ORCID Profile
0000-0002-4152-0681
Current Organisation
University of Tasmania
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Publisher: American Physiological Society
Date: 05-2009
Publisher: Oxford University Press (OUP)
Date: 05-2004
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.COLSURFB.2015.10.015
Abstract: The purpose of the present study was to investigate the antimicrobial effects of functionalized polyanilines (fPANIs) against stationary phase cells and biofilms of Pseudomonas aeruginosa and Staphylococcus aureus using homopolymer of sulfanilic acid (poly-SO3H) as a model. The chemically synthesized poly-SO3H was characterized using Fourier Transform Infra-Red (FTIR) and Ultraviolet-Visible (UV-Vis) spectroscopies. The molecular weight (Mw) and elemental analysis of homopolymer poly-SO3H were also examined. We found that poly-SO3H was bactericidal against stationary phase cells of P. aeruginosa and S. aureus at a concentration of 20 mgml(-1). Surprisingly, we discovered that the same concentration (20 mgml(-1)) of poly-SO3H significantly disrupted and killed bacterial cells present in pre-established forty-eight hour static biofilms of these organisms, as shown by crystal violet and bacterial live/dead fluorescence staining assays. In support of these data, poly-SO3H extensively diminished the expression of bacterial genes related to biofilm formation in stationary phase cells of P. aeruginosa, and seemed to greatly reduce the amount of the quorum sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL) able to be recovered from biofilms of this organism. Furthermore, we found that poly-SO3H was able to effectively penetrate and kill cells in biofilms formed by the P. aeruginosa (AESIII) isolate derived from the sputum of a cystic fibrosis patient. Taken together, the results of the present study emphasise the broad antimicrobial activities of fPANI, and suggest that they could be developed further and used in some novel ways to construct medical devices and/or industrial equipment that are refractory to colonization by biofilm-forming bacteria.
Publisher: Elsevier BV
Date: 06-2020
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/AN19283
Abstract: Both whole-grain feeding and exogenous phytases have been widely accepted by the chicken-meat industry, so any interactions that arise from this combined supplementation are potentially important. Nevertheless, there is a paucity of research evaluating the effect of phytase under whole-grain feeding regimens. Whole-grain feeding increases relative gizzard weights and gizzard functionality. However, the gizzard is the primary site of phytate degradation by phytase, so this combined supplementation should enhance phytase efficacy. Moreover, there has been recent progress towards understanding the influence of whole-grain feeding and exogenous phytase on broiler performance, which is discussed. Further research is warranted to establish a whole-grain feeding regimen that generates robust gizzard responses so as to enhance feed efficiency, energy utilisation and phytase efficacy.
Publisher: American Society for Microbiology
Date: 08-2013
DOI: 10.1128/IAI.00418-13
Abstract: Pseudomonas aeruginosa chronically infects the lungs of more than 80% of adult patients with cystic fibrosis (CF) and is a major contributor to the progression of disease pathology. P. aeruginosa requires iron for growth and has multiple iron uptake systems that have been studied in bacteria grown in laboratory culture. The purpose of this research was to determine which of these are active during infection in CF. RNA was extracted from 149 sputum s les obtained from 23 CF patients. Reverse transcription–quantitative real-time PCR (RT-qPCR) was used to measure the expression of P. aeruginosa genes encoding transport systems for the siderophores pyoverdine and pyochelin, for heme, and for ferrous ions. Expression of P. aeruginosa genes could be quantified in 89% of the sputum s les. Expression of genes associated with siderophore-mediated iron uptake was detected in most s les but was at low levels in some s les, indicating that other iron uptake mechanisms are active. Expression of genes encoding heme transport systems was also detected in most s les, indicating that heme uptake occurs during infection in CF. feoB expression was detected in all sputum s les, implying an important role for ferrous ion uptake by P. aeruginosa in CF. Our data show that multiple P. aeruginosa iron uptake mechanisms are active in chronic CF infection and that RT-qPCR of RNA extracted from sputum provides a powerful tool for investigating bacterial physiology during infection in CF.
