl toxins with a detection limit of 0.1 µM. The developed e-tongue allows the detection of these toxins at concentration levels observed in bivalves with PST toxicity close to the regulatory limit. The quantification of a sum of N-sulfocarbamoyl PSTs in naturally contaminated mussel extracts using the developed impedimetric e-tongue has been demonstrated. [ABSTRACT FROM AUTHOR]

The present study investigated the potential application of the bacteriophage (or phage) phT4A, ECA2 and the phage cocktail phT4A/ECA2 to decrease the concentration of Escherichia coli during the depuration of natural and artificially contaminated cockles. Depuration in static seawater at multiplicity of infection (MOI) of 1 with single phage suspensions of phT4A and ECA2 was the best condition, as it decreased by ∼2.0 log CFU/g the concentration of E . coli in artificially contaminated cockles after a 4 h of treatment. When naturally contaminated cockles were treated in static seawater with single phage suspensions and the phage cocktail, similar decreases in the concentration of E . coli (∼0.7 log CFU/g) were achieved. However, when employing the phage cocktail, a longer treatment time was required to obtain comparable results to those achieved when using single phage suspensions. When naturally contaminated cockles were depurated with phage phT4A in a recirculated seawater system (mimicking industrial depuration conditions), a 0.6 log CFU/g reduction of E . coli was achieved after a 2 h of treatment. When the depuration process was performed without phage addition, a 4 h treatment was necessary to obtain a similar decrease. By combining phage therapy and depuration procedures, a reduction in bivalves depuration period can be achieved for, thus decreasing the cost associated with this procedure and even enhance the quality and safety of depurated bivalves destined for human consumption. [ABSTRACT FROM AUTHOR]

In the present study two new phages (phT4A and ECA2) were characterized and their efficacy was evaluated separately and in cocktail (phT4A/ECA2) to control Escherichia coli . The isolated phages, phT4A and ECA2, belonged to the Myoviridae and Podoviridae family, respectively and both are safe (no integrase and toxin codifying genes) to be used in bacterial control. In general, the increase of multiplicity of infection (MOI) from 1 to 100 promoted a significant increase in the efficiency of phage phT4A and phage cocktail phT4A/ECA2. Both phages were effective against E. coli , but phage phT4A (reduction of 5.8 log CFU/mL after 8 h treatment) was more effective than phage ECA2 phage (reduction of 4.7 log CFU/mL after 8 h treatment). The use of a cocktail phT4A/ECA2 was significantly more effective (reductions of 6.2 log CFU/mL after 6 h treatment) than the use single phage suspensions of phT4A and ECA2 (reductions 5.3 log CFU/mL and 4.9 log CFU/mL, respectively, after 6 h treatment). The rate of emergence of phage-resistant mutants was lower for phage phT4A when compared with phage ECA2 and phage cocktail phT4A/ECA2.The results indicate that in addition to the efficacy, the potential development of phage-resistant mutants must also be considered in the design of phage cocktails. [ABSTRACT FROM AUTHOR]

As bivalve molluscs are filter feeder, often consumed raw or lightly cooked and are frequently cultivated in contaminated waters, they are implicated in food-borne disease transmission to human. The present study investigated the potential application of bacteriophage (or phage) phSE-2, phage phSE-5 and phage cocktail phSE-2/phSE-5 to decrease the concentration of Salmonella enterica serovar Typhimurium ( Salmonella Typhimurium) during the depuration of natural and artificially contaminated cockles ( Cerastoderma edule ). Cockles were artificially infected with 10 5 and 10 6 colony-forming units (CFU)/mL of S . Typhimurium in static seawater and infected group were treated with phages at four different MOI values: 0.1, 1, 10 and 100. Depuration in static seawater at multiplicity of infection (MOI) of 0.1 with single phage suspensions of phSE-2 and phSE-5 provided the best results, as it decreased by ~ 1.3 and 1.7 log CFU/g, respectively, the concentration of Salmonella spp. after a 4 h treatment. At a MOI of 0.1, the rate of inactivation with single phage suspensions was higher when compared with the results obtained using the phage cocktail. However, in naturally contaminated cockles treated in static seawater with single phage suspensions and phage cocktail phSE-2/phSE-5, similar decreases in cultivable bacteria concentration (~ 0.7–0.9 log CFU/g) were achieved after 6 h of treatment. When artificially contaminated cockles were depurated with phage phSE-5 in a recirculated seawater system (mimicking industrial depuration conditions), a 0.9 and 2.0 log CFU/g reduction of Salmonella spp. was reached after 4 and 6 h treatment. Once the depuration process was performed without phage, a 6 h treatment was needed to obtain a 1.1 log CFU/g reduction of Salmonella spp. Results indicated that combining phage biocontrol with depuration procedures enhance bivalve microbial safety for human consumption by improving decontamination efficiency, proving that this technology can be transposed to the bivalves industry. Moreover, this approach also displays the advantage of reducing the time required for depuration and consequently its associated costs. [ABSTRACT FROM AUTHOR]

