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High frequency distribution of heterogeneous vancomycin resistant Enterococcous faecium (VREfm) in Iranian hospitals

Leili Shokoohizadeh1, Ashraf Mohabati Mobarez1*, Mohammad Reza Zali2, Reza Ranjbar3, Masoud Alebouyeh2, Türkan Sakinc4 and Liaqat Ali45

Author Affiliations

1 Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, P. O. Box: 14115-111, Tehran, Iran

2 Research Center of Gastroenterology and Liver Diseases Shahid Beheshti, University of Medical Sciences, Tehran, Iran

3 Molecular Biology Research Center, Baqiyatallah, University of Medical Sciences of Tehran, Tehran, Iran

4 Department of Internal Medicine II, University Hospital Freiburg, Freiburg, Germany

5 Faculty of Biology, Albert Ludwigs University of Freiburg, Freiburg, Germany

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Diagnostic Pathology 2013, 8:163  doi:10.1186/1746-1596-8-163

Published: 2 October 2013



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 ≥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.

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E. faecium; Vancomycin resistant; Hospital and PFGE