51 research outputs found
Colistin and kanamycin together in association with Coridothymus capitatus to enhance their antimicrobial activity and fight multidrug resistance pathogens
No full textIt should be remembered that bacteria continue to spread and develop new types of resistance, so further actions are needed to deal with antibiotic resistance. As a result, antibacterial drugs have become less effective, resulting in the accelerated discovery of available alternative treatments, including essential oils. The aim of this work was to intensify and promote the action of two antibiotics, kanamycin, and colistin, to fight antibiotic resistance thanks to the action of essential oil obtained from the flowers of Coridothymus capitatus grown on the Iblei mountains. To this end, a comparison of biological and chemical assays was carried out. The results showed a broad antimicrobial power of the essential oil itself and a great synergistic activity in combination with Kanamycin and Colistin against multidrug-resistant bacteria. These combinations increased the range of antibiotics, leading us to speculate that it could be incorporated into new pharmaceutical formulations for therapies of infections caused by increasingly dangerous bacteria. Antibiotic resistance represents an ever-greater danger to human health. This work re-evaluates the use of colistin and kanamycin thanks to the synergistic action found with the addition of a natural substance to pave the way for new therapeutic strategies
Preparation and Microbiological Evaluation of Amphiphilic Kanamycin-Lipoamino Acid Ion-Pairs
No full textAmphiphilic ion-pairs of kanamycin (KAN) were prepared by evaporation of a water-ethanol co-solution of KAN base and a lipoamino acid bearing a 12-carbon atoms alkyl side chain (LAA12), at different molar ratios. Infrared spectroscopy confirmed the structure of ion-pairs, while differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) studies supported the formation of new saline species with a different crystalline structure than the starting components. The solubility pattern shown in a range of both aqueous and organic solvents confirmed that the ion-pairs possess an amphiphilic character. The LAA12 counter-ion showed not to improve the antibacterial activity of KAN, suggesting that such chemical strategy is not able to favor the penetration of this drug inside the bacteria cells. Nevertheless, a slight improving, i.e., a one-fold dilution, was observed in E. coli. The present study can also serve as the basis for a further evaluation of LAA ion-pairing of antibiotics, as a means to improve the loading of hydrophilic drugs into lipid-based nanocarriers
Endosymbionts of entomopathogenic nematodes from south Italy: A phenotypic study
No full textWe examined different Xenorhabdus strains (five of X. bovienii and two of X. kozodoii), obtained from EPN isolates belonging to the genus Steinernema (S. feltiae, S. ichnusae, S. apuliae, S. vulcanicum) of different geographic origin by both genotypic and phenotypic analysis. Common laboratory assays were done for traits such as antibiotic resistance, haemolytic activity, lactose utilisation, biofilm production, chosen as the least selectable traits for EPN life-cycle, and thus as (presumably) neutral traits. As selective marker, the activity of the endosymbiont’s toxins was verified in an in vivo assay on G. mellonella larvae. Genotyping done by 16S partial sequencing was used for identification purposes. Xenorhabdus bovienii isolates showed a broad phenotypic spectrum; on the other hand, X. kozodoii showed a less degree of phenotypic variation, reduced ability of biofilm production and conspicuous ?-galactosidase activity. However, all the strains were able to kill G. mellonella larvae with high efficiency
Lipid Nanoparticles And Active Natural Compounds: A Perfect Combination For Pharmaceutical Applications
No full textPhytochemicals represent an important class of bioactive compounds characterized by significant health benefits. Notwithstanding these important features, their potential therapeutic properties suffer from poor water solubility and membrane permeability limiting their approach to nutraceutical and pharmaceutical applications. Lipid nanoparticles are well-known carrier systems endowed with high biodegradation and extraordinary biocompatible chemical nature, successfully used as a platform for advanced delivery of many active compounds, including the oral, topical and systemic routes. This article is aimed at reviewing the last ten years of studies about the application of lipid nanoparticles in active natural compounds reporting examples and advantages of these colloidal carrier systems
Spiroplasma spp.: a plant, arthropod, animal and human pathogen