High pressure processing is an emergent technology for food preservation that causes minimal changes in the characteristics of the foods, preventing food spoilage and foodborne diseases. In this work, 12 different foodborne bacteria were submitted to high pressure (300 MPa, 15 min, room temperature) in order to assess the bacterial reduction and the alterations induced with this processing in cellular components. It was observed that all the Gram-negative bacteria were inactivated to undetectable levels while Gram-positive showed resistance to pressure, being Staphylococcus aureus and Bacillus cereus the most resistant, decreasing only 2 logs. Listeria monocytogenes decreased about 5 logs. IR spectroscopy was used to investigate the differences in the spectra of the cells after the pressurization. Regarding cellular modifications, it was possible to notice that changes in hydrogen bounds appear to be on the basis of the modifications observed in the spectra after high pressure processing. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the dynamics of three previously isolated bacteriophages (or phages) individually (phSE-1, phSE-2 and phSE-5) or combined in cocktails of two or three phages (phSE-1/phSE-2, phSE-1/phSE-5, phSE-2/phSE-5 and phSE-1/phSE-2/phSE-5) to control Salmonella enterica serovar Typhimurium ( Salmonella Typhimurium) in order to evaluate their potential application during depuration. Phages were assigned to the family Siphoviridae and revealed identical restriction digest profiles, although they showed a different phage adsorption, host range, burst size, explosion time and survival in seawater. The three phages were effective against S. Typhimurium (reduction of ∼2.0 log CFU/mL after 4 h treatment). The use of cocktails was not significantly more effective than the use of single phages. A big fraction of the remained bacteria are phage-resistant mutants (frequency of phage-resistant mutants 9.19 × 10 −5 –5.11 × 10 −4 ) but phage- resistant bacterial mutants was lower for the cocktail phages than for the single phage suspensions and the phage phSE-1 presented the highest rate of resistance and phage phSE-5 the lowest one. The spectral changes of S. Typhimurium resistant and phage-sensitive cells were compared and revealed relevant differences for peaks associated to amide I (1620 cm −1 ) and amide II (1515 cm −1 ) from proteins and from carbohydrates and phosphates region (1080–1000 cm −1 ). Despite the similar efficiency of individual phages, the development of lower resistance indicates that phage cocktails might be the most promising choice to be used during the bivalve depuration to control the transmission of salmonellosis. [ABSTRACT FROM AUTHOR]

