Mariana Carmen Chifiriuc

University of Bucharest, Bucureşti, Bucureşti, Romania

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Publications (111)113.18 Total impact

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    ABSTRACT: Novel derivatives were prepared by reaction of aromatic amines with 2-(4-ethylphenoxymethyl)benzoyl isothiocyanate, affording the N-[2-(4-ethylphenoxymethyl) benzoyl]-Nꞌ-(substituted phenyl)thiourea. Structural elucidation of these compounds was performed by IR, NMR spectroscopy and elemental analysis. The new compounds were used in combination with Fe3O4 and polyvinylpyrrolidone (PVP) for the coating of medical surfaces. In our experiments, catheter pieces were coated by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The microbial adherence ability was investigated in 6 multi-well plates by using culture based methods. The obtained surfaces were also assessed for their cytotoxicity with respect to osteoblast cells, by using fluorescence microscopy and MTT assay. The prepared surfaces by advanced laser processing inhibited the adherence and biofilm development ability of Staphylococcus aureus and Pseudomonas aeruginosa tested strains while cytotoxic effects on the 3T3-E1 preosteoblasts embedded in layer shaped alginate hydrogels were not observed. These results suggest that the obtained medical surfaces, based on the novel thiourea derivatives and magnetic nanoparticles with a polymeric shell could represent a promising alternative for the development of new and effective anti-infective strategies.
    Molecules 08/2014; 19(8):12011-12030. · 2.43 Impact Factor
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    ABSTRACT: This is the first study performed on a significant number of strains (79 carbapenem resistant Enterobacteriaceae and 84 carbapenem resistant non-fermenting Gram negative rods) recently isolated from the intensive care units of two big hospitals from Bucharest, the capital city of Romania. The obtained results revealed a high prevalence and a great diversity of carbapenemase genes (CGRs), both in fermenting and non-fermenting Gram negative beta-lactam resistant strains isolated from the intensive care units of two big hospitals located in Bucharest, South Romania. The molecular screening of carbapenem resistant GNRs revealed the presence of worldwide distributed carbepenem resistance genes - CRGs (i.e. blaOXA-48 and blaNDM-1 in Enterobacteriaceae and blaOXA-23, blaVIM-4, blaOXA-10-like, blaOXA-60-like,blaSPM-like, blaGES-like in non-fermenting GNR), reflecting the rapid evolution and spreading of carbapenemase producers, particularly in hospital settings and the need for the rapid identification of the colonized or infected patients, as well as for epidemiological investigations for establishing the local or imported origin of the respective strains.
    Journal of medical microbiology. 07/2014;
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    ABSTRACT: The emergence of antibiotic resistance in microbial strains is representing one of the major threats to public health worldwide, due to the decreased or total cancelling of the available antibiotics effectiveness, correlated with the slow development of novel antibiotics. Due to their excellent biodegradability and biocompatibility, the synthetic polymers could find a lot of biomedical applications, such as the development of biomaterials with optimized properties and of drug delivery systems. This review is focusing on the applications of synthetic, biodegradable polymers for the improvement of antiinfective therapeutic and prophylactic agents (i.e., antimicrobial and anti-inflammatory agents and vaccines) activity, as well as for the design of biomaterials with increased biocompatibility and resistance to microbial colonization.
    Current Medicinal Chemistry 03/2014; · 3.72 Impact Factor
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    Digest Journal of Nanomaterials and Biostructures 01/2014; 9(1):123. · 1.09 Impact Factor
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    ABSTRACT: Pseudomonas aeruginosa infections represent one of the major threats for injured or transplanted lungs and for their healing. Considering that the mesenchymal stem cells (MSCs) are a major tool for the regenerative medicine, including therapy of lung damaging diseases, the aim of this paper was to investigate the effects of P. aeruginosa quorum sensing signaling molecules (QSSMs) on human MSCs death signaling pathways and cytokine profile. Our data revealed that N-(3-Oxododecanoyl)-L-homoserine lactone (OdDHL), N-butanoyl-L-homoserine lactone (C4-HSL), 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), and its precursor, 2-heptyl-4-quinolone (HHQ) significantly impact on several core signaling mechanisms of MSCs in a specific and time dependent manner. Even if all tested autoinducers interfered with the MSCs apoptotic genes expression, only OdDHL and HHQ significantly promoted MSCs apoptosis, by 14- and 23-fold respectively, this aspect being confirmed by the flow cytometry analysis. The tested QSSMs induced a heterogeneous cytokine profile of the treated MSCs. The level of IL-1β was increased by OdDHL, IL-8 production was stimulated by all tested autoinducers, IL-6 was modulated mostly by PQS and IL-10 by HHQ. The significant influence of the purified bacterial autoinducers on the MSCs signaling pathways may suggest that the accumulation of these mediators could interfere with the normal function of these cells in the human body, and eventually, impair or abolish the success of the stem cells therapy during P. aeruginosa infections.
