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: 2.25). 12/2011; 61(Pt 4):600-2. DOI: 10.1099/jmm.0.036780-0
Source: PubMed


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.

Download full-text


Available from: Yaeghob Sharifi, Feb 08, 2014
  • Source
    • "The prevalence of E. faecium has been increased in Iranian hospitals during the last few years. In the present study, the ratio of infections due to E. faecalis to those caused by E. faecium was 1.2: 1 (51.3% versus 41.4%) which is still higher than some previous reports published from Iran and some other countries [4,15,16]. The increased ratio was supported by enhancement of VREfm strains. "
    [Show abstract] [Hide abstract]
    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:
    Full-text · Article · Oct 2013 · Diagnostic Pathology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Infectious diseases are one of the most common causes of morbidity and mortality and the spread of resistant microorganisms is playing a significant role in this regard. The purpose of this study was to assess the trend in antimicrobial resistance of gram-positive bacteria at the main referral teaching hospital in Tehran during a 4-year period. All patients' biological isolates such as blood, urine, wound drainage, synovial fluid, sputum, and cerebrospinal fluid sent to the central laboratory of the hospital from 2007 to 2010 for identification and subsequently, antimicrobial susceptibility testing by Kirby-Bauer disc diffusion method were considered. All isolates (100%) of S. aureus were sensitive to vancomycin and linezolid and resistant to amoxicillin. The rate of S. aureus resistance to oxacillin increased from 60.78% in 2007 to 72% in 2010. All isolates of Streptococci in 2007 and 2008 were sensitive to vancomycin; while, 3.33% and 4.76% of Streptococci isolates were reported to be vancomycin-resistant in 2009 and 2010, respectively. Enterococci isolated from the entire specimens were identified to be sensitive to teicoplanin and linezolid and resistant to cloxacillin and oxacillin. The rates of Enterococci sensitivity to vancomycin were 90.91%, 81.25%, 86.67%, and 93.3% in 2007, 2008, 2009, and 2010, respectively. Changes of antibiotics sensitivity against g positive pathogens were significant during four years in this study. To minimize the spread of resistant gram positive pathogens, periodic and regular surveillance of antimicrobial resistance pattern is highly recommended.
    Full-text · Article · Jul 2012 · Acta medica Iranica
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dendrimers are nano-sized, radially symmetric molecules with well-defined, homogeneous, and monodisperse structure that has a typically symmetric core, an inner shell, and an outer shell. Their three traditional macromolecular architectural classes are broadly recognized to generate rather polydisperse products of different molecular weights. A variety of dendrimers exist, and each has biological properties such as polyvalency, self-assembling, electrostatic interactions, chemical stability, low cytotoxicity, and solubility. These varied characteristics make dendrimers a good choice in the medical field, and this review covers their diverse applications.
    Full-text · Article · May 2014 · Nanoscale Research Letters
Show more