A COMPARATIVE STUDY ON ANTIMICROBIAL RESISTANCE PATTERN INCLUDING HIGH LEVEL AMINOGLYCOSIDE AND IMIPENEM REISTANCE OF ENTEROCOCCAL URINARY AND NON URINARY ISOLATES

Enterococci are the second leading cause of nosocomial infections .During the past decade, Enterococci resistant to multiple antibiotics (Vancomycin, lactams and Aminoglycosides) have been recognized making it a formidable nosocomial pathogen.It is crucial for laboratories to provide accurate antimicrobial resistance patterns for Enterococci so that effective therapy can be instituted .UTI is the commonest form of presentation of Enterococcal infections.Aim The present study was undertaken with the objectives to isolate, identify and speciate the Enterococci isolated from different specimens and to compare anti microbial resistance pattern of different Enterococcal species isolated from UTI with those isolated from other sources with special reference to High level Aminoglycoside (HLAR) and Imipenem resistance.Materials and methods A total of 100 non repetitive Enterococcal isolates, 50 consecutively from urine and 50 consecutively from various other sources (pus,wound swab,sterile fluids,blood etc.) were included in this study. Antimicrobial susceptibility testing was performed as recommended by CLSI for various antibiotics. Gentamicin (120 mg) and Streptomycin(300 g) was used to detect High level Aminoglycoside resistance. For Imipenem sensitivity, Ampicillin (10 g) and Imipenem disks (10g) were used. Vancomycin MIC was determined.Results E.faecalis was the commonest species isolated (63) in this study. E.faecium was the commonest isolate in blood stream infections and was also more resistant to antimicrobials. Identification to species level is important for deciding treatment options. Imipenem Ampicillin resistance was noted in 46 of the total isolates.70 of the Enterococci showed HLAR. Combined HLGR and HLSR was higher in E.faecium (48) than E.faecalis(42). Resistance to lactam antibiotics was higher in Enterococci isolated from urine than those isolated from other sources where as resistance to High level Aminoglycosides was found more in Enterococci isolated from other sources than those isolated from urine. An Initiative of The Tamil Nadu Dr. M.G.R. Medical University University Journal of Pre and Para Clinical Sciences HLAR Enterococci were found to be resistant to multiple antibiotics. The overall resistance to Chloramphenicol and Rifampin was found to be 24 and 20 in our study and stills remains as a treatment option of enterococcal infections. VRE was noted in 2 of cases in this study.