Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 6 6 2014 12 15 382 386 EN Mohammad Taghi Haghi-Ashtiani Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran. Majid Sadeghian Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran. Bahram Nikmanesh Departement of parasitology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Babak Pourakbari Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran. Shima Mahmoudi Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran. Setareh Mamishi Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Department of Infectious Disease, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 16 Background and Objectives: The appearance of antibiotic resistance in Streptococcus pneumoniae has raised a global concern over the past three decades. This study was conducted to determine the antimicrobial susceptibility of S. pneumoniae isolated from patients in Children´s Medical Center (CMC) Hospital during 2001 to 2011. Materials and Methods: During the 11 years period, a total of 194 S. pneumoniae isolates were collected in CMC Hospital. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method and time-series analysis was used to evaluate the antimicrobial susceptibility changes over the time. Results and Conclusion: Antimicrobial susceptibility of S. pneumoniae to different antibiotics decreased from 2001 to 2011 as: penicillin from 78% to 32%, erythromycin from 75% to 35%, chloramphenicol from 94% to 55%, ampicillin from 70% to 62%, ceftriaxone from 100% to 87%, sulfametoxazole from 57% to 40%. We did not find any significant difference between the susceptibility of isolates from sterile and non-sterile sources. It would be an important key to consider antimicrobial stewardship as an essential factor to prevent the development of antimicrobial resistance. https://ijm.tums.ac.ir/index.php/ijm/article/view/368 https://ijm.tums.ac.ir/index.php/ijm/article/download/368/145