Publisher: Informa UK Limited
Date: 05-2019
DOI: 10.1080/00071668.2019.1605154
Abstract: 1.The objective of the present study was to rank the importance of the following dietary factors canola meal, wheat, whole barley, digestible lysine, phytate-P, calcium, available P, sodium and three NSP-degrading feed enzymes. Their influence on growth performance, gastro-intestinal tract parameters, energy utilisation, ileal N digestibility and disappearance rates were determined via the Plackett-Burman design in broiler chickens offered phytase-supplemented diets. 2. The eleven dietary factors were assigned two levels in the Plackett-Burman design matrix. The resulting twelve dietary treatments were offered to six replicates per treatment (six birds per cage) with a total of 468 male Ross 308 broiler chicks from 7 to 28 d post-hatch. 3. Increasing digestible lysine levels improved weight gain by 15.6% (P < 0.001) and gain:feed by 9.36% (P < 0.001). Increasing calcium levels reduced weight gain by 6.36% (P < 0.001) and gain:feed by 2.60% (P < 0.001). The high calcium level increased gizzard pH from 2.78 to 3.01 (P < 0.005). Whole barley significantly increased relative gizzard weights and contents, pancreas weights and both ileal N digestibility coefficients (0.774 versus 0.803 P < 0.001) and ileal N disappearance rates (23. 3 versus 24.5 g/bird/day P < 0.001). 4. Overall, digestible lysine level and calcium level were identified as the most influential dietary factors to influence growth performance of broilers offered phytase-supplemented diets, which hold implications for practical diet formulations.
Publisher: American Thoracic Society
Date: 05-2019
Publisher: American Society for Microbiology
Date: 26-03-2020
DOI: 10.1128/MRA.00060-20
Abstract: Pandoraea fibrosis is a newly identified Gram-negative bacterial species that was isolated from the respiratory tract of an Australian cystic fibrosis patient. The complete assembled genome sequences of two consecutive isolates (second isolate collected 11 months after antibiotic treatment) from the same in idual are presented here.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 05-1997
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 02-2020
Publisher: Wiley
Date: 08-02-2019
DOI: 10.1111/IMCB.12230
Abstract: Cystic fibrosis (CF) is caused by mutations to the CF transmembrane conductance regulator (CFTR) gene. CFTR is known to be expressed on multiple immune cell subtypes, dendritic cells, monocytes/macrophages, neutrophils and lymphocytes. We hypothesized that the lack of CFTR expression on peripheral blood innate immune cells would result in an altered cell profile in the periphery and that this profile would reflect lung pathology. We performed a flow cytometric phenotypic investigation of innate immune cell proportions in peripheral blood collected from 17 CF patients and 15 age-matched healthy controls. We observed significant differences between CF patients and controls in the relative proportions of natural killer (NK) cells, monocytes and their subsets, with significant correlations observed between proportions of NK and monocyte cell subsets and lung function (forced expiratory volume in 1 sec, % predicted FEV1% predicted) in CF patients. This study demonstrates the widespread nature of immune dysregulation in CF and provides a basis for identification of potential therapeutic targets. Modulation of the distinct CF-related immune cell phenotype identified could also be an important biomarker for evaluating CFTR-targeted drug efficacy.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.JCF.2013.03.008
Abstract: Intravenous antibiotics for pulmonary exacerbations (PEs) of cystic fibrosis (CF) usually target Pseudomonas aeruginosa. Insights into the CF lung microbiome have questioned this approach. We used RT-qPCR to determine whether intravenous antibiotics reduced P. aeruginosa numbers and whether this correlated with improved lung function. We also investigated antibiotic effects on other common respiratory pathogens in CF. Sputa were collected from patients when stable and again during a PE. Sputa were expectorated into a RNA preservation buffer for RNA extraction and preparation of cDNA. qPCR was used to enumerate viable P. aeruginosa as well as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Burkholderia cepacia complex and Aspergillus fumigatus. Fifteen CF patients were followed through 21 PEs. A complete set of serial sputum s les was unavailable for two patients (three separate PEs). P. aeruginosa numbers did not increase immediately prior to a PE, but numbers during intravenous antibiotic treatment were reduced ≥4-log in 6/18 and ≥1-log in 4/18 PEs. In 7/18 PEs, P. aeruginosa numbers changed very little with intravenous antibiotics and one patient demonstrated a ≥2-log increase in P. aeruginosa load. H. influenzae and S. pneumoniae were detected in ten and five PEs respectively, but with antibiotic treatment these bacteria rapidly became undetectable in 6/10 and 4/5 PEs, respectively. There was a negative correlation between P. aeruginosa numbers and FEV1 during stable phase (r(s)=0.75, p<0.05), and reductions in P. aeruginosa load with intravenous antibiotic treatment correlated with improved FEV1 (r(s)=0.52, p<0.05). Exacerbations are not due to increased P. aeruginosa numbers in CF adults. However, lung function improvements correlate with reduced P. aeruginosa burden suggesting that current antibiotic treatment strategies remain appropriate in most patients. Improved understanding of PE characterised by unchanged P. aeruginosa numbers and minimal lung function improvement following treatment may allow better targeted therapies.
