Hybrid magnetite nanoparticles/Rosmarinus officinalis essential oil nanobiosystem with antibiofilm activity

Biofilms formed by fungal organisms are associated with drastically enhanced resistance against most antimicrobial agents, contributing to the persistence of the fungi despite antifungal therapy. The purpose of this study is to combine the unique properties of nanoparticles with the antimicrobial activity of the Rosmarinus officinalis essential oil in order to obtain a nanobiosystem that could be pelliculised on the surface of catheter pieces, in order to obtain an improved resistance to microbial colonization and biofilm development by Candida albicans and C. tropicalis clinical strains. The R. officinalis essential oils were extracted in a Neo-Clevenger type apparatus, and its chemical composition was settled by GC-MS analysis. Functionalized magnetite nanoparticles of up to 20 nm size had been synthesized by precipitation method adapted for microwave conditions, with oleic acid as surfactant. The catheter pieces were coated with suspended core/shell nanoparticles (Fe3O4/oleic acid:CHCl3), by applying a magnetic field on nanofluid, while the CHCl3 diluted essential oil was applied by adsorption in a secondary covering treatment. The fungal adherence ability was investigated in six multiwell plates, in which there have been placed catheters pieces with and without hybrid nanoparticles/essential oil nanobiosystem pellicle, by using culture-based methods and confocal laser scanning microscopy (CLSM). The R. officinalis essential oil coated nanoparticles strongly inhibited the adherence ability and biofilm development of the C. albicans and C. tropicalis tested strains to the catheter surface, as shown by viable cell counts and CLSM examination. Due to the important implications of Candida spp. in human pathogenesis, especially in prosthetic devices related infections and the emergence of antifungal tolerance/resistance, using the new core/shell/coated shell based on essential oil of R. officinalis to inhibit the fungal adherence could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with antibiofilm properties

Seasonal monitoring of microbiological air contamination from a museum - a case study

The aim of this study was to monitor microbial contamination in the work place of a museum, for estimating the influence of seasons, microclimatic parameters and tourists. The analysis was carried out in artefacts deposits, restoration laboratories and exhibition spaces. The media used to demonstrate the presence of biological agents, non-pathogenic and with pathogenic potential (opportunistic bacteria and filamentous fungi with haemolytic properties) were: simple agar, blood agar and Sabouraud with chloramphenicol. The isolated bacterial strains were identified by API tests and the fungal strains by examination of features with taxonomic value, aspects based on macroscopic observations of colony/cultures and microscopic assessment of mycelia. The counts of the microorganisms in the air were higher especially in the textiles deposits (the mesophilic microorganisms ranged from 200 to 1.4x104 CFU/m3). The filamentous fungi most frequently isolated species were: Aspergillus spp.; Penicillium spp., Cladosporium spp. The most frequently isolated bacteria swere: Staphylococcus (S. epidermidis, S. xylosus, S. capitis); Bacillus (B. cereus, Bacillus spp). The results of this study indicate a microbial air load containing both filamentous fungi and bacteria strains, including some opportunistic pathogens which can represent a health risk for the museums workers, especially in the seasons with higher exposure

Antimicrobial Activity of Olea europaea Fatty Oil against Multi-Drug Resistant and Biofilm Forming Microorganisms

The aim of the present study was to investigate the potential antimicrobial activity of Olea europaea fatty oil against a collection of bacterial (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and fungal (Candida albicans) clinical isolates. The antimicrobial and antibiofilm activity were evaluated by broth microdilution method for establishing the minimal inhibitory concentration (MIC) and microtiter assay for determining the minimal biofilm eradication concentration (MBEC). Some of the potential microbial targets of the fatty oil were investigated by flow cytometry (FCM). The results obtained hereby revealed that Olea europaea fatty oil inhibited microbial planktonic growth (MICs values of 5.23-41.8 mg/ mL) and biofilm development on inert substrata (MBEC values of 1.31-20.9 mg/ mL). The FCM measurements confirmed that the analyzed oil induced microbial membrane damages and inhibited microbial efflux pump activity

Strategies for Decentering the Narratives of Modernity: Goody, Wolff, Chakrabarty and Fabian – Part 1 Veronică Lazăr

