PCR Fingerprinting Analysis of Genes Encoding Penicillin-binding Proteins of Multidrug-resistant Streptococcus pneumoniae Isolated from Korea / 감염

ABSTRACT

BACKGROUND: The rate of pneumococcal resistance in Korea has surged up to the world's highest level in a short period. To investigate the genetic relatedness and the spread of resistant pneumococci within Korea, and to obtain the basic data about structural changes of penicillin-binding proteins(PBPs), we performed a fingerprinting analysis of PBP 1A, 2X, and 2B genes of multidrug-resistant pneumococci isolated in Korea. METHODS: A total of 22 pneumococcal strains isolated from clinical specimens in 2 university-affiliated hospitals during the period from 1989 to 1996 were tested. PBP 1A, 2X, and 2B genes were amplified from chromosomal DNA by the polymerase chain reaction with specific primers. Amplified products were digested with HinfI or MseI and DdeI and were followed by end-labeling with [alpha-32P] dCTP. Direct comparison of fingerprinting patterns between resistant strains and dendrogram analysis which was based on the UPGMA method were carried out. RESULTS: Fingerprinting analysis of PBP 1A, 2X, and 2B genes digested with HinfI showed that 17 out of 22 strains had almost identical patterns. Dendrogram showed that clusters with greater than 90% similarities existed in 77%, 77%, and 82% of strains with PBP 1A, PBP 2X, PBP 2B, respectively. Fingerprinting patterns with MseI and DdeI were the same as those with HinfI. CONCLUSION: Data from PCR fingerprinting analysis of PBP 1A, 2X, 2B genes of multidrug- resistant pneumococci in this study indicate the genetic relatedness between the resistant strains and suggest the possible spread of pneumococcal resistance within Korea.