sedecamycin and Dysentery

The sensitivity of 332 strains of Serpulina hyodysenteriae isolated in Hungary between 1978 and 1992 was tested against seven chemotherapeutic drugs frequently used for the treatment of swine dysentery, and the changes in the patterns of resistance were also monitored. All the strains remained sensitive to carbadox, with minimum inhibitory concentrations (MIC) of only 0.05 to 0.40 microgram/ml at present. The susceptibility of the strains to dimetridazole has gradually decreased, but about half of the strains are still sensitive, with large numbers of "moderately sensitive' strains; the MIC values varied within wide limits (0.1 to 50 micrograms/ml). Most of the strains were resistant to tylosin, with MIC values from 0.1 to 100 micrograms/ml. The number of strains resistant to lincomycin has gradually increased, but about half of the strains remain sensitive; the MIC values ranged from 0.2 to 100 micrograms/ml. Recently, tiamulin has proved the most effective antibiotic, but some resistant strains have already emerged (MIC values 0.05 to 50 micrograms/ml). Monensin was good for the prevention of swine dysentery, but resistance may evolve quickly; the MIC values ranged from 0.4 to 25 micrograms/ml. For sedecamycin, the MIC values (6.25 to 100 micrograms/ml) were much higher than expected.

Topics: Animals; Anti-Bacterial Agents; Brachyspira hyodysenteriae; Carbadox; Dimetridazole; Diterpenes; Dose-Response Relationship, Drug; Drug Resistance, Microbial; Dysentery; Hungary; Lincomycin; Macrolides; Microbial Sensitivity Tests; Monensin; Spirochaetales Infections; Swine; Swine Diseases; Tylosin

The authors evaluated the effect of terdecamycin, a novel antibiotic, on experimentally induced Serpulina (S.) hyodysenteriae infection in pigs. In a prophylactic test, feed containing terdecamycin was fed to pigs for 7 days before inoculation and 21 days after inoculation. Dysenteric diarrhea, development of lesions in the large intestinal mucosa and colonization of S. hyodysenteriae in colonic mucosa were completely inhibited by treatment with 5 ppm or 10 ppm terdecamycin. In the therapeutic test, an unmedicated feed was fed to pigs inoculated with S. hyodysenteriae, until the typical mucohemorrhagic diarrhea appeared after inoculation, and was then changed to the medicated feed for 10 days. By treating with 20 ppm terdecamycin, the clinical signs in the pigs were improved and S. hyodysenteriae was completely eradicated.

Topics: Animals; Anti-Bacterial Agents; Brachyspira hyodysenteriae; Dysentery; Macrolides; Spirochaetales Infections; Swine; Swine Diseases