    Virulence 01/2014; 5(2). · 2.79 Impact Factor
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    ABSTRACT: The synthesis of carboxymethyl-cellulose/magnetite (CMC/Fe3O4) was carried out. This magnetic hybrid material was characterized by infrared spectroscopy, scanning electron microscopy and X-ray diffractometry. The adsorption of norfloxacin and cefotaxim antimicrobial substances (ATB) onto the CMC/Fe3O4 was performed in order to investigate the capacity of the magnetic scaffold to improve the antimicrobial activity of the respective therapeutic agents, assessed by an in vitro quantitative assay. The obtained results proved that CMC/Fe3O4/ATBs might be a promising candidate for the development of efficient and cheap antimicrobial drugs carriers under magnetic field.
    Bio-medical materials and engineering 01/2014; 24(3):1639-46. · 1.09 Impact Factor
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    Aurora Reiss, Mariana Carmen Chifiriuc, Emilia Amzoiu, Cezar Ionuţ Spînu
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    ABSTRACT: New [ML2(H2O)2] complexes, where M = Co(II), Ni(II), Cu(II), and Zn(II) while L corresponds to the Schiff base ligand, were synthesized by condensation of cefotaxime with salicylaldehyde in situ in the presence of divalent metal salts in ethanolic medium. The complexes were characterized by elemental analyses, conductance, and magnetic measurements, as well as by IR and UV-Vis spectroscopy. The low values of the molar conductance indicate nonelectrolyte type of complexes. Based on spectral data and magnetic moments, an octahedral geometry may be proposed for Co(II), Ni(II), and Zn(II) complexes while a tetragonal geometry for Cu(II) complex. Molecular structure of the Schiff base ligand and its complexes were studied using programs dedicated to chemical modeling and quantomolecular calculation of chemical properties. All the synthesized complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, namely Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains revealed that the metal complexes possess superior antibacterial activity than the Schiff base.
    Bioinorganic Chemistry and Applications 01/2014; 2014:926287. · 1.17 Impact Factor
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    ABSTRACT: Intracellular invasion of professional phagocytic cells like monocytes and macrophages by a pathogen usually triggers the apoptosis of the host cells. The aim of this study was to evaluate if Pseudomonas aeruginosa, although not considered a classic intracellular pathogen, could adhere to endothelial cell surface, invade the intracellular compartment and subsequently induce apoptosis of the cells. The adherence and invasion capacity of P. aeruginosa to endothelial cells was monitored using Cravioto's adapted method. The apoptotic cells were evidenced by staining with Acridine orange÷Ethidium bromide. The qualitative assay of bacterial adherence to the cellular substrate revealed that all tested strains adhered to endothelial cells surface, exhibiting a diffuse, aggregative or mixed (diffuse-aggregative or localized-aggregative) pattern and 20-70% adherence rates. The adherence of P. aeruginosa induced the reorganization of cytoskeleton filaments and formation of endocytic membrane expansions. Cell free P. aeruginosa culture supernatants did not induce any cell death response, as noticed in case of whole bacterial culture, showing the capacity to induce apoptosis of endothelial cells. The fluorescence microscopy examination revealed chromatin condensation, fragmented nuclei, and membrane blebbing and apoptotic bodies in pathogen invaded cells.
    01/2014; 55(2):313-7.
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    ABSTRACT: Competition of probiotic bacteria with other species from the intestinal microbiota involves different mechanisms that occur regardless of probiotics' viability. The objective of this paper was to assess the cytokine serum levels in holoxenic mice after oral administration of non-viable components (NVC) of Enterococcus faecium probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus in comparison to NVC of unstimulated E. faecium probiotic culture.
