Mariana Carmen Chifiriuc

University of Bucharest, Bucureşti, Bucureşti, Romania

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Publications (140)167.99 Total impact

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    ABSTRACT: The spectacular progress of research in the nanotechnology field led to the achievement of important knowledge of materials at the atomic and molecular scale and the extent of the use of nanoparticles in the design of medical products, ecological processes, cosmetics and other biotechnological processes. Nanotechnology has become increasingly employed for medical applications and is particularly of great interest especially for developing new strategies to inhibit the activity of different microorganisms. The purpose of this review was to present the antimicrobial activity of metal cations in micro- and nanoparticulate forms and the dependence of this biological activity on shape, size and physico-chemical conditions.
    Current topics in medicinal chemistry 04/2015; · 3.45 Impact Factor
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    ABSTRACT: The majority of chronic infections are associated with mono- or polymicrobial biofilms, having a significant impact on the patients' quality of life and survival rates. Although the use of medical devices revolutionized health care services and significantly improved patient outcomes, it also led to complications associated with biofilms and to the emergence of multidrug resistant bacteria. Immunocompromised patients, institutionalized or hospitalized individuals, elderly people are at greater risk due to life-threatening septic complications, but immunocompetent individuals with predisposing genetic or acquired diseases can also be affected, almost any body part being able to shelter persistent biofilms. Moreover, chronic biofilm-related infections can lead to the occurrence of systemic diseases, as in the case of chronic periodontitis, linked to atherosclerosis, cardiovascular disease and diabetes. The more researchers discover, new unknown issues add up to the complexity of biofilm infections, in which microbial species establish relationships of cooperation and competition, and elaborate phenotypic differentiation into functional, adapted communities. Their interaction with the host's immune system or with therapeutic agents contributes to the complex puzzle that still misses a lot of pieces. In this comprehensive review we aimed to highlight the microbial composition, developmental stages, architecture and properties of medical biofilms, as well as the diagnostic tools used in the management of biofilm related infections. Also, we present recently acquired knowledge on the etiopathogenesis, diagnosis and treatment of four chronic diseases associated with biofilm development in tissues (chronic periodontitis, chronic lung infection in cystic fibrosis, chronic wounds) and artificial substrata (medical devices-related infections).
    Current topics in medicinal chemistry 04/2015; · 3.45 Impact Factor
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    ABSTRACT: At present, the use of dental implants is a very common practice as tooth loss is a frequent problem and can occur as a result of disease or trauma. An implant is usually made of biocompatible materials that do not cause rejection reactions and allow the implant union with the respective bone. To achieve this goal, the implant surface may have different structures and coatings, generally used to increase the adherence of the implant to the bone and to decrease the risk of the periimplantar inflammatory reactions. This review gives some insights of the metal based materials used for dental implants, their limits, improvement strategies as well as the pathophysiology, diagnosis, treatment and prevention of periimplantary diseases.
    Current topics in medicinal chemistry 04/2015; · 3.45 Impact Factor
  • Alina-Maria Holban, Mariana Carmen Chifiriuc, Veronica Lazar
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    ABSTRACT: Microbe-host signalling is now a well accepted concept and an intensively studied research field. Although some of the observed bacterial phenotypes are atributed to host-recognition and inter-kingdom signalling, most of them are not relying on a proved molecular mechanism. Recent progress revealed some recognition and signalling pathways for host molecules in bacterial cells, which try to explain their modulatory effect on growth and virulence. Since the current knowledge on the field is poor and debatable, the purpose of this paper is to review and discuss the research performed in order to elucidate the ways by which microbial cells recognize and decode the host molecules signals.
