CLASS-D AND CLASS-E TETRACYCLINE RESISTANCE DETERMINANTS IN GRAM-NEGATIVE BACTERIA FROM CATFISH PONDS

DNA probes were used to examine tetracycline-resistant Gram-negative b acteria (281 strains representing eight species) from catfish ponds. T he isolates, which did not previously hybridize with the Tet A, B and C determinants, were examined for the presence of tetracycline-resista nce Tet D and Tet E determinants. The distribution of the Tet D determ inant ranged from 0 to 83%, depending on the bacterial species. Tet E was found only in 69% of Aeromonas hydrophila isolates. Eighteen per c ent failed to hybridize with any of the five Tet determinants. (C) 199 5 Academic Press Limited