Genome editing reemerged in 2012 with the development of CRISPR/Cas9 technology, which is a genetic manipulation tool derived from the defense system of certain bacteria against viruses and plasmids. ...This method is easy to apply and has been used in a wide variety of experimental models, including cell lines, laboratory animals, plants, and even in human clinical trials. The CRISPR/Cas9 system consists of directing the Cas9 nuclease to create a site‑directed double‑strand DNA break using a small RNA molecule as a guide. A process that allows a permanent modification of the genomic target sequence can repair the damage caused to DNA. In the present study, the basic principles of the CRISPR/Cas9 system are reviewed, as well as the strategies and modifications of the enzyme Cas9 to eliminate the off‑target cuts, and the different applications of CRISPR/Cas9 as a system for visualization and gene expression activation or suppression. In addition, the review emphasizes on the potential application of this system in the treatment of different diseases, such as pulmonary, gastrointestinal, hematologic, immune system, viral, autoimmune and inflammatory diseases, and cancer.
Infections caused by resistant bacteria are nowadays too common, and some pathogens have even become resistant to multiple types of antibiotics, in which case few or even no treatments are available. ...In recent years, the most successful strategy in anti-infective drug discovery for the treatment of such problematic infections is the combination therapy “antibiotic + inhibitor of resistance”. These inhibitors allow the repurposing of antibiotics that have already proven to be safe and effective for clinical use. Three main types of compounds have been developed to block the principal bacterial resistance mechanisms: (i) β-lactamase inhibitors; (ii) outer membrane permeabilizers; (iii) efflux pump inhibitors. This Perspective is focused on β-lactamase inhibitors that disable the most prevalent cause of antibiotic resistance in Gram-negative bacteria, i.e., the deactivation of the most widely used antibiotics, β-lactams (penicillins, cephalosporines, carbapenems, and monobactams), by the production of β-lactamases. An overview of the most recently identified β-lactamase inhibitors and of combination therapy is provided. The article also covers the mechanism of action of the different types of β-lactamase enzymes as a basis for inhibitor design and target inactivation.
This paper describes the characteristics of a series parallel wind farm (SPWF) topology and investigates the control strategy to ensure its safe operation. The SPWF was found to have advantages over ...other pure dc wind farm architectures in terms of lower construction cost and lower power losses in the collection system. However, unbalanced power productions among the wind turbines cause the variations of their output voltages, which may endanger the safe operation of the entire wind farm. This paper proposes a global control strategy that prevents wind turbines from operating above their overvoltage capabilities. With an active participation of the onshore converter, the proposed strategy allows maximum power point tracking of the wind turbines. The practical limitations of this strategy are discussed and improvements are given. The feasibility of the proposed method is validated in a simulation of 300 MW wind farm developed in EMTP-RV.
One of the important factors for surgical site infection prevention is the implementation of an ultraclean operating room. This study was designed to evaluate back-table sterility during total joint ...arthroplasty.
This prospective study includes 52 patients undergoing primary total joint arthroplasty between November 2021 and January 2022. A total of 4 swabs (2 air swabs and 2 table swabs) were obtained for each case, at the conclusion of surgery and prior to the takedown of drapes. One swab from each set was sent for culture, and the other was sent for next-generation sequencing (NGS) analysis.
Among 104 back-table swabs, a total of 13 (12.5%) organisms were isolated. Of these, 7 organisms were isolated by culture and 6 by NGS. No microorganisms were isolated by both culture and NGS from back-table swabs. Among 104 air swabs, a total of 11 (10.6%) organisms were isolated. Of these, 6 microorganisms were isolated by culture and 5 by NGS. In 4 of the 104 swabs, both culture- and NGS-isolated organisms were from air swabs. Of the 104 (12.5%) back-table and air swabs, 13 were culture positive. While more than 1 pathogen was identified in 2 air swabs, all back-table swabs were monomicrobial by culture. Pathogens were identified from 11 of 104 (10.6%) swabs by NGS, while more than 1 pathogen was identified in 4 swabs (2 air and 2 back table).
