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Updated: Jun 27, 2026

Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Molecular analysis of vanHAX element in vancomycin resistant enterococci isolated from hospitalized patients in
Malihe Talebi1, Mohammad R Pourshafie, Mahvash Oskouii
1Dept. of Bacteriology, School of Public Health, Tehran University/Medical Sciences, Tehran, Iran.
Background:
Vancomycin (glycopeptide)-resistant enterococci (VRE or GRE) can cause serious problems for hospitalized patients due to the limited options for treatment of VRE infections. As infection with VRE increases in hospitals, further knowledge about vancomycin resistant genes is needed.
Methods:
Isolates of Enterococcus spp. were collected from hospitalized patients in Tehran (Iran) during 2006. Detailed molecular analysis was performed for vancomycin resistance genotype and vanHAX using conventional PCR and PCR- RFLP (restriction fragment length polymorphism), respectively.
Results:
out of 830 enterococci spp., 48 VRE isolates (5.8 percent) were obtained. All of VRE isolates carried vanA gene. DdeI digestion of vanHAX element showed the presence of point mutation at 8234 position.
Conclusion:
This study indicates that vanA is a predominant genotype in Iranian isolates. In addition, PCR-RFLP analysis revealed the presence of two types of vanHAX element in vanA harboring transposons.
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