Irina Codita - Academia.edu (original) (raw)
Papers by Irina Codita
PubMed, Jan 6, 2016
Staphylococcus aureus (S. aureus) is a major cause of hospital-acquired (HA-SA) and community-acq... more Staphylococcus aureus (S. aureus) is a major cause of hospital-acquired (HA-SA) and community-acquired (CA-SA) infections worldwide. It is isolated from many human body sites, from animals and from foods, from the environment. Pathogenesis is caused by many virulence factors and antibiotic resistance. The host immune system tries to keep under control this pathogen, but many virulence factors produced by this under the regulatory systems control attack the immune system. The epidemiology of S. aureus is in permanent dynamic and is changing quickly. Therefore, it is necessary to monitor infections, to find new effective molecules and vaccines against this pathogen. In order to reduce this problem which affects public health as a whole, the search for new therapeutic alternatives must be associated with policies to control antibiotic use. Community-acquired and hospital-acquired infections epidemiological surveillance guided by scientific studies should be constant habits among health professionals and hospitals.
Autoimmune diseases etiology is hard to be determined. It implies the interrelation between genet... more Autoimmune diseases etiology is hard to be determined. It implies the interrelation between genetic and environmental factors. Reactive arthritis is an autoimmune disease that develops in response to an infection, usually with Chlamydia spp., Salmonella spp., Yersinia spp., Shigella spp., Campylobacter spp. Postinfection persistence of bacterial antigens (DNA, RNA, lipopolysaccharide) was demonstrated. Nevertheless, the complete mechanism of reactive arthritis etiopathogenesis remains to be clarified. It seems that gut microbiota plays a key role, its perturbation leading to increased intestinal permeability which results in translocation of the microbial antigens to the joints. Uncovering the mechanisms underlying the pathogenesis of the disease would help conceive novel therapeutic targets for the treatment of reactive arthritis.
Romanian Biotechnological Letters, 2019
The aim of this study was to characterise S. aureus strains from community onset Skin and Soft Ti... more The aim of this study was to characterise S. aureus strains from community onset Skin and Soft Tissues Infections (SSTIs) in two locations: Cantacuzino Institute (A strains) and Elias University Emergency Hospital (B strains), in the January 2014-August 2015 interval. All strains from the A location, and three strains from the B location have been isolated from recurrent staphylococcal infections. Materials: Seventyone S. aureus strains (A-42; B-29) have been collected from different types of SSTIs. Methods: PCR was used to identify virulence factors and AMR genes, disc diffusion and broth microdilution for AST, SCCmec and spa typing. Results and discussions. MRSA rate of 59.52% and 17.24% among A and B strains, respectively. Twenty of A strains and one of B strains were positive for lukS/F-PV genes; two A strains and four B strains were positive for tst1 gene. Panton-Valentine Leukocidin was present in all t008 and t044 strains. Four strains from A location and seven strains from B location were positive for Staphylococcal Enterotoxins. Three new spa-types were discovered. Conclusions. The most prevalent S. aureus clone in community onset SSTIs was spa type t127, followed by spa types t044, t008. Molecular characterisation of S. aureus strains may predict the tendency to recurrence of stapylococcal SSTIs.
Roumanian Archives of Microbiology and Immunology, May 3, 2014
Revista Romana de Medicina de Laborator, 2018
A prolonged outbreak of Healthcare-Associated Infections (HCAIs) evolved since December 2013, in ... more A prolonged outbreak of Healthcare-Associated Infections (HCAIs) evolved since December 2013, in a Newborns Unit from Hospital A, sited in the North-Eastern development region, Romania. A first cluster consisted of 19 cases, of which 18 infections in newborns and 1 labour infectious complication in a mother. Except for five cases declared and treated in the Neonatology Unit as hospital-acquired infections, the other cases were discharged and further required rehospitalisation and treatment. Eight of these innitialy discharged cases were readmitted to the Pediatric Surgery Unit and two others to the Pediatrics Unit of Hospital B, while three others were readmitted to three hospitals: one to the Pediatrics Unit of Hospital C, and other two to Hospital A and Hospital D, respectively. The mother with the labour infectious complication was readmitted to the Gynecology Unit of the Hospital A. A number of fifteen Staphylococcus aureus (S. aureus) strains isolated from the HCAI first episod...
