Antimicrobial susceptibility of Streptococcus pneumoniae in the oropharynx of healthy preschool children and identification of risk factors.

To determine the prevalence and antimicrobial susceptibility of Streptococcus pneumoniae in the oropharynx of healthy children, throat swabs were obtained from 683 children and cultured. The disk diffusion method and the E test were used to test the antimicrobial susceptibility of the isolated organisms. Twenty-nine children (4.2%) harbored S. pneumoniae in their oropharynx. Fifteen (51.7%) of the isolates showed intermediate resistance to penicillin and 14 (48.3%) were susceptible. All strains were susceptible to rifampicin and moxifloxacin. One was resistant to telithromycin. The rates of resistance to clindamycin, erythromycin, chloramphenicol and tetracycline were 41.3, 44.8, 34.4, and 44.8%, respectively. Risk factors for S. pneumoniae carriage were also assessed.