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CLASSEN H.L.,University of Saskatchewan | APAJALAHTI J.,Alimetrics Ltd. | SVIHUS B.,Norwegian University of Life Sciences | CHOCT M.,University of New England of Australia
World's Poultry Science Journal | Year: 2016

The importance of the crop is often underestimated in poultry production. In addition to storing ingested feed, it also can impact nutrient digestion by digesta softening and the initial activity of feed (endogenous and exogenous) and microbial enzymes. The crop represents the first major defence against poultry pathogens and zoonotic organisms with well established adaptive and innate immune function, and a lactobacilli dominated microbiota capable of reducing the passage of these organisms further along the digestive tract. However, the potential to improve bird productivity and health, as well as affect meat and egg safety, are influenced by the nature of the diet, and in particular feed entry and extended presence in the crop. This is required to promote lactobacilli fermentation, the production of lactic acid and other volatile fatty acids, and the lowering of crop pH. Management practices such as meal feeding and the use of lighting programs with extended dark periods encourage crop utilisation. Further, the use of feed additives such as prebiotics and probiotics may enhance crop function, which in turn contributes to well-being of the entire digestive tract. A healthy and functional crop, along with other segments of digestive tract, has increased importance in an era of reduced antibiotic use in poultry feeds. Copyright © World's Poultry Science Association2016

Aro H.,Mtt Agrifood Research Finland | Jarvenpaa E.,Mtt Agrifood Research Finland | Makinen J.,Mtt Agrifood Research Finland | Lauraeus M.,Alimetrics Ltd. | And 2 more authors.
LWT - Food Science and Technology | Year: 2013

Oats contain ingredients that have potential health-promoting properties. Oat lipids contain several essential fatty acids. The polar lipids in oats include glycolipids and phospholipids, which are typically extracted from oat flakes with polar organic solvents. Supercritical carbon dioxide (SC-CO2) has been proposed as an alternative to organic solvents in the food sector for environmental and safety reasons. SC-CO2 was used in this study without and with ethanol as a co-solvent to isolate the polar lipid fractions from oat flakes with or without heat treatments. The polar lipids were collected as a solution in ethanol and precipitated using SC-CO2 as an antisolvent. The fatty acid compositions of different lipid fractions were determined. The precipitated oat polar lipids were tested as an encapsulative and protective agent of probiotics in a human digestive tract simulation. The protective effects of the oat polar lipids were evaluated by measuring the gas production, microbial activity, acetic and lactic acid production, and pH changes in different test mediums. The results demonstrate that the oat polar lipids are able to protect Bifidobacterium breve in a phosphate buffer, thereby providing a useful stabilization method to improve the shelf life of probiotic products. © 2013 Elsevier Ltd.

Vaara M.,Northern Antibiotics Ltd. | Vaara M.,University of Helsinki | Siikanen O.,Alimetrics Ltd. | Apajalahti J.,Alimetrics Ltd. | And 7 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010

Polymyxins are cationic lipopeptides (five cationic charges) and the last resort for the treatment of serious Gram-negative infections caused by multiresistant strains. NAB741 has a cyclic peptide portion identical to that of polymyxin B but carries in the linear peptide portion a threonyl-D-serinyl residue (no cationic charges) instead of the diaminobutyryl-threonyl- diaminobutyryl residue (two cationic charges). At the N terminus of the peptide, NAB741 carries an acetyl group instead of a mixture of methyl octanoyl and methyl heptanoyl residues. NAB741 sensitized Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Acinetobacter baumannii to antibiotics against which the intact outer membrane is an effective permeability barrier. When tested by using Etest strips on plates containing increasing concentrations of NAB741, the fractional inhibition concentration index (FICI) of the combination of NAB741 with rifampin ranged from ≤0.111 to 0.158 and that with clarithromycin from ≤0.094 to 0.292. When tested by the checkerboard method, the corresponding FICI values against E. coli ATCC 25922 were ≤0.141 to ≤0.155 with rifampin and 0.094 with clarithromycin. In addition, at 4 μg/ml, NAB741 decreased the MICs of azithromycin, mupirocin, fusidic acid, and vancomycin for E. coli strains and E. cloacae by factors ranging from 8 to 200. A sister peptide, NAB752, carrying a threonyl-aminobutyryl residue as the linear peptide portion, was inactive. Furthermore, NAB741 sensitized E. coli to the bactericidal activity of fresh guinea pig serum. The renal clearance of NAB741 was approximately 400-fold, 16-fold, and 8-fold higher than those measured for colistin, NAB7061, and NAB739, respectively. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Vaara M.,Northern Antibiotics Ltd. | Vaara M.,University of Helsinki | Siikanen O.,Alimetrics Ltd. | Apajalahti J.,Alimetrics Ltd. | And 2 more authors.
Journal of Antimicrobial Chemotherapy | Year: 2010

