Effects of selenium-enriched Bacillus sp. compounds on growth performance, antioxidant status, and lipid parameters breast meat quality of Chinese Huainan partridge chicks in winter cold stress.

BACKGROUND: Both selenium (Se) and probiotic Bacillus regulate the metabolism to help defense clod stress and improve the meat quality in breeding chicks. The purpose of this study was to evaluate the effect of supplemental Se and Bacillus in the form of Se-enriched Bacillus (SECB) on the growth performance, lipid parameters, breast Se and antibiotic levels, and breast meat quality of chicken in winter cold stress. METHODS: Five hundred 1-d-old chickens were divided into five groups randomly: Control, inorganic Se, compound Bacillus, SECB, and antibiotic. The feed duration was 56 d. RESULTS: After 28 d of treatment, chicks feed SECB or compound Bacillus had higher body weights than the control, and after 56 d, chicks given either SECB or compound Bacillus had higher body weights than the control chicks or those given inorganic Se. Adding SECB to feed significantly increased the lightness, redness, and yellowness of breast meat, improved the water-holding capacity, and reduced the shear force and cooking loss. The concentration of Se in the breast muscle very significantly increased after SECB and inorganic Se supplementation, which was opposite to the concentration of flavomycin in antibiotic supplemented chicks. The antioxidative status of plasma and breast meat was significantly improved with added compound Bacillus and SECB: the total antioxidant capacity, total superoxide dismutase, and glutathione peroxidase ability in the breast muscle significantly improved, and the malondialdehyde concentration in plasma decreased. The levels of total cholesterol plasma triglyceride and very-low-density lipoprotein cholesterol in the plasma and breast muscle was decreased compared to that of the control, while the plasma high-density lipoprotein cholesterol concentration increased. CONCLUSIONS: In conclusion, SECB supplementation promoted the body growth, antioxidative status, and Se concentrations in the plasma and breast meat, and also improved the breast meat quality.

Development of bacterial transglycosylase inhibitors as new antibiotics: moenomycin A treatment for drug-resistant Helicobacter pylori.

The problem of multidrug-resistant Helicobacter pylori requires new antibiotics development. We have evaluated a potential antibiotics, moenomycin A, which is classified as a phosphoglycolipid antibiotics that targets transglycosylase and is previously thought to be limited in Gram-positive bacteria. Herein, we report the activity of moenomycin A against multidrug-resistant H. pylori and the isolates from patients with different gastrointestinal diseases.

Synthesis and evaluation of a new fluorescent transglycosylase substrate: lipid II-based molecule possessing a dansyl-C20 polyprenyl moiety.

The preparation of a novel fluorescent lipid II-based substrate for transglycosylases (TGases) is described. This substrate has characteristic structural features including a shorter lipid chain, a fluorophore tag at the end of the lipid chain rather than on the peptide chain, and no labeling with a radioactive atom. This fluorescent substrate is readily utilized in TGase activity assays to characterize TGases and also to evaluate the activities of TGase inhibitors.

Effect of lactoferrin on the growth performance, intestinal morphology, and expression of PR-39 and protegrin-1 genes in weaned piglets.

A total of 90 weaned female pigs (Duroc x Landrace x Yorkshire) were used in a 15-d growth experiment to investigate the effect of lactoferrin on growth performance, intestinal morphology, and expression of PR-39 and protegrin-1 genes. The pigs were allocated on the basis of BW and litter to 3 dietary treatments in a randomized complete block design. There were 3 replicate pens per treatment, and the pigs were grouped with 10 pigs per pen. The dietary treatments were (1) basal diet; (2) basal diet + 20 mg of flavomycin/kg + 110 mg of aureomycin/kg; (3) basal diet + 1.0 g of lactoferrin/kg. Six pigs, randomly selected from each treatment (2 piglets/pen) were slaughtered for intestinal morphology and expression of PR-39 and protegrin-1 genes at the end of the experiment. Supplementation with lactoferrin improved growth performance; it increased ADG by 41.80% (P < 0.01) and efficiency of gain (G:F) by 17.20% (P < 0.05). Intestinal villus height was increased by 15.30% (P < 0.05), and crypt depth was decreased by 9.60% (P < 0.05). Supplemental lactoferrin increased the relative abundance of mRNA for PR-39 and protegrin-1 by 143% (P < 0.01) and 217% (P < 0.01), respectively. The use of lactoferrin as an additive to improve nonspecific immunity and strengthen host defenses would be good a method of defending weaned pigs from infections and weanling stress.

