Twenty-four rams inoculated with Brucella ovis by conjunctival and preputial routes were treated with a long-acting oxytetracycline alone or in combination with dihydrostreptomycin sulfate. The combined treatment eliminated Brucella ovis from 11 of 12 (91.6%) treated rams. Only 4 of 12 (33.3%) rams treated with oxytetracycline alone were bacteriologically negative. Neither treatment resolved clinical epididymitis in 2 rams affected before treatment. Many rams had pathologic lesions in the epididymis and ampullae, which limited the efficacy of antibiotic treatment.

Parallux (IDEXX Laboratories, USA), a solid-phase fluorescence immunoassay (SPFIA) developed for antibiotics residue detection in milk, was applied for analysis of antibiotics in muscle tissue of olive flounder (Paralichthys olivaceus), rockfish (Sebastes schlegeli), and red sea bream (Pagrus major). Fishes were dipped in streptomycin 20 g/ton water, the recommended therapeutic dose, for 3 consecutive days. Muscle was sampled after 1st, 2nd, 3rd, 4th and 5th day drug treatment. The concentration of streptomycin in muscle, determined by SPFIA, was compared with that of internal standard (200 ppb as streptomycin).

We established an in vitro experimental system using the following procedure. We first introduced tritium-labeled norepinephrine ([³H]-NE) into PC12 cells. The [³H]-NE incorporated into PC12 cells were then stimulated by a high concentration (60 mM) of K+ buffer during 12 minutes. Then, we collected 100 μl supernatant and counted the amount of [³H]-NE release from PC12 cells with a scintillation counter. After screening fungal, Streptomyces spp. or bacterial product using this experimental sytem, we obtained FS11052 from Streptomyces spp. which inhibited [³H]-NE release from PC12 cells.

A total of 108 strains of C jejuni isolated from pigs and chickens were examined for the susceptibility to 10 antimicrobial agents and normal sera of cattle, sheep, guinea pigs and chickens. Minimal inhibitory concentration (MIC) ranges of antimicrobial agents to C jejuni isolates were = 100 micro g/ml for erythromycin, rifamycin, streptomycin and tetracycline, 50 to 100 micro g for cephalothin, = 50 micro g for ampicillin,