Publisher: Springer Science and Business Media LLC
Date: 04-10-2019
DOI: 10.1186/S40104-019-0385-Y
Abstract: The reduction of crude protein levels in diets for broiler chickens may generate economic, environmental and flock welfare and health benefits however, performance is usually compromised. Whole grain feeding and phytase may improve the utilization of reduced crude protein diets. The effects of pre-pellet cracked maize (0, 15% and 30%) and phytase (0, 750 and 1500 FTU/kg) in iso-energetic maize-soy diets with three levels of crude protein (22%, 19.5% and 17%) were evaluated via a Box-Behnken response surface design. Each of 13 dietary treatments were offered to 6 replicate cages (6 birds/cage) of male Ross 308 broiler chicks from 7 to 28 d post-hatch. Model prediction and response surface plots were generated from experimental data via polynomial regression in R and only significant coefficients were included and discussed in the predicted models. Weight gain, feed intake and FCR were all influenced by pre-pellet cracked maize, phytase and crude protein level, where crude protein level had the greatest influence. Consequently, the reduction from 22% to 17% dietary crude protein in non-supplemented diets reduced weight gain, feed intake, relative gizzard weight, relative gizzard content and relative pancreas weight but improved FCR. However, the inclusion of 30% cracked maize to 17% crude protein diets restored gizzard weight and 1500 FTU phytase inclusion to 17% crude protein diets increased relative gizzard contents and pancreas weights. Cracked maize and phytase inclusion in tandem to 17% crude protein diets increased weight gain, feed intake and FCR however, this FCR was still more efficient than broilers offered the non-supplemented 22% crude protein diet. Broilers offered the pre-pellet cracked maize and phytase inclusions reduced AME in 22% crude protein diets but improved AME by 2.92 MJ (14.16 versus 11.24 MJ P 0.001) in diets containing 17% crude protein. Ileal N digestibility was greater in broilers offered diets with 17% crude protein than those offered the 22% crude protein diet irrespective of phytase and pre-pellet cracked maize. Pre-pellet cracked maize and phytase inclusions will improve the performance of broilers offered reduced crude protein diets.
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/AN17594
Abstract: After an extended delay, the level of acceptance of exogenous phytases by the global chicken-meat industry is now almost complete. Contemporary bacterial phytases degrade phytate primarily in the gizzard. The extent of phytate degradation determines the extent to which phytate-bound phosphorus (P) is liberated however, studies designed to investigate phytate degradation along the digestive tract have generated some confusing outcomes. This may be related to the reactivity of the phytate moiety, coupled with problems with inert dietary markers and perhaps a lack of complete and uniform extractions of phytate from digesta due to variations in digesta pH and phytate solubility. Quite recently, phytase was shown to have profound impacts on sodium (Na) digestibility coefficients in four segments of the small intestine. This has obvious implications for intestinal uptakes of glucose and amino acids via their respective Na+-dependent transport systems and it is possible that phytate and phytase have reciprocal impacts on ‘sodium pump’ (Na+, K+-ATPase) activity. It has been recently demonstrated unequivocally that phytase has the capacity to increase amino acid digestibility coefficients to the extent that phytase may generate a ‘proximal shift’ in the sites of amino acid absorption. The impact of phytase on starch digestibility is more equivocal and phytase responses may stem more from enhanced glucose absorption rather than starch digestion. The acceptance of phytase is hardly surprising, given its capacity to increase P utilisation coupled with numerous other positive influences that are still being properly realised.
