Evaluation of the Activities of Antimicrobial Agents on Multi-drug Resistant Gram Positive Bacteria Isolated from Intensive Care Units

Abstract

Multi-drug resistant Gram-positive bacteria are responsible for nosocomial infections. It is important to show the minimal inhibitory concentrations and new antibiotic resistance profiles of these bacteria to antimicrobials which are commonly used in treatment. The aim was to evaluate the new and more efficient antibiotics minimal inhibitory concentrations which can be used for treatment of Gram positive multiple drug resistant microorganisms. In this study, 337 Gram positive bacterial strains were isolated from clinical samples of 192 patients who were hospitalized at intensive care units. Minimum Inhibitory Concentration (MIC) values of antibiotics were investigated in 72 Gram positive bacterial strain. Broth macrodilution and disc diffusion methods were performed to evaluate the activities of antibiotics against Gram positive bacteria. All the 72 Gram positive bacterial strains including 38 coagulase negative Staphylococci, 18 Staphylococcus aureus and 16 Enterococci strains were sensitive to tigecycline, linezolid and daptomycin. All coagulase negative staphylococci and Staphylococcus aureus strains were sensitive to vancomycin and teicoplanin. Additionally, 2 Enterococci strains were resistant to vancomycin, while 1 strain was resistant and 1 strain was intermediately sensitive to teicoplanin. Vancomycin, teicoplanin, tigecycline, linezolid and daptomycin might be useful and good alternative for the treatment of multi-drug resistant bacterial infections. Different antibiotic resistance profiles and the MIC’s of antibiotics should be searched for the treatment of intensive care unit patients.