Molecular Analysis of vanHAX Element in Vancomycin Resistant Enterococci Isolated from Hospitalized Patients in Tehran

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 PCRRFLP (restriction fragment length polymorphism), respectively. Results: out of 830 enterococci spp., 48 VRE isolates (5.8%) 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.