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The existence of biofilms as heterogeneous structures, comprising bacterial cells embedded in a self-synthesized polymeric matrix and adhered to biotic and abiotic surfaces, exhibiting high antibiotic tolerance, is a fact that, in recent years, has exerted selective pressure on healthcare systems with the emergence of numerous infections. This review provides a historical overview of the emergence of biofilms, the latest insights into their functionality and distribution, as well as data on innovative strategies to combat them. Special attention is given to significant diseases caused by biofilms, alongside current data on the molecular mechanisms underpinning their tolerance and resistance. [ABSTRACT FROM AUTHOR]

The article aims to present a cyber–physical system (CPS) to support the cultivation of aquaculture in a closed aquaponic system using the deep-water culture (DWC) method. The CPS uses precision sensors as TriOxmatic 700 IQ (for dissolved oxygen and water temperature), AmmoLyt Plus 700 IQ (for ammonium), NiCaVis 701 IQ NI (for nitrites and nitrates), SensoLyt® 700 IQ (for pH), and SL-M5 (for water level). It is built with a Raspberry Pi 4, 8 GB as a server, OpenHAB 3.0 software, and other specialized software for measuring water parameters. Some of the parameters are maintained completely autonomously, while others are indirectly controlled. Basic knowledge of hydroponics and aquaculture is required to set up the system, but day-to-day maintenance can be carried out by employees who receive instructions from the CPS. A method for the physical modification of the fish tank surface by using laser processing is proposed. This results in a change in surface topography (creating diverse microstructure patterns) and its roughness, which is of crucial importance for the bacterial adhesion mechanism. [ABSTRACT FROM AUTHOR]

Novel AB-Polybenzimidazole (AB-PBI)/TiO2 nanocomposite membranes have been prepared using a synthetic green chemistry approach. Modified Eaton's reagent (methansulfonic acid/P2O5) was used as both reaction media for microwave-assisted synthesis of AB-PBI and as an efficient dispersant of partially agglomerated titanium dioxide powders. Composite membranes of 80 µm thickness have been prepared by a film casting approach involving subsequent anti-solvent inversion in order to obtain porous composite membranes possessing high sorption capacity. The maximal TiO2 filler content achieved was 20 wt.% TiO2 nanoparticles (NPs). Titania particles were green synthesized (using a different content of Mentha Spicata (MS) aqueous extract) by hydrothermal activation (150 °C), followed by thermal treatment at 400 °C. The various methods such as powder X-ray diffraction and Thermogravimetric analyses, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Energy-dispersive X-ray spectroscopy, Electronic paramagnetic resonance, Scanning Electron Microscopy and Transmission Electron Microscopy have been used to study the phase and surface composition, structure, morphology, and thermal behavior of the synthesized nanocomposite membranes. The photocatalytic ability of the so-prepared AB-Polybenzimidazole/bio-TiO2 membranes was studied for decolorization of Reactive Black 5 (RB5) as a model azo dye pollutant under UV light illumination. The polymer membrane in basic form, containing TiO2 particles, was obtained with a 40 mL quantity of the MS extract, exhibiting the highest decolorization rate (96%) after 180 min of UV irradiation. The so-prepared AB-Polybenzimidazole/TiO2 samples have a powerful antibacterial effect on E. coli when irradiated by UV light. [ABSTRACT FROM AUTHOR]

Biofilms are a well-known multifactorial virulence factor with a pivotal role in chronic bacterial infections. Their pathogenicity is determined by the combination of strain-specific mechanisms of virulence and the biofilm extracellular matrix (ECM) protecting the bacteria from the host immune defense and the action of antibacterials. The successful antibiofilm agents should combine antibacterial activity and good biocompatibility with the capacity to penetrate through the ECM. The objective of the study is the elaboration of biofilm-ECM-destructive drug delivery systems: mixed polymeric micelles (MPMs) based on a cationic poly(2-(dimethylamino)ethyl methacrylate)-b-poly(ε-caprolactone)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA35-b-PCL70-b-PDMAEMA35) and a non-ionic poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO100-b-PPO65-b-PEO100) triblock copolymers, loaded with ciprofloxacin or azithromycin. The MPMs were applied on 24 h pre-formed biofilms of Escherichia coli and Pseudomonas aeruginosa (laboratory strains and clinical isolates). The results showed that the MPMs were able to destruct the biofilms, and the viability experiments supported drug delivery. The biofilm response to the MPMs loaded with the two antibiotics revealed two distinct patterns of action. These were registered on the level of both bacterial cell-structural alterations (demonstrated by scanning electron microscopy) and the interaction with host tissues (ex vivo biofilm infection model on skin samples with tests on nitric oxide and interleukin (IL)-17A production). [ABSTRACT FROM AUTHOR]

