RESUMEN
There are many reports associated with growing increase in incidence of drug resistance in streptococcus pneumoniae strains, complications caused by these organisms during clinical treatment, increasing cost of therapy, and poor prognosis. To determine pneumococcus drug resistance in Zanjan hospitals. This was a cross-sectional study in which all positive cultures for pneumococci were collected from Bouali pulmonary center laboratory and Vali-e-Asr laboratory for determination of MIC. The data were gathered through a questionnaire and further analyzed by chi-square test using SPSS 11.5 for windows package. Of 57 patients, 25 were males and 32 females. The average age of patients was 49.4 with a range of 13-87 years. MIC test for penicillin showed that 24 [42.1%] samples were sensitive, 24 [42.1%] with intermediate susceptibility and 9 [15.8%] resistant. MIC results for ceftriaxone showed higher sensitivity among 52 samples [91/2%] and lower resistance in 5 [8/8%] specimens. All cases were sensitive to vancomycin. There was a significant relationship between underlying diseases and sensitivity to ceftriaxone. Regarding the high resistance of pneumococci to penicillin, it is recommended ceftriaxone to be used as the first line treatment and in case of resistance it should be replaced with vancomycin