No full textMollicutes is a class of smallest and free-living bacteria. They have no cell wall and their plasma membrane contains cholesterol; nevertheless, cellular organization does not dif- fer from that of other prokaryotes. They are used as simple model systems for studying general biological problems, such as those concerning membrane structure and func- tions, symbiosis between arthropods and microrganisms, animal and plant pathogens. Mollicutes includes the family of Spiroplamataceae, which contains Spiroplasma genus, a group of species associated, in different manner, with arthropods (insects, mites, crusta- ceans). Spiroplasma species can be commensals or parasites and even be involved in more close symbiosis, such as synergism or mutualism. Out of 38 described Spiroplasma spe-cies, only three have been associated with plant diseases and three with arthropod dis-eases. Moreover, some species have been related to animal diseases, such as transmissible spongiform encephalopathy (TSE), and their role in human disease has been assessed. The chapter describes the taxonomic situation of the genus and reports the most impor-tant diseases due to the presence of Spiroplasma in different living organisms with special emphasis on citrus in which it causes one of the most economically damaging infectious diseases in a number of citrus growing areas worldwide
A sustainable porous composite material based on loofah-halloysite for gas adsorption and drug delivery
No full textThe development of new advanced polymers has led researchers to look at nature to find new, high-performance, low-cost materials. This work aims to easily functionalize fibers, made up of polysaccharides, of loofah with halloysite through crosslinkers. Bio-composites have been extensively characterized using different techniques. The synthesized loofah-halloysite composites have improved CO2 adsorption properties superior to those of both individual components and materials currently used in industry. In particular, compared to BEA and the MOR zeolites, an improvement in CO2 capture of about 50% and 23%, respectively, was observed. Moreover, the composite investigated in this work showed superior CO2 capture compared to other cellulose-based and sustainable materials. Furthermore, the presence of halloysite also increased the mechanical properties of the cellulosic polymer. The new cellulose composites have proved to be excellent candidates for the delivery of resveratrol, maintaining its anticancer activity. The results underline the synergistic effect of functionalization on increasing the adsorption properties compared to the starting materials and the possibility of using this eco-sustainable and low-cost porous system in various fields such as gas adsorption and drug administration
Synthesis, characterization and in\ua0vitro evaluation of amphiphilic ion pairs of erythromycin and kanamycin antibiotics with liposaccharides
No full textThe hydrophilic ion paring strategy (HIP) is a method explored to improve the cell/tissue uptake of poorly adsorbed drugs and to optimize their physico-chemical characteristics. In this context, we here describe the synthesis of some ion pairs of two model cationic antibiotics, erythromycin (ERY) and kanamycin A (KAN), with liposaccharides having different levels of lipophilicity and charge. The formation of drug-liposaccharide complexes was confirmed by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) analysis. The effect of the amphiphilic liposaccharide moieties on the antimicrobial activity of ERY and KAN was assessed by measuring the minimal inhibitory concentration (MIC) of the compounds against a panel of bacterial strains that were susceptible or resistant to the parent antibiotics. The ion pairing did not depress the in vitro antibiotic activity, although no lowering of MIC values was registered. The experimental findings would motivate the future investigation of this ion pairing strategy in drug design, for instance allowing improvement of the encapsulation efficiency of hydrophilic antibiotics in lipid-based nanocarriers, or changing their in vivo biodistribution and pharmacokinetic profile
Management of Aerobic Vaginitis
No full textAerobic vaginitis is a new nonclassifiable pathology that is neither specific vaginitis nor bacterial vaginosis. The diversity of this microbiological peculiarity could also explain several therapeutic failures when patients were treated for infections identified as bacterial vaginosis. The diagnosis ‘aerobic vaginitis’ is essentially based on microscopic examinations using a phase-contrast microscope (at ×400 magnification). The therapeutic choice for ‘aerobic vaginitis’ should take into consideration an antibiotic characterized by an intrinsic activity against the majority of bacteria of fecal origin, bactericidal effect and poor/absent interference with the vaginal microbiota. Regarding the therapy for aerobic vaginitis when antimicrobial agents are prescribed, not only the antimicrobial spectrum but also the presumed ecological disturbance on the anaerobic and aerobic vaginal and rectal microbiota should be taken into a consideration. Because of their very low impact on the vaginal microbiota, kanamycin or quinolones are to be considered a good choice for therapy.</jats:p
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