Distribution of enterococcus species colonized in gastrointestinal tract of patients in hemato-oncology, intensive care units and their resistance profiles against vancomycin

IVABSTRACTDISTRIBUTION OF ENTEROCOCCUS SPECIES COLONIZED IN GASTRO-INTESTINAL TRACT OF PATIENTS IN HEMATO-ONCOLOGY, INTENSIVECARE UNITS AND THEİR RESISTANCE PROFILES AGAINST VANCOMYCINDr. Gül Özlem MENTEŞSpecialty Thesis, Department of Microbiolgy and Clinical MicrobiologyThesis Supervisor:Prof. Dr. İclal BALCIJuly 2007, 52 pagesEnterococci are the gram-positive cocci within the family ofStreptoptococcaceae. They are found in the soil, water and foods; and present inthe human and animal intestines, biliary tracts, mouths and sometimes in theirskins, in normal flora.This microorganism, the virulence of which is low generally causes infectionsresulting from the patient?s own endogenous flora. All enterococci includingvancomycin-resistant enterococci (VRE) are passed to others from a patientdirectly or indirectly via contaminated hands, contaminated environmentalsurfaces, contaminated medical devices, and it can be spread intra-hospital orinter-hospitals.Our study was carried out with the patients defined as the risk group for VRElining in the Surgical and Internal Intensive Care Unit, Adult Oncology-Hematologyand Pediatric Oncology Departments in the hospital of Gaziantep UniversityFaculty of Medicine between the March 2006 and December 2006. Rectal swabssamples were taken from 180 patients in total, and according to the results ofcultures, enterococci production was observed in 126 patients (70%). As a resultof the identification in terms of species, they were identified as 53 strains of(42.06%) E. faecium, 39 strains of (30.95%) E. faecalis, 15 strains of (11.90%) E.avium, 10 strains of (%7.93) E. gallinarum, 7 strains of (%5.55) E. casseliflavus, 1strain of (%0.79) E. hirae,1 strain of(%0.79) E. durans. Four patients in total(3.17%) were detected to be colonized with VRE. Four strains identified as E.faecium were found to show resistance to vancomycin according to antibiogramand E-test results. (E-test is MIC>256 mg/ml). The strains which were found toshow resistance were examined for their resistance genotypes via PCR method,and the four strains were found to be VanA genotype. One of the strains withresistance to vancomycin was detected in Internal Intensive Care Unit, one inSurgical Intensive Care Unit and the other two in Adult Oncology Unit. Threemonths after the discharge of one of the patients E. faecium containing VanA-typeresistance had been detected in the oncology unit, vancomycin resistance was notdetected in the culture repeated when the patient was hospitalized for the secondtime. Beta-lactamase production was studied with Nitrocefin Disk, and beta-lactamase production was detected in none of the strains.VKey words: VRE, Gastro-intestinal colonization, Patients at risk group, E-test.