Objectives: To determine the susceptibility of carbapenemase-producing strains of Klebsiella pneumoniae and Escherichia coli to the direct antibacterial activity of NAB739 and to the synergistic activity of NAB7061 with rifampicin and clarithromycin. NAB739 and NAB7061 are novel polymyxin derivatives that lack the cationic charges in the linear peptide portion of polymyxin B and have pharmacokinetic properties different from those of polymyxin B. Methods: MIC determinations were performed by the agar dilution method using CLSI guidelines. Polymyxin B was used as a comparison. Synergism studies measured fractional inhibitory concentration indices (FICIs) by using increasing concentrations of the compounds in Mueller-Hinton agar and Etests™. Results: The MICs of NAB739 for all nine polymyxin-susceptible, carbapenemase-producing strains were identical or very close to those determined for E. coli ATCC 25922, for K. pneumoniae ATCC 13883, as well as for 18 clinical carbapenem-susceptible isolates. At a concentration of 4 mg/L, NAB7061 decreased the MIC of rifampicin and clarithromycin for all carbapenemase strains by factors ranging from 6 to 500. The polymyxin-resistant strain K. pneumoniae CL5762B was sensitized by a factor of 24 to rifampicin (FICI, 0.167) and by a factor of 12 to clarithromycin (FICI, 0.208). Conclusions: Polymyxin-susceptible, carbapenemase-producing strains are as susceptible to NAB739 as are the carbapenem-susceptible clinical isolates. In addition, NAB7061 has notable synergism with rifampicin and clarithromycin against all the carbapenemase-producing strains tested, including the polymyxin-resistant K. pneumoniae strain. © The Author 2010. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Apajalahti J.,Alimetrics Ltd. | Vienola K.,Alimetrics Ltd.
Animal Feed Science and Technology | Year: 2016

The different sections of the broiler chicken intestinal tract are inhabited by specialist microbiota adapted to the physicochemical conditions, host physiology and available nutrients of the specific habitat. The small intestine is dominated by lactic acid bacteria which have complex nutrient requirements resembling those of the chicken host itself. Lactobacilli are unable to synthesise amino acids for their anabolism and are therefore highly dependent on amino acid availability in the growth environment. Thus, in the small intestine there is competition for amino acids between the microbiota and the chicken host. According to rough estimates, lactobacilli in the small intestine may assimilate 3-6% of total dietary amino acids. If the protein is highly digestible and amino acids are largely absorbed in the upper small intestine, where bacterial growth is suppressed, the proportion captured by the host may be higher. Exogenous enzymes which promote protein digestion are also likely to provide a competitive advantage to the chicken, offering less growth potential for amino acid-dependent bacteria.Protein escaping the ileum comprises resistant protein of dietary origin, protein assimilated to intestinal bacteria and endogenous protein synthesised and secreted by the host, the latter synthesised in host tissues from dietary amino acids and thus representing true endogenous protein. Activities of small intestinal bacteria affect the size of the microbial protein fraction and also the production of endogenous proteins originating from mucin, epithelial cells and antibodies.Ileal bypass protein is subject to fermentation by putrefactive bacteria in the caecum. Putrefaction produces many harmful and toxic compounds, which in high concentrations may have adverse effects on chicken growth and performance. The protein fermentation products include amines, indoles, phenols, cresol and ammonia, which can all negatively affect host or cell health. All actions to reduce the amount of ileal bypass protein potentially also reduce production of toxic protein fermentation metabolites in the caecum. Enzymes which facilitate protein digestion in the upper intestine and soluble carbohydrates resistant to ileal digestion both reduce caecal putrefaction. In the distal intestine, saccharolytic fermentation is preferred and putrefaction accelerates only when utilisable carbohydrates are depleted. Soluble oligo- and polysaccharides are produced in situ by non-starch polysaccharide degrading enzymes and can also be added directly to the diet as health-promoting prebiotics. © 2016 Elsevier B.V.

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