    Microbial ecology in health and disease. 01/2014; 25.
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    ABSTRACT: Ag–TiO2 nanocomposites were successfully developed from colloidal suspensions containing 750 or 1,500 ppm silver nanoparticles (AgNPs) deposited on 5 % (w/v) titanium dioxide nanoparticles (TiO2NPs) by a chemical reduction approach. The nanocomposites were characterized by diffuse reflectance UV–Vis spectroscopy (DRS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) and dynamic light scattering (DLS). DRS spectra showed an absorption band in visible region with maximum absorbance peaks at 452 and 444 nm attributed to AgNPs plasmon peaks, indicating the formation of small spherical or quasi-spherical Ag nanocrystals in nanocomposites. TEM and SEM analysis proved a nearly spherical morphology of particles (15–30 ± 5 nm average size in diameter). EDX analysis revealed the presence of Ti, O, and Ag in both nanocomposite powders having 1.37 or 2.34 wt% Ag content. DLS analysis yielded a bimodal particle size distribution in a narrow range (31.3 ± 0.5 or 23.4 ± 0.4 nm average particle diameter) and a good polydispersity (0.247 or 0.293 polydispersity index). The nanocomposites were screened for their in vitro antimicrobial activity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) bacterial and fungal (Candida albicans) reference and clinical strains, in planktonic and adherent state, by qualitative and quantitative assays. The antibacterial activity increased with the increasing AgNPs content, being more intensive for Gram-positive bacteria. Both Ag–TiO2 nanocomposites exhibited a high antibiofilm activity. The obtained results recommend the use of the developed nanocomposites as antimicrobial and antibiofilm agents in practical applications without UV irradiation. The most effective agent proved to be the one with 2.34 wt% AgNPs content.
    Journal of Nanoparticle Research 01/2014; 16(1). · 2.18 Impact Factor
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    ABSTRACT: Acute and chronic wounds represent a very common health problem in the entire world. The dermal wounds are colonized by aerobic and anaerobic bacterial and fungal strains, most of theM belonging to the resident microbiota of the surrounding skin, oral cavity and gut, or from the external environment, forming polymicrobial communities called biofilms, which are prevalent especially in chronic wounds. A better understanding of the precise mechanisms by which microbial biofilms delay repair processes together with optimizing methods for biofilm detection and prevention may enhance opportunities for chronic wounds healing. The purpose of this minireview is to assess the role of polymicrobial biofilms in the occurrence and evolution of wound infections, as well as the current and future preventive and therapeutic strategies used for the management of polymicrobial wound infections.
    International Journal of Pharmaceutics 12/2013; · 3.99 Impact Factor
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    ABSTRACT: The aims of this study were the development, characterization and bioevaluation of a novel biocompatible, resorbable and bio-active wound dressing prototype, based on anionic polymers (sodium alginate - AlgNa, carboximethylcellulose - CMC) and magnetic nanoparticles loaded with usnic acid (Fe3O4@UA). The antimicrobial activity was tested against Staphylococcus aureus grown in biofilms. The biocompatibility testing model included an endothelial cell line from human umbilical vein and human fetal progenitor cells derived from the amniotic fluid, that express a wide spectrum of surface molecules involved in different vascular functions and inflammatory response, and may be used as skin regenerative support. The obtained results demonstrated that CMC/Fe3O4@UA and AlgNa/Fe3O4@UA are exhibiting structural and functional properties that recommend them for further applications in the biomedical field. They could be used alone or coated with different bio-active compounds as Fe3O4@UA for the development of novel, multifunctional porous materials used in tissues regeneration, as antimicrobial substances releasing devices, providing also a mechanical support for the eukaryotic cells adhesion, and exhibiting the advantage of low cytotoxicity on human progenitor cells. The great antimicrobial properties exhibited by the newly synthesized nano-bioactive coatings, are recommending them as successful candidates for improving implanted devices surfaces used in regenerative medicine.
