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Equine Veterinary Journal Mar 1998Abnormal behaviour commonly develops in intensively managed horses. A possible cause is the change in diet occurring when the horse is stabled. An experiment was...
Abnormal behaviour commonly develops in intensively managed horses. A possible cause is the change in diet occurring when the horse is stabled. An experiment was performed to examine this possibility by manipulating the diet with the feed supplement virginiamycin, as Founderguard. During 4 weeks, 18 horses were fed diets ranging from hay alone to concentrate plus hay in the ratio of 3:1. The rations of half the horses given concentrate were supplemented with Founderguard. Horses eating high concentrate rations displayed abnormal oral behaviours at a higher frequency than those eating only hay. The incidence of these behaviours was reduced when diets were supplemented with Founderguard. The drop in faecal pH of animals on concentrate diets was also reduced by Founderguard. Animals on concentrate diets had an average of 21 kg less gut fill post mortem. Dietary supplementation with virginiamycin as Founderguard apparently lessens some behavioural problems associated with management of stabled horses and the intake of grain. It may allow concentrate to be fed at higher levels than customary without adverse behavioural side effects. The suggested mechanism for the improved behaviour due to Founderguard supplementation is reduced fermentative acidosis in the hindgut.
Topics: Animal Feed; Animal Husbandry; Animals; Anti-Bacterial Agents; Behavior, Animal; Diet; Dietary Supplements; Feces; Female; Gastrointestinal Contents; Horses; Housing, Animal; Hydrogen-Ion Concentration; Lactic Acid; Male; Stereotyped Behavior; Virginiamycin; Viscera
PubMed: 9535070
DOI: 10.1111/j.2042-3306.1998.tb04473.x -
Antimicrobial Agents and Chemotherapy Mar 1996In a cell extract of Streptomyces virginiae, virginiamycin M1 was inactivated in the presence of NADPH, while virginiamycin S remained intact. The inactivated product of...
In a cell extract of Streptomyces virginiae, virginiamycin M1 was inactivated in the presence of NADPH, while virginiamycin S remained intact. The inactivated product of virginiamycin M1 was isolated, and structure analysis revealed that the inactivation involves reduction of a C-16 carbonyl group leading to the formation of 16-dihydrovirginiamycin M1. Acetonide and benzylidene acetal derivatives were synthesized from the two hydroxyl groups on C-14 and C-16, and the C-16 stereochemistry was determined by 13C nuclear magnetic resonance spectroscopy. Two methyl groups of the acetonide derivative gave 13C signals of 20.1 and 30.1 ppm, indicating that the relative stereochemistry of the C-14 and C-16 hydroxy groups is syn. Furthermore, irradiation of the benzylidene methine proton gave clear nuclear Overhauser effect enhancement of the C-14 or C-16 methine protons, indicating that H-14 and H-16 were in an axial configuration. From the (14S) absolute configuration of natural virginiamycin M1 and the syn relative configuration for the C-14 and C-16 hydroxyl groups of the inactivated product, the C-16 absolute configuration of the inactivated product was thus identified as R.
Topics: Anti-Bacterial Agents; Chromatography, High Pressure Liquid; Drug Resistance, Microbial; Magnetic Resonance Spectroscopy; Microbial Sensitivity Tests; Oxidation-Reduction; Spectrophotometry, Infrared; Stereoisomerism; Streptomyces; Virginiamycin
PubMed: 8851577
DOI: 10.1128/AAC.40.3.595 -
The Journal of Antibiotics Apr 1993
Topics: Animals; Anti-Bacterial Agents; Brain; Cholecystokinin; Guinea Pigs; Humans; Microbial Sensitivity Tests; Pancreas; Rats; Receptors, Cholecystokinin; Virginiamycin
PubMed: 8501005
DOI: 10.7164/antibiotics.46.623 -
International Journal of Medical... Jul 2002The new semi-synthetic streptogramin antibiotic combination quinupristin/dalfopristin (Synercid) is a promising alternative for a treatment of infections with multiple... (Review)
Review
The new semi-synthetic streptogramin antibiotic combination quinupristin/dalfopristin (Synercid) is a promising alternative for a treatment of infections with multiple resistant gram-positive pathogens, e.g. glycopeptide- and multi-resistant Enterococcus faecium. Streptogramins consist of two unrelated compounds, a streptogramin A and B, which act synergistically when given in combination. Mechanisms conferring resistance against both components are essential for resistance against the combination in E. faecium. In this species resistance to streptogramin A compounds is mediated via related acetyltransferases VatD and VatE. Resistance against streptogramins B is either encoded by the widespread ermB gene cluster conferring resistance to macrolide-lincosamide-streptogramin B antibiotics or via expression of the vgbA gene, which encodes a staphylococcal-type lactonase. E. faecalis is intrinsically resistant to streptogramins. Due to a wide use of streptogramins (virginiamycins S/M) in commercial animal farming a reservoir of streptogramin-resistant E. faecium isolates had already been selected. Determinants for streptogramin resistance are localized on plasmids that can be transferred into an E. faecium recipient both in vitro in filter-matings and in vivo in the digestive tracts of rats. Hybridization and sequencing experiments revealed a linkage of resistance determinants for streptogramins A and B on definite plasmid fragments.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Drug Synergism; Drug Therapy, Combination; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans; Streptogramins; Virginiamycin
PubMed: 12195739
DOI: 10.1078/1438-4221-00194 -
Biochimica Et Biophysica Acta May 2007The three-dimensional structure of acetylated virginiamycin M(1) (acetylated VM1) in chloroform and in a water/acetonitrile mixture (83:17 v/v) have been established...
