title: Drug resistance and R plasmids in Vibrio anguillarum isolated in cultured ayu (Plecoglossus altivelis).
abstract: Two hundred twenty-six strains of Vibrio anguillarum collected from cultured ayu ( Plecoglossus altivelis ) between 1978 and 1980 were studied for their sensitivities to 10 chemotherapeutics. In order to determine whether the drug-resistant strains possessed transferable R plasmids, they were conjugated with Escherichia coli. Almost all the strains isolated during the 3 years showed resistance to nalidixic acid (NA) and/or furazolidone (NF). NA and NF resistance were not transferred to Escherichia coli from any of the strains. Chloramphenicol-resistant strains were isolated in every year and almost all of them carried transferable R plasmids. Only one strain with tetracycline resistance was found among the strains tested. Strains resistant to sulfonamides, streptomycin, ampicillin (ABP), and trimethoprim (TMP) increased rapidly in 1980, and a large number of them carried transferable R plasmids. Transferable R plasmids encoded with resistance to ABP and TMP were detected for the first time in V. anguillarum strains. The R plasmids detected in the strains isolated in 1980 were classified into incompatibility groups E, A, and an untypable group. The R plasmid DNAs were cleaved by EcoRI to yield 11 to 13 fragments. The estimated molecular weights of the R plasmids from the five strains ranged from 97 to 104 M daltons.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D005393:Fish Diseases / Q000188:drug therapy / Q000382:microbiology; D005399:Fishes / Q000382:microbiology*; D007564:Japan; D008970:Molecular Weight; D011815:R Factors; D014733:Vibrio / Q000187:drug effects* / Q000235:genetics; D014735:Vibrio Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary
chemical_list: D000900:Anti-Bacterial Agents