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 12-2020
Publisher: Oxford University Press (OUP)
Date: 03-2009
Publisher: Informa UK Limited
Date: 15-10-2021
DOI: 10.1080/00071668.2021.1975260
Abstract: 1. A study was conducted to assess the effects of supplemental protease (0 or 15,000 units/kg) and diet type (maize- or wheat-based) on apparent jejunal and ileal digestibility and apparent total tract metabolisability of nutrients in Cobb 500 mixed-sex broilers from 6 to 31 d of age.2. Birds were randomly distributed into 56 metabolism cages (6 birds/cage 14 replicates/treatment). At 22 d of age, jejunal and ileal digesta contents were collected and pooled from 4 birds/cage to determine apparent digestibility coefficients (DC) and digestible energy (DE). Feed intake was measured, and total excreta were collected from 8 to 11 and 18 to 21 d of age to determine apparent metabolisable energy (AME) and total tract nitrogen and starch metabolisability coefficients.3. Broilers offered the maize-based diet with protease had greater (P < 0.05) jejunal nitrogen DC, starch DC, and DE (8.2, 6.5, and 14.9%, respectively) and ileal nitrogen DC and DE (5.1 and 6.8%, respectively) than those offered the maize-based diet without protease. Ileal starch DC was increased (P < 0.05) by 1.1% with protease supplementation.4. Broilers offered maize-based diets had greater (P < 0.05) nitrogen (7.3%) and starch (0.6%) metabolisability coefficients and AME (4.7%) from 8 to 11 d of age, and nitrogen (4.3%) metabolisability coefficients and AME (2.0%) from 18 to 21 d of age compared with those offered wheat-based diets.5. Thus, protease supplementation and diet type can affect digestive dynamics and nutrient utilisation in broilers.
Publisher: Frontiers Media SA
Date: 2011
DOI: 10.1080/09674845.2011.11732833
Abstract: Pseudomonas aeruginosa is an important pathogen in humans, particularly in the context of nosocomial infection and infections of the cystic fibrosis (CF) lung. In order to provide clinicians with information about the likely effectiveness of specific antimicrobial treatment for P. aeruginosa infections, clinical laboratories employ in vitro antimicrobial susceptibility testing. Two commonly employed methods are the CLSI disc-diffusion and Etest methods. The purpose of this study is to compare the accuracy of susceptibility results generated by these two methods against agar dilution as the reference method. Susceptible or nonsusceptible (resistant and intermediate) results of the Etest and CLSI disc-diffusion methods are compared with CLSI agar dilution results for a large cohort of clinical cystic fibrosis (n = 71) and non-cystic fibrosis (n = 83) isolates using CLSI interpretive criteria. An unacceptable number of major and very major errors were observed for various antimicrobials tested against both CF and non-CF isolates when using the Etest and CLSI disc-diffusion methods. The potential for error in standard laboratory antimicrobial susceptibility testing should be considered by clinicians when being guided by the results of such tests in the prescription of antimicrobial agents for P. aeruginosa infection.
