GENOMIC DNA-FINGERPRINTING, USING PULSED-FIELD GEL-ELECTROPHORESIS, OF STAPHYLOCOCCUS-INTERMEDIUS ISOLATED FROM DOGS

Objectives-To investigate the degree ei polymorphism in the pulsed-fie ld gel electrophoresis (PFGE) patterns of Staphylococcus intermedius a nd to assess the value of this typing method for discriminating strain s. Sample population-52 S intermedius isolates from diseased and healt hy dogs. Procedure-Chromosomal DNA of S intermedius was digested with restriction endonuclease Sma I, and the fragments were separated by PF GE in a 1% agarose gel. Results-Sma I cut the chromosomal DNA into 15 to 23 fragments ranging from about < 1 to 679 kb, and mast of the dete ctable fragments were < 155 kb. Nine fragments, 115, 48, 33, 26, 16, 1 3, 10, 4, and < 1 kb, were shared by all or almost all (> 71%) of the strains examined. Of the 52 strains, each had a different pattern. S i ntermedius had a high degree of restriction fragment length polymorphi sm. The PFGE patterns obtained for S intermedius were stable and repro ducible when the strains were tested in the different experiments. Con clusions-Genomic DNA fingerprinting by PFGE is an effective technique for discriminating S intermedius strains. The PFGE method appears to b e a useful molecular marker for epidemiologic or ecologic studies of S intermedius.