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,

Objetivou-se avaliar a flora microbiana no sêmen fresco e congelado de reprodutores caprinos, assim como a eficácia dos antibióticos estreptomicina, penicilina e gentamicina, na viabilidade de doses de sêmen congeladas. Foram utilizados 25 reprodutores de diferentes raças, submetidos a duas colheitas de sêmen através do método da vagina artificial, após higiene da região prepucial. A primeira colheita do sêmen foi realizada visando o exame microbiológico e a segunda teve como objetivo proceder a congelação, após diluição em leite desnatado, utilizando penicilina + estreptomicina (A1), gentamicina (A2) ou sem antibiótico (A3). Ao proceder a avaliação microscópica no sêmen fresco, evidenciou-se média de 87,92 ± 7,76% de motilidade individual progressiva (MIP) e 4,96 ± 0,20 de vigor espermático. Em relação à avaliação bacteriana, constatou-se principalmente bactérias do gênero Staphylococcus spp e Bacillus sp. Após a congelação do sêmen, não foram evidenciadas diferenças (P>;0,05) entre os grupos quanto a MIP e vigor espermático. Entretanto, na avaliação microbiológica pós-descongelação, a bactéria do gênero Staphylococcus spp esteve presente na maioria das amostras. Observou-se também que a gentamicina (13,3mg/mL) apresentou melhor atividade anti-microbiana no processo de congelação do sêmen, concluindo-se que pode ser o antibiótico usado na congelação do sêmen de reprodutores caprinos. | The aim of this research was to evaluate the microbial flora in the fresh and frozen semen of goat reproducers, as well as the effectiveness of the antibiotics estreptomicin, penicillin and gentamicin in cryopreservation of semen. It were used 25 males of different breeds, submitted to two semen collect through the artificial vagina method after cleanliness of prepucial region. The first collection of semen aimed the microbiological exam. The second collection had as goal accomplish freezing, after dilution in skimmed milk, with penicillin + estreptomicin (A1), gentamicin (A2) or control (A3). After microscopic evaluation, it was evidenced average of 87.92 ± 7.76% of MIP and 4.96 ± 0.20 of spermatic vigor in fresh semen. Regarding bacterin evaluation, it was verified, mostly, bacteria of the gender Sthaphylococcus spp and Bacillus sp. After semen cryopreservation, it was observed that there wasn't difference (P>;0.05) among groups in MIP and spermatic vigor. However, in the microbiological evaluation of frozen-thawed semen, bacteria of Sthaphylococcus spp gender was present in great part of samples. Gentamicin (13.3mg/mL) promoted larger inhibition of the bacterial growth in the semen post-freezing, concluding that gentamicin can be the antibiotic used for freezing of goat semen.