One of the major sources of financial loss for the fish farming industry is the occurrence of infections by pathogenic bacteria, especially multidrug-resistant variants. This problem is most prominent during the early stages of fish development and is difficult to address with traditional antibiotic treatment or vaccination. In this way, alternative environmentally-friendly biological strategies to control bacterial infections need to be implemented. Under this scenario, phage therapy appears as a useful and flexible tool for the inactivation of bacterial pathogens in aquaculture. The aim of this study was to test the efficacy of phage therapy to inactivate Aeromonas salmonicida , the causative agent of furunculosis, a fish disease characterized by high mortality and morbidity. In order to achieve this goal, a new phage was isolated, characterized and tested in artificially-infected Solea senegalensis juveniles and in batch bacterial cultures. Results showed that after 6 h of treatment the phage inhibited the growth of A. salmonicida both in batch cultures and seawater in the presence of fish juveniles (≈ 4 and 2.5 Log PFU mL − 1 , respectively). After 72 h, fish juveniles treated with phages after exposure to A. salmonicida showed no mortality, contrarily to fishes that were only exposed to the bacterium, which presented a mortality of 36%. This result indicated that phage treatment was effective. In general, a limited regrowth of resistant cells and absence of lysogeny conversion were observed. No significant impact of phage inoculation on natural bacterial communities of aquaculture water was detected. However, the bacterial community associated with fish intestinal tract was moderately affected by the addition of the phage. Interestingly, the differences were not significant when the phage was added in the presence of the host bacteria. Taking this into account, this study provides evidences that the tested phage can be effective and safe against furunculosis during the production of juvenile fish. Statement of relevance A major source of financial loss for the fish-farming industry is the occurrence of bacterial infections. This problem is most prominent in early stages of fish development, and is difficult to address with antibiotics/vaccination. Alternative environmentally-friendly strategies to control bacterial infections are needed. This study indicates that phages can be effective and safe against furunculosis during fish juvenile production. [ABSTRACT FROM AUTHOR]

The accurate reliable detection and identification of microorganisms in food is critical to public safety. Consequently, it is extremely important to develop rapid and inexpensive methods for the detection of food microorganisms in order to minimize or even replace the traditional analysis methods that are expensive and time-consuming. In this study, the potential of mid-infrared spectroscopy was evaluated, for the first time, to detect changes in colony forming units of microorganisms in freshly cut ham along the time. A partial least squares regression model was performed and a good linear relationship was obtained between spectra information and microbial load. It was concluded that infrared spectroscopy easily and quickly allows the separation of ham samples according to their microbial content and could be used to predict the microbial concentration from the spectra, using the fingerprint region (1,200-950 cm−1), without sample preparation or handling. Practical Applications As it is essential to avoid infections caused by foodborne bacteria, it is important to develop a rapid, low cost and easy to perform technique to face the increasing demands of the food industry. Mid-infrared spectroscopy, coupled to multivariate analysis, has potential to be used as a first-screening approach and to assess the microbial concentration in ham samples, avoiding the traditional plating methods that are time-consuming. [ABSTRACT FROM AUTHOR]

Knowledge of the molecular effects of UV radiation (UVR) on bacteria can contribute to a better understanding of the environmental consequences of enhanced UV levels associated with global climate changes and will help to optimize UV-based disinfection strategies. In the present work, the effects of exposure to UVR in different spectral regions (UVC, 100-280 nm; UVB, 280-320 nm; and UVA, 320-400 nm) on the lipids and proteins of two bacterial strains (Acinetobacter sp. strain PT5I1.2G and Pseudomonas sp. strain NT5I1.2B) with distinct UV sensitivities were studied by mid-infrared spectroscopy. Exposure to UVR caused an increase in methyl groups associated with lipids, lipid oxidation, and also led to alterations in lipid composition, which were confirmed by gas chromatography. Additionally, mid-infrared spectroscopy revealed the effects of UVR on protein conformation and protein composition, which were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), oxidative damage to amino acids, and changes in the propionylation, glycosylation and/or phosphorylation status of cell proteins. Differences in the targets of UVR in the two strains tested were identified and may explain their discrepant UV sensitivities. The significance of the results is discussed from an ecological standpoint and with respect to potential improvements in UV-based disinfection technologies. [ABSTRACT FROM AUTHOR]

