virginiamycin and Dysentery

Griseoviridin, a known antibiotic produced by Streptomyces cacaoi subsp. cacaoi, was found to be active against Brachyspira hyodysenteriae--the bacterium causing swine dysentery. An in vitro synergism is observed when it is used in combination with viridogrisein--a simultaneously produced antibiotic. In mouse experiments, the effect of griseoviridin alone was less than that of lincomycin--a commercially available swine dysentery medication. However, a 1:1 mixture of griseoviridin and viridogrisein revealed a noticeable synergistic effect. In an evaluation using pigs artificially infected with B. hyodysenteriae, a large difference was not observed between the effect of griseoviridin alone and that in combination with viridogrisein. Nevertheless, griseoviridin alone exhibited a therapeutic effect superior to that of lincomycin.

Topics: Animals; Anti-Bacterial Agents; Drug Synergism; Dysentery; Lincomycin; Macrolides; Male; Mice; Mice, Inbred Strains; Microbial Sensitivity Tests; Molecular Structure; Peptides; Specific Pathogen-Free Organisms; Spirochaetales; Spirochaetales Infections; Swine; Swine Diseases; Virginiamycin

Topics: Animal Feed; Animals; Brachyspira hyodysenteriae; Drug Resistance, Microbial; Dysentery; Rectum; Specific Pathogen-Free Organisms; Spirochaetales Infections; Swine; Swine Diseases; Virginiamycin

Topics: Animals; Body Weight; Diet; Dysentery; Swine; Swine Diseases; Virginiamycin

Topics: Animals; Arsenates; Colon; Drug Resistance; Dysentery; Gentamicins; Hydroxyquinolines; Recurrence; Ronidazole; Swine; Swine Diseases; Virginiamycin

Topics: Animals; Anti-Bacterial Agents; Carbadox; Cyclic N-Oxides; Dysentery; Leucomycins; Quinoxalines; Swine; Swine Diseases; Treponema; Treponemal Infections; Virginiamycin

Virginiamycin, fed at a concentration of 110 mg/kg of feed for 2 weeks followed by concentrations of either 27.5 or 55 mg/kg for 3 weeks, was effective in treatment and control of experimentally induced swine dysentery. However, diarrhea recurred 4 days after withdrawal of medicated feed. Subsequently, the frequency of diarrhea decreased in 3 of 4 groups retreated with virginiamycin (110 mg/kg of feed) for 5 days. Feeding of virginiamycin (110 mg/kg) for 1 week after onset of diarrhea was of little value because of the development of a more severe (augmented) form of the disease after withdrawal of medicated feed. Feeding of virginiamycin (55 mg/kg) at the time of exposure and continuing for 3 weeks (followed by intermittent retreatments of 55 mg/kg) aided in treatment and control of swine dysentery. With this regimen, a few swine developed diarrhea during initial medication, but all developed diarrhea after withdrawal fo medicated feed. Frequency of diarrhea was less after each retreatment. This was attributed to the development of immunity from the recurring diarrhea.

Topics: Administration, Oral; Animal Feed; Animals; Dysentery; Swine; Swine Diseases; Virginiamycin

Serums from 119 swine exposed to swine dysentery inoculum, and medicated with various drugs, were tested for antibodies to the large spirochete, using the indirect fluorescent antibody test, and were compared in tests with known positive serums from 18 nonmedicated swine which had recovered naturally. An inverse relationship existed between the efficacy of the drug and the serum antibody titer (highest dilution of the serum producing immunofluorescence of large spirochetes). The more efficacious drugs or doses resulted in lesser development of serum antibody. Diarrhea usually seemed necessary for the development of serum antibody. With the less efficacious drugs, there were more days of diarrhea. Some swine had diarrhea but did not develop an antibody titer, and a few swine had a titer but did not develop diarrhea. Swine which developed a titer were more immune against reexposure with infective inoculum. The medicaments, especially those given at higher concentrations, seemed to resolve the diarrhea or prevent the development of diarrhea, occurrences which were necessary for the development of immunity.

Topics: Animals; Antibodies; Dysentery; Fluorescent Antibody Technique; Leucomycins; Lincomycin; Ronidazole; Spectinomycin; Spirochaetales; Spirochaetales Infections; Swine; Swine Diseases; Virginiamycin

Topics: Animals; Dysentery; Swine; Virginiamycin

Topics: Animals; Anti-Bacterial Agents; Dysentery; Swine; Swine Diseases; Virginiamycin