Annals of the Academy of Romanian Scientists Series on Biological Sciences, 2021
Periodontal disease is a plaque microbiome related, that disrupts the homeostasis of the periodon... more Periodontal disease is a plaque microbiome related, that disrupts the homeostasis of the periodontium and the supporting alveolar bone. The aim of this brief review is to offer the reader the theoretical background of the current status of immunomodulatory therapies used in the management of periodontitis using staphylococcal antigens. In response to the hypothesis that Staphylococcus aureus helps ameliorate periodontal disease, the National Development Institute for Microbiology and Immunology Cantacuzino, Romania, produced the "Staphylococcal D Vaccine". The proponents of this product claim that Staphylococcal Vaccine is highly efficacious in the management of periodontitis particularly in patients with clinical signs of edema, papillary hypertrophy, bleeding on probing, and pockets > 7-8 mm in depth. Although the mechanism of action of staphylococcal antigen vaccines is elusive as yet, it appears that such vaccination leads to a dramatic reduction in periodontal inflammation, and periodontal pocket depth. However, more research is required to obtain conclusive data on the subject.
Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie
Histological, histochemical and electronmicroscopic investigations were carried out on gum biopsi... more Histological, histochemical and electronmicroscopic investigations were carried out on gum biopsies taken from cases with chronic marginal periodontal disease before and after the treatment with staphylococcic vaccine, thus, morphopathologically proving the findings of Gafar et al. (1985) and of Georgescu et al. (1973; 1974; 1975; 1979; 1995). Before treatment, gum lesions were severe, consisting in an abundance of polymorphic inflammatory infiltrates in the chorion along with oedema and disorganised connective fibres, atrophies and ulceration of the mucosa, purulent deposits at the surface with bacteria and fungi. After the treatment with the staphylococcic vaccine, an epithelial regeneration was seen together with the absence of the chronic inflammation. The intensely fibroparius granulated tissue was also noted, in all cases observing abundant connective fibres, accounting for good results after treatment, notably the firmness of the tooth fitting.
Revista de chirurgie, oncologie, radiologie, o. r. l., oftalmologie, stomatologie. Seria: Stomatologie
... [The role of the staphylococcal infectious-allergic process in chronic marginal periodontal d... more ... [The role of the staphylococcal infectious-allergic process in chronic marginal periodontal diseases, and specific therapeutic possibilities with staphylococcal vaccine. Preliminary note]. [Article in Romanian]. Gafar M, Georgescu T, Dumitriu H, Codiţă I, Neguţ M. ...
Bacteriologia, virusologia, parazitologia, epidemiologia (Bucharest, Romania : 1990)
Bacteriologia, virusologia, parazitologia, epidemiologia (Bucharest, Romania : 1990)
The authors tested for "slime" elaboration 48 S. epidermidis s.s. strains; 24 of these ... more The authors tested for "slime" elaboration 48 S. epidermidis s.s. strains; 24 of these strains were isolated from bloodstream infections and 24 from resident cutaneous microbiota. The semiquantitative method of Christensen was used for testing "slime" elaboration. The predictive value of the positive test of "slime" elaboration was 92% in this study.
PLoS ONE, Nov 23, 2015
Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Functional Nanostructured Interfaces for Environmental and Biomedical Applications, 2019
Among metal oxides, TiO2 represents one of the most studied materials with enormous potential for... more Among metal oxides, TiO2 represents one of the most studied materials with enormous potential for biological defense and in health-care-associated infection prevention applications due to its germicidal action. This chapter will focus and synthesize the recent advances on TiO2-based nanostructured materials with germicidal properties and their applications.
