Serotype and Antimicrobial Susceptibility of Streptococcus pneumoniae

ABSTRACT

BACKGROUND: Pneumococcus is the most common cause of acute otitis media, community acquired pneumonia and invasive bacterial diseases in children. Ninety serotypes have been identified, and the distribution differs according to geographic area and ages. The 7 valent pneumococcal protein conjugate vaccine is used widely. To evaluate the efficacy of the vaccine, it is essential to investigate the distribution of the pneumococcal serotypes. MATERIALS AND METHODS: The serotypes and antibiotic resistance of the pneumococcus isolated from 308 patients at Shinchon Severance hospital from September of 2001 to July of 2005 were analyzed. RESULTS: The pneumococcci were isolated mostly from sputum and blood, and ear discharge in the descending order. Serotyping was possible in 265 cases, and the distribution of serotypes were 19F (16.2%), 19A (12.8%), 23F (8.7%), 6B (7.9%), and 6A (7.2%). Fifty two cases were isolated from those patients less than 16 years of age and the distribution of serotypes was 19F, 19A, 23F, 14, 6B, 6A and 4. Resistance to penicillin was 64.6% in all cases and 67.3% in children. The more common serotype showed the higher rate of penicillin resistance. Multi-drug resistance was demonstrated in 64.7%. Forty three percent of the total identified serotypes were included in the 7 valent pneumococcal conjugate vaccine. And 61.5% of the serotypes identified in children were included in the vaccine. CONCLUSION: The 7 valent vaccine may be used effetively in Korea. But, further study is needed to address serotype switching after the use of the protein conjugated vaccine, which has been reported in other countries.