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Wastewater treatment plants (WWTP) are considered to be an important reservoir of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) that may contribute to an increase release of resistance into environment, which menace human and animal health. The resistance selection processes of ARB and ARGs transfer that occurs into WWTP are poorly understood and studies are required to advance our current knowledge in the field and thus optimizing wastewater treatment for the removal of ARB and ARGs. The aim of this paper is to summarize methods used for analyzing the antibiotic resistance in environmental samples, providing information that can be used by professionals to improve the wastewater treatment for the removal of ARB and ARGs. [ABSTRACT FROM AUTHOR]

The present study aimed to synthesize, characterize, and validate a separation and quantification method of new N-acyl thiourea derivatives (1a–1o), incorporating thiazole or pyridine nucleus in the same molecule and showing antimicrobial potential previously predicted in silico. The compounds have been physiochemically characterized by their melting points, IR, NMR and MS spectra. Among the tested compounds, 1a, 1g, 1h, and 1o were the most active against planktonic Staphylococcus aureus and Pseudomonas aeruginosa, as revealed by the minimal inhibitory concentration values, while 1e exhibited the best anti-biofilm activity against Escherichia coli (showing the lowest value of minimal inhibitory concentration of biofilm development). The total antioxidant activity (TAC) assessed by the DPPH method, evidenced the highest values for the compound 1i, followed by 1a. A routine quality control method for the separation of highly related compounds bearing a chlorine atom on the molecular backbone (1g, 1h, 1i, 1j, 1m, 1n) has been developed and validated by reversed-phase high-performance liquid chromatography (RP—HPLC), the results being satisfactory for all validation parameters recommended by the ICH guidelines (i.e., system suitability, specificity, the limits of detection and quantification, linearity, precision, accuracy and robustness) and recommending it for routine separation of these highly similar compounds. [ABSTRACT FROM AUTHOR]

Background: Romania is one of the European countries reporting very high antimicrobial resistance (AMR) rates and consumption of antimicrobials. We aimed to characterize the AMR profiles and clonality of 304 multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) strains isolated during two consecutive years (2018 and 2019) from hospital settings, hospital collecting sewage tanks and the receiving wastewater treatment plants (WWTPs) located in the main geographical regions of Romania. Methods: The strains were isolated on chromogenic media and identified by MALDI-TOF-MS. Antibiotic susceptibility testing and confirmation of ESBL- and CP- producing phenotypes and genotypes were performed. The genetic characterization also included horizontal gene transfer experiments, whole-genome sequencing (WGS), assembling, annotation and characterization. Results: Both clinical and aquatic isolates exhibited high MDR rates, especially the Ab strains isolated from nosocomial infections and hospital effluents. The phenotypic resistance profiles and MDR rates have largely varied by sampling point and geographic location. The highest MDR rates in the aquatic isolates were recorded in Galați WWTP, followed by Bucharest. The Ab strains harbored mostly blaOXA-23, blaOXA-24, blaSHV, blaTEM and blaGES, while Pa strains blaIMP, blaVIM, blaNDM, blaVEB, blaGES and blaTEM, with high variations depending on the geographical zone and the sampling point. The WGS analysis revealed the presence of antibiotic resistance genes (ARGs) to other antibiotic classes, such as aminoglycosides, tetracyclines, sulphonamides, fosfomycin, phenicols, trimethoprim-sulfamethoxazole as well as class 1 integrons. The molecular analyses highlighted: (i) The presence of epidemic clones such as ST2 for Ab and ST233 and ST357 for Pa; (ii) The relatedness between clinical and hospital wastewater strains and (iii) The possible dissemination of clinical Ab belonging to ST2 (also proved in the conjugation assays for blaOXA-23 or blaOXA-72 genes), ST79 and ST492 and of Pa strains belonging to ST357, ST640 and ST621 in the wastewaters. Conclusion: Our study reveals the presence of CP-producing Ab and Pa in all sampling points and the clonal dissemination of clinical Ab ST2 strains in the wastewaters. The prevalent clones were correlated with the presence of class 1 integrons, suggesting that these isolates could be a significant reservoir of ARGs, being able to persist in the environment. [ABSTRACT FROM AUTHOR]

Wound healing-associated difficulties continue to drive biotechnological creativeness into complex grounds. The sophisticated architecture of skin wound sites and the intricate processes involved in the response to the use of regenerative devices play a critical role in successful skin regeneration approaches and their possible outcomes. Due to a plethora of complications involved in wound healing processes as well as the coordination of various cellular mechanisms, biomimetic approaches seems to be the most promising starting ground. This study evaluates the behavior of a crosslinked, porous collagen scaffold obtained by lyophilization and dehydrothermal reticulation (DHT). We address the key physio-chemical and mechanical factors, such as swelling, density and porosity, mechano-dynamic properties, SEM and TG-DSC, as well as important biological outcomes regarding scaffold biocompatibility and cellular metabolic activity, cytokine expression in inflammation, apoptosis and necrosis, as well as hemocompatibility and biodegradation. The mechanical and visco-elastic behavior are correlated, with the samples found to present similar thermal behavior and increased rigidity after DHT treatment. High biocompatibility rates were obtained, with no inflammatory stimulation and a reduction in necrotic cells. Higher percentages of cellular early apoptosis were observed. The hemocompatibility rate was under 2%, coagulation effects expressed after 4 min, and the DHT scaffold was more resistant to the biodegradation of collagenase compared with the untreated sample. [ABSTRACT FROM AUTHOR]

