Enterococcus Resistance to Linezolid without History of Use

Background and Resistance to choice antibiotics is serious and focus of concern. Therefore، the current study was done to identify the enterococcus resistance pattern to Linezolid- choice antibiotic، which has not yet been used in the country. This descriptive study was a laboratory research done on 100 stool samples gathered from hospitalized patients of Shahid Beheshti Hospital، Kashan، 2012. The samples were transferred to the university microbiology laboratory in transport media and the entrococcus identity was established through biochemical tests. Then Linezolid and Vancomycin antibiogram was recorded by means of Disk Diffusion method. On the other hand، Minimum Inhibition Concentration (MIC) for Vancomycine was measured by E-test method. Finally، the results were analyzed by means of SPSS software- Chi square test، and paired T-test. The mean age was 52. 26±18. 29 years old. Forty eight subjects were females (48%) and the rest were males. Thirty four subjects were colonized with Vancomycine Resistant entrococci and 33 others with Linezolid Resistant entrococci. Using the E-test method، 73 strains were sensitive to vancomycine (MIC≤4g/ml)، 27 resistant (MIC>33g/ml)، and none was intermediate. Using antibiotic was one of the most important risk factors for vancomycine resistance in enterococci (P<0. 05). The duration of antibiotic use with Linezoid in the past was the only effective factor in resistance (P<0. 05). The resistance rate of enterococci was 33%، without any history of linezolid use in the past، this can conclude that sort of cross resistance to both vancomycine and linezolid، synchronically; that suggests the necessity of future studies about genome basics of the issue.