Identification of Vancomycin Resistance Determinants in Twin Cities of Rawalpindi/Islamabad

Vancomycin resistant Enterococci have emerged rapidly in the recent years leading to treatment failure. The aim of this work was to identify vancomycin resistance determinants; vanA and vanB genes in Enterococci. The blood, urine and throat samples were collected from 150 patients from local hospitals of twin cities of Rawalpindi/Islamabad. Forty-nine phenotypically confirmed isolates were further confirmed by PCR amplification for vancomycin determinants (genes for vanA and vanB) for vancomycin resistant Enterococci. Dependence and frequency distribution of VRE and VSE bacteraemia with respect to age, gender and source was also studied. Phenotypically resistant strains were positive for vanA while negative for vanB. vancomycin susceptible enterococci (VSE) could be isolated more from urine samples as compared to blood whereas vancomycin resistant enterococci (VRE) was found more prevalent in the blood samples (p value= 0.000). VRE was more frequently isolated from patients aged 50 or above whereas VSE prevalence was same in both age groups (p value=0.002). Gender was not found to have any significant impact on VRE or VSE bacteraemia. This study reports vanA gene cluster responsible for resistance in Pakistani population and frequently isolation of VRE from blood samples. Keywords: Enterococcus, Vancomycin resistant Enterococci, Pakistan