Molecules
Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely towa... more Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely toward not only the efficient design of innovative nanomaterials or nanostructures, but to the improvement of their functionality, we benefit from an important asset in the battle against pathogenic illnesses. Herein, we report a versatile biocompatible plasmonic nanoplatform based on a Whatman paper incorporating positively-charged gold nanospherical particles via the immersion approach. The morphological characterization of the as-engineered-plasmonic paper was examined by SEM (scanning electron microscopy) and HRTEM (high-resolution transmission electron microscopy) investigations, while its surface chemical modification with a synthetic polypeptide, specifically RRWHRWWRR-NH2 (P2), was proved by monitoring the plasmonic response of loaded gold nanospheres and the emission signal of P2 via fluorescence spectroscopy. The as-functionalized plasmonic paper is non-cytotoxic towards BJ fibrobl...
Scientific Reports
In recent years methicillin-resistant Staphylococcus aureus has posed a challenge in treating ski... more In recent years methicillin-resistant Staphylococcus aureus has posed a challenge in treating skin and soft tissue infections. Finding new antimicrobial agents has therefore become imperative. We evaluated the in vitro antimicrobial activity of a synthetic peptide, P6, against multidrug resistant clinical strains of Staphylococcus aureus isolated from skin and soft tissue infections. The P6 antimicrobial effect was evaluated in vitro by determining MIC/MBC, the ratio of live/dead cells and the effects induced at membrane level. The therapeutic efficiency was determined against human skin cells. P6 inhibited growth for all strains between 8 and 16 mg/L and killed all bacterial strains at 16 mg/L. The therapeutic potential was found to be 30 and 15 in the presence of BSA. We showed that P6 localizes at membrane level, where it acts slowly, by depolarizing it and affecting its integrity. P6 can be considered a good candidate for use as an antimicrobial agent in topical applications.
Experimental and Therapeutic Medicine
Spondyloarthritis (SpA) is a group of associated chronic systemic inflammatory immune-mediated rh... more Spondyloarthritis (SpA) is a group of associated chronic systemic inflammatory immune-mediated rheumatic diseases affecting axial and peripheral joints and entheses. The aim of the present study was to identify what parameters are useful to determine in order to better understand the correlation between the disease activity/severity and the microbiological results/immune status against intestinal and/or urogenital pathogens. Microorganisms known to trigger SpA, including Klebsiella spp., Yersinia spp., Salmonella spp., Campylobacter spp. and Chlamydia spp., were analyzed in various specimens (stool, urine, synovial fluid and serum) collected from 27 randomly selected SpA patients and 26 healthy controls using a combined direct and indirect approach relying on conventional culture technique and nucleic acid-based assays together with serological testing by ELISA. Although Escherichia coli derived from phylogroup A prevailed in the gut microflora of the patients and controls, differences were observed regarding the representatives of the other phylogroups with a higher prevalence of E.coli members of phylogenetic group B1 in the stool specimens of patients. Antibodies against the targeted species were detected in SpA patients and controls, and the serological profiles of the former were more diverse and complex. In conclusion, the detection of anti-bacterial antibodies combined with other specific laboratory investigations should be more extensively used to monitor SpA patients in association with their symptoms and in order to determine and administer more effective therapeutics.
Polymers
In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a c... more In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a candidate for food packaging applications is proposed. Poly(3-hydroxybutyrate) was modified by bacterial cellulose nanofibers (BC) using a melt compounding technique and by plasma treatment or zinc oxide (ZnO) nanoparticle plasma coating for better properties and antibacterial activity. Plasma treatment preserved the thermal stability, crystallinity and melting behavior of PHB‒BC nanocomposites, regardless of the amount of BC nanofibers. However, a remarkable increase of stiffness and strength and an increase of the antibacterial activity were noted. After the plasma treatment, the storage modulus of PHB having 2 wt % BC increases by 19% at room temperature and by 43% at 100 °C. The tensile strength increases as well by 21%. In addition, plasma treatment also inhibits the growth of Staphylococcus aureus and Escherichia coli by 44% and 63%, respectively. The ZnO plasma coating led to impor...