    International Journal of Pharmaceutics 08/2013; · 3.99 Impact Factor
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    ABSTRACT: In this paper, we report the synthesis, characterization (FT-IR, XRD, BET, HR-TEM) and bioevaluation of a novel γ-aminobutiric acid/silica (noted GABA-SiO2 or γ-SiO2) hybrid nanotructure, for the improved release of topical antibiotics, used in the treatment of Staphylococcus aureus infections. GABA-SiO2 showed IR bands which were assigned to Si-O-Si (stretch mode). The XRD pattern showed a broad peak in the range of 18-30∘ (2θ), indicating an amorphous structure. Based on the BET analysis, estimations about surface area (438,14 m(2)/g) and pore diameters (4,76nm) were done. TEM observation reveals that the prepared structure presented homogeneity and an average size of particles not exceeding 10nm. The prepared nanostructure has significantly improved the anti-staphylococcal activity of bacitracin and kanamycin sulfate, as demonstrated by the drastic decrease of the minimal inhibitory concentration of the respective antibiotics loaded in the GABA-SiO2 nanostructure. These results, correlated with the high biocompatibility of this porous structure, is highlighting the possibility of using this carrier for the local delivery of the antimicrobial substances in lower active doses, thus reducing their cytotoxicity and side-effects.
    International Journal of Pharmaceutics 07/2013; · 3.99 Impact Factor
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    ABSTRACT: Considering the great diversity and prevalence of opportunistic pathogens as well as the medical consequences arising from increasingly frequent cases of infections with resistant pathogens, the aim of this study was to analyze and compare the virulence profiles of some recent isolates of the most frequently encountered human pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. We screened for the production of seven soluble virulence factors (hemolysins, caseinases, amylases, DNA-se, gelatinase, lipase and lecithinase) in 181 clinical isolates, using a method of culturing on specific substrates. Adherence to host cells was analyzed using Cravioto’s adapted method, and invasive potentials were established by an antibiotic protection assay. The results demonstrated that these pathogens may act differently when they are the protagonists of infections and may occur in different clinical condition. We revealed that the analyzed strains display different patterns of soluble virulence factors and different invasive capacity, according to the isolation source; many of the observed differences are statistically significant. By investigating the development of infectious process in various clinical conditions, our studies provide a high contribution to the development of personalized anti-infectious therapies.
    African journal of microbiology research 07/2013; 7(27):3453-3460,. · 0.54 Impact Factor
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    ABSTRACT: The aim of the study was to synthesize some new compounds with potential anti-tuberculosis activity, containing isoniazid and α,β-unsaturated thiocinnamamide-like thioamides as precursors. The obtained derivatives were evaluated regarding their biological activity (antioxidant and antibacterial), as well as their influence on the eukaryotic cell cycle. The results suggested that the newly obtained derivatives of isoniazid exhibited different biological activities, depending on their structure; thus, the most active compound in terms of anti-oxidant and anti-Mycobacterium tuberculosis effects proved to be the isonicotinic acid N'-(1-amino-1-mercapto-3-phenyl-propen-1-yl)-hydrazide. This compound also increased the expression of NAT1 and NAT2 genes, which are implicated in the metabolism of the isoniazid, demonstrating that it could be rapidly metabolized, and thus well tolerated. The largest spectrum of antibacterial activity (excluding M. tuberculosis) was noticed for the isonicotinic acid N'-[1-amino-1-mercapto-3-(p-chloro-phenyl)-propen-1-yl]-hydrazide, which was also the most cytotoxic, especially at high concentrations, although not significantly affecting the cellular cycle phases. The obtained results showed that the new derivatives could represent potential candidates for the treatment of M. tuberculosis infections, but further research is needed in order to improve their pharmacological properties, by increasing their antimicrobial activity and reducing the risk of side-effects.