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    ABSTRACT: Objectives: The present study was designed to provide a snapshot on carbapenemase-producing Pseudomonas aeruginosa (n¼11) and Acinetobacter baumannii (n¼7) isolates in hospitalized patients (November 2011, January–March 2012) from two main hospitals in Bucharest, south Romania. Methods: Clonality among isolates was established by PFGE, MLST and Fourier transform infrared spectroscopy. Carbapenemases were screened by the Blue-Carba test, PCR and sequencing. Transferability of blaOXA-23 was tested by conjugation and plasmid typing (number, size and identity) was assessed by S1-PFGE, replicon typing, hybridization and PCR mapping. Results: All P. aeruginosa isolates carried chromosomally located blaVIM-2, associated with a common class 1 integron (aacA7-blaVIM-2) or an atypical configuration (aacA7-blaVIM-2-dfrB5-tniC). These isolates belonged to unusual lineages; mostly ST233 disseminated in one hospital unit, with ST364 and ST1074 also being detected. A. baumannii isolates carried blaOXA-23 in Tn2008, which was found truncating a TnaphA6 transposon located in a common 60 kb GR6 (aci6) pABKp1-like conjugative plasmid in highly related CC92 clones (ST437, ST764 and ST765), where CC stands for clonal complex. Conclusions: Our results show the spread of VIM-2-producing P. aeruginosa and OXA-23-producing A. baumannii clinical isolates in two hospitals from Bucharest and highlight a peculiar population structure in this Eastern European country. Also, we demonstrate the dissemination of a common and conjugative aci6 pABKp1-like plasmid scaffold in different A. baumannii clones and we report the first known identification of Tnaph6-carrying pACICU2-like plasmids in Europe.
    Journal of Antimicrobial Chemotherapy 01/2015; DOI:10.1093/jac/dku527 · 5.44 Impact Factor
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    ABSTRACT: The purpose of this study was the fabrication of functionalized anti-adherent surfaces based on the polyvinyl chloride (PVC) coated with 3-amino propyltrimethoxysilane (APTMS) by matrix assisted pulsed laser evaporation (MAPLE) in order to improve the resistance of PVC based prosthetic devices to microbial colonization. Infrared microscopy (IRM) investigations of APTMS thin films proved the compositional homogeneity of the prepared thin film. Scanning electron microscopy (SEM) micrographs revealed a granular morphology with microspheres harboring a diameter between 15 and 60 nm. The microbiological assays proved that MAPLE deposited APTMS films inhibited the adherence capacity and biofilm development of Pseudomonas aeruginosa and Staphylococcus aureus strains. Furthermore, this material proved to be highly biocompatible, allowing the normal growth and development of human endothelial cells. These traits highlight the fact that the fabricated APTMS thin films may be efficiently used for improving different surfaces of medical use, including prostheses and implantable devices.
    Applied Surface Science 01/2015; DOI:10.1016/j.apsusc.2015.01.080 · 2.54 Impact Factor
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    ABSTRACT: This study reports the effect of some essential oils (EOs) and of some of their major fractions on soluble virulence factors and quorum sensing (QS) gene expression profiles of 15 Staphylococcus aureus and Pseudomonas aeruginosa clinical strains. EOs were extracted from various angiosperm and gymnosperm vegetal taxons by hydrodistillation in a Neo-Clevenger-type apparatus and characterized by measuring the density and refractive index, as well as by gas chromatographic analysis. EOs and their major components proved to inhibit the phenotypic expression of six soluble virulence determinants (haemolysins, gelatinase, DN-ase, lipase, amylase, esculin hydrolysis) when used in sub-inhibitory concentrations, in both P. aeruginosa and S. aureus strains. EOs extracted from Salvia officinalis, Rosmarinus officinalis, Abies alba and Eugenia caryophyllata as well as some of their major compounds (limonene, eugenol and eucalyptol) inhibited QS genes expression in S. aureus, while in P. aeruginosa only E. caryophyllata EO proved to inhibit both las and rhl QS genes expression. Our results demonstrate that essential oils are efficient candidates for developing novel ecological antimicrobial strategies aiming to attenuate the pathogenicity and virulence of opportunistic pathogens isolated from severe infections.
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    ABSTRACT: We report the fabrication of biofunctionalized magnetite core/sodium lauryl sulfate shell/antibiotic adsorption-shell nanoparticles assembled thin coatings by matrix assisted pulsed laser evaporation for antibacterial drug-targeted delivery. Magnetite nanoparticles have been synthesized and subsequently characterized by transmission electron microscopy and x-ray diffraction. The obtained thin coatings have been investigated by FTIR and scanning electron microscope, and tested by in vitro biological assays, for their influence on in vitro bacterial biofilm development and cytotoxicity on human epidermoid carcinoma (HEp2) cells.
