Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during th...

BarA of Streptomyces virginiae is a specific receptor protein for virginiae butanolide (VB), one of the gamma-butyrolactone autoregulators of the Streptomyces species, and acts as a transcriptional regulator controlling both virginiamycin production and VB biosynthesis. The downstream gene barB, the transcription of which is under the tight control of the VB-BarA system, was found to be transcr...

The M component of virginiamycin inhibited growth of Plectonema boryanum under both photoautotrophic and heterotrophic conditions. Though the S component of this antibiotic had no apparent activity per se, it enhanced the inhibitory action of its partner. Cells incubated with suitable concentrations of either M or M + S stopped growing and lysed. Loss of the colony-forming capacity occurred qui...

Virginiamycin M inhibits both peptide bond formation and binding of aminoacyl-tRNA to bacterial ribosomes, and induces a lasting inactivation of the 50 S subunit (50 S). In the present work, the effects of this antibiotic on the acceptor and donor sites of peptidyltransferase have been explored, in the presence of virginiamycin M as well as after its removal. Virginiamycin M inhibited the bindi...

Bacterial contaminants from commercial fuel ethanol production facilities were previously shown to form biofilms as mixed cultures under laboratory conditions. In this study, a rapid assay was developed to simultaneously compare isolates for their ability to form biofilms as pure cultures. A total of 10 strains were isolated from a dry-grind fuel ethanol plant that routinely doses with virginia...

Virginiamycin produced by Streptomyces virginiae as a natural mix of macrocyclic peptidolactones M and S is widely used in the industrial production of ethanol fuel and as an antibiotic feed additive for cattle and poultry. Its main antimicrobial components, M1 and S1 factors, act synergistically if the M1:S1 ratio in the final product is 70-75:25-30. This fact significantly complicates the dev...

Background: Some medicinal plants can stimulate growth in poultry. Objective: To compare the effects of dietary addition virginiamycin antibiotic and galbanum plant (Ferula gummosa) on performance, carcass characteristics, immune system, blood factors broiler chickens. Methods: A total 250 one-day-old male Ross 308 chickens were randomly assigned to five treatments with replicates (10 birds per...

From 1995 to 2000, a total of 673 Enterococcus faecium and 1,088 Enterococcus faecalis isolates from pigs together with 856 E. faecium isolates from broilers were isolated and tested for susceptibility to four classes of antimicrobial agents used for growth promotion as part of the Danish program of monitoring for antimicrobial resistance. The four antimicrobials were avilamycin, erythromycin, ...

OBJECTIVES To detect quinupristin-dalfopristin and virginiamycin M1 resistance in Enterococcus faecium from human, food and environmental sources. MATERIALS AND METHODS Enterococcal isolates derived from human faeces and urine, meat and seawater were screened for resistance to quinupristin-dalfopristin and virginiamycin M1 by an agar dilution method. Identification of all E. faecium strains a...

Three balance trials, each involving 12 crossbred gilts averaging 35.2 kg body weight, were conducted to determine the effects of dietary fiber and virginiamycin on nutrient digestibility, mineral absorption and retention, and digesta rate of passage (RP). Two levels of fiber (13.5 and 20.2% neutral detergent fiber) and two levels of virginiamycin (0 and 11 ppm) were used in a 2 X 2 factorial a...