Control of Multidrug-Resistant Pathogenic Staphylococci Associated with Vaginal Infection Using Biosurfactants Derived from Potential Probiotic Bacillus Strain

Biosurfactants exhibit antioxidant, antibacterial, antifungal, and antiviral activities. They can be used as therapeutic agents and in the fight against infectious diseases. Moreover, the anti-adhesive properties against several pathogens point to the possibility that they might serve as an anti-adhesive coating agent for medical inserts and prevent nosocomial infections, without using synthetic substances. In this study, the antimicrobial, antibiofilm, cell surface hydrophobicity, and antioxidative activities of biosurfactant extracted from Bacillus sp., against four pathogenic strains of Staphylococcus spp. associated with vaginal infection, were studied. Our results have shown that the tested biosurfactant possesses a promising antioxidant potential, and an antibacterial potency against multidrug clinical isolates of Staphylococcus, with an inhibitory diameter ranging between 27 and 37 mm, and a bacterial growth inhibition at an MIC of 1 mg/ mL, obtained. The BioSa3 was highly effective on the biofilm formation of different tested pathogenic strains. Following their treatment by BioSa3, a significant decrease in bacterial attachment (p < 0.05) was justified by the reduction in the optical (from 0.709 to 0.111) following their treatment by BioSa3. The antibiofilm effect can be attributed to its ability to alter the membrane physiology of the tested pathogens to cause a significant decrease (p < 0.05) of over 50% of the surface hydrophobicity. Based on the obtained result of the bioactivities in the current study, BioSa3 is a good candidate in new therapeutics to better control multidrug-resistant bacteria and overcome bacterial biofilm-associated infections by protecting surfaces from microbial contamination.

Adhesive Antimicrobial Peptides Containing 3,4-Dihydroxy-L-Phenylalanine Residues for Direct One-Step Surface Coating

Bacterial colonization and transmission via surfaces increase the risk of infection. In this study, we design and employ novel adhesive antimicrobial peptides to prevent bacterial contamination of surfaces. Repeats of 3,4-dihydroxy-L-phenylalanine (DOPA) were added to the C-terminus of NKC, a potent synthetic antimicrobial peptide, and the adhesiveness and antibacterial properties of the resulting peptides are evaluated. The peptide is successfully immobilized on polystyrene, titanium, and polydimethylsiloxane surfaces within 10 min in a one-step coating process with no prior surface functionalization. The antibacterial effectiveness of the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces is confirmed by complete inhibition of the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus within 2 h. The stability of the peptide coated on the substrate surface is maintained for 84 days, as confirmed by its bactericidal activity. Additionally, the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces show no cytotoxicity toward the human keratinocyte cell line HaCaT. The antimicrobial properties of the peptide-coated surfaces are confirmed in a subcutaneous implantation animal model. The adhesive antimicrobial peptide developed in this study exhibits potential as an antimicrobial surface-coating agent for efficiently killing a broad spectrum of bacteria on contact.

Developing a Biomimetic Evaluation Method for Antiviral Coatings Using Artificial Saliva Droplets.

Respiratory infections pose a serious threat worldwide, and many new antiviral agents and coatings have been developed to reduce the overall risk of viral infection. Here, we evaluate the methodology used to test these antiviral coatings and developed a novel system that is more similar to real-world conditions. Contact infection is largely mediated via contact with saliva containing the active virus released as droplets by coughing or sneezing, with these droplets adhering to objects and surfaces and subsequently entering the human body via indirect contact with the mucous membranes. Here, we evaluated the antiviral effect of a known antiviral coating agent using an artificial saliva based system, where artificial saliva containing phages were sprayed onto the antiviral coating under various conditions associated with viral replication and infectious spread. We used a commercially available antiviral coating in this evaluation, and M13 bacteriophages as model viruses. This method enables simple biomimetic evaluations of any product antiviral effects.

Comparison of Gut Bacterial Communities of Fall Armyworm (Spodoptera frugiperda) Reared on Different Host Plants

Spodoptera frugiperda is a highly polyphagous and invasive agricultural pest that can harm more than 300 plants and cause huge economic losses to crops. Symbiotic bacteria play an important role in the host biology and ecology of herbivores, and have a wide range of effects on host growth and adaptation. In this study, high-throughput sequencing technology was used to investigate the effects of different hosts (corn, wild oat, oilseed rape, pepper, and artificial diet) on gut microbial community structure and diversity. Corn is one of the most favored plants of S. frugiperda. We compared the gut microbiota on corn with and without a seed coating agent. The results showed that Firmicutes and Bacteroidetes dominated the gut microbial community. The microbial abundance on oilseed rape was the highest, the microbial diversity on wild oat was the lowest, and the microbial diversity on corn without a seed coating agent was significantly higher than that with such an agent. PCoA analysis showed that there were significant differences in the gut microbial community among different hosts. PICRUSt analysis showed that most of the functional prediction categories were related to metabolic and cellular processes. The results showed that the gut microbial community of S. frugiperda was affected not only by the host species, but also by different host treatments, which played an important role in host adaptation. It is important to deepen our understanding of the symbiotic relationships between invasive organisms and microorganisms. The study of the adaptability of host insects contributes to the development of more effective and environmentally friendly pest management strategies.