The findings of this study raise an important issue that the surgical field including the sterile table setup for instruments is not “sterile” and can harbor pathogens.
Adhesion to mucosal surfaces is a critical step in many bacterial and fungal infections. Here, using a mouse model of oral infection by the human fungal pathobiont Candida albicans, we report the ...identification of a novel regulator of C. albicans adhesion to the oral mucosa. The regulator is a member of the regulatory factor X (RFX) family of transcription factors, which control cellular processes ranging from genome integrity in model yeasts to tissue differentiation in vertebrates. Mice infected with the C. albicans rfx1 deletion mutant displayed increased fungal burden in tongues compared to animals infected with the reference strain. High‐resolution imaging revealed RFX1 transcripts being expressed by C. albicans cells during infection. Concomitant with the increase in fungal burden, the rfx1 mutant elicited an enhanced innate immune response. Transcriptome analyses uncovered HWP1, a gene encoding an adhesion protein that mediates covalent attachment to buccal cells, as a major RFX1‐regulated locus. Consistent with this result, we establish that C. albicans adhesion to oral cells is modulated by RFX1 in an HWP1‐dependent manner. Our findings expand the repertoire of biological processes controlled by the RFX family and illustrate a mechanism whereby C. albicans can adjust adhesion to the oral epithelium.
The regulatory factor X (RFX) gene family comprises a diverse group of transcriptional regulators with a unique winged‐helix DNA binding domain. In contrast to model yeasts that harbor a single RFX gene, the genome of the pathogenic yeast C. albicans encodes two RFX homologs. One homolog has roles in DNA repair, reminiscent of the function of the RFX gene in model yeasts, whereas the second homolog regulates C. albicans interactions with the mammalian host.
The fate of polar organic micropollutants (logDOW (pH 7) between −4.2 and +3.5) during riverbank filtration (RBF) at the river Thur was studied using both spatiotemporally resolved sampling and ...single-well push–pull tests (PPT), followed by LC-MS/MS analysis. The Thur is a dynamic prealpine river with an alluvial sandy-gravel aquifer, which is characterized by short groundwater travel times (a few days) from surface water infiltration to groundwater extraction. The spatiotemporal sampling allowed tracing concentration dynamics in the river and the groundwater and revealed persistence for the drug carbamazepine, while the herbicide MCPA (2-methyl-4-chloro-phenoxyacetic acid) and the drug 4-acetamidoantipyrine were very quickly degraded under the prevalent aerobic conditions. The corrosion inhibitor 1H-benzotriazole was degraded slightly, particularly in a transect influenced by river restoration measures. For the first time in situ first-order degradation rate constants for three pesticides and two pharmaceuticals were determined by PPTs, which confirmed the results of the spatiotemporal sampling. Atenolol was transformed almost completely to atenolol acid. Rate constants of 0.1–1.3 h–1 for MCPA, 2,4-D, mecoprop, atenolol, and diclofenac, corresponding to half-lives of 0.6–6.3 h, demonstrated the great potential of RBF systems to degrade organic micropollutants and simultaneously the applicability of PPTs for micropollutants in such dynamic systems.
Membrane-assisted amyloid formation is implicated in human diseases, and many of the aggregating species accelerate amyloid formation and induce cell death. While structures of membrane-associated ...intermediates would provide tremendous insights into the pathology and aid in the design of compounds to potentially treat the diseases, it has not been feasible to overcome the challenges posed by the cell membrane. Here, we use NMR experimental constraints to solve the structure of a type-2 diabetes related human islet amyloid polypeptide intermediate stabilized in nanodiscs. ROSETTA and MD simulations resulted in a unique β-strand structure distinct from the conventional amyloid β-hairpin and revealed that the nucleating NFGAIL region remains flexible and accessible within this isolated intermediate, suggesting a mechanism by which membrane-associated aggregation may be propagated. The ability of nanodiscs to trap amyloid intermediates as demonstrated could become one of the most powerful approaches to dissect the complicated misfolding pathways of protein aggregation.
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