[1] BUNDESFORSCH ANSTALT VIRUSKRANKHEITEN TIERE,INST MIKROBIOL,POSTFACH 1149,W-7400 TUBINGEN,GERMANY
[2] INST PASTEUR,UNITE ANAEROBIES,F-75724 PARIS 15,FRANCE
[3] NW FISHERIES CTR,SEATTLE,WA 98112
[4] OSAKA PREFECTURAL UNIV,COLL AGR,OSAKA 591,JAPAN
[5] UNIV CALIF IRVINE,DEPT MOLEC BIOL & BIOCHEM,IRVINE,CA 92717
[6] TUFTS UNIV,SCH MED,DEPT MOLEC BIOL & MICROBIOL,BOSTON,MA 02111