This two-part article attempts to decipher four different critical strategies for decentering Eurocentrist narratives that promoted “the West” simultaneously as an agent, as a goal and as a yardstick for evaluating modernization processes across the globe: in the first part, it will examine Jack Goody’s interrogation of the alleged European preeminence and exceptionalism and its imposition of value-laden temporal categories on the non-Western world, as well as Eric Wolff ’s reconstruction of the so-called invention of “Eastern Europe” by the Western mind during the Enlightenment; in the second part, it will take on Dipesh Chakrabarty’s notion of “provincializing” Western epistemology and Johannes Fabian’s focus on the “denial of coevalness” for non-Western temporalities. The article will focus on the analysis these four authors provided for the emergence of specific temporal and geographical systems that backed the epistemic hegemony of the “West” and reinforced, therefore, its already established political domination. It will also examine the practice of translating spacial distance in historical time and its reverse, both at the core of Enlightenment and post-Enlightenment understanding and construction of the cultural and historical “other”

Expression of adhesins by some Bordetella pertussis strains isolated in Romania in different time periods

Bordetella pertussis is the etiological agent of whooping cough or pertussis, a respiratory infection in humans which can be prevented by vaccination. B. pertussis is characterized by a set of virulence factors involved in bacterial adherence to host-cells and consecutive colonization of the respiratory epithelium and in immunity too. In this study, we compared the expression of the specific adhesins with antigenic properties in some B. pertussis strains, including collection strains, vaccine strains and recently-isolated strains. The specific adhesins / surface antigens of B. pertussis are: a surface protein, named FHA (filamentous hemagglutinin) and fimbria Fim2 and Fim3. These antigens were evidenced using an indirect ELISA method, based on specific monoclonal antibodies binding to specific epitopes. The results showed that fimbrial antigens Fim3 are expressed by all new-isolated strains, compared to the older isolates, which expressed Fim2 or both Fim2, 3. Oprea et Lazar (PDF

Serum cytokine and chemokine profiles of patients with confirmed bacterial and viral meningitis

Introduction: Cerebrospinal fluid (CSF) cytokines and chemokines have been reported by several studies as useful markers to discriminate bacterial and viral meningitis (BM and VM). This study aimed to investigate if serum cytokine and chemokine profiles could also differentiate BM from VM, thus circumventing the need for an invasive lumbar puncture

Antibacterial Efficiency of <i>Tanacetum vulgare</i> Essential Oil against ESKAPE Pathogens and Synergisms with Antibiotics

Medicinal plants with multiple targets of action have become one of the most promising solutions in the fight against multidrug-resistant (MDR) bacterial infections. Tanacetum vulgare (Tansy) is one of the medicinal plants with antibacterial qualities that deserve to be studied. Thus, this research takes a closer look at tansy extract’s composition and antibacterial properties, aiming to highlight its potential against clinically relevant bacterial strains. In this respect, the antibacterial test was performed against several drug-resistant pathogenic strains, and we correlated them with the main isolated compounds, demonstrating the therapeutic properties of the extract. The essential oil was extracted via hydrodistillation, and its composition was characterized via gas chromatography. The main isolated compounds known for their antibacterial effects were α-Thujone, β-Thujone, Eucalyptol, Sabinene, Chrysanthenon, Camphor, Linalool oxide acetate, cis-Carveol, trans-Carveyl acetate, and Germacrene. The evaluation of the antibacterial activity was carried out using the Kirby–Bauer and binary microdilution methods on Gram-positive and Gram-negative MDR strains belonging to the ESKAPE group (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). Tansy essential oil showed MIC values ranging from 62.5 to 500 μg/mL against the tested strains. Synergistic activity with different classes of antibiotics (penicillins, cephalosporins, carbapenems, monobactams, aminoglycosides, and quinolones) has also been noted. The obtained results demonstrate that tansy essential oil represents a promising lead for developing new antimicrobials active against MDR alone or in combination with antibiotics

