Search results for "microbial"
showing 10 items of 2041 documents
A New 1D Ni (II) Coordination Polymer of s-Triazine Type Ligand and Thiocyanate as Linker via Unexpected Hydrolysis of 2,4-Bis(3,5-dimethyl-1H-pyrazo…
2023
A new 1D Ni(II) coordination polymer was synthesized by the reaction of NiSO4·6H2O with 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPT) and SCN− as a linker in an acidic medium by heating under reflux conditions. Unusually, the BPT ligand underwent acid-mediated hydrolysis by losing one of the pyrazolyl arms afforded the polymeric [Ni(MPT)(H2O)(SCN)2]n complex (MPT: 4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazin-2-ol. The Ni(II) center is coordinated with one MPT as a bidentate NN-chelate, one water molecule, and two thiocyanate groups in cis positions to one another. One of the thiocyanate groups acts as a bridging ligand between metal centers, l…
Targeting antibiotic resistant bacteria with phage reduces bacterial density in an insect host
2019
Phage therapy is attracting growing interest among clinicians as antibiotic resistance continues becoming harder to control. However, clinical trials and animal model studies on bacteriophage treatment are still scarce and results on the efficacy vary. Recent research suggests that using traditional antimicrobials in concert with phage could have desirable synergistic effects that hinder the evolution of resistance. Here, we present a novel insect gut model to study phage–antibiotic interaction in a system where antibiotic resistance initially exists in very low frequency and phage specifically targets the resistance bearing cells. We demonstrate that while phage therapy could not reduce th…
Encapsulation of the Bacillus thuringiensis secretable toxins Vip3Aa and Cry1Ia in Pseudomonas fluorescens
2013
Vip3A and Cry1I toxins are secreted during the vegetative growth of Bacillus thuringiensis. Vip3A toxins do not share homology to the crystal (Cry) proteins and are active against a different spectrum of lepidopteran species. Cry1I toxins share similarity with the Cry1 protein group but do not accumulate in the parasporal crystal. Since Vip3A and Cry1I toxins are released from the cell, they are excluded from biological formulates based on spores and crystals of B. thuringiensis. As an approach to obtain novel sprayable insecticides containing Vip3 or Cry1I toxins, Vip3Aa and Cry1Ia proteins were expressed in Pseudomonas fluorescens. This bacterium, non-pathogenic to animals or plants, can …
Epidemiology, clinical characteristics, resistance, and treatment of infections by
2018
Candida spp. infections are a major cause of morbidity and mortality in critically ill patients. Candida auris is an emerging multi-drug-resistant fungus that is rapidly spreading worldwide. Since the first reports in 2009, many isolates across five continents have been identified as agents of hospital-associated infections. Independent and simultaneous outbreaks of C. auris are becoming a major concern for healthcare and scientific community. Moreover, laboratory misidentification and multi-drug-resistant profiles, rarely observed for other non-albicans Candida species, result in difficult eradication and frequent therapeutic failures of C. auris infections. The aim of this review was to p…
Thymus essential oil extraction, characterization and incorporation in phospholipid vesicles for the antioxidant/antibacterial treatment of oral cavi…
2018
The aim of the work was to extract, characterize, and formulate Thymus capitatus (Tymbra capitata) essential oil in phospholipid vesicles: liposomes, glycerosomes and Penetration Enhancer-containing Vesicles (PEVs). The steam-distilled essential oil was mainly composed of carvacrol. The oil was mixed with lecithin and water to produce liposomes, or different ratios of water/glycerol or water/propylene glycol (PG) to produce glycerosomes and PG-PEVs, respectively. Cryo-TEM showed the formation of unilamellar, spherical vesicles, and light scattering disclosed that their size increased in the presence of glycerol or PG, which improved long-term stability. The formulations were highly biocompa…
Resealing of large transmembrane pores produced by streptolysin O in nucleated cells is accompanied by NF‐κB activation and downstream events
2001
Streptolysin O (SLO), archetype of a cholesterol-binding bacterial cytolysin, forms large pores in the plasma membrane of mammalian cells. We have recently reported that when a limited number of pores are generated in a cell, they can be sealed in a Ca++-dependent process. Here, we show that resealing is followed by the release of IL-6 and IL-8 from keratinocytes and from endothelial cells, both relevant targets for SLO attack. Production of cytokines by these cells was preceded by activation of transcription factor nuclear factor kappaB, which thus emerges as a common denominator of stress responses to various pore-forming agents, including alpha-toxin of Staphylococcus aureus and compleme…
Synthesis and biological evaluation of dehydroabietic acid derivatives.
2010
A series of C18-oxygenated derivatives of dehydroabietic acid were synthesized from commercial abietic acid and evaluated for their cytotoxic, antimycotic, and antiviral activities.
Comparison of the degradation mechanisms of diclofenac in the presence of iron octacarboxyphthalocyanine and myeloperoxidase
2023
The degradation process of diclofenac (DCF) by hematoprotein myeloperoxidase (MPO) and iron octacarboxyphthalocyanine (FePcOC) in the presence of hydrogen peroxide was compared. During the oxidation of diclofenac, in the presence of iron octacarboxyphthalocyanine (FePcOC) and hydroxyl radicals (HO•) (from H2O2), an intermediate product (dimer with an m/z value of 587) with the characteristic yellow colouration and an intense band at λmax = 451 nm is formed. Iron octacarboxyphthalocyanine oxidises in the presence of hydrogen peroxide, following the first-order reaction kinetics for FePcOC and H2O2. The concentration of diclofenac does not affect the initial reaction rate. For comparison, the…
Genomic epidemiology and antimicrobial resistance of Klebsiella pneumoniae in the Comunitat Valenciana
2023
La resistencia antimicrobiana (RAM) es una importante amenaza para la salud pública a nivel mundial. El mal uso de los antibióticos ha llevado al surgimiento y propagación de infecciones resistentes a los antibióticos. Entre los patógenos que más muertes causan asociadas a la RAM bacteriana se encuentra Klebsiella pneumoniae, uno de los patógenos más preocupantes. DE hecho, en 2019, K. pneumoniae se clasificó como la segunda causa de muertes atribuible a la RAM. Entre las resistencias adquiridas en K. pneumoniae, las que mayor preocupación causan son las cepas que han desarrollado resistencia a cefalosporinas de tercera generación (3GC) y carbapenems (CRKp). En esta tesis se ha investigado …
Enterobacter and Klebsiella species isolated from fresh vegetables marketed in Valencia (Spain) and their clinically relevant resistances to chemothe…
2013
Occurrence of antibiotic-resistant pathogenic or commensal enterobacteria in marketed agricultural foodstuffs may contribute to their incorporation into the food chain and constitutes an additional food safety concern. In this work, we have determined the clinically relevant resistances to 11 common chemotherapeutic agents in Enterobacter and Klebsiella isolates from fresh vegetables from various sources (supermarkets and greengrocers' shops in Valencia, Spain). A total of 96 isolates were obtained from 160 vegetables analyzed (50% positive samples): 68 Enterobacter isolates (59 E. cloacae, two E. aerogenes, two E. cancerogenus, one E. gergoviae, and four E. sakazakii, currently Cronobacter…