A differential response in turkey poults to various antibiotics in diets designed to be deficient or adequate in certain essential nutrients.

Two experiments, each consisting of two trials, were conducted with day-old Nicholas Large White turkey poults to compare the effectiveness of four antibiotics for growth promotion and the utilization of sulfur amino acids. A corn-soybean meal basal diet that contained no supplemental methionine, choline, or inorganic sulfate was used in order to furnish nutritional stress. The diet was calculated to contain 25.4% protein, .448% methionine, .403% cystine, 1014 mg/kg choline, and 2990 kcal metabolizable energy/kg. In Experiment 1, a 2 X 4 factorial arrangement of treatments was used. This included two levels, (0% (control) and .18%), of supplemental DL-methionine and no antibiotic or bacitracin MD, flavomycin, or virginiamycin; antibiotics were fed at 50, 2, and 20 g/ton, respectively. In Experiment 2, lincomycin also was included as a treatment (at 4 g per ton) resulting in a 2 X 5 factorial arrangement of treatments. Only the addition of Virginiamycin to the control diet in Experiment 1 resulted in significantly increased body weights. Supplementation by .18% methionine increased body weights and feed efficiency. In addition, all three antibiotics increased body weights significantly when added to the .18% methionine diets. Feed efficiency values were improved by all four antibiotics at both methionine levels. In Experiment 2, increases in body weights similar to those in Experiment 1 were obtained with the addition of .18% methionine to the basal diets. Addition of lincomycin and virginiamycin improved body weights and feed efficiencies in the presence and absence of supplemental methionine.

The effect of flavomycin on the synthesis and transfer of lipid-linked saccharides in pig brain.

Particulate membrane fractions from pig brain catalyse the synthesis of lipid-linked sugar derivatives of the dolichyl phosphate pathway. Flavomycin, a phosphoglycolipid antibiotic produced by various species of streptomycetes, interferes with the formation of these glycolipids to a different extent. The formation of dolichyl phosphate glucose was shown to be most susceptible to the antibiotic, being blocked by about 50% in the presence of 0.2mm-flavomycin, whereas the synthesis of dolichyl diphosphate N-acetylglucosamine, dolichyl diphosphate chitobiose and dolichyl diphosphate chitobiosyl mannose required higher concentrations to achieve a comparable inhibition. Although the formation of dolichyl phosphate mannose was hardly affected, the accumulation of oligosaccharides with five to seven sugar units was observed, when dolichyl diphosphate oligosaccharides were synthesized with GDP-[(14)C]mannose in the presence of 1mm-flavomycin. This indicates that the inhibition of the synthesis of larger-sized oligosaccharides, known to be mediated by lipid-bound mannose, was not caused by an actual deficiency in dolichyl phosphate mannose. At flavomycin concentrations that inhibited the formation of dolichyl phosphate glucose by 50%, the transfer of lipid-linked saccharides to either the hexapeptide Tyr-Asn-Gly-Thr-Ser-Val or endogenous protein acceptors was hardly influenced. The mode of action of flavomycin is still obscure, but seems not to be of a competitive nature, since the inhibition was unaffected by increasing concentrations of dolichyl phosphate. Some evidence indicates that, besides a direct interaction of the antibiotic with some transferases, a non-specific incorporation into the membrane and alteration of its properties might be responsible for those inhibitory effects on all enzymes which were observed at high concentrations of flavomycin.