Serotypes and antibiotic resistance of Streptococcus pneumoniae from adenoids in preschool children with recurrent upper respiratory tract infections.

We investigated children aged 2-5, who had gone adenoidectomy for recurrent and/or persistent symptoms of upper respiratory tract infections for prevalence of pneumococci in adenoid tissue. Serotypes and antibiotic resistance patterns of the isolated pneumococci were determined and also risk factors of pneumococcal colonization were defined. S. pneumoniae colonization in adenoids was found in 62 (60.2%) children. Serotypes belonged to 10-valent and 13-valent pneumococcal conjugated vaccines (PCVs) constituted 56.1% and 68.2% of the isolates, respectively. Decreased susceptibility to penicillin was found in 45.5% of isolates; pneumococci were resistant to cotrimoxazole (62.1%), tetracycline (43.9%), erythromycin (54.5%), clindamycin (54.5%) and chloramphenicol (31.8%). Multidrug resistant S. pneumoniae comprised 57.6% of the isolates. Antibiotic resistant pneumococci were mostly distributed among serotypes belonged to 10-valent and 13-valent PCVs. Good vaccine coverage among the isolated pneumococci confirmed that the introduction of PCVs in the national immunization programme may reduce the pool of resistant and multidrug resistant pneumococci in a community.