DETECTION OF VANA, VANB, VANC GENES BY MULTIPLEX PCR IN ENTEROCOCCUS FEACALIS AND ENTEROCOCCUS FEACIUM ISOLATES IN HOSPITALIZED PATIENTS

After Vancomycin resistant Enterococci (VRE) was first detected in the mid
1980s, VRE spread rapidly worldwide and became one of the most serious problems in many hospitals
specially in hospitalized patients. Among different enterococcal species Enterococcus feacalis and
Enterococus faecium are the leading causes of life threatening infections. VanA/B/C genes are
responsible for resistance to vancomycin. The aim of this research was to detect the type of genes
VanA/B/C in E. faecalis and E. faecium isolates in some Tabriz hospitals.
Material & Methods: In total non-repetitive 120 isolates of enteroccci were collected from some
hospitals in Tabriz. Isolates were taken from rectal swap, stool, and different clinical samples and
identified as enterococci by standard microbiological tests. Determination of Vancomycin MIC was
done by the macrodilution broth method and for detection of VanA, VanB and VanC genes in VRE
isolates multiplex PCR was carried out by using three sets of primers.
Results: Out of 120 enterococci isolates, 105 strains were identified as E. faecalis and 15 isolates were
identified as E.faecium. Out of 120 isolates, 22(18.3%) isolates were found to be resistant to
vancomycin (VRE). All of these isolates were isolated from fecal (6 isolates) or from urine samples
(16 isolates). The PCR analyses showed that VanA genotype was present in 10 E.faecium and in 2 E.
faecalis isolates where as VanB genotype was detected in 5 E.faecium and 5 E.feacalis isolates. None
of the VRE isolates had VanC genotype.
Conclusion: like our findings, regional, national and international studies show the VRE isolates are
from normal flora and clinical samples. On the other hand the VanA genotype is more prevalent than
VanB among VRE isolates. Detection of infected or colonized patients with VRE is essential for
preventing VRE spread