Vancomycin-resistant enterococci among clinical isolates from north-west Iran: identification of therapeutic surrogates.
ABSTRACT Global emergence and dissemination of vancomycin resistance among enterococci is a serious concern especially in developing countries, requiring progressive research efforts. Present investigation was carried out on clinical isolates of enterococci obtained from three tertiary hospitals located in northwest of Iran. Multiplex PCR was performed on 220 enterococcal isolates for the presence of vanA, vanB, genus - species specific targets. Subsequently, alternative therapeutic options were evaluated for vancomycin resistant enterococci (VRE) strains. From isolated enterococci, 152 (69.1%) and 68 (30.9%) were E. faecalis and E. faecium, respectively. Of 48 VRE strains detected genotypically, vanA genotype was the predominant and three strains were found to possess vanB genes. One hundred and thirty three isolates (60.45%) revealed high level resistance to gentamicin. Amongst alternative agents, resistance towards quinipristin/dalfopristin was distinctly revealed by VRE isolates while, all were found sensitive to linezolid and except one strain to daptomycin, rendering latter antibiotics better therapeutic options. Clinicians and microbiologists should thus, be aware of the increasing prevalence of VRE and alternative agents should be evaluated against them.
Full-textDOI: · Available from: Yaeghob Sharifi, Feb 08, 2014
SourceAvailable from: Mehran Mesgari Abbasi[Show abstract] [Hide abstract]
ABSTRACT: Abstract In the field of cancer therapy, magnetic nanoparticles modified with biocompatible copolymers are promising vehicles for the delivery of hydrophobic drugs such as Cisplatin. The major aim of this effort was to evaluate whether Cisplatin-Encapsulated magnetic nanoparticles improved the anti-tumour effect of free Cisplatin in lung cancer cells. The PLGA-PEG triblock copolymer was synthesised by ring-opening polymerisation of d,l-lactide and glycolide with polyethylene glycol (PEG6000) as an initiator. The bulk properties of these copolymers were characterised using Fourier transform infrared spectroscopy. Cisplatin-loaded nanoparticles (NPs) were prepared by double emulsion solvent evaporation technique and were characterised for size, drug entrapment efficiency (%), drug content (% w/w), and surface morphology. In vitro release profile of cisplatin-loaded NP formulations was determined. Cytotoxic assays were evaluated in lung carcinoma (A549)-treated cells by the MTT assay technique. In addition, the particles were characterised by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The anti-proliferative effect of Cisplatin appeared much earlier when the drug was encapsulated in magnetic nanoparticles than when it was free. Cisplatin-Encapsulated magnetic nanoparticles significantly enhanced the decrease in IC50 rate. The in vitro cytotoxicity test showed that the Fe3O4-PLGA-PEG6000 magnetic nanoparticles had no cytotoxicity and were biocompatible. The chemotherapeutic effect of free Cisplatin on lung cancer cells is improved by its encapsulation in modified magnetic nanoparticles. This approach has the prospective to overcome some major limitations of conventional chemotherapy and may be a promising strategy for future applications in lung cancer therapy.Journal of Microencapsulation 08/2014; DOI:10.3109/02652048.2014.940011 · 1.88 Impact Factor
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ABSTRACT: Enterococcis are a part of the normal flora of the human gastrointestinal tract, and play an important role in the spread of resistance genes and produce antibiotic-resistant strains. With increasing the use of vancomycin antibiotics, Vancomycin-resistant enterococci (VRE) are one of the major nosocomial pathogens in worldwide. The aim of this study was to investigate the frequency of phenotype and genotype of van genes in vancomycine resistant Enterococci. Methods: In this cross-sectional descriptive study, after isolating and identifying 165 strains of enterococci from clinical specimens in different wards of Alzahra hospital, the enterococcus isolates were identified by biochemical confirmation tests. Resistance of each isolate to vancomycin determined by disk diffusion and E-Test method and was tested for the presence of the Van A and Van B genes by Real time PCR. Results: The results of the 165 isolates of enterococci collected from clinical specimens showed 79 (48%) enterococcus was resistant by disk diffusion method to vancomycin, but using E-test, only 40 (25%) enterococci was resistant in high level to vancomycin. Real-time-PCR assay of 40 samples showed 37 patients (92/5%) included Van A gene and 3 (7/5%) with Van B gene. Conclusion: Based on the results of the present study, the rate of isolation of Van A-containing strains was higher than that of Van B-containing of Alzahra Hospital in Isfahan. Real Time-PCR has a high specificity compared to other phenotypic methods E-Test and disk diffusion method.
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ABSTRACT: Background: Vancomycin-Resistant Enterococci (VRE) pose an emerging problem in Iran hospitals. Objectives: The present study was undertaken to determine the prevalence of van genes among vancomycin low resistant Enterococccus (VLRE) isolate in Tehran hospitals. Materials and Methods: Totally 162 and 152 isolates of enterococcal species were obtained from fecal and clinical samples of hospitalized patients between March and November of 2012. The antibiotic susceptibility of the isolates and minimum inhibitory concentration (MIC) were determined according to CLSI. The presence of the van A and B resistant genes in VLREs isolates were evaluated by PCR method. Results: VLRE accounted for 162 (38.4%) and 159 (38.7%) of Enterococal isolates from clinical and fecal flora samples respectively (MIC’s in the range of 16 to 64 μg/mL). VanA and vanB genotypes were detected with polymerase chain reaction (PCR) in 85 (27%) and 35 (11%) of VLRE isolates, respectively. Conclusions: VLRE cause serious problems in healthcare settings because their detection is difficult and treatment of these infections may not be successful. These species are miss-identified as vancomycin susceptible isolates. By detection of VLRE, we can evaluate perspective of vancomycin high level resistant Enterococcus rate in future.