    Biofabrication 01/2015; 7(1):015014. DOI:10.1088/1758-5090/7/1/015014 · 4.30 Impact Factor
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    ABSTRACT: This study reports the synthesis of silver nanoparticles (Ag NPs) by the sodium borohydride reduction method and their embedding in a silica shell functionalized with several antibiotics (ampicillin, penicillin G and isoniazide). The characterization of the novel materials was made by UV-visible absorption spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, dynamic light scattering and thermal analysis. TEM micrographs revealed the formation of spherical nanoparticles with size ranging between 20 and 50 nm. The Ag NPs embedded in the silica network exhibited a good antimicrobial efficiency, comparable or even superior to that of antibiotic-containing formulations. This is the first report regarding the synergic antimicrobial effect of Ag NPs embedded in silica and ampicillin, both against planktonic cells and biofilms formed by P. aeruginosa and S. aureus, two of the most fearful resistant bugs. These results are demonstrating the great potential of these nanocomposites to be used in developing novel antimicrobial agents or improving the existent ones, by increasing their efficiency, extending their spectrum of activity and decreasing the probability to select resistance, by simultaneously targeting multiple targets in the microbial cells.
    Journal of Inorganic and Organometallic Polymers and Materials 01/2015; DOI:10.1007/s10904-015-0176-7 · 1.08 Impact Factor
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    ABSTRACT: The development of effective packaging materials is crucial, because food microorganisms determine economic and public health issues. The current paper describes some of the most recent findings in regards of food preservation through novel packaging methods, using biodegradable polymers, efficient antimicrobial agents and nanocomposites with improved mechanical and oxidation stability, increased biodegradability and barrier effect comparatively with conventional polymeric matrices.
    Current Pharmaceutical Biotechnology 12/2014; · 2.51 Impact Factor
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    ABSTRACT: Antimicrobial resistance is a growing threat for all clinical branches. This phenomenon poses important challenges in controlling infectious diseases. However, multidrug resistance is not the only issue, as bacteria that are otherwise susceptible to common antibiotics express other patterns for evading antibiotherapy, for example they can aggregate within a self-produced matrix to form biofilm. We intend to perform a prospective laboratory study of the germs isolated from different samples collected from patients admitted with infectious pathology in reference hospitals in Romania. We will perform antibiotic resistance testing as well as phage testing, both on solid and liquid growth medium, for Staphylococcus spp., Enterococcus spp., and Pseudomonas spp. We intend to collect data for 150 patients with different infections with these identified pathogens. Phage susceptibility testing will be performed using 5 types of strain-specific bacteriophage mixtures: PYO, INTESTI, STAPHYLOCOCCAL (Eliava BioPreparations, Tbilisi, Georgia), PHAGYO, PHAGESTI (JSC "Biochimpharm", Tbilisi, Georgia). For phage-susceptible strains, we will evaluate biofilm formation in the presence of phages, as well as phage effect on already formed biofilm. Through this study, we intend to provide the first set of results on bacteriophage-susceptibility of bacteria isolated from patients with hard to treat infections, from reference hospitals in Romania. By evaluating a large number of bacterial strains we aim to predict and project biofilm kinetics, while adding binary phage dilutions at key timepoints during biofilm formation. POSDRU/159/1.5/S/141531; Carol Davila University of Medicine and Pharmacy, Young Researchers Grant no. 28341/2013.
    12/2014; 4(4):92-6. DOI:10.11599/germs.2014.1062
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    ABSTRACT: Chronic wounds represent an important burden on the healthcare system, requiring frequent hospitalizations and expensive treatments. It is now recognized that a primary factor contributing to a non-healing trajectory and a low therapeutic response is the biofilm infection. The purpose of this study was to identify the bacterial isolates collected from chronic skin wounds of hospitalized patients and to evaluate their antimicrobial susceptibility profiles, virulence factors, as well as the ability to develop biofilms in vitro. A number of 44 wound samples were collected from 39 patients. The isolated strains belonged to seven different microbial species, i.e.: Staphylococcus aureus (32 strains), followed by Pseudomonas aeruginosa (4), Escherichia coli (3), Klebsiella pneumoniae (2), Proteus mirabilis (1), Citrobacter freundii (1), group G β-hemolytic streptococci (1). In comparison to the other isolates, P. aeruginosa strains exhibited the highest capacity to develop complex biofilm structures in vitro, followed by S. aureus, with insignificant differences between MRSA and non-methicillin resistant isolates. The Enterobacteriaceae strains expressed less virulent phenotypes, lower adherence to epithelial cells and biofilm forming capacity, but also significant resistance phenotypes with a potential of unfavorable epidemiological outcome. The isolation of MRSA, ESBL-producing microorganisms and multiple antibiotic resistant P. aeruginosa suggests the potential risk of nosocomial spread and the potential severe outcome in case of bacteremia and sepsis. This study represents an important step in elucidating the host-wound microbiome interaction, by describing various resistance and virulence threats of microorganisms colonizing and÷or infecting the chronic wounds. However, in order to establish a statistical relevant correlation, larger studies are needed.
    Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie 12/2014; 55(4):1401-8. · 0.72 Impact Factor
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    ABSTRACT: Biofilms formed by bacterial cells are associated with drastically enhanced resistance against most antimicrobial agents, contributing to the persistence and chronicization of the microbial infections and to therapy failure. The purpose of this study was to combine the unique properties of magnetic nanoparticles with the antimicrobial activity of three essential oils to obtain novel nanobiosystems that could be used as coatings for catheter pieces with an improved resistance to Staphylococcus aureus and Klebsiella pneumoniae clinical strains adherence and biofilm development. The essential oils of ylang ylang, patchouli and vanilla were stabilized by the interaction with iron oxide@C14 nanoparticles to be further used as coating agents for medical surfaces. Iron oxide@C14 was prepared by co-precipitation of Fe+2 and Fe+3 and myristic acid (C14) in basic medium. Vanilla essential oil loaded nanoparticles pelliculised on the catheter samples surface strongly inhibited both the initial adherence of S. aureus cells (quantified at 24 h) and the development of the mature biofilm quantified at 48 h. Patchouli and ylang-ylang essential oils inhibited mostly the initial adherence phase of S. aureus biofilm development. In the case of K. pneumoniae, all tested nanosystems exhibited similar efficiency, being active mostly against the adherence K. pneumoniae cells to the tested catheter specimens. The new nanobiosystems based on vanilla, patchouli and ylang-ylang essential oils could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with anti-adherence and anti-biofilm properties.
    Molecules 11/2014; 19(11):17943-17956. DOI:10.3390/molecules191117943 · 2.10 Impact Factor
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    ABSTRACT: New species of type MLCl2·nH2O (M:Ni, n = 4.5; M:Cu, n = 0 and M:Zn, n = 0; L: (4,5-11,12)-bisphenylen-1,3,6,8,10,13-hexaazacyclotetradecan-bis(pyrid-3-yl)methanone resulted by 1,2-phenylendiamine, nicotinamide and formaldehyde template condensation) were synthesised. The complex features have been assigned from microanalytical, IR, UV–Vis, 1H NMR and EPR spectra as well as magnetic data at room temperature. Simultaneous TG/DTA and TG/DSC/EGA measurements were performed in order to evidence the thermal decomposition pattern and the nature of the gaseous products formed in each step. Processes as water and chloride elimination as well as fragmentation and oxidative degradation of the organic ligand were observed during the thermal decomposition. The final product of decomposition was metal(II) oxide. The obtained complexes exhibited an improved antimicrobial activity in comparison with the ligand, both on planktonic and biofilm embedded cells, as well as a low cytotoxicity. The microbicidal and anti-biofilm activity of the complex (3) against the Gram-negative strains recommend it for the development of new antimicrobial solutions for these emerging multidrug-resistant bacteria causing life-threatening infectious diseases often untreatable with the existing antimicrobial agents. The assay on HEp-2 cells indicates a low cytotoxicity for all complexes. The plethysmometry assays indicate an anti-inflammatory activity for Cu(II) complex.
    Journal of Thermal Analysis and Calorimetry 11/2014; 118(2). DOI:10.1007/s10973-014-3857-5 · 2.21 Impact Factor
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    ABSTRACT: Although a great number of antibiotics are currently available, they are often rendered ineffective by the ability of microbial strains to develop genetic resistance and to grow in biofilms. Since many antimicrobial agents poorly penetrate biofilms, biofilm-associated infections often require high concentrations of antimicrobial agents for effective treatment. Among the various strategies that may be used to inhibit microbial biofilms, one strategy that has generated significant interest involves the use of bioactive surfaces that are resistant to microbial colonization. In this respect, we used matrix assisted pulsed laser evaporation (MAPLE) involving a pulsed KrF* excimer laser source (λ = 248 nm, τ = 25 ns, ν = 10 Hz) to obtain thin composite biopolymeric films containing natural (flavonoid) or synthetic (antibiotic) compounds as bioactive substances. Chemical composition and film structures were investigated by Fourier transform infrared spectroscopy and X-ray diffraction. Films morphology was studied by scanning electron microscopy and transmission electron microscopy. The antimicrobial assay of the microbial biofilms formed on these films was assessed by the viable cell counts method. The flavonoid-containing thin films showed increased resistance to microbial colonization, highlighting their potential to be used for the design of anti-biofilm surfaces.
