title: In vitro study of the influence of virginiamycin and spiramycin on the composition and biochemical activities of the gastrointestinal flora of piglets. I. influence on the composition of the flora.
abstract: In vitro fermentations with the gastro-intestinal flora of 18 treated piglets (Control, Virginiamycin, Spiramycin) were carried out to study the influence of Nutritional doses of Virginiamycin and Spiramycin on the composition of the microflora. Each total flora was used for three different incubations: Control, 50 ppm Virginiamycin, 50 ppm Spiramycin. To obtain comparable results with experiments in vivo, an artificial fermentation medium was made on the basis of several chemical analyses of intestinal contents. The treatments with nutritional doses in vivo had little influence on the different in vitro fermentations. Addition of Spiramycin during incubation was of little influence on the growth and the composition of the flora. Virginiamycin on the other hand caused marked changes in the gastro-intestinal microflora, such as a decrease of the total growth and a decrease in the number of Lactobacilli and Enterococci, combined with a slight increase of the Gram negative aerobic population.
mesh_terms: D000693:Anaerobiosis; D000821:Animal Feed; D000818:Animals; D004064:Digestive System / Q000187:drug effects* / Q000382:microbiology; D004926:Escherichia coli / Q000302:isolation & purification; D005285:Fermentation; D066298:In Vitro Techniques; D007778:Lactobacillus / Q000302:isolation & purification; D007933:Leucomycins / Q000494:pharmacology*; D008722:Methods; D008835:Micrococcaceae / Q000302:isolation & purification; D013291:Streptococcus / Q000302:isolation & purification; D013552:Swine / Q000382:microbiology*; D014769:Virginiamycin / Q000494:pharmacology*
chemical_list: D007933:Leucomycins; D014769:Virginiamycin