Simple Summary: The knowledge of the biosynthetic pathways and the biological role of secondary metabolites produced by the third domain of life is limited when compared with bacteria or eukaryotes. Herein, we investigated, in more detail, genes encoding enzymes that are predicted to be involved in the biosynthesis of peptide secondary metabolites in halophilic archaea regarding (i) their transcription, (ii) their association with antimicrobial activity, and (iii) the impact of their absence on the biomolecular profile of the cells. Research on secondary metabolites produced by Archaea such as ribosomally synthesized and post-translationally modified peptides (RiPPs) is limited. The genome of Haloferax mediterranei ATCC 33500 encodes lanthipeptide synthetases (medM1, medM2, and medM3) and a thiazole-forming cyclodehydratase (ycaO), possibly involved in the biosynthesis of lanthipeptides and the TOMMs haloazolisins, respectively. Lanthipeptides and TOMMs often have antimicrobial activity, and H. mediterranei has antagonistic activity towards haloarchaea shown to be independent of medM genes. This study investigated (i) the transcription of ycaO and medM genes, (ii) the involvement of YcaO in bioactivity, and (iii) the impact of YcaO and MedM-encoding genes' absence in the biomolecular profile of H. mediterranei. The assays were performed with biomass grown in agar and included RT-qPCR, the generation of knockout mutants, bioassays, and FTIR analysis. Results suggest that ycaO and medM genes are transcriptionally active, with the highest number of transcripts observed for medM2. The deletion of ycaO gene had no effect on H. mediterranei antihaloarchaea activity. FTIR analysis of medM and ycaO knockout mutants suggest that MedMs and YcaO activity might be directly or indirectly related t lipids, a novel perspective that deserves further investigation. [ABSTRACT FROM AUTHOR]

In this study, brewers spent grain (BSG) arabinoxylans-based nanocomposite films were prepared by solvent casting of arabinoxylans (AX) suspensions containing different amounts of nanofibrillated cellulose (NFC, 5, 10, 25, 50 and 75% mass fraction). The obtained nanocomposite films were homogeneous and presented thermal stability up to 230 °C and good mechanical properties (Young's modulus up to 7.5 GPa). Additionally, the films with 50% NFC were loaded with ferulic acid or feruloylated arabinoxylo-oligosaccharides enriched fraction from BSG (75 mg per g of film). This combination enhanced the UV–Vis barrier properties and imparted additional functionalities to the films, namely (i) antioxidant activity up to 90% (DPPH scavenging activity), (ii) antibacterial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, and (iii) antifungal activity towards the polymorphic fungus Candida albicans. Therefore, these fully biobased nanocomposite films show potential for application as active food packaging systems. Image 1 • Nanocomposite films of nanocellulose (NFC) and brewer spent grain arabinoxylans were prepared. • Films containing brewing by-products (AX) have enhanced thermal and mechanical properties. • Feruloylated arabinoxylo-oligosaccharides (FAXOS) were used as active agents. • Active agents imparted the films with UV-barrier, antioxidant and antimicrobial properties. • Bioactive AX–NFC–based nanocomposite films have potential for active food packaging. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) is becoming an important substrate for engineering multifunctional nanomaterials with singular and tunable properties for application in several domains. Here, antimicrobial conductive nanocomposites composed of poly(sulfobetaine methacrylate) (PSBMA) and BNC were fabricated as freestanding films for application in food packaging. The nanocomposite films were prepared through the one-pot polymerization of sulfobetaine methacrylate (SBMA) inside the BNC nanofibrous network and in the presence of poly(ethylene glycol) diacrylate as cross-linking agent. The ensuing films are macroscopically homogeneous, more transparent than pristine BNC, and present thermal stability up to 265 °C in a nitrogen atmosphere. Furthermore, the films have good mechanical performance (Young's modulus ≥ 3.1 GPa), high water-uptake capacity (450–559%) and UV-blocking properties. The zwitterion film with 62 wt.% cross-linked PSBMA showed bactericidal activity against Staphylococcus aureus (4.3–log CFU mL−1 reduction) and Escherichia coli (1.1–log CFU mL−1 reduction), and proton conductivity ranging between 1.5 × 10−4 mS cm−1 (40 °C, 60% relative humidity (RH)) and 1.5 mS cm−1 (94 °C, 98% RH). Considering the current set of properties, PSBMA/BNC nanocomposites disclose potential as films for active food packaging, due to their UV-barrier properties, moisture scavenging ability, and antimicrobial activity towards pathogenic microorganisms responsible for food spoilage and foodborne illness; and also for intelligent food packaging, due to the proton motion relevant for protonic-conduction humidity sensors that monitor food humidity levels. [ABSTRACT FROM AUTHOR]

