antimicrobial susceptibility trends among streptococcus pneumoniae over an 11-year period in an iranian referral children hospital.

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.