The three-dimensional structure of acetylated virginiamycin M(1) (acetylated VM1) in chloroform and in a water/acetonitrile mixture (83:17 v/v) have been established through 2D high resolution NMR experiments and molecular dynamics modeling and the results compared with the conformation of the antibiotic VM1 in the same and other solvents. The results indicated that acetylation of the C-14 OH group of VM1 caused it to rotate about 90 degrees from the position it assumed in non-acetylated VM1. The conformation of both VM1 and acetylated VM1 appear to flatten in moving from a nonpolar to polar solvent. However, the acetylated form has a more hydrophobic nature. The acetylated VM1 in chloroform and in water/acetonitrile solution had a similar configuration to that of VM1 bound to 50S ribosomes and to the Vat(D) active sites as previously determined by X-ray crystallography. Docking studies of VM1 to the 50S ribosomal binding site and the Vat(D) gave conformations very similar to those derived from X-ray crystallographic studies. The docking studies with acetylated VM1 suggested the possibility of a hydrogen bond from the acetyl carbonyl group oxygen of acetylated VM1 to the 2' hydroxyl group of ribose of adenosine 2538 at the ribosomal VM1 binding site. No hydrogen bonds between acetylated VM1 and the Vat(D) active sites were found; the loss of this binding interaction partly accounts for the release of the product from the active site.
Topics: Acetylation; Binding Sites; Models, Molecular; Molecular Conformation; Solvents; Virginiamycin
PubMed: 17442646
DOI: 10.1016/j.bbapap.2007.03.002 -
The Annals of Pharmacotherapy Oct 1995To review the current knowledge on RP 59500 (quinupristin/dalfopristin, Synercid), a new streptogramin antibiotic, with respect to its pharmacology, pharmacokinetics,... (Comparative Study)
Comparative Study Review
OBJECTIVE
To review the current knowledge on RP 59500 (quinupristin/dalfopristin, Synercid), a new streptogramin antibiotic, with respect to its pharmacology, pharmacokinetics, pharmacodynamics, mechanism of resistance, and in vitro inhibitory and bactericidal activity.
DATA SOURCES
A MEDLINE search using keywords RP 59500, pristinamycin, virginiamycin, and streptogramin was performed. Relevant abstracts presented at recent scientific conferences also were consulted.
STUDY SELECTION
Because RP 59500 is a relatively new investigational agent, relevant in vitro and animal studies were selected. All available human studies were included as well.
DATA EXTRACTION
Data from in vitro and in vivo studies were included, with particular emphasis on human studies.
DATA SYNTHESIS
RP 59500 is a new injectable streptogramin antibiotic consisting of a mixture o 2 synergistic pristinamycin compounds. RP 59500 possesses in vitro inhibitory and bactericidal activity against most isolates of gram-positive organisms including vancomycin-resistant Enterococcus faecium, selected gram-negative bacteria, and most anaerobic organisms. Based on preliminary data, the drug appears to be metabolized rapidly and extensively while exhibiting a significant postantibiotic effect. Data from ongoing clinical trials suggests that RP 59500 is well-tolerated except for mild injection site irritations. However, before the role of RP 59500 within the vast armamentarium of antimicrobials can be elucidated, additional studies need to be conducted to document its clinical efficacy.
