virginiamycin and avoparcin

Topics: Animal Feed; Animals; Animals, Domestic; Anti-Bacterial Agents; Drug Resistance, Microbial; Glycopeptides; Humans; Virginiamycin

A microbiological screening method (three-plate) for the detection of the antimicrobial growth promoters tylosin, spiramycin, virginiamycin, zinc bacitracin, and avoparcin in animal feed has been developed and validated successfully. A collaborative study involving 18 laboratories receiving 172 samples was carried out to verify the performance characteristics. The detection level for tylosin/virginiamycin/spiramycin, expressed in microbiological activity, was 1 mg kg(-1) (false-positives, 2%; false-negatives, 3, 0, and 6%, respectively). Avoparcin could be detected at 1 mg kg(-1) in feed in general (false-positives, 2%; false-negatives, 0%). However, in calf feed the sensitivity was lower. The percentages of false-negatives were found to be 12%, 7%, and 0% at 1, 3, and 5 mg kg(-1), respectively (false-positives, 4%). The limit of detection for zinc bacitracin was 3-5 mg kg(-1) (false-positives, 5-10%; false-negatives, 77% at 1 mg kg(-1), 45% at 2 mg kg(-1), 12% at 3 mg kg(-1), and 4% at 5 mg kg(-1)). The method allowed for a distinction to be made between the groups of antibiotics: avoparcin/zinc bacitracin versus tylosin/virginiamycin/spiramycin. This definitely gives added value to the method in the framework of a follow-up of positive screening results by post-screening and confirmatory analysis.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Biological Assay; Drug Residues; Food Analysis; Glycopeptides; Growth Substances; Reproducibility of Results; Sensitivity and Specificity; Spiramycin; Tylosin; Virginiamycin

Three plate systems (combinations of indicator organism and growth medium) were evaluated for the detection of analytical standards of the banned feed additives avoparcin, bacitracin zinc, spiramycin, tylosin and virginiamycin. When authorized in the EU, the previously recommended minimum inclusion rate (MIR) for each compound was 5 mg kg(-1). One of the plate systems (Micrococcus luteus ATCC 10240, nutrient agar) detected all five additives. This plate was used in a further study that evaluated the suitability of accelerated solvent extraction (ASE) as a first step in the development of a rapid single-plate screening assay. A drug-free (negative control) feedingstuff was fortified with the compounds (0-50 mg kg(-1)), extracted by ASE and the extracts applied to the plate at each of three pH ranges - unadjusted extract (pH 5.7-5.9), pH 6.5 and 8.0. At pH 6.5, sub-MIR concentrations of virginiamycin and tylosin were detectable. Avoparcin was detectable at 6.3 mg kg(-1). The detection of zinc bacitracin was#10; pH-independent (10 mg kg(-1)). At pH 8.0, spiramycin was detectable at 5.4 mg kg(-1). Mean +/- SD analytical recoveries from fortified feedingstuffs (n = 10) ranged from 57 +/- 1.5% for avoparcin to 96 +/- 4% for virginiamycin. The five additives were also detectable following ASE extraction from a range of different feedingstuffs fortified with each of the drugs. A further 24 compounds permitted for use in animal feeds were tested. Of these, nine were detectable at their recommended MIR. It is concluded that ASE is a versatile technique suitable for the automated extraction of a range of antimicrobials from animal feedingstuffs. Employing ASE with this single-plate detection system permits the rapid antimicrobial screening of animal feedingstuffs and allows the detection of the banned additives. Whilst the method is applicable as a screening test, more specific postscreening methods would be necessary for subsequent identification (and quantification) of antimicrobials in screening-positive samples.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Drug Residues; Drug Resistance, Microbial; False Negative Reactions; False Positive Reactions; Food Additives; Glycopeptides; Sensitivity and Specificity; Solvents; Spiramycin; Tylosin; Virginiamycin

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Chickens; Drug Resistance, Bacterial; Enrofloxacin; Enterococcus; Europe; Feces; Fluoroquinolones; Glycopeptides; Humans; Quinolones; Swine; United States; United States Food and Drug Administration; Vancomycin; Vancomycin Resistance; Virginiamycin

Topics: Animal Feed; Animals; Animals, Domestic; Anti-Bacterial Agents; Drug Resistance, Bacterial; Europe; Glycopeptides; Humans; United States; Vancomycin Resistance; Virginiamycin