• Fecal microbiomes and resistomes were compared between 174 WWTP workers/ controls. • Minor or no difference in ARG abundance between workers at WWTPs and controls. • Minor or no difference in microbiome between WWTP workers and controls. • Women had higher abundance of disinfectant resistance genes compared to men. Urban wastewater treatment plants harbor a large collection of antibiotic resistant enteric bacteria. It is therefore reasonable to hypothesize that workers at such plants would possess a more diverse set of resistant enteric bacteria, compared to the general population. To address this hypothesis, we have compared the fecal microbiome and resistome of 87 workers at wastewater treatment plants (WWTPs) from Romania and the Netherlands to those of 87 control individuals, using shotgun metagenomics. Controlling for potential confounders, neither the total antibiotic resistance gene (ARG) abundance, nor the overall bacterial composition were significantly different between the two groups. If anything, the ARG richness was slightly lower in WWTP workers, and in a stratified analysis the total ARG abundance was significantly lower in Dutch workers compared to Dutch control participants. We identified country of residence, together with recent antibiotic intake in the Dutch population, as the largest contributing factors to the total abundance of ARGs. A striking side-finding was that sex was associated with carriage of disinfectant resistance genes, with women in both Romania and the Netherlands having significantly higher abundance compared to men. A follow up investigation including an additional 313 publicly available samples from healthy individuals from three additional countries showed that the difference was significant for three genes conferring resistance to chemicals commonly used in cosmetics and cleaning products. We therefore hypothesize that the use of cosmetics and, possibly, cleaning products leads to higher abundance of disinfectant resistance genes in the microbiome of the users. Altogether, this study shows that working at a WWTP does not lead to a higher abundance or diversity of ARGs and no large shifts in the overall gut microbial composition in comparison to participants not working at a WWTP. Instead, other factors such as country of residence, recent antibiotic intake and sex seem to play a larger role. [ABSTRACT FROM AUTHOR]

Novel complexes of type [Cu(N-N)(dmtp)2(OH2)](ClO4)2·dmtp ((1) N-N: 2,2′-bipyridine; (2) L: 1,10-phenantroline and dmtp: 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine) were designed in order to obtain biologically active compounds. Complexes were characterized as mononuclear species that crystallized in the space group P-1 of the triclinic system with a square pyramidal geometry around the copper (II). In addition to the antiproliferative effect on murine melanoma B16 cells, complex (1) exhibited low toxicity on normal BJ cells and did not affect membrane integrity. Complex (2) proved to be a more potent antimicrobial in comparison with (1), but both compounds were more active in comparison with dmtp—both against planktonic cells and biofilms. A stronger antimicrobial and antibiofilm effect was noticed against the Gram-positive strains, including methicillin-resistant Staphylococcus aureus (MRSA). Both electron paramagnetic resonance (EPR) and Saccharomyces cerevisiae studies indicated that the complexes were scavengers rather than reactive oxygen species promoters. Their DNA intercalating capacity was evidenced by modifications in both absorption and fluorescence spectra. Furthermore, both complexes exhibited nuclease-like activity, which increased in the presence of hydrogen peroxide. [ABSTRACT FROM AUTHOR]

5-fluorouracil (5-FU) remains the gold standard of treatment for colorectal cancer, but its poor bioavailability and high systemic toxicity highlight the urgent need for the development of novel delivery strategies to increase the efficacy of 5-FU treatment. The present study is aimed to design and validate a PEGylated Silk Fibroin Nanocarrier (SF/PEG nanoparticles (NPs)) as an efficient 5-FU delivery system for potential intravenous administration. Using the human adenocarcinoma HT–29 cell line as an in vitro model for colorectal cancer, the cytotoxicity screening of the SF/PEG NPs showed that pristine nanocarriers were highly biocompatible, while the addition of 5-FU triggers a dramatic reduction in tumor cell viability, proliferation potential and mitochondrial integrity as well as a significant increase in nitric oxide production. Despite their high in vitro cytotoxicity, the 5-FU SF/PEG NPs were found hemocompatible as no impact on red blood cells hemolysis or the phagocytic activity of the granulocytes was observed. Exposure of HT–29 tumor cells and blood samples to 5-FU SF/PEG NPs augmented the tumor necrosis factor-α levels. Moreover, 5-FU SF/PEG NPs showed an impact on tumor cell migration and invasive potential as both of these processes were inhibited by the NP treatment. [ABSTRACT FROM AUTHOR]