The development of efficient and environmentally-friendly nanomaterials to remove contaminants and pollutants (including harmful organic dyes) ravaging water sources is of major importance. Herein, zwitterionic nanocomposite membranes consisting of cross-linked poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and bacterial nanocellulose (BNC) were prepared and tested as tools for water remediation. These nanocomposite membranes fabricated via the one-pot polymerization of the zwitterionic monomer, 2-methacryloyloxyethyl phosphorylcholine, within the BNC three-dimensional porous network, exhibit thermal stability up to 250 °C, good mechanical performance (Young's modulus ≥ 430 MPa) and high water-uptake capacity (627%–912%) in different pH media. Moreover, these zwitterionic membranes reduced the bacterial concentration of both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) pathogenic bacteria with maxima of 4.3– and 1.8–log CFU reduction, respectively, which might be a major advantage in reducing or avoiding bacterial growth in contaminated water. The removal of two water-soluble model dyes, namely methylene blue (MB, cationic) and methyl orange (MO, anionic), from water was also assessed and the results demonstrated that both dyes were successfully removed under the studied conditions, reaching a maximum of ionic dye adsorption of ca. 4.4–4.5 mg g−1. This combination of properties provides these PMPC/BNC nanocomposites with potential for application as antibacterial bio-based adsorbent membranes for water remediation of anionic and cationic dyes. [ABSTRACT FROM AUTHOR]

Cutaneous wounds frequently require the use of patches to promote healing, nevertheless, most commercial products are fabricated with non-biodegradable synthetic substrates that pose environmental problems upon disposal. Herein, the partnership between two biobased nanofibrous polymers, namely a polysaccharide (nanofibrillated cellulose (NFC)) and a protein (lysozyme nanofibers (LNFs)), is explored to design sustainable fibrous patches with good mechanical performance and biological functionalities for wound healing applications. Two patches with different morphologies were prepared by vacuum filtration of a water-based suspension of both nanofibers and by sequential filtration of the separated suspensions (layered patch). The resultant freestanding patches exhibited high thermal stability (up to 250 °C), mechanical performance (Young's modulus ≥3.7 GPa), and UV-barrier properties. The combination of the bioactive LNFs with the mechanically robust NFC conveyed antioxidant activity (76–79% DPPH scavenging) and antimicrobial activity against Staphylococcus aureus (3.5–log CFU mL−1 reduction), which is a major benefit to prevent microbial wound infections. Moreover, these patches are biocompatible towards L929 fibroblast cells, and the in vitro wound healing assay evidenced a good migration capacity leading to an almost complete wound occlusion. Therefore, the partnership between the two naturally derived nanofibrous polymers represents a potential blueprint to engineer sustainable multifunctional patches for cutaneous wound healing. Unlabelled Image • Nanofibrillated cellulose (NFC) and lysozyme nanofibers (LNFs) patches were fabricated. • Nanofibrous robust patches with UV-barrier, antioxidant, and antimicrobial properties • Biocompatible patches with good migration capacity leading to complete wound closure • Sustainable multifunctional NFC/LNFs-based patches for cutaneous wound healing [ABSTRACT FROM AUTHOR]

A major source of financial loss for the fish-farming industry is the occurrence of bacterial infections. Phage therapy can be a useful alternative tool to conventional treatments to control bacterial infections in aquaculture. The promising results obtained with phage AS-A to control the agent of furunculosis, Aeromonas salmonicida , led us to isolate two new phages and evaluate their dynamics, in cocktails and individually, to control this pathogenic bacterium. Moreover, considering that in outdoor facilities aquaculture water is exposed to the natural variability of physical and chemical parameters, the influence of pH, salinity, temperature, solar radiation and UV radiation on phage AS-D stability was also evaluated in this study, in order to develop an effective phage therapy protocol. Phages were assigned to the family Myoviridae and revealed identical morphological characteristics. Phage AS-A presents a higher burst size and a shorter latent period, decreasing the concentration of A. salmonicida sooner than phages AS-D and AS-E. However, phage AS-D presented higher rate of bacterial reduction, inducing also less bacterial resistance. Bacterial control with the cocktails was higher, namely when phage AS-A was combined with one of the two new phages or with both, but the main difference in the bacterial control was in the treatment time. Phage cocktails decrease the concentration of A. salmonicida sooner than single suspensions. The use of phage cocktails, in general, decreased phage-resistant mutants. The survival of AS-D phage was mostly affected by sunlight exposure (decrease of 3 log PFU/mL after 12 h) and high temperatures (decrease of 3 PFU/mL after 21 days and of 7 log PFU/mL after 49 days at 37 °C, but no decrease after 21 and 49 days at 25 °C and decrease of only 1 and 2 log PFU/mL after 21 and 49 days, respectively, at ambient temperature). The high bacterial control and low development of phage-resistant bacterial clones suggest that these phages can be used to control the furunculosis in aquaculture. Nonetheless, the stability of the phages was affected by solar radiation, this can be overcome by the application of phages at the end of the day or at night. [ABSTRACT FROM AUTHOR]