Publisher: Public Library of Science (PLoS)
Date: 24-03-2015
Publisher: Elsevier BV
Date: 07-2003
DOI: 10.1016/S1046-5928(03)00061-5
Abstract: Until recently, glycosylation of proteins in prokaryotes was regarded as uncommon and thought to be limited to special cases such as S-layer proteins and some archeal outer membrane proteins. Now, there are an increasing number of reports of bacterial proteins that are glycosylated. Pilin of pathogenic Neisseria is one of the best characterised post-translationally modified bacterial proteins, with four different types of modifications reported, including a novel glycosylation. Pilin monomers assemble to form pilus fibres, which are long protein filaments that protrude from the surface of bacterial cells and are key virulence factors. To aid in the investigation of these modifications, pure pilin is required. A number of pilin purification methods have been published, but none are appropriate for the routine purification of pilin from many different isolates. This study describes a novel, rapid, and simple method of pilin purification from Neisseria meningitidis C311#3, which facilitates the production of consistent quantities of pure, native pilin. A 6x histidine tag was fused to the C-terminus of the pilin subunit structural gene, pilE, via homologous recombination placing the 6x histidine-tagged allele in the chromosome of N. meningitidis C311#3. Pilin was purified under non-denaturing conditions via a two-step process using immobilised metal affinity chromatography (IMAC), followed by dye affinity chromatography. Analysis of the purified pilin confirmed that it retained both of the post-translational modifications examined. This novel approach may prove to be a generally applicable method for purification and analysis of post-translationally modified proteins in bacteria.
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.JCF.2009.12.003
Abstract: Two recent studies have demonstrated the presence of biologically significant amounts of cyanide within the airways of cystic fibrosis (CF) patients infected with Pseudomonas aeruginosa. Whilst environmental strains of P. aeruginosa are known to synthesise cyanide, there has been a relative lack of investigation into bacterial cyanogenesis from a medical viewpoint, despite the role P. aeruginosa plays in many serious infection settings and especially in CF lung disease. This review discusses the implications of cyanogenesis in the CF airway in terms of bacterial ecology, host immune response, progression of lung disease and potential treatment options.
Publisher: Wiley
Date: 08-2003
DOI: 10.1046/J.1365-2958.2003.03602.X
Abstract: Pili of Neisseria meningitidis are a key virulence factor, being the major adhesin of this capsulate organism and contributing to specificity for the human host. Pili are post-translationally modified by addition of either an O-linked trisaccharide, Gal (beta1-4) Gal (alpha1-3) 2,4-diacetamido-2,4,6-trideoxyhexose or an O-linked disaccharide Gal (alpha1,3) GlcNAc. The role of these structures in meningococcal pathogenesis has not been resolved. In previous studies we identified two separate genetic loci, pglA and pglBCD, involved in pilin glycosylation. Putative functions have been allocated to these genes however, there are not enough genes to account for the complete biosynthesis of the described structures, suggesting additional genes remain to be identified. In addition, it is not known why some strains express the trisaccharide structure and some the disaccharide structure. In order to find additional genes involved in the biosynthesis of these structures, we used the recently published group A strain Z2491 and group B strain MC58 Neisseria meningitidis genomes and the unfinished Neisseria meningitidis group C strain FAM18 and Neisseria gonorrhoeae strain FA1090 genomes to identify novel genes involved in pilin glycosylation, based on homology to known oligosaccharide biosynthetic genes. We identified a new gene involved in pilin glycosylation designated pglE and examined four additional genes pglB/B2, pglF, pglG and pglH. A strain survey revealed that pglE and pglF were present in each strain examined. The pglG, pglH and pglB2 polymorphisms were not found in strain C311 musical sharp 3 but were present in a large number of clinical isolates. Insertional mutations were constructed in pglE and pglF in N. meningitidis strain C311 musical sharp 3, a strain with well-defined lipopolysaccharide (LPS) and pilin-linked glycan structures. Increased gel migration of the pilin subunit molecules of pglE and pglF mutants was observed by Western analysis, indicating truncation of the trisaccharide structure. Antisera specific for the C311 musical sharp 3 trisaccharide failed to react with pilin from these pglE and pglF mutants. GC-MS analysis of the sugar composition of the pglE mutant showed a reduction in galactose compared with C311 musical sharp 3 wild type. Analysis of amino acid sequence homologies has suggested specific roles for pglE and pglF in the biosynthesis of the trisaccharide structure. Further, we present evidence that pglE, which contains heptanucleotide repeats, is responsible for the phase variation between trisaccharide and disaccharide structures in strain C311 musical sharp 3 and other strains. We also present evidence that pglG, pglH and pglB2 are potentially phase variable.