Aminopropyl-silica nanoparticles S0 were obtained and further functionalized with eight halogen-reactive organic compounds 1–8 , leading to the S1–S8 hybrid organic-inorganic materials, with spherical morphology and having a 50–200 nm size, as showed TEM analysis. These were further characterized by IR and DLS. Biological assays were performed using five microbial strains, belonging to species frequently encountered in the aetiology of human infections (Enterococcus faecalis, Staphylococcus aureus , Pseudomonas aeruginosa, Escherichia coli and Candida albicans). The obtained materials exhibited promising antimicrobial properties, being active against planktonic, but particularly on biofilm-embedded cells. Among the tested hybrid nanomaterials, S6 seemed to exhibit the most promising antimicrobial profile. Image 1 • Aminopropyl-silica nanoparticles synthetized. • Functionalized with 8 halogeno-reactive organic compounds. • Characterised by IR, TEM, DLS. • Biological assays were performed using five microbial strains. • Active both against planktonic and biofilm-embedded cells. [ABSTRACT FROM AUTHOR]

In an effort to improve the antimicrobial activity of norfloxacin, a series of hybrid norfloxacin–thiazolidinedione molecules were synthesized and screened for their direct antimicrobial activity and their anti-biofilm properties. The new hybrids were intended to have a new binding mode to DNA gyrase, that will allow for a more potent antibacterial effect, and for activity against current quinolone-resistant bacterial strains. Moreover, the thiazolidinedione moiety aimed to include additional anti-pathogenicity by preventing biofilm formation. The resulting compounds showed promising direct activity against Gram-negative strains, and anti-biofilm activity against Gram-positive strains. Docking studies and ADMET were also used in order to explain the biological properties and revealed some potential advantages over the parent molecule norfloxacin. [ABSTRACT FROM AUTHOR]

Five new copper(II) acrylate complexes (acr is the acrylate anion: C3H3O2) with imidazole derivatives (2-methylimidazole/2-MeIm, 5-methylimidazole/5-MeIm, 2-ethylimidazole/2-EtIm) of type: cis-[Cu(2-RIm)2(acr)2]·xH2O ((1): R = –CH3, x = 2; (4): R = –CH2–CH3, x = 0), trans-[Cu(2-RIm)2(acr)2] ((2): R = –CH3; (5): R = –CH2–CH3) and trans-[Cu(5-RIm)2(acr)2] ((3): R = –CH3) have been prepared and characterized by elemental analysis, Fourier Transform Infrared spectrometry (FTIR), Electron Paramagnetic Resonance (EPR), electronic reflectance spectroscopy, scanning electron microscopy, and mass spectrometry. The single crystal X-ray diffraction study of complexes (2) and (5) reveals that the copper(II) ion is located on an inversion center and show elongated octahedral geometry completed by two coplanar bidentate acrylates and two unidentate imidazole derivatives displayed in trans positions. For complex (4) the single crystal X-ray diffraction shows that the copper(II) ion is in a distorted octahedral environment which can be easily confused with a trigonal prism completed by two bidentate acrylates and two unidentate imidazole derivatives displayed in cis positions. These results indicate the fact that complexes (4) and (5) are the geometric isomers of the same compound bis(acrylate)-bis(2-ethylimidazole)-copper(II). Complexes (1) and (2), as well as (4) and (5), were produced simultaneously in the reaction of the corresponding copper(II) acrylate with imidazole derivatives in methanol solution. Furthermore, in order to be able to formulate potential applications of the obtained compounds, our next goal was to investigate the in vitro antimicrobial activity of the synthesized complexes against Gram-positive and Gram-negative bacteria, as well as fungal strains, of both clinical and ecological importance (biodeterioration of historical buildings). The trans isomers (2) and (5), followed by (4) have shown the broadest range of antimicrobial activity. In case of (1) and (2) isomers, the trans isomer (2) was significantly more active than cis (1), while the cis isomer (4) proved to be more active than trans (5). Taken together, the biological evaluation results indicate that the trans (2) was the most active complex, demonstrating its potential for the development of novel antimicrobial agents, with potential applications in the biomedical and restoration of architectural monuments fields. [ABSTRACT FROM AUTHOR]

C. albicans is the most frequently occurring fungal pathogen, and is becoming an increasing public health problem, especially in the context of increased microbial resistance. This opportunistic pathogen is characterized by a versatility explained mainly by its ability to form complex biofilm structures that lead to enhanced virulence and antibiotic resistance. In this context, a review of the known C. albicans biofilm formation inhibitors were performed and a new N-(oxazolylmethyl)-thiazolidinedione scaffold was constructed. 16 new compounds were synthesized and characterized in order to confirm their proposed structures. A general antimicrobial screening against Gram-positive and Gram-negative bacteria, as well as fungi, was performed and revealed that the compounds do not have direct antimicrobial activity. The anti-biofilm activity evaluation confirmed the compounds act as selective inhibitors of C. albicans biofilm formation. In an effort to substantiate this biologic profile, we used in silico investigations which suggest that the compounds could act by binding, and thus obstructing the functions of, the C. albicans Als surface proteins, especially Als1, Als3, Als5 and Als6. Considering the well documented role of Als1 and Als3 in biofilm formation, our new class of compounds that target these proteins could represent a new approach in C. albicans infection prevention and management. [ABSTRACT FROM AUTHOR]