The Journal of antimicrobial chemotherapy, Jan 7, 2018
We present the results of two European external quality assessments (EQAs) conducted in 2014 and ... more We present the results of two European external quality assessments (EQAs) conducted in 2014 and 2016 under the auspices of the Study Group on Staphylococci and Staphylococcal Infections of ESCMID. The objective was to assess the performance of participating centres in characterizing Staphylococcus aureus using their standard in-house phenotypic and genotypic protocols. A total of 11 well-characterized blindly coded S. aureus (n = 9), Staphylococcus argenteus (n = 1) and Staphylococcus capitis (n = 1) strains were distributed to participants for analysis. Species identification, MIC determination, antimicrobial susceptibility testing, antimicrobial resistance and toxin gene detection and molecular typing including spa typing, SCCmec typing and MLST were performed. Thirteen laboratories from 12 European countries participated in one EQA or both EQAs. Despite considerable diversity in the methods employed, good concordance (90%-100%) with expected results was obtained. Discrepancies w...
Microbial Pathogenesis, 2016
Despite their commensal status, staphylococci can become problematic pathogens expressing multipl... more Despite their commensal status, staphylococci can become problematic pathogens expressing multiple and redundant virulence factors. This study aimed to evaluate aggressiveness markers comparatively in staphylococcal strains isolated from severe infections versus asymptomatic carriage in order to identify clinically relevant bacterial traits that could easily be detected in clinical practice and could be suggestive for particular host-pathogen interactions such as cyto-adhesion or biofilm formation, ultimately orienting the clinical decision-making process. We have used in vitro phenotypic methods to assess adhesion to and invasion of eukaryotic cells, biofilm development, and expression of soluble virulence factors in 92 Staphylococcus spp. strains. The adhesion index, invasion capacity, biofilm formation and expression of soluble factors did not differ significantly between clinical and commensal strains. The major bacterial traits we found to be significantly more prevalent in clinical staphylococci were the aggregative adhesion pattern (P = 0.012), cluster adhesion (P = 0.001) and tetrad morphology (P = 0.018). The aggregative adhesion pattern was correlated with higher cyto-adhesion (P < 0.001), higher invasion capacity (P = 0.003) and lower Carmeli scores (P = 0.002). Three major bacterial traits, namely tetrad morphology, aggregative adhesion pattern, and resistance to methicillin (acronym: TAM), can be used to compute an aggressiveness score (SAS) predictive of the staphylococcal strain's virulence and capacity to initiate and develop a biofilm-driven chronic infectious process versus a fulminant acute infection, in a susceptible host.
FEMS microbiology letters, Jan 11, 2016
The increasing burden of invasive biofilm-related staphylococcal infections led to a dire need fo... more The increasing burden of invasive biofilm-related staphylococcal infections led to a dire need for new agents to prevent biofilm formation. Bacteriophages may hypothetically alter biofilm through several mechanisms, including induction of depolymerizing enzymes, and lysis of persistent bacteria. We have assessed the influence of commercially-available bacteriophage cocktails on Staphylococcus spp. clinical strains viability and biofilm formation. We analyzed 83 staphylococcal strains from patients consecutively admitted to a Romanian infection reference center from October 2014 through May 2015; the strains were characterized by phenotypic and genetic tools for their resistance and virulence features and for their phyliation. Experiments were performed in triplicate. Methicillin-susceptible strains were significantly more susceptible to all tested phages - 1.7-fold higher susceptibility for PYO, 1.4-fold for INTESTI, 2.9-fold for PHAGYO, 2.7-fold for PHAGESTI and 3.9 for STAPHYLOCOC...
Revista Romana de Medicina de Laborator, 2015
In March 2012, a food poisoning outbreak was reported in a Romanian county, with a total number o... more In March 2012, a food poisoning outbreak was reported in a Romanian county, with a total number of 30 children affected. The symptoms (vomiting, diarrhea and abdominal pain), with onset within 1-2 hours after the ingestion of a particular food (milk), suggested a possible staphylococcal aetiology. An outbreak investigation was carried out, in accordance with the national surveillance methodology and 25 samples: stool (n=9), vomit (n=5), nasal swabs (n=9), and milk (n=2) were collected from the affected children, food handlers and suspected food. All isolated strains were sent to the Reference Centre for Staphylococci within the “Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, Bucharest, Romania, for confirmation and further analysis. The aim of this study was to increase the reference laboratory capacity to confirm staphylococcal food poisoning (SFP) outbreak by defining the molecular basis of toxicity of Staphylococcus aureus (S. aureus) iso...