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/AN19308
Abstract: Most of the world’s arable area is sown to either grains or oilseeds, and it is the big movements in the profitability of these crops that determine the pressure on global cropping-area supply. This perspective incorporates publicly available data, primarily from the FAO, to demonstrate some of the shifting pressures on global agriculture. Additionally, it argues that the advent of biofuel policies created additional demand for the area to produce cereal and oil crops from 2002. However, with a slowing demand growth for ethanol biofuels, crops for human and animal consumption will once again become the main driver for crop acreage. In particular, protein crops will be favoured as higher incomes are strongly linked to a greater animal-product consumption. In addition, a shift to a more intensive animal production is further increasing the demand for protein crops. Therefore, we could ultimately see a contraction in cereal crops and much faster growth in oilseeds, albeit from a lower base, as the demand for feed becomes the main driver for global agriculture. Yet, this is occurring during a time in which protein content of the major oil crops has been declining (albeit while yields continue to increase).
Publisher: Elsevier BV
Date: 2020
DOI: 10.3382/PS/PEZ573
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/PP00107_ER
Abstract: The nodulation failure resulting from the interaction between Rhizobium leguminosarum biovar trifolii strain ANU794 and the Trifolium subterraneum cv. Woogenellup was examined by transposon mutagenesis to resolve whether multiple determinants were involved in cultivar-specificity. Three new transposon-induced mutants of ANU794 (W72, W78 and W710) with significantly enhanced nodulation ability on cv. Woogenellup were identified. The W72 and W78 mutations are chromosomally-located, whereas the W710 mutation isplasmid-located. The ethylene synthesis inhibitor, aminoethoxyvinylglycine, fails to enhance the nodulation ability of ANU794, ANU7943 (csn1::Tn5) and W78 on cv. Woogenellup, but enhances the nodulation ability of W72,W710 and ANU7941 (nodM::Tn5). DNA sequencing of the W78 locus reveals strong homology to an unknown Mycobacterium open reading frame, and to several bacterial non-haem chloroperoxidases. The previously identified csn1 locus showed homology to the 50S ribosomal protein, L9, with the Tn5 insertion being located in the 5′-untranslated region. The results suggest that cultivar-specificity is mediated by at least two independent mechanisms or determinants, and not by a simple gene-for-gene interaction. The role of ethylene in cultivar specificity is discussed. Cultivar-specific interactions may prove useful in identifying pathways involved in efficient nodule formation and plant-microbe interactions.
Publisher: Public Library of Science (PLoS)
Date: 31-07-2012
Publisher: Public Library of Science (PLoS)
Date: 24-09-2020
Publisher: Microbiology Society
Date: 08-2010
Abstract: The virulence factor genotypes of a large cohort of clinical, nosocomial environment and community environment isolates (184 in total) of Pseudomonas aeruginosa from Tasmania, Australia, were determined by PCR. The virulence factor genotype of the majority of isolates was highly conserved, with the exception of the virulence gene exoU , which demonstrated low prevalence (33 isolates 18 %) in the population tested. Isolates collected from the environment of intensive therapy wards (intensive care unit and neurosurgical units) of the major tertiary referral hospital in Tasmania were found to be more likely ( P .001 and P .05, respectively) to possess the virulence factor gene exoU than all other isolates. Adult cystic fibrosis isolates showed a decreased prevalence of the exoU gene ( P .01) when compared to other clinical isolates ( P .01), which may indicate decreased virulence. No specific virulence factor genotype was associated with the cystic fibrosis epidemic strains tested.