The aim of this study was to evaluate the effect of different antibiotics used as growth promoters on the control of porcine intestinal adenomatosis when administered in weaning, growing and fattening pig diets, according to Annex I of the European Union directive (70/524/EEC and its subsequent amendments to date) for the use of feed additives. On a farm with a previous history of proliferative enteropathy outbreaks, 648 weaned piglets (23 days old) were divided into nine experimental groups according to bodyweight and sex ratio, each group comprising four pens with 18 pigs in each pen. One group served the trial as a negative (unmedicated) control: another (the positive control) received monensin via feed at 100 p.p.m. up to the end of the growing phase (107 days old) and 50 p.p.m. up to slaughter age (156 days old). The remaining seven groups were offered feed with the addition of the following antibiotics: virginia-mycin (50-20 p.p.m.), avilamycin (40-20 p.p.m.), spiramycin (50-20 p.p.m.), zinc bacitracin (50-10 p.p.m.), avoparcin (40-20 p.p.m.), tylosin (40-20 p.p.m.) and salinomycin (60-30 p.p.m.), respectively. The performance of the pigs in the positive control group was very satisfying and among the highest in the trial, verifying earlier field studies. As a general conclusion it seems that all tested growth promoters had a beneficial effect compared with the untreated control, indicated by the decrease of mortality rate, the elimination of diarrhoeal incidence and the enhancement of growth performance, although the proliferative enteropathy control achieved by each substance was not always satisfactory. More specifically, the antibiotic growth promoters tested can be scaled according to their total efficacy as follows: 1. Salinomycin, tylosin, spiramycin; 2. Virginiamycin, zinc bacitracin, avilamycin; and 3. Avoparcin. Finally, it is considered that part of the growth promotion efficacy of the tested substances is due to their potential capacity to control porcine intestinal adenomatosis; thus, in future growth performance trials, the disease background of the trial farms must be examined, especially for porcine enteropathy challenges.

Topics: Abattoirs; Animals; Anti-Bacterial Agents; Antibiotic Prophylaxis; Bacitracin; Bacterial Infections; Disease Outbreaks; Female; Food, Fortified; Glycopeptides; Greece; Growth Substances; Ileitis; Ileum; Intestinal Mucosa; Male; Monensin; Oligosaccharides; Pyrans; Spiramycin; Swine; Swine Diseases; Tylosin; Virginiamycin

1. An experiment was carried out with male broiler chicks to evaluate the combined effect of monensin (150 mg/kg) and the growth promoters (GPs) Zn bacitracin (BAC, 50 mg/kg), virginiamycin (VIR, 25 mg/kg) and avoparcin (AVO, 20 mg/kg) fed from 7 to 28 d of age on performance, utilisation of dietary nutrients, yield of defeathered eviscerated carcases (DEC) and size of various organs. The effect of the GPs in the monensin-unsupplemented diets fed up to 49 d of age on performance and carcase was also determined. 2. Monensin significantly (P < 0.05) depressed food intake, weight gain and food efficiency from 7 to 28 d of age. None of the GPs was able to counteract these effects. However, AVO slightly ameliorated them. AVO also significantly increased food intake and improved gain and food efficiency during 7 to 28, but not 28 to 49 or 7 to 49 d of age. VIR and BAC did not affect performance in either age period. 3. Monensin did not affect the utilisation of dietary dry matter, fat or energy, but it significantly decreased nitrogen utilisation. AVO improved nitrogen and fat utilisation and increased dietary AME(n) content. AME(n) was also increased by VIR. The utilisation of these nutrients was not affected by the interactions between monensin and the GPs. 4. Monensin did not affect yield of the DEC or the relative liver size at 31 d of age. It significantly increased the relative length of the small intestine (SI) and decreased its specific weight. AVO significantly increased yield at 31, but not at 53 d of age. BAC and VIR did not affect this variable. AVO and VIR, but not BAC, at both age periods reduced, at times significantly, the size, length and specific weight of the SI. 5. Our conclusions: BAC, VIR and AVO do not counteract the toxic effect of monensin. The effect of GPs in improving performance decreases and even disappears with age, while their effect in reducing the size of the SI is still evident in 49-d-old birds.