    Applied Surface Science 11/2014; 336. DOI:10.1016/j.apsusc.2014.11.145 · 2.54 Impact Factor
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    ABSTRACT: Four coordination compounds of copper(II) were synthesised and characterised in solid state by elemental analysis, infrared, electronic and EPR spectroscopy, as well as by thermal analysis (TG/DTA). The complexes were formulated on the basis of experimental data as: [Cu(BzIm)(2)(H2O)]center dot H2O (1), [Cu-2(Acr)(4)(HBzIm)(2)] (2), [Cu(Acr)(2)(HBzIm)(2)] (3) and [Cu(Acr)(2)(HBzIm)(2)(H2O)]center dot H2O (4). IR data are in accordance with the unidentate nature of benzimidazole, in complexes (2), (3) and (4), and bridge bidentate nature of benzimidazole, in complex (1), while acrylato acts as uni- or bridge/chelate ligand. The electronic spectra display the characteristic pattern of square planar, square pyramidal, or octahedral stereochemistry, also confirmed by EPR spectra. Thermal decomposition evidenced several well-defined steps as dehydration of complexes (1) and (4), benzimidazole molecule releases for all complexes and acrylate decomposition in carbonate for complexes (3) and (4). In all four cases, the final residue after thermal treatment in air flow is copper(II) oxide, formed during the decomposition steps for complexes (3) and (4), and, respectively, after the oxidation of the metallic copper for complexes (1) and (2). Antimicrobial activities of the complexes have been determined by in vitro assays, against various Gram-negative and Gram-positive bacterial and fungal strains. Copper(II) complexes were also evaluated for their cytotoxicity on eukaryotic cells.
    Journal of Thermal Analysis and Calorimetry 11/2014; 118(2):1119-1133. DOI:10.1007/s10973-014-3745-z · 2.21 Impact Factor
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    ABSTRACT: Abstract Heat shock proteins (HSP) represent important antigenic targets for the immune response, playing an important role in the pathology and infectious diseases control. The purpose of this work was to investigate the levels of HSP60 and HSP70 specific antibodies in the bloodstream of patients with different bacterial infections and cancer, in order to evaluate their potential role as diagnosis markers of different infectious diseases. Detection of specific anti-HSP 60 and HSP 70 serum levels was performed by ELISA. Statistical analysis of data by multivariate logistic regression was performed using GraphPadPrism software and statistical tests based on chi-square and Student t-test. High levels of anti-HSP60 were found in patients with localized infections, while the levels of anti- HSP70 were higher in the group with generalized infections. The serum levels of both anti-HSP 60 and anti-HSP70 were significantly increased in patients with Gram-negative bacterial infections, as compared with patients harbouring infections produced by Gram-positive and fungal strains, demonstrating their potential use as additional diagnosis and prognosis markers in infections with this etiology.
    Virulence 10/2014; 5(8). DOI:10.4161/21505594.2014.973800 · 3.32 Impact Factor
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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 09/2014; 25. DOI:10.3402/mehd.v25.23239
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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. DOI:10.3390/molecules190812011 · 2.10 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.

Publication Stats

404 Citations
167.99 Total Impact Points

Institutions

  • 2008–2015
    • University of Bucharest
      • • Faculty of Biology
      • • Department of Botany and Microbiology
      Bucureşti, Bucureşti, Romania
    • Institutul National de Cercetari Economice (INCE)
      Bucureşti, Hunedoara, Romania
  • 2010–2011
    • Carol Davila University of Medicine and Pharmacy
      • Facultatea de Farmacie
      Bucharest, Bucuresti, Romania
  • 2009
    • Institutul Clinic Fundeni
      Bucureşti, Bucureşti, Romania
  • 2007
    • Cantacuzino Institute
      Bucureşti, Bucureşti, Romania