Publisher: Elsevier BV
Date: 03-2018
Publisher: Informa UK Limited
Date: 12-12-2016
DOI: 10.1080/00071668.2016.1257777
Abstract: 1. The two red grain sorghums were extensively characterised. Kafirin, polyphenolic compounds, free, conjugated and bound phenolic acids, phytate concentrations and starch pasting profiles were determined. 2. The experiment consisted of a 2 × 4 factorial array of dietary treatments comprising two red sorghum varieties (Tiger and Block I) ground through 4 hammer-mill screen sizes (2.0, 3.2, 4.8 6.0 mm) prior to incorporation into nutritionally equivalent diets. Eight steam-pelleted dietary treatments were each offered to 7 replicates (6 male Ross 308 birds per cage) from 7 to 28 d post-hatch. 3. Effects of dietary treatments on growth performance, relative gizzard and pancreas weights, nutrient utilisation, apparent starch and protein (N) digestibility coefficients and disappearance rates from 4 small intestinal segments were determined. 4. The 2.0-mm hammer-mill screen generated an average geometric mean particle size of 794 μm and the 6.0-mm screen a mean particle size of 1405 μm. However, hammer-mill screen size did not influence weight gain or FCR. The 6.0-mm screen size generated significantly higher starch and protein (N) digestibility coefficients in the distal jejunum and distal ileum than the 2.0-mm hammer-mill screen. 5. Tiger sorghum was superior to Block I sorghum, as significant advantages were observed for feed conversion ratios (3.25%), AME (0.37 MJ), ME:GE ratios (4.15%), AMEn (0.53 MJ), distal ileal starch digestibility coefficients (2.46%) and protein (N) digestibility coefficients in the distal jejunum (4.66%), proximal ileum (1.96%) and distal ileum (2.16%). The inferior Block I sorghum contained more kafirin (67.1 versus 51.3 g/kg), phytate (9.79 versus 8.40 g/kg), total phenolic compounds (4.68 versus 4.12 mg GAE/g), flavan-4-ols (7.98 versus 5.04 ABS/ml/g), total phenolic acids (554 versus 402 μg/g) and total ferulic acid (375 versus 281 μg/g) in comparison to Tiger sorghum.
Publisher: MDPI AG
Date: 16-03-2021
DOI: 10.3390/RS13061128
Abstract: Hyperspectral imaging (HSI) is an emerging rapid and non-destructive technology that has promising application within feed mills and processing plants in poultry and other intensive animal industries. HSI may be advantageous over near infrared spectroscopy (NIRS) as it scans entire s les, which enables compositional gradients and s le heterogenicity to be visualised and analysed. This study was a preliminary investigation to compare the performance of HSI with that of NIRS for quality measurements of ground s les of Australian wheat and to identify the most important spectral regions for predicting carbon (C) and nitrogen (N) concentrations. In total, 69 s les were scanned using an NIRS (400–2500 nm), and two HSI cameras operated in 400–1000 nm (VNIR) and 1000–2500 nm (SWIR) spectral regions. Partial least square regression (PLSR) models were used to correlate C and N concentrations of 63 calibration s les with their spectral reflectance, with 6 additional s les used for testing the models. The accuracy of the HSI predictions (full spectra) were similar or slightly higher than those of NIRS (NIRS Rc2 for C = 0.90 and N = 0.96 vs. HSI Rc2 for C (VNIR) = 0.97 and N (SWIR) = 0.97). The most important spectral region for C prediction identified using HSI reflectance was 400–550 nm with R2 of 0.93 and RMSE of 0.17% in the calibration set and R2 of 0.86, RMSE of 0.21% and ratio of performance to deviation (RPD) of 2.03 in the test set. The most important spectral regions for predicting N concentrations in the feed s les included 1451–1600 nm, 1901–2050 nm and 2051–2200 nm, providing prediction with R2 ranging from 0.91 to 0.93, RMSE ranging from 0.06% to 0.07% in the calibration sets, R2 from 0.96 to 0.99, RMSE of 0.06% and RPD from 3.47 to 3.92 in the test sets. The prediction accuracy of HSI and NIRS were comparable possibly due to the larger statistical population (larger number of pixels) that HSI provided, despite the fact that HSI had smaller spectral range compared with that of NIRS. In addition, HSI enabled visualising the variability of C and N in the s les. Therefore, HSI is advantageous compared to NIRS as it is a multifunctional tool that poses many potential applications in data collection and quality assurance within feed mills and poultry processing plants. The ability to more accurately measure and visualise the properties of feed ingredients has potential economic benefits and therefore additional investigation and development of HSI in this application is warranted.
