Vancomycin-resistant enterococci among clinical isolates from north-west Iran: identification of therapeutic surrogates.

Tabriz University of Medical Sciences, Iran.
Journal of Medical Microbiology (Impact Factor: 2.3). 12/2011; 61(Pt 4):600-2. DOI: 10.1099/jmm.0.036780-0
Source: PubMed

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.

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    ABSTRACT: Enterococcus faecium is a multi-resistant nosocomial pathogen causing infection in debilitated patients. Vancomycin-resistant enterococcus faecium (VREfm) are a major concern and increased dramatically worldwide especially in hospitals environment. The current study focused on determining the high prevalence and distribution patterns of antibiotic resistance and also its genetic linkages among various VREfm strains isolated from indoor hospitalized patients in four major Iranian teaching hospitals of Tehran. The clinical samples were obtained from hospitalized patients during September 2010 to June 2011 from different teaching hospitals of Tehran. Antibiotics Resistance patterns, minimum inhibition concentration (MIC) value for vancomycin, ampicillin, gentamicin and presence of genetic linkage among the isolates were determined by pulsed-field gel electrophoresis (PFGE). Overall, total of 92 (41.4%) isolates were identified as E. faecium, 45 (49%) were resistant to vancomycin with an MIC50 of [greater than or equal to] 128 mg/L. The results showed that simultaneous resistance to teicoplanin, ampicillin, gentamicin, ciprofloxacine, tetracycline and erythromycin were observed the most frequent pattern. All the vancomycin resistant E. faecium isolates carried the vanA gene. intensive care units (ICUs) and Kidney transplantation, are most probably the wards with highest risk of infection by VRE. 17 pulsotypes were also detected by PFGE, most of the related pulsotypes belongs to the same hospitals. This study shows the high alarming prevalence of Enterococcus faecium infection and similar clones of VREfm strains in Iranian hospitals with threatening resistance phenotypes. Virtual slides: The virtual slides for this article can be found here:
    Diagnostic Pathology 10/2013; 8(1):163. · 1.85 Impact Factor


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May 29, 2014