Hastane kaynaklı enterokok izolatlarının pulsed-field jel elektroforezis yöntemiyle moleküler tiplendirilmesi.

Objective: Enterococci are the second most common cause of nosocomial urinary tract and wound infections, also third most common cause of nosocomial bacteremia. Currently, especially vancomycin-resistant enterococci (VRE) are one of the significant pathogens that cause nosocomial infections and increase mortality, morbidity, and healthcare costs. Therefore prevention and control of the nosocomial VRE outbreaks and epidemiological analysis of the infection are important. Pulsed-Field Gel Electrophoresis (PFGE) is accepted as a "gold standard" method in the molecular epidemiological analysis of enterococcal infections. The aims of this study are to determine the clonal relationship among the nosocomial enterococcal isolates and the rate of cross-contamination between them. Method: Thirty-six Enterococcus strains isolated from hospitalized patients with nosocomial infection in different clinics of Dicle University Hospital between November 2010 and June 2012 were included in this study. A total of 36 isolates were obtained from various clinical samples including urine (n=18), blood (n=6), bronchoalveolar lavage (BAL) fluid (n=5), wound biopsy sample (n=5), vaginal smear (n=1) and catheter tip (n=1). Nine of the thirty-six isolates were VRE. Isolation and identification of the isolates were conducted in the bacteriology laboratories of Dicle University Medical Faculty, Department of Medical Microbiology. The conventional methods and BD PhoenixTM 100 (Becton Dickinson, MD, USA) fully automated microbiology system were used for the identification. Antimicrobial susceptibilities of enterococcal strains were determined by a fully automated microbiology system according to the Clinical and Laboratory Standards Institute (CLSI). In addition, vancomycin susceptibilities of the isolates were performed by E-test method. Staphylococcus aureus ATCC 25923 strain was used for quality control. PFGE was studied for determining of rate of cross-contamination. PFGE was performed in National Molecular Microbiology Referance Laboratory, Public Health Institution of Turkey (PHIT). DNA restriction fragments were obtained by cutting bacterial DNA with the SmaI enzyme. DNA restriction fragments were used by CHEF DR II (Bio-Rad Laboratories, Nazareth, Belgium) system. PFGE results were evaluated by Bionumerics software system (version 6.01; Applied Maths, Sint-Martens-Latem, Belgium). Results: DNA patterns of the isolates were obtained by PFGE, and dendrogram of DNA patterns were made. Comparison of DNA patterns obtained by PFGE showed that 26 E. faecium strains were divided into four different clusters and one major group, 10 E. faecalis strains were three clusters and one major group. Twenty-six Enterococcus faecium isolates were involved in a joint cluster (97% similarity). The cluster rate was found to be 77% (20/26), number of E. faecium strains in each cluster ranged from 2 to 14 strains. Conclusion: In this study, cross-contamination was highlighted among enterococcal strains causing nosocomial infections in Dicle University Hospital between November 2010 and June 2012. Our data revealed that more effective infection control programs should be implemented to prevent cross-transmission. [ABSTRACT FROM AUTHOR]