PubMed, Jan 6, 2016
Staphylococcus aureus (S. aureus) is a major cause of hospital-acquired (HA-SA) and community-acq... more Staphylococcus aureus (S. aureus) is a major cause of hospital-acquired (HA-SA) and community-acquired (CA-SA) infections worldwide. It is isolated from many human body sites, from animals and from foods, from the environment. Pathogenesis is caused by many virulence factors and antibiotic resistance. The host immune system tries to keep under control this pathogen, but many virulence factors produced by this under the regulatory systems control attack the immune system. The epidemiology of S. aureus is in permanent dynamic and is changing quickly. Therefore, it is necessary to monitor infections, to find new effective molecules and vaccines against this pathogen. In order to reduce this problem which affects public health as a whole, the search for new therapeutic alternatives must be associated with policies to control antibiotic use. Community-acquired and hospital-acquired infections epidemiological surveillance guided by scientific studies should be constant habits among health professionals and hospitals.
Autoimmune diseases etiology is hard to be determined. It implies the interrelation between genet... more Autoimmune diseases etiology is hard to be determined. It implies the interrelation between genetic and environmental factors. Reactive arthritis is an autoimmune disease that develops in response to an infection, usually with Chlamydia spp., Salmonella spp., Yersinia spp., Shigella spp., Campylobacter spp. Postinfection persistence of bacterial antigens (DNA, RNA, lipopolysaccharide) was demonstrated. Nevertheless, the complete mechanism of reactive arthritis etiopathogenesis remains to be clarified. It seems that gut microbiota plays a key role, its perturbation leading to increased intestinal permeability which results in translocation of the microbial antigens to the joints. Uncovering the mechanisms underlying the pathogenesis of the disease would help conceive novel therapeutic targets for the treatment of reactive arthritis.
Romanian Biotechnological Letters, 2019
The aim of this study was to characterise S. aureus strains from community onset Skin and Soft Ti... more The aim of this study was to characterise S. aureus strains from community onset Skin and Soft Tissues Infections (SSTIs) in two locations: Cantacuzino Institute (A strains) and Elias University Emergency Hospital (B strains), in the January 2014-August 2015 interval. All strains from the A location, and three strains from the B location have been isolated from recurrent staphylococcal infections. Materials: Seventyone S. aureus strains (A-42; B-29) have been collected from different types of SSTIs. Methods: PCR was used to identify virulence factors and AMR genes, disc diffusion and broth microdilution for AST, SCCmec and spa typing. Results and discussions. MRSA rate of 59.52% and 17.24% among A and B strains, respectively. Twenty of A strains and one of B strains were positive for lukS/F-PV genes; two A strains and four B strains were positive for tst1 gene. Panton-Valentine Leukocidin was present in all t008 and t044 strains. Four strains from A location and seven strains from B location were positive for Staphylococcal Enterotoxins. Three new spa-types were discovered. Conclusions. The most prevalent S. aureus clone in community onset SSTIs was spa type t127, followed by spa types t044, t008. Molecular characterisation of S. aureus strains may predict the tendency to recurrence of stapylococcal SSTIs.
Roumanian Archives of Microbiology and Immunology, May 3, 2014
Revista Romana de Medicina de Laborator, 2018
A prolonged outbreak of Healthcare-Associated Infections (HCAIs) evolved since December 2013, in ... more A prolonged outbreak of Healthcare-Associated Infections (HCAIs) evolved since December 2013, in a Newborns Unit from Hospital A, sited in the North-Eastern development region, Romania. A first cluster consisted of 19 cases, of which 18 infections in newborns and 1 labour infectious complication in a mother. Except for five cases declared and treated in the Neonatology Unit as hospital-acquired infections, the other cases were discharged and further required rehospitalisation and treatment. Eight of these innitialy discharged cases were readmitted to the Pediatric Surgery Unit and two others to the Pediatrics Unit of Hospital B, while three others were readmitted to three hospitals: one to the Pediatrics Unit of Hospital C, and other two to Hospital A and Hospital D, respectively. The mother with the labour infectious complication was readmitted to the Gynecology Unit of the Hospital A. A number of fifteen Staphylococcus aureus (S. aureus) strains isolated from the HCAI first episod...
