İnvestigation and molecular analysis of high level aminoglycoside resistant enterococci isolated from Medical Faculty Hospital of Gaziantep University

Enterococci are the most common nosocomial pathogens that encountered currently in surveillance cultures as colonization agent, increased ratios in clinical samples as factor. As well as having natural resistance mechanisms enterococcus are the most resistant bacteria with gained resistance genes. Since the use of aminoglycoside group antibodies in enterococ infections alone is not suitable to the metabolic activity of the bacteria, generally they have to use with a antibody that inhibits cell wall synthesis. However, if there is a high level of aminoglycoside resistant in the bacteria this synergistic combination also has not been used in treatment. High level of aminoglycoside resistance is a gained resistance that arises with aminoglycoside modifying enzymes. This study has been conducted to determine the aminoglycoside modifying enzymes that encountered in enterocuccus isolated from our hospital, or to determine the genes that make the synthesizing of these. This study was conducted with vancomycin resistant enteroccus (VRE) isolated from rectal swap samples sent to the Gaziantep University Faculty of Medicine, Microbiology laboratory for surveillance. The samples sent for the surveillance are incubated to vancomycin selective agar. The MIC value for the vancomycin of the enterecoc isolates that reproduce was calculated with E test. The identification of the bacteria has been made by Bruker (BD, USA). High level of aminoglycoside resistance of the isolates has been determined with the disk that contains 120 µg gentamycin. The following areas of the isolates that have high level of aminoglycoside resistance have been studied with multiplex PCR; [aac(6_)-Ie-aph(2_)-Ia, aph(2_)-Ib1, aph(2_)-Ic, aph(2_)-Id, aph(3_)-III]. The literature has been used for gene design. The designed areas have been studied with Light Cycler (Roche). 82 (82 %) of the enterococ strains included in the study has been determined as E. feacium, 11 (11 %) as E. facealis, 7 (7 %) as E. gallinarum. Positivity has been found in 67 (67 %) of the strains aph(3_)-IIIa gene region, in 2 (2 %) of the strains aph(2_)-Id gene region and in 1 isolate aph(2_)-Ib1 region. aac(6_)-Ie-aph(2_)-Ia and aph(2_)-Ic regions have not been determined in any isolate. Positivity has not been determined in any gene region of 30 of the isolates. It has been found that aminoglycoside modifying enzymes are responsible for aminoglycoside resistance in entercoccus in our hospital too. Since these genes may be transferred, rational antibody usage is important for the control of resistance development.