Antibiotic resistance rates in Enterococcus stranis isolated from clinical specimens

Enterococci are gram-positive bacteria commonly found in normal intestinal flora of humans and animals. They frequently cause urinary tract infections in humans. In recent years, it is observed that they also cause hospital infections increasingly. Enterococci are the most problematic bacteria due to their resistance to antibiotics. Enterococci have become a major problem for they are resistant to many antibiotics due to their natural intrinsic resistance, they develop resistance to antibiotics quickly and they spread this resistance. The strains of enterococci isolated from clinical specimens by conventional microbiological methods are identified according to their biochemical characteristics. Then their species-level identifications are identified at specie-level by Vitek-2 GP system method. Beta-lactamase-productions are examined by means of nitrocefin chromogenic substrate method. Their high level aminoglycoside-resistance is examined by disc diffusion technique using 120 µg gentamicin and 300 µg streptomycin discs. Their susceptibilities to various antibiotics are studied by using Kirby-Bauer disk diffusion technique in line with CLSI recommendations.15.3% of enterococcal strains examined are isolated from in-patient samples and 84.7% of enterococcal strains examined are isolated from outpatient samples. 58 (80.5%) of 72 enterococcal strains examined is defined as E.faecalis and 14 (19.5%) of 72 enterococcal strains examined is defined as E.faecium. Construction of beta-lactamase is determined through nitrocefin method in only two of these bacteria (2.8%). High level amino glycoside resistance to streptomycin is determined in 47% of enterococci examined and to gentamicin in 43% of enterococci examined. All strains of enterococci examined are found to be susceptible to vancomycin and teicoplanin. Resistance to linezolid is determined in only one strain. Strain resistant to phosphomycine by 4% is found. Enterococci resistant to ampicilline by 22% and to penicillin by 20% are determined. Enterococci resistant to levofloxacin by 43%, to ciprofloxacin by 47% and to tetracycline by 50% are determined.No VRE is determined in enterococcal strains examined in this study. Enterococci examined are largely isolated from urine samples and outpatients. Thus, the problem of enterococcal antibiotic resistance is not determined in an anticipated extent in this study. On the other hand, in order to prevent the spread and development of the antibiotic resistance in enterococci, it is required that hospital infection committees and microbiology laboratories are in cooperation with each other; treatment is planned by taking into consideration the high-level resistance to aminoglycoside and the antibiotic susceptibility test results in the treatment of enterococcal infections. It is of paramount importance to isolate the patients undergoing infections by enterococci identified as VRE and with serious antibiotic resistance profile and to prevent the spread of bacteria from such patients to other patients.