ANTIBIOTIC-RESISTANCE AMONG ENTEROCOCCI ISOLATED FROM CLINICAL SPECIMENS BETWEEN 1953 AND 1954

Two hundred twenty group D streptococci isolated from 1953 to 1953 fro m patients in the Washington, D.C., area were characterized, All were susceptible to ampicillin, vancomycin, and gentamicin; none produced b eta-lactamase activity. High-level resistance to streptomycin was expr essed by 117 strains, and 2 strains were resistant to >8 mu g of chlor amphenicol per mi, Three isolates were resistant to both erythromycin and lincomycin, and DNA from these hybridized to an ermAM probe, Of 11 8 strains resistant to tetracycline and minocycline, genomic DNA from 63 was examined for homology to tet(M), tet(O), and tet(S). DNA from 2 0 strains hybridized to fet(M), DNA from 37 strains hybridized to tet( S), and DNA from none of the strains hybridized to tet(O).