A microbial survey of the museal airborne fungal biodeteriogens

El Patrimonio cultural material está expuesto a múltiples factores ambientales de riesgo que pueden afectar a su integridad y función cultural. Estos factores pueden ser físicos, químicos y también microbiológicos. El biodeterioro producido por hongos es un conocido causante de daño estético y estructural de los materiales, con un efecto mayor en el caso de deposición inadecuada o accidentes, como inundaciones o fugas de agua. Al mismo tiempo, la contaminación del aire con diferentes esporas de hongos puede constituir un factor de riesgo para la seguridad de los bienes patrimoniales. El rastreo de la biocontaminación aérea en museos tiene una doble utilidad: protección de la salud de los trabajadores en el museo ante bio-aerosoles peligrosos y el control de la presencia de agentes biodeteriorantes capaces de descomponer las piezas del museo. El presente documento presenta la metodología utilizada para la detección de especies de hongos en el aire de un museo etnográfico en Rumania, tanto en salas de almacenamiento, como de exposición. Los resultados preliminares muestran un predominio de géneros de hongos con actividad celulolítica reconocida, tales como Aspergillus, Penicillium y Cladosporium y una correlación directa entre los valores de temperatura y humedad con la concentración y los tipos de hongos presentes en el aire. Además, los medios de cultivo utilizados para el aislamiento de las especies fúngicas del aire se mostraron como un factor importante en la metodología de aislamiento.Tangible cultural heritage is exposed to multiple environmental risk factors able to affect its integrity and cultural function. Such factors are physical, chemical and also microbiological. Fungal biodeterioration is known to cause aesthetical and structural damage to materials, the effect increasing in the case of improper depositing or accidents like floods or water leakage. At the same time, air contamination with different fungal spores can add more a risking factor for heritage goods safety. Tracing of air biocontamination has a double significance: protection of museum` workers health from hazardous bio-aerosols and the control of the presence of biodeteriogens able to decompose museum pieces. The present paper will present the methodology used for the detection of the fungal species in the air of an ethnographical museum in Romania, in storage rooms, as well as in exposition rooms. Preliminary results show the predominance of fungal genera with known cellulolytic activity, such as Aspergillus, Penicillium and Cladosporium and direct correlation between the values of temperature and humidity and the concentration and types of air cultivable fungal species. Further more, the culture media used for the isolation of the air fungal species proved to be an important factor in the isolation methodology

THE INFLUENCE OF CULTURE TECHNOLOGY ON CONTENT NITRATES AND NITRITES IN CARROT (Daucus carrota XYZ) ROOTS

In optimal growth and development conditions of plants, ammoniacal salts and nitrates are absorbed in higher quantity than their ability to transform into protein substances. Achievement of a rational system of supplementary fertilization requires setting of the most appropriate combination of fertilizers, the ratio between these epochs and the doses of administration and knowledge of how each variety or hybrid reacts to fertilizers used. The behavior way of carrots on the content of nitrate and nitrite as a response to the experimental factors is different. The highest nitrate content in carrots roots from variant Nantes-sown early- chemical fertilized (17.03 mg/100 g sp) is descending followed, at statistically significant difference, by variant Nantes-sown later chemically-fertilized (15.27 mg/100 g sp). Flakker variety has the lowest content of nitrates into variant with late sown and chemical fertilization 10.85 mg/100 g sp Regarding the nitrite content, the values obtained from each experimental variants, did not exceed the admited norms but they framed between 0,17 and 0,33 mg/100 g s.p

Seasonal monitoring of microbiological air contamination from a museum - a case study

The aim of this study was to monitor microbial contamination in the work place of a museum, for estimating the influence of seasons, microclimatic parameters and tourists. The analysis was carried out in artefacts deposits, restoration laboratories and exhibition spaces. The media used to demonstrate the presence of biological agents, non-pathogenic and with pathogenic potential (opportunistic bacteria and filamentous fungi with haemolytic properties) were: simple agar, blood agar and Sabouraud with chloramphenicol. The isolated bacterial strains were identified by API tests and the fungal strains by examination of features with taxonomic value, aspects based on macroscopic observations of colony/cultures and microscopic assessment of mycelia. The counts of the microorganisms in the air were higher especially in the textiles deposits (the mesophilic microorganisms ranged from 200 to 1.4x104 CFU/m3). The filamentous fungi most frequently isolated species were: Aspergillus spp.; Penicillium spp., Cladosporium spp. The most frequently isolated bacteria swere: Staphylococcus (S. epidermidis, S. xylosus, S. capitis); Bacillus (B. cereus, Bacillus spp). The results of this study indicate a microbial air load containing both filamentous fungi and bacteria strains, including some opportunistic pathogens which can represent a health risk for the museums workers, especially in the seasons with higher exposure