Annals of the Academy of Romanian Scientists Series on Biological Sciences, 2021
Periodontal disease is a plaque microbiome related, that disrupts the homeostasis of the periodon... more Periodontal disease is a plaque microbiome related, that disrupts the homeostasis of the periodontium and the supporting alveolar bone. The aim of this brief review is to offer the reader the theoretical background of the current status of immunomodulatory therapies used in the management of periodontitis using staphylococcal antigens. In response to the hypothesis that Staphylococcus aureus helps ameliorate periodontal disease, the National Development Institute for Microbiology and Immunology Cantacuzino, Romania, produced the "Staphylococcal D Vaccine". The proponents of this product claim that Staphylococcal Vaccine is highly efficacious in the management of periodontitis particularly in patients with clinical signs of edema, papillary hypertrophy, bleeding on probing, and pockets > 7-8 mm in depth. Although the mechanism of action of staphylococcal antigen vaccines is elusive as yet, it appears that such vaccination leads to a dramatic reduction in periodontal inflammation, and periodontal pocket depth. However, more research is required to obtain conclusive data on the subject.
Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie
Histological, histochemical and electronmicroscopic investigations were carried out on gum biopsi... more Histological, histochemical and electronmicroscopic investigations were carried out on gum biopsies taken from cases with chronic marginal periodontal disease before and after the treatment with staphylococcic vaccine, thus, morphopathologically proving the findings of Gafar et al. (1985) and of Georgescu et al. (1973; 1974; 1975; 1979; 1995). Before treatment, gum lesions were severe, consisting in an abundance of polymorphic inflammatory infiltrates in the chorion along with oedema and disorganised connective fibres, atrophies and ulceration of the mucosa, purulent deposits at the surface with bacteria and fungi. After the treatment with the staphylococcic vaccine, an epithelial regeneration was seen together with the absence of the chronic inflammation. The intensely fibroparius granulated tissue was also noted, in all cases observing abundant connective fibres, accounting for good results after treatment, notably the firmness of the tooth fitting.
Revista de chirurgie, oncologie, radiologie, o. r. l., oftalmologie, stomatologie. Seria: Stomatologie
... [The role of the staphylococcal infectious-allergic process in chronic marginal periodontal d... more ... [The role of the staphylococcal infectious-allergic process in chronic marginal periodontal diseases, and specific therapeutic possibilities with staphylococcal vaccine. Preliminary note]. [Article in Romanian]. Gafar M, Georgescu T, Dumitriu H, Codiţă I, Neguţ M. ...
Bacteriologia, virusologia, parazitologia, epidemiologia (Bucharest, Romania : 1990)
Bacteriologia, virusologia, parazitologia, epidemiologia (Bucharest, Romania : 1990)
The authors tested for "slime" elaboration 48 S. epidermidis s.s. strains; 24 of these ... more The authors tested for "slime" elaboration 48 S. epidermidis s.s. strains; 24 of these strains were isolated from bloodstream infections and 24 from resident cutaneous microbiota. The semiquantitative method of Christensen was used for testing "slime" elaboration. The predictive value of the positive test of "slime" elaboration was 92% in this study.
PLoS ONE, Nov 23, 2015
Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Functional Nanostructured Interfaces for Environmental and Biomedical Applications, 2019
Among metal oxides, TiO2 represents one of the most studied materials with enormous potential for... more Among metal oxides, TiO2 represents one of the most studied materials with enormous potential for biological defense and in health-care-associated infection prevention applications due to its germicidal action. This chapter will focus and synthesize the recent advances on TiO2-based nanostructured materials with germicidal properties and their applications.