    Bioorganic & medicinal chemistry 06/2013; · 2.82 Impact Factor
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    ABSTRACT: A new water-dispersible nanostructure based on magnetite (Fe3O4) and usnic acid (UA) was prepared in a well-shaped spherical form by a precipitation method. Nanoparticles were well individualized and homogeneous in size. The presence of Fe3O4@UA was confirmed by transmission electron microscopy, Fourier transform-infrared spectroscopy, and X-ray diffraction. The UA was entrapped in the magnetic nanoparticles during preparation and the amount of entrapped UA was estimated by thermogravimetric analysis. Fabricated nanostructures were tested on planktonic cells growth (minimal inhibitory concentration assay) and biofilm development on Gram-positive Staphylococcus aureus (S. aureus), Enterococcus faecalis (E. faecalis) and Gram-negative Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) reference strains. Concerning the influence of Fe3O4@UA on the planktonic bacterial cells, the functionalized magnetic nanoparticles exhibited a significantly improved antimicrobial activity against E. faecalis and E. coli, as comparedwith the Fe3O4 control. The UA incorporated into the magnetic nanoparticles exhibited a very significant inhibitory effect on the biofilm formed by the S. aureus and E. faecalis, on a wide range of concentrations,while in case of theGramnegative microbial strains, theUA-loaded nanoparticles inhibited the E. coli biofilm development, only at high concentrations, while for P. aeruginosa biofilms, no inhibitory effect was observed. The obtained results demonstrate that the new water-dispersible Fe3O4@UA nanosystem, combining the advantages of the intrinsic antimicrobial features of the UA with the higher surface to volume ratio provided by the magnetic nanocarrier dispersible in water, exhibits efficient antimicrobial activity against planktonic and adherent cells, especially on Gram-positive strains.
    Journal of Nanoparticle Research 05/2013; 15:1766. · 2.18 Impact Factor
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    ABSTRACT: The objective of this study was to investigate the potential of magnetic nanoparticles to potentiate, but also to accomplish a sustained and controlled drug release and subsequently improve the efficacy of antibiotics against Enterococcus faecalis, one of the most resistant opportunistic pathogens, that poses a threat to chronically infected or immunocompromised patients and is difficult to eradicate from medical devices. To our knowledge, this is the first study trying to investigate the ability of magnetite nanoparticles to improve the anti-bacterial activity of the current antibiotics against planktonic and biofilm growing E. faecalis. Our results are suggesting that the magnetite nanoparticles may be considered an effective aminoglycoside antibiotics carrier, but a complete understanding of the way in which they selectively interact with different antibiotics and with the bacterial cell is needed, in order to obtain improved strategies for elimination of E. faecalis biofilms on biomedical devices or human tissues.
    Anaerobe 05/2013; · 2.02 Impact Factor
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    ABSTRACT: Starting from benzocaine, a well-known anaesthetic, ten derivatives were synthesized and characterized by UV–vis, IR, NMR, and elemental analysis. Most of the compounds contain residues with recognized biological activity, like nicotinic acid (vitamin B3 or PP), biotin (vitamin B7 or H), lipoic acid (thioctic acid), adamantine, as well as other residues of crown-ether type, benzofurazane, naphtylurea, di- and tri-nitrobenzene, and a nitroxide radical. The biological evaluation of the obtained compounds included hydrophobicity (lipophobicity) assay, total antioxidant and microbiological activity tests.
    Comptes Rendus Chimie 05/2013; 16(7):665-671. · 1.92 Impact Factor
  • Alina Holban, Stephan Heeb, Mariana Carmen Chifiriuc, Veronica Lazar, Paul Williams
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    ABSTRACT: Bacteria are able to recognize and respond to various molecules produced by the host in stressful situations. Although there is a growing interest on deciphering pathogen-host communication during infection and other stressful situations, there is little information on the impact of catecholamine stress hormones on the opportunistic pathogen Pseudomonas aeruginosa. The aim of this study was to investigate the impact of the catecholamine neurohormone noradrenaline (NA) on the growth, swarming motility and expression of key P.aeruginosa quorum sensing (QS) genes in vitro using both phenotypic and reporter gene fusion approaches.
    23rd ECCMID, Berlin; 04/2013

Publication Stats

231 Citations
113.18 Total Impact Points

Institutions

  • 2008–2014
    • University of Bucharest
      • Faculty of Biology
      Bucureşti, Bucureşti, Romania
  • 2012–2013
    • Polytechnic University of Bucharest
      • • Department of Science and Engineering of Oxide Materials and Nanomaterials
      • • Faculty of Applied Chemistry and Materials Science
      Bucharest, Bucuresti, Romania
    • The National Institute of Materials Physics
      • Laboratory of Multifunctional Materials and Structures
      Măgurele, Romania
  • 2010–2013
    • Carol Davila University of Medicine and Pharmacy
      • Faculty of Pharmacy
      Bucureşti, Bucureşti, Romania
  • 2009
    • Institutul Clinic Fundeni
      Bucureşti, Bucureşti, Romania
  • 2007
    • Cantacuzino Institute
      Bucureşti, Bucureşti, Romania