Searching clonal origin and identification of resistant genes of vancomycin resistant enterococcus strains which were isolated from patients from the department of nephrology service and high dependency haemodialysis unit

Although enterococci have not virulence factors, which many types of bacteria have, they are resistant to environment conditions, intrinsically resistant to various antibiotics, and also capable of acquiring new mechanisms of resistance. Thus, these bacteria have become one of the most important causes of hospital infections during the last decade. Rectal swab cultures are recommended for this purpose. This study aimed to compare the enterococci strains obtained from the rectal swab of 100 patients with chronic renal failure in the our high dependency haemodialysis unit and the department of nephrology service between September 2010 and September 2011 to enterococci strains obtained from various inanimate environment and to investigate whether environmental conditions would be a source of spreading out of the bacteria. The isolated vancomycine resistant Enterococcus (VRE) strains were studied. Species and class level were defined by conventional methods and Vitek 2 (bioMerieux, France). Vancomycine susceptibility was explored by disk diffusion method. Minimum Inhibitory Concentration (MIC) of resistant strains was determined by E test. Genotyping was performed by DiversiLab (bioMerieux, France) device with rep-PCR method. During the collecting of samples, totally 34 VRE strains were isolated, twenty-eight of them from the rectal swap of 100 patients and 6 of them from 900 environmental samples. Twenty-nine of these isolated VRE strains were found to be as E. faecium (85 %), remain was identified as E. gallinarum (15 %). While the study aimed to include vancomycine resistant enterococci, moderately susceptible E. gallinarum strains were isolated in 5 samples and they were also included the study. DNA fingerprint analysis revealed a similarity between the strains isolated from environmental sources and a sample which was isolated from patients. It showed that 5 of 28 VRE strains isolated from the patients were also identical. It was concluded that transmission from patient to patient was more frequent than that of environment sources, and disinfection measures in our hospital were implemented properly, however, there was some defects with regard to implementation of isolation measures.