Molecules
Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely towa... more Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely toward not only the efficient design of innovative nanomaterials or nanostructures, but to the improvement of their functionality, we benefit from an important asset in the battle against pathogenic illnesses. Herein, we report a versatile biocompatible plasmonic nanoplatform based on a Whatman paper incorporating positively-charged gold nanospherical particles via the immersion approach. The morphological characterization of the as-engineered-plasmonic paper was examined by SEM (scanning electron microscopy) and HRTEM (high-resolution transmission electron microscopy) investigations, while its surface chemical modification with a synthetic polypeptide, specifically RRWHRWWRR-NH2 (P2), was proved by monitoring the plasmonic response of loaded gold nanospheres and the emission signal of P2 via fluorescence spectroscopy. The as-functionalized plasmonic paper is non-cytotoxic towards BJ fibrobl...
Scientific Reports
In recent years methicillin-resistant Staphylococcus aureus has posed a challenge in treating ski... more In recent years methicillin-resistant Staphylococcus aureus has posed a challenge in treating skin and soft tissue infections. Finding new antimicrobial agents has therefore become imperative. We evaluated the in vitro antimicrobial activity of a synthetic peptide, P6, against multidrug resistant clinical strains of Staphylococcus aureus isolated from skin and soft tissue infections. The P6 antimicrobial effect was evaluated in vitro by determining MIC/MBC, the ratio of live/dead cells and the effects induced at membrane level. The therapeutic efficiency was determined against human skin cells. P6 inhibited growth for all strains between 8 and 16 mg/L and killed all bacterial strains at 16 mg/L. The therapeutic potential was found to be 30 and 15 in the presence of BSA. We showed that P6 localizes at membrane level, where it acts slowly, by depolarizing it and affecting its integrity. P6 can be considered a good candidate for use as an antimicrobial agent in topical applications.
Experimental and Therapeutic Medicine
Spondyloarthritis (SpA) is a group of associated chronic systemic inflammatory immune-mediated rh... more Spondyloarthritis (SpA) is a group of associated chronic systemic inflammatory immune-mediated rheumatic diseases affecting axial and peripheral joints and entheses. The aim of the present study was to identify what parameters are useful to determine in order to better understand the correlation between the disease activity/severity and the microbiological results/immune status against intestinal and/or urogenital pathogens. Microorganisms known to trigger SpA, including Klebsiella spp., Yersinia spp., Salmonella spp., Campylobacter spp. and Chlamydia spp., were analyzed in various specimens (stool, urine, synovial fluid and serum) collected from 27 randomly selected SpA patients and 26 healthy controls using a combined direct and indirect approach relying on conventional culture technique and nucleic acid-based assays together with serological testing by ELISA. Although Escherichia coli derived from phylogroup A prevailed in the gut microflora of the patients and controls, differences were observed regarding the representatives of the other phylogroups with a higher prevalence of E.coli members of phylogenetic group B1 in the stool specimens of patients. Antibodies against the targeted species were detected in SpA patients and controls, and the serological profiles of the former were more diverse and complex. In conclusion, the detection of anti-bacterial antibodies combined with other specific laboratory investigations should be more extensively used to monitor SpA patients in association with their symptoms and in order to determine and administer more effective therapeutics.
Polymers
In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a c... more In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a candidate for food packaging applications is proposed. Poly(3-hydroxybutyrate) was modified by bacterial cellulose nanofibers (BC) using a melt compounding technique and by plasma treatment or zinc oxide (ZnO) nanoparticle plasma coating for better properties and antibacterial activity. Plasma treatment preserved the thermal stability, crystallinity and melting behavior of PHB‒BC nanocomposites, regardless of the amount of BC nanofibers. However, a remarkable increase of stiffness and strength and an increase of the antibacterial activity were noted. After the plasma treatment, the storage modulus of PHB having 2 wt % BC increases by 19% at room temperature and by 43% at 100 °C. The tensile strength increases as well by 21%. In addition, plasma treatment also inhibits the growth of Staphylococcus aureus and Escherichia coli by 44% and 63%, respectively. The ZnO plasma coating led to impor...