CONCLUSIONS
Based on in vitro susceptibility testing, in vivo studies, and preliminary clinical data, RP 59500 may be an alternative to the glycopeptides, especially for inherently resistant organisms. Further studies are needed to confirm this agent's in vitro activity and to establish its clinical efficacy.
Topics: Anti-Bacterial Agents; Drug Resistance, Microbial; Humans; Virginiamycin
PubMed: 8845540
DOI: 10.1177/106002809502901013 -
Presse Medicale (Paris, France : 1983) Sep 2001
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Multiple; Drug Therapy, Combination; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Humans; Virginiamycin
PubMed: 11603272
DOI: No ID Found -
Journal of Applied Microbiology Dec 2015The purpose of this study was to compare the effects of feeding virginiamycin or bacitracin methylene disalicylate (BMD), two in-feed antibiotics typically used by...
AIMS
The purpose of this study was to compare the effects of feeding virginiamycin or bacitracin methylene disalicylate (BMD), two in-feed antibiotics typically used by commercial poultry producers in the United States, on the chicken gastrointestinal microbiota.
METHODS AND RESULTS
454 pyrosequencing of the V6-V8 region of the 16S rRNA gene and quantitative PCR were employed to examine the bacterial microbiota and Clostridium perfringens, respectively, in the jejunum and caecum of market-age broiler chickens over four replicate grow-outs.
CONCLUSIONS
Our results suggest that virginiamycin has a more pronounced impact on broiler gastrointestinal tract bacterial communities, relative to BMD, manifested primarily through significant enrichments in the genus Faecalibacterium in the caecum and a distinct population of Lactobacillus, OTU_02, in both the jejunum and caecum. No evidence for a difference among the diets in Cl. perfringens levels in the jejunum or caecum was observed.
SIGNIFICANCE AND IMPACT OF THE STUDY
This work represents the highest resolution comparison to date of the jejunum and caecum microbiota in broilers fed either virginiamycin or BMD, and provides evidence for specific bacterial OTUs potentially involved in the health and performance benefits typically attributed to these in-feed antibiotics.
Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Bacitracin; Bacteria; Chickens; Gastrointestinal Microbiome; Intestines; Salicylates; Virginiamycin
PubMed: 26425940
DOI: 10.1111/jam.12960 -
Antimicrobial Agents and Chemotherapy Dec 1999
Review
Topics: Anti-Bacterial Agents; Drug Resistance, Microbial; Genes, Bacterial; Lincosamides; Macrolides; Terminology as Topic; Virginiamycin
PubMed: 10582867
DOI: 10.1128/AAC.43.12.2823 -
Journal of Chromatographic Science Mar 2018A quantitative LC-MS/MS method has been developed for simultaneous determination of bacitracin A, bacitracin B, colistin A, colistin B and virginiamycin M1 in feed. This...
Analysis of Major Components of Bacitracin, Colistin and Virginiamycin in Feed Using Matrix Solid-phase Dispersion Extraction by Liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry.
A quantitative LC-MS/MS method has been developed for simultaneous determination of bacitracin A, bacitracin B, colistin A, colistin B and virginiamycin M1 in feed. This rapid simple and effective extraction method was based on matrix solid-phase dispersion. Qualitative and quantitative analyses were performed by LC-ESI-MS/MS. CCβ of polypeptide antibiotics upon the method ranged from 9.6 to 15.8 μg kg-1 and 19.4 to 27.5 μg kg-1, respectively. The limit of quantification of polypeptide antibiotics was 25 μg kg-1 in feed samples. The recoveries of polypeptide antibiotics spiked in feed samples at a concentration range of 25-100 μg kg-1 were found above 75.9-87.9% with relative standard deviations within days less than 15.7% and between days less than 20.6%. This rapid and reliable method can be used to efficiently separate, characterize and quantify the residues of polypeptide antibiotics in feed with advantages of simple pretreatment and environmental friendly.
Topics: Animal Feed; Bacitracin; Chromatography, Liquid; Colistin; Drug Residues; Limit of Detection; Linear Models; Reproducibility of Results; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Virginiamycin
PubMed: 29244148
DOI: 10.1093/chromsci/bmx096