Finding Use for Sorghum Bicolor Leaf Sheath in Coating Technology

This study aimed to investigate the potential use of aqueous extract of Sorghum bicolor leaf sheath (SBLS) as a coating agent for paracetamol tablets. The mechanical properties of the coated tablets were assessed using crushing strength and friability test, while the release properties of the tablet were evaluated using disintegration and dissolution tests. The physicochemical properties of the coated tablets did not show any striking differences when compared with the uncoated tablet as par compendium specifications, which formed the basis for performing further in vitro dissolution study. Our data showed that SBLS enhanced the hardness and friability of the tablets in a dose-dependent manner. Tablets coated with 3, 5, and 7.5% of SBLS disintegrated in 8.13, 6.25, and 4.13 minutes, respectively, while the uncoated tablet disintegrated in 0.7 minutes. Furthermore, 3, 5, and 7.5% of SBLS-coated tablets exhibited slower release of their active ingredient (releasing 21, 16, and 17%, respectively) than that of the uncoated tablet (releasing 40%) in 5 minutes. Besides, comparison between the dissolution profiles was successfully achieved using difference factor (f1) and similarity factor (f2). The apparent dissimilarity between our coated tablets and the uncoated one led to further study of convolution in vitro–in vivo correlation, with the aim to obtain data that converted into mathematical prediction of in vivo data. For all batches, the percent predictable errors of C max and T max were within the acceptable limit of no more than 10%. In summary, SBLS aqueous extract is a potential and protective coat agent for paracetamol tablets. The in vitro established dissolution of the coated tablets provided scientific information for the prediction of the in vivo plasma drug profile.

Bubble-Liquid Membrane Method for Preparing Spherical Calcium Carbonate Nanoparticles

In this work, we describe the principle and operation of a bubble-liquid membrane reactor, and use of the reactor to prepare spherical calcium carbonate nanoparticles. The products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and laser particle size analysis. The effects of additives to control crystal morphology, coating agents, and the stirring speed of the bubble-liquid membrane reactor were investigated. Spherical calcium carbonate nanoparticles with uniform dispersion and no agglomeration were obtained when a disodium hydrogen phosphate/ethylenediaminetetraacetic acid disodium salt mixture (1:1 mass ratio) was used as the additive, oleic acid was used as the coating agent (1.5 wt%), and the stirring speed was 5000–6000 r/min. The results indicate that the bubble-liquid membrane reactor may be suitable for continuous industrial production of calcium carbonate nanoparticles.

Study of a Late Bronze Age Casting Mould and Its Black Residue by 3D Imaging, pXRF, SEM-EDS, Micro-FTIR and Micro-Raman

In the present work, a fragment of a stone mould recently found in Galicia (NW Spain) was studied by multiple analytical techniques approach involving 3D optical imaging reconstruction to obtain data about the shape of the mould, typology of artefact produced, and distribution of a black residue at the surface of the mould and pXRF, SEM-EDS, micro-FTIR, and micro-Raman to investigate the nature of the black residue. The study shows that the mould was likely used for socketed axes with a side loop, was originally composed of two valves and one core, and that it might have been subjected to a repair during use. The black residue is distributed in the carved surface and spreads to nearby surfaces as a result of the use of the mould. The alloy cast in the mould was a ternary bronze (Cu + Sn + Pb). The analyses by SEM-EDS of black residue covering the surface did show the presence of scattered micro particles with P and Ca, and micro-Raman analysis detected the presence of a carbon black of animal source, while micro-FTIR analysis detected remains of proteins, oxalates, and hydroxyapatite. These results are amongst the very few studies made on black residues of ancient moulds and suggest that the mould was dressed with a carbon black of animal origin, such as burned bones, prior to metal casting, probably used as a coating agent to improve the casting and artefact recovery.

Microencapsulation of Phenolic Extracts from Cocoa Shells to Enrich Chocolate Bars

Cocoa bean shells were subjected to green extraction technologies, based on the absence of toxic organic solvents, to recover polyphenols; the extract was then encapsulated using a spray dryer and maltodextrin as coating agent. The best conditions observed in the spray drying tests (core-to-coating ratio 1:5; inlet temperature 150 °C; flow rate 6 ml min−1) were applied to produce the microcapsules used to enrich the same cocoa mass as the shells and processed for the preparation of the chocolate bars. Sensory analysis showed no significant differences between enriched chocolate bar and the unenriched reference one, except for the appearance. Both samples were then subjected to accelerated storage tests, at the end of which the polyphenols in the control chocolate bar (0.85 g 100 g−1) were reduced by about 50% (0.42 g 100 g−1), while in the enriched chocolate (1.17 g 100 g−1) by only 22% (0.97 g 100 g−1). The proposed process significantly enriched the chocolate bars with phenolic antioxidants recovered from cocoa waste without increasing the sensations of bitterness and astringency.

Soybean Response to Seed Coating with Chitosan + Alginate/PEG and/or Inoculation

Inoculated or coated soybean seeds are often sown in agricultural practice. These treatments play a different role depending on the chemical composition of the preparation. The aim of the field experiment was to demonstrate the effectiveness of the developed coating (chitosan + alginate/PEG) and commercial inoculant (HiStick® Soy) applied alone or in combination to soybean seeds. Uncoated (control) seeds were sown for comparison. The research was carried out in 2018–2020 using the cultivar ‘Mavka’. The experiment was located in Makowisko, Podkarpackie Province, Poland. Coating composition was developed in a laboratory belonging to the Łukasiewicz Research Network—Institute of Biopolymers and Chemical Fibers in Łódź, Poland. The main role of the coating is to protect soybean seeds from low temperatures. HiStick® Soy inoculant contains Bradyrhizobium japonicum bacteria which increase nodulation on the roots. The conducted research demonstrated that sowing only coated seeds was not very effective, because the suitable number of nodules had not developed on soybean roots. The application of the inoculant alone positively affected the assessed traits compared to control, however, plant population was lower than expected. The highest seed yield was obtained after sowing coated seeds in combination with the inoculant (4.32 t·ha−1) and only inoculated seeds (4.23 t·ha−1) compared to control (3.64 t·ha−1). The test of the novel seed-coating agent showed that it had an good effect and efficacy, but only in combination with the inoculation procedure.