A major concern of phage therapy is the emergency of phage-resistant mutants. This limitation can be overcome by the combined use of phages and antibiotics. It has been shown that the combination of antibiotics and phages is an alternative that cannot only be effective at reducing bacterial numbers, but also to contribute to the management of resistance levels. However, this view has only been discussed with regard to antibiotic resistance and not to control phage-mutant emergence. In our study we compared not only the resistance of the bacteria to the four antibiotics tested with and without phages addition, but also the resistance to the phages in the presence and absence of antibiotics. The aim of this study was to evaluate the potential synergistic effect of phages and antibiotics in the inactivation of Escherichia coli in order to control infections, namely urinary tract infection (UTI), and to reduce the development of bacterial resistance to phages. Phage therapy combined with antibiotics (ampicillin, piperacillin, kamanycin, tetracycline, chloramphenicol and ciprofloxacin) was evaluated in the inactivation of E. coli , both in saline solution and urine samples. Phage and antibiotic combinations could result in high synergistic effects in the inactivation of bacteria. The combination of phage and ciprofloxacin at sublethal concentration decreased the bacterial counts in urine samples by 7.8 ± 0.1 log CFU/ml after 8 h, but when phages or the antibiotic were tested alone, the decrease was of 3.9 ± 0.3 log CFU/mL and 1.2 ± 0.1 log CFU/mL, respectively, after the same time. The efficacy of the combination of the two therapies depends on the antibiotic resistance status of the targeted bacteria to the employed antibiotic and of the antibiotic type (bactericide or bacteriostatic), causing the same or less bacterial resistance than phages and antibiotics applied alone (1.2 ± 1.0 × 10 −5 to 2.4 ± 1.5 × 10 −7 CFU/mL for the combined treatment, 2.7 ± 0.2 × 10 −4 CFU/mL for the antibiotics and 5.0 ± 1.5 × 10 −6 CFU/mL for the phages). The addition of antibiotics, at subinhibitory concentration, during phage treatment can control the phage-mutant. The high bacterial inactivation efficiency of these combined techniques and the long periods of phage survival in urine, pave the way for depth studies to control UTI and to overcome the development of resistances by bacteria. [ABSTRACT FROM AUTHOR]

New sulfonyl-lapachones were efficiently obtained through the catalytic oxidation of arylthio- and cyclohexylthio-lapachone derivatives with hydrogen peroxide in the presence of a Mn(III) porphyrin complex. The antibacterial activities of the non-oxidized and oxidized lapachone derivatives against the Gram-negative bacteria Escherichia coli and the Gram-positive bacteria Staphylococcus aureus were evaluated after their incorporation into polyvinylpyrrolidone (PVP) micelles. The obtained results show that the PVP-formulations of the lapachones 4b-g and of the sulfonyl-lapachones 7e and 7g reduced the growth of S. aureus. [ABSTRACT FROM AUTHOR]

Direct laser scribing (DLS) technology is applied to commercial polyimide (PI) coated optical fibers producing laser-induced graphene (LIG) coated optical fibers. The PI-coated optical fiber is first inscribed with off-center Bragg gratings via point-by-point method using a femtosecond laser system. Then, the off-center Bragg grating is irradiated with a CO 2 laser and the PI coating is photothermally converted into LIG without affecting the grating. Scanning electron microscopy (SEM) and Raman spectroscopy prove the presence of the laser-induced graphene layer on the optical fiber, and Fourier transform infrared (FTIR) spectroscopy confirms that all the PI coating was converted into LIG. The resulting LIG-coated off-center Bragg grating (FBG) sensors respond to variations of the surrounding refractive index (RI) with a sensitivity of 38.08 ± 1.57 nm per RI units (RIU). In addition, after removal of the PI coating, obtaining a bare-FBG, the sensitivity decreases to 25.63 ± 0.66 nm R I U − 1 . Therefore, this strategy, here reported for the first time, paves the way to produce promising novel optical transducers aiming to develop bio- and chem-sensing devices. • Direct laser scribing technology applied to commercial polyimide optical fibers. • Laser-induced graphene produced directly on optical fiber for sensing. • The resulting LIG-coated off-center FBG sensors respond to variations of the surrounding RI. • High sensitivity compared with after removal of the PI coating. [ABSTRACT FROM AUTHOR]