Topics: Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Bacitracin; Chickens; Drug Interactions; Eating; Glycopeptides; Male; Monensin; Virginiamycin; Weight Gain

Small groups of chickens were given feed containing either avoparcin, nitrovin, virginiamycin or zinc bacitracin from the day of their purchase as day-olds. Differences between the birds receiving growth promoters and the untreated controls were observed during the last third of the 23 d survey period. The enterococcal population of the 'dosed' birds contained a greater proportion of Enterococcus faecium than did that of the control birds while the converse was true for Ent. gallinarum. This apparent selection of Ent. faecium by the growth-promoting antibiotics had an influence on the incidence of resistance to therapeutic antibiotics among the enterococcal population as a whole. This was because this species was generally more resistant than Ent. gallinarum to cephalothin, the MLS antibiotics (erythromycin, lincomycin and tylosin) and tetracycline.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Chickens; Drug Resistance, Microbial; Enterococcus faecalis; Feces; Glycopeptides; Nitrovin; Streptococcus; Virginiamycin

Morphologic studies were carried out on the liver, kidneys, and small intestine of broiler birds that had been given antibiotics with the feed (virginiamycin, 20.0 ppm, flavomycin, 4.8 ppm, and avotan, 10.0 ppm) in the course of 49 days, kept with a group of controls. The liver of the test birds showed protein and fatty dystrophy, and the kidneys--protein dystrophy. The small intestine showed thinning of the wall and increase in the villi intestinales length. The manifestation of the morphologic changes depended on the amount of the antibiotic taken in. Those of the birds that were offered flavomycin had well manifested lesions, while in birds that were given virginiamycin and avotan only the lesions were more slightly expressed.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bambermycins; Chickens; Glycopeptides; Intestine, Small; Kidney; Liver; Virginiamycin

Susceptibility and resistance of ruminal bacterial species to avoparcin, narasin, salinomycin, thiopeptin, tylosin, virginiamycin, and two new ionophore antibiotics, RO22-6924/004 and RO21-6447/009, were determined. Generally, antimicrobial compounds were inhibitory to gram-positive bacteria and those bacteria that have gram-positive-like cell wall structure. MICs ranged from 0.09 to 24.0 micrograms/ml. Gram-negative bacteria were resistant at the highest concentration tested (48.0 micrograms/ml). On the basis of their fermentation products, ruminal bacteria that produce lactic acid, butyric acid, formic acid, or hydrogen were susceptible and bacteria that produce succinic acid or ferment lactic acid were resistant to the antimicrobial compounds. Selenomonas ruminantium was the only major lactic acid-producing bacteria resistant to all the antimicrobial compounds tested. Avoparcin and tylosin appeared to be less inhibitory (MIC greater than 6.0 micrograms/ml) than the other compounds to the two major lactic acid-producing bacteria, Streptococcus bovis and Lactobacillus sp. Ionophore compounds seemed to be more inhibitory (MIC, 0.09 to 1.50 micrograms/ml) than nonionophore compounds (MIC, 0.75 to 12.0 micrograms/ml) to the major butyric acid-producing bacteria. Treponema bryantii, an anaerobic rumen spirochete, was less sensitive to virginiamycin than to the other antimicrobial compounds. Ionophore compounds were generally bacteriostatic, and nonionophore compounds were bactericidal. The specific growth rate of Bacteroides ruminicola was reduced by all the antimicrobial compounds except avoparcin. The antibacterial spectra of the feed additives were remarkably similar, and it appears that MICs may not be good indicators of the potency of the compounds in altering ruminal fermentation characteristics.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacteria; Carboxylic Acids; Drug Resistance, Microbial; Furans; Glycopeptides; Hydrogen; Indenes; Ionophores; Leucomycins; Peptides; Pyrans; Rumen; Tylosin; Virginiamycin

The effect of growth-stimulating agents (15 ppm of virginiamycin, 10 ppm of avoparcin and 12 ppm of nitrovin) and that of seven days' treatment with 300 ppm of furazolidone on the performance of broilers was studied in an experimental study of 9,600 animals. Furazolidone was fed in either the fourth or the fifth week of life and combined with virginiamycin or nitrovin. Non-significant improvements in growth were observed when virginiamycin (1.5 per cent), avoparcin (0.7 per cent) and nitrovin (0.7 per cent) were administered. Treatment with furazolidone for seven days resulted in substantial retardation of growth. When broilers were treated during the fourth week of life, the retardation of growth was largely compensated for during the other two weeks. Treatment in the fifth week of life resulted in lower weights prior to slaughter. Therefore, care should be taken in recommending treatment with furazolidone at the end of the fattening period of broilers.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Chickens; Food Additives; Furazolidone; Glycopeptides; Growth Substances; Nitrovin; Virginiamycin

Topics: Animals; Animals, Newborn; Anti-Bacterial Agents; Chickens; Female; Glycopeptides; Male; Salmonella typhimurium; Virginiamycin

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Female; Food Additives; Glycopeptides; Male; Salmonella; Turkeys; Virginiamycin