COMPARATIVE-STUDY OF 5 DIFFERENT DNA FINGERPRINT TECHNIQUES FOR MOLECULAR TYPING OF STREPTOCOCCUS-PNEUMONIAE STRAINS

The aim of this study was to identify the strengths and weaknesses of five DNA fingerprint methods for epidemiological typing of Streptococc us pneumoniae, We investigated the usefulness of (i) ribotyping, (ii) BOX fingerprinting with the BOX repetitive sequence of S, pneumoniae a s a DNA probe, (iii) PCR fingerprinting with a primer homologous to th e enterobacterial repetitive intergenic consensus sequence, (iv) pulse d-field gel electrophoresis of large DNA fragments, and (v) restrictio n fragment end labeling to detect restriction fragment length polymorp hism of small DNA fragments, Twenty-eight S. pneumoniae strains isolat ed from the blood and/or cerebrospinal fluid of 21 patients were analy zed, Genetic clustering among the 28 strains was independent of the DN A fingerprint technique used, However, the discriminatory power and th e similarity values differed significantly among the individual techni ques. BOX fingerprinting, pulsed-field gel electrophoresis, and restri ction fragment end labeling provided the highest degree of discriminat ory power, Furthermore, the ease with which computerized fingerprint a nalysis could be conducted also varied significantly among the techniq ues. Ribotyping, BOX fingerprinting, and restriction fragment end labe ling were very suitable techniques for accurate computerized data anal ysis. Because of their high discriminatory potential and ease of accur ate analysis, we conclude that BOX fingerprinting and restriction frag ment end labeling are the most suitable techniques to type pneumococca l strains.