The self‐organization of microbes into biofilms provides multiple benefits including tolerance to mechanical stress and resistance to immune defences and antibiotics. Coupled to a compromised mucociliary function, these traits have dire consequences in cystic fibrosis patients – persistent infections are the main reason for morbidity and mortality. Thereby, disease progression is associated with universal colonization by Pseudomonas aeruginosa, which selects for a slimy phenotype to adapt to the lung microenvironment. Recognizing this, drug‐delivery vehicles that break down the mucoid extracellular matrix made of alginate are designed to enable better penetration and biofilm dispersion. In parallel, a protective layer responds to the proteolytic activity of the pathogen and thus controls drug availability. To realize this architecture, silica nanoparticles are loaded with imipenem, and then coated with elastin and alginate lyase in a layer‐by‐layer fashion using ultrasound. The nanoscale formulations eradicate up to 80% of the total biomass and reduce the bacterial viability in biofilms by 3 logs, considerably outperforming the bulk antibiotic in vitro, whereby the effects are correlated to changes in the viscoelasticity. Furthermore, the stimuli‐responsive nanocarriers are safe and effective in animal models of P. aeruginosa infection, presenting a considerable therapeutic promise in the challenging context of lung diseases. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a ubiquitous environmental Gram-negative bacterium and also an opportunistic pathogen for both humans and animals, causing acute or chronic infections. It has been frequently detected in healthy and diseased reptiles, more commonly in captive ones. Since most studies are primarily on clinical isolates, the pathogenic potential of strains originating from wild animals is poorly explored. We isolated the strain P. aeruginosa PM1012 from the cloacal microbiota of a common wall lizard (Podarcis muralis Laurenti, 1768) from a free-living population. The effect of temperature, pH and salinity on its growth was evaluated. Antibiotic resistance, the expression of several virulence factors as some extracellular enzymes, pyocyanin production and biofilm formation were also assessed. Apart from intrinsic resistance, the newly isolated strain P. aeruginosa PM1012 presented an antibiotic susceptibility profile with a low resistance rate limited to meropenem and intermediate to ceftazidime and aztreonam. Protease, lipase and gelatinase secretion was detected. Strong pyocyanin production was observed in the optimal range of growth conditions. An excellent biofilm-forming capacity was manifested. [ABSTRACT FROM AUTHOR]

In this study, UHPLC-HRMS analysis of the defatted methanol extract obtained from Inula salicina L. led to the identification of 58 compounds—hydroxycinnamic and hydroxybenzoic acids and their glycosides, acylquinic and caffeoylhexaric acids, and flavonoids and their glycosides. In addition, a new natural compound, N-(8-methylnepetin)-3-hydroxypiperidin-2-one was isolated and its structure was elucidated by NMR spectroscopy. The presence of a flavoalkaloid in genus Inula is described now for the first time. Chlorogenic acid was the main compound followed by 3,5-, 1,5- and 4,5-dicaffeoylquinic acids. The methanol extract was studied for its antioxidant potential by DPPH, ABTS, and FRAP assays and sun protective properties. In addition, a study was conducted to assess the effectiveness of the tested extract in inhibiting biofilm formation by Gram-positive and Gram-negative strains. Results from crystal violet tests revealed a notable decrease in biofilm mass due to the extract. The anti-biofilm efficacy was confirmed through the observation of the biofilm viability by live/dead staining. The obtained results showed that this plant extract could be used in the development of cosmetic products with antibacterial and sun protection properties. [ABSTRACT FROM AUTHOR]

Reptiles are known to be asymptomatic carriers of various zoonotic pathogens. A number of Gram-negative opportunistic commensals are causative agents of bacterial infections in immunocompromised or stressed hosts and are disseminated by reptiles, whose epidemiological role should not be neglected. Since most studies have focused on exotic species, in captivity or as pet animals, the role of wild populations as a potential source of pathogens still remains understudied. In the present study, we isolated a variety of Gram-negative bacteria from the cloacal microbiota of free-living lizard and tortoise hosts (Reptilia: Sauria and Testudines) from the Bulgarian herpetofauna. We evaluated their pathogenic potential according to their antibiotic susceptibility patterns, biofilm-forming capacity, and extracellular production of some enzymes considered to play roles as virulence factors. To our knowledge, the phenotypic manifestation of virulence factors/enzymatic activity and biofilm formation in wild reptile microbiota has not yet been widely investigated. All isolates were found to be capable of forming biofilms to some extent and 29.6% of them could be categorized as strong producers. Two strains proved to be excellent producers. The majority of the isolated strains showed extracellular production of at least one exoenzyme. The most pronounced pathogenicity could be attributed to the newly isolated Pseudomonas aeruginosa strain due to its multiresistance, excellent biofilm formation, and expression of exoenzymes. [ABSTRACT FROM AUTHOR]