PULSED-FIELD GEL-ELECTROPHORESIS OF STAPHYLOCOCCUS-HYICUS AND STAPHYLOCOCCUS CHROMOGENES GENOMIC DNA AND ITS TAXONOMIC, EPIDEMIOLOGIC AND ECOLOGIC APPLICATIONS IN VETERINARY-MEDICINE

One hundred and thirty-eight strains of Staphylococcus hyicus and 21 s trains of S. chromogenes isolated from animals were analyzed by pulsed -field gel electrophoresis (PFGE) after restriction endonuclease SmaI digestion of chromosomal DNA. Eighty-eight strains of S. hyicus from p igs with or without exudative epidermitis (EE) generated 16 to 26 frag ments in the size range of <1 to 485 kb, and yielded 39 different patt erns. With regard to the strains from pigs with EE, PFGE patterns diff ered according to the country of origin. Outbreaks of EE occurring on four separate pig farms in Japan involved S. hyicus with different PFG E patterns. The PFGE patterns shown by S. hyicus strains from 4 kinds of animals were compared. Strains from pigs differed from those isolat ed from chickens (n=45; 18 to 24 fragments of <1 to 425 kb), cows (n=3 ; 17 to 19 fragments of <1 to 475 kb), and goats (n=2; 16 or 17 fragme nts of <1 to 1,125 kb). Also, each of the chicken, cow and goat strain s had a host-specific fragment. The results suggest that PFGE analysis might be a useful marker for distinguishing ecovars within S. hyicus. In contrast, strains of S. chromogenes from pigs and cows generated 1 7 to 24 fragments ranging from <1 to 545 kb. The PFGE patterns of S. c hromogenes strains were more highly conserved than those of S. hyicus. S. chromogenes strains could be distinguished from S. hyicus strains by fragments within the range of 305 to 545 kb. The results indicate t hat PFGE analysis could be used to distinguish between S. hyicus and S . chromogenes. We conclude that PFGE analysis is a useful tool not onl y for species or strain identification but also for epidemiologic or e cologic studies of S. hyicus and S. chromogenes.