The Journal of antimicrobial chemotherapy, Jan 7, 2018
We present the results of two European external quality assessments (EQAs) conducted in 2014 and ... more We present the results of two European external quality assessments (EQAs) conducted in 2014 and 2016 under the auspices of the Study Group on Staphylococci and Staphylococcal Infections of ESCMID. The objective was to assess the performance of participating centres in characterizing Staphylococcus aureus using their standard in-house phenotypic and genotypic protocols. A total of 11 well-characterized blindly coded S. aureus (n = 9), Staphylococcus argenteus (n = 1) and Staphylococcus capitis (n = 1) strains were distributed to participants for analysis. Species identification, MIC determination, antimicrobial susceptibility testing, antimicrobial resistance and toxin gene detection and molecular typing including spa typing, SCCmec typing and MLST were performed. Thirteen laboratories from 12 European countries participated in one EQA or both EQAs. Despite considerable diversity in the methods employed, good concordance (90%-100%) with expected results was obtained. Discrepancies w...
Microbial Pathogenesis, 2016
Despite their commensal status, staphylococci can become problematic pathogens expressing multipl... more Despite their commensal status, staphylococci can become problematic pathogens expressing multiple and redundant virulence factors. This study aimed to evaluate aggressiveness markers comparatively in staphylococcal strains isolated from severe infections versus asymptomatic carriage in order to identify clinically relevant bacterial traits that could easily be detected in clinical practice and could be suggestive for particular host-pathogen interactions such as cyto-adhesion or biofilm formation, ultimately orienting the clinical decision-making process. We have used in vitro phenotypic methods to assess adhesion to and invasion of eukaryotic cells, biofilm development, and expression of soluble virulence factors in 92 Staphylococcus spp. strains. The adhesion index, invasion capacity, biofilm formation and expression of soluble factors did not differ significantly between clinical and commensal strains. The major bacterial traits we found to be significantly more prevalent in clinical staphylococci were the aggregative adhesion pattern (P = 0.012), cluster adhesion (P = 0.001) and tetrad morphology (P = 0.018). The aggregative adhesion pattern was correlated with higher cyto-adhesion (P < 0.001), higher invasion capacity (P = 0.003) and lower Carmeli scores (P = 0.002). Three major bacterial traits, namely tetrad morphology, aggregative adhesion pattern, and resistance to methicillin (acronym: TAM), can be used to compute an aggressiveness score (SAS) predictive of the staphylococcal strain's virulence and capacity to initiate and develop a biofilm-driven chronic infectious process versus a fulminant acute infection, in a susceptible host.
FEMS microbiology letters, Jan 11, 2016
The increasing burden of invasive biofilm-related staphylococcal infections led to a dire need fo... more The increasing burden of invasive biofilm-related staphylococcal infections led to a dire need for new agents to prevent biofilm formation. Bacteriophages may hypothetically alter biofilm through several mechanisms, including induction of depolymerizing enzymes, and lysis of persistent bacteria. We have assessed the influence of commercially-available bacteriophage cocktails on Staphylococcus spp. clinical strains viability and biofilm formation. We analyzed 83 staphylococcal strains from patients consecutively admitted to a Romanian infection reference center from October 2014 through May 2015; the strains were characterized by phenotypic and genetic tools for their resistance and virulence features and for their phyliation. Experiments were performed in triplicate. Methicillin-susceptible strains were significantly more susceptible to all tested phages - 1.7-fold higher susceptibility for PYO, 1.4-fold for INTESTI, 2.9-fold for PHAGYO, 2.7-fold for PHAGESTI and 3.9 for STAPHYLOCOC...
Revista Romana de Medicina de Laborator, 2015
In March 2012, a food poisoning outbreak was reported in a Romanian county, with a total number o... more In March 2012, a food poisoning outbreak was reported in a Romanian county, with a total number of 30 children affected. The symptoms (vomiting, diarrhea and abdominal pain), with onset within 1-2 hours after the ingestion of a particular food (milk), suggested a possible staphylococcal aetiology. An outbreak investigation was carried out, in accordance with the national surveillance methodology and 25 samples: stool (n=9), vomit (n=5), nasal swabs (n=9), and milk (n=2) were collected from the affected children, food handlers and suspected food. All isolated strains were sent to the Reference Centre for Staphylococci within the “Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, Bucharest, Romania, for confirmation and further analysis. The aim of this study was to increase the reference laboratory capacity to confirm staphylococcal food poisoning (SFP) outbreak by defining the molecular basis of toxicity of Staphylococcus aureus (S. aureus) iso...