국내 침습성 원인폐렴균 혈청형 분석 및 백신 후보물질 탐색

초록

Purpose : Streptococcus pneumoniae is a major pathogen which causes pneumonia, bacteremia and meningitis. S. pneumoniae isolates are classified more than 90 serotypes as their capsular polysaccharides of which distribution depends on periods, age groups, regions. Capsular polysaccharide-based vaccine are currently used. However, present studies on vaccine efficacy and development in Korea are insufficient. In this study, we collected invasive isolates and described distribution of S. pneumoniae serotypes which cause infections. Methods : Three hundred and seven invasive isolates were collected from blood and CSF of local hospitals in 6 cities between January, 2006 and December, 2007. Three hundred and forty-three non-invasive isolates were collected from Acute Respiratory Surveillance Network between December, 2005 and May, 2007. All of 650 isolates were tested for analysis of serotype and antimicrobial susceptibility. Results : Resistance to penicillin, erythromycin, clindamycin and tetracycline were present in 56.4%, 73.5%, 64.3% and 54.5% of invasive isolates and 95.6%, 93.3%, 87.2% and 86.8% of non-invasive isolates. Most prevalent serotypes of invasive isolates were 19F>23F>19A>6A>9V>14>1>6B and those of non-invasive isolates were 19F>23F>6A>19A>6B>35B>14>9V. Serotypes included in 7-valent protein conjugate vaccine(PCV7) and 23-valent capsular polysaccharide vaccine(PS23) formulation accounted for 74.9% and 44.3% of invasive isolates and 70.3% and 54.2% of non-invasive isolates. Vaccine efficacy of PS23 was 75.8% under 5 years old and 74.3% in adults. However, we expected vaccine efficacy of PCV7 was 59.1% under 5 years old and 32.6% in adults. Conclusions : Antibiotic therapy of invasive S. pneumoniae infections seems to be difficult as the reason of high resistance of most prevalent isolates. Current vaccine efficacy is expected to be low from our results, therefore new vaccine formulation for Korea prevalent serotypes needs to be developed.

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