fa تحقيقي Original Paper <div><strong>ABSTRACT</strong><br> <strong>Background</strong> <strong>and Objectives:</strong> The resistance of gram-negative bacteria to antibiotics has become a serious problem, which imposes a significant increase in treatment costs. <em>Klebsiella pneumoniae</em> is an important nosocomial pathogen from the <em>Enterobacteriaceae</em> family. The aim of this study was to investigate the frequency and pattern of antibiotic resistance in <em>K. pneumoniae</em> strains isolated from clinical samples.<br> <strong>Methods:</strong> This descriptive, cross-sectional study was performed on 150 <em>K. pneumonia </em>strains isolated from different clinical samples such as urine, sputum, blood, ulcers, lung secretions and abdominal abscess. Antibiogram test was performed using the disk diffusion method (Kirby-Bauer). Minimum inhibitory concentration of amikacin, tobramycin and gentamicin was determined via the E-test for 50 strains with high resistance rates.<br> <strong>Results:</strong> In this study, the highest rate of resistance was observed against carbenicilin, ceftriaxone, cefepime and streptomycin. <em>K. pneumonia </em>isolates were most frequent in urine and sputum samples. In the E-test, the highest rate of resistance was observed against gentamicin, tobramycin (16&micro;g/ml) and amikacin (64&micro;g/ml).<br> <strong>Conclusion:</strong> Based on our results, tigecycline, netilmicin, kanamycin and amikacin are the most effective antibiotics for the treatment of <em>K. pneumoniae</em> infections.<br> <strong>Keywords:</strong> <em>Klebsiella pneumoniae</em>, antimicrobial resistance, E-test method</div> Klebsiella pneumoniae, antimicrobial resistance, E-test method 41 45 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1-517&slc_lang=fa&sid=1 Mohammad Bokaeian 100319475328460014262 100319475328460014262 No Infectious Diseases and Tropical Medicine Research Center, Resistant Tuberculosis Institute, Department of Microbiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran Shahram Shahraki Zahedani 100319475328460014263 100319475328460014263 No Infectious Diseases and Tropical Medicine Research Center, Resistant Tuberculosis Institute, Department of Microbiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran Abbasali Delarampoor abbasalidelarami@gmail.com 100319475328460014264 0000000175144760 Yes Department of Microbiology, Faculty of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran Mohammadreza Atashgah 100319475328460014265 100319475328460014265 No Department of Microbiology, Faculty of Medicine, Zahedan University of Medical Science, Zahedan, Iran Bahram Dahmarde 100319475328460014266 100319475328460014266 No Department of Microbiology, Faculty of Medicine, Zahedan University of Medical Science, Zahedan, Iran