Reactive oxygen species can be responsible for microbial photodynamic inactivation due to its toxic effects, which include severe damage to proteins, lipids and nucleic acids. In this study, the photo-oxidative modifications of the proteins of a non-enveloped T4-like bacteriophage, induced by the cationic porphyrin 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide were evaluated. Two methods were used: sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and infrared spectroscopy. SDS-PAGE analysis showed that the phage protein profile was considerably altered after photodynamic treatment. Seven protein bands putatively corresponding to capsid and tail tube proteins were attenuated and two other were enhanced. Infrared spectroscopy confirmed the time-dependent alteration on the phage protein profile detected by SDS-PAGE, indicative of a response to oxidative damage. Infrared analysis showed to be a promising and rapid screening approach for the analysis of the modifications induced on viral proteins by photosensitization. In fact, one single infrared spectrum can highlight the changes induced to all viral molecular structures, overcoming the delays and complex protocols of the conventional methods, in a much simple and cost effective way. [ABSTRACT FROM AUTHOR]

The present study reports the quantity, shape, colour and chemical properties of microplastics (MP) and MP-like in whole soft tissues of the mussel Mytilus spp. collected in January and February 2019 from four natural banks in the Portuguese coast. Three sites are located in estuarine areas influenced by anthropogenic pressures and freshwater discharges, and one in the coast far from urbanised areas. An alkaline digestion (KOH) of biological tissues was used and a polymeric identification of 20% of the visually sorted particles was achieved using the Fourier-transform mid-infrared spectroscopy (FT-MIR). MP and MP-like concentrations ranged from 0.54 to 3.0 items g−1 without significant differences among the sites. Particle size varied from 36 to 4439 μm, being fibers the most abundant shape (50%) followed by films (22%) and spherules (18%). FT-MIR revealed that 69% of the analysed particles were plastic, being identified six polymers and two polymeric blends, and 32% were cellulose-based materials. Fibers identified in mussel tissues were mainly composed of cotton and viscose (77%). This study emphasizes the importance of the polymer's spectroscopic identification after microscopic observation to recognise MP. [Display omitted] • Concentrations of 0.54–3.0 items g−1 are comparable with other regions worldwide. • No significant differences in item concentrations among sites from Portuguese coast. • Fibres were the most common shape of particle. • Six plastic polymers and two plastic-cellulosic polymer blends were identified. [ABSTRACT FROM AUTHOR]

Antibacterial multi-layered patches composed of an oxidized bacterial cellulose (OBC) membrane loaded with dexpanthenol (DEX) and coated with several chitosan (CH) and alginate (ALG) layers were fabricated by spin-assisted layer-by-layer (LbL) assembly. Four patches with a distinct number of layers (5, 11, 17, and 21) were prepared. These nanostructured multi-layered patches reveal a thermal stability up to 200 °C, high mechanical performance (Young's modulus ≥ 4 GPa), and good moisture-uptake capacity (240–250%). Moreover, they inhibited the growth of the skin pathogen Staphylococcus aureus (3.2–log CFU mL−1 reduction) and were non-cytotoxic to human keratinocytes (HaCaT cells). The in vitro release profile of DEX was prolonged with the increasing number of layers, and the time-dependent data imply a diffusion/swelling-controlled drug release mechanism. In addition, the in vitro wound healing assay demonstrated a good cell migration capacity, headed to a complete gap closure after 24 h. These results certify the potential of these multi-layered polysaccharides-based patches toward their application in wound healing. [ABSTRACT FROM AUTHOR]