TWENTY-THIRD ANNUAL EASTERN FISH HEALTH WORKSHOP JOHN CARVER INN, PLYMOUTH, MA 30 MARCH - 2 APRIL, 1998 Biochemical And Molecular Typing Of Streptococcus iniae Isolates From Fish And Human Cases Sarah V. Meads1, Emmett B. Shotts, Jr2, and John Maurer3 1Department of Medical Microbiology and 3Department of Avian Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA. 2National Fish Health Research Laboratory, Leetown, WV. Streptococcus iniae is an important bacterial pathogen of fish causing up to 50% mortality in stocks. S. iniae has recently been associated with infections in humans. Based on epidemiological evidence, transmission is believed to be associated with wounds acquired while cleaning fish. Currently, it is not known whether the S. iniae associated with human infections are different from the pathogenic fish isolates. We hypothesized that there is no difference between the fish and human isolates of S. iniae. To determine whether S. iniae isolates from humans and fish are similar, we examined their genetic relatedness by random amplification polymorphic DNA (RAPD) using common 10-mer oligonucleotides for typing microbial pathogens. Several different methods for preparing DNA templates were compared for simplicity, duration of procedure, and reproducibility. Template generated from boiling cells produced the same DNA pattern by RAPD PCR as DNA prepared using a mutanolysin-proteinase K extraction procedure. The boiling procedure was not only more rapid and less complicated than the other procedures, it was also reproducible. Preliminary data suggests that the human pathogenic isolates are genetically indistinguishable from the fish isolates. These isolates can, however, be separated from other beta-hemolytic streptococci. These results support the hypothesis that the fish and human S. iniae isolates are the same. Return to 23rd Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page