Publisher: CSIRO Publishing
Date: 17-02-2022
DOI: 10.1071/AN21539
Abstract: Context Mineralisation of the bone matrix is a pivotal factor affecting bone strength in broilers. Reduced bone strength might cause fracture during catching and transportation to slaughterhouses, leading to economic loss. Aims This study was conducted to investigate the effects of l-arginine (Arg), guanidinoacetic acid (GAA), and l-citrulline (Cit) supplementation to Arg-deficient reduced-protein diets on bone mineral composition and mineral digestibility of broiler chickens. Methods Day-old Ross 308 males were allocated to one of eight dietary treatments with six replicates of 16 birds per treatment. The treatments were standard protein (SP), reduced protein deficient in Arg (RP), and RP with two levels of either Arg (0.238% and 0.476%), GAA (0.309% and 0.618%) or Cit (0.238% and 0.476%). The difference in crude protein content between RP and SP was five percentage points. Key results Birds fed the RP diet had higher ileal digestibility of P, Na, Mg, S, Al, Fe, Cu and Zn than did those fed the SP on Day 23 (P 0.01). Supplementation of both Arg, GAA and Cit to the RP reduced Mg digestibility on Day 23 (P 0.001). The tibia and femur Ca and P concentrations were not different among the dietary treatments on either Day 23 or Day 35 (P 0.05). Birds fed the RP had lower tibia and femur B concentrations and higher tibia and femur Zn concentrations on Day 23 and Day 35 and higher tibia and femur Mn concentrations on Day 35 than did those fed the SP (P 0.01). Supplementation of Arg at the high level and Cit at both levels to the RP increased tibia S concentration on Day 23 (P 0.001). Supplementation of Arg, Cit and GAA to the RP decreased femur Zn concentration on Day 35 (P 0.001). Supplementation of GAA at the high level decreased concentrations of the tibia and femur B and Fe on Day 23, but increased tibia and femur Mn concentrations on Day 23 and Day 35 (P 0.01). Conclusions The findings indicated an increased mineral digestibility but relatively similar bone mineral concentrations in broilers fed the RP diets when compared with the SP diets. Implications The results of the current study may provide useful information on the bird bone mineralisation and help expand the adoption of reduced-protein diets in the poultry industry.
Publisher: Informa UK Limited
Date: 22-11-2018
DOI: 10.1080/00071668.2017.1400658
Abstract: 1. The objective was to compare three whole grain (WG) inclusion levels (7.5, 15 and 30%) offered to broiler chickens by three modes of WG incorporation: (i) pre-pellet WG inclusion, (ii) post-pellet WG inclusion as a blend of WG and pelleted concentrate and (iii) post-pellet WG inclusion where WG and pelleted concentrate were provided in separate feed trays against a ground-grain, wheat-based control diet. 2. Ten dietary treatments were offered to 6 replicate cages (6 birds per cage) of male Ross 308 chickens from 7 to 28 d post-hatch. The effects of treatment on relative gizzard weights, gizzard contents, pancreatic weights and pH of gizzard digesta were monitored. Parameters of growth performance, nutrient utilisation (apparent metabolisable energy [AME], metabolisable to gross energy [ME:GE] ratios, nitrogen [N] retention and N-corrected AME [AMEn]), apparent starch and protein (N) digestibility coefficients and disappearance rates in for small intestinal segments and concentrations of free amino acids in plasma taken from the anterior mesenteric vein were determined. 3. Whole grain feeding (WGF) did not influence weight gain, but 30% post-pellet blended and 15 and 30% post-pellet separated treatments significantly depressed (P < 0.05) feed intakes while the 30% post-pellet separated treatment improved (P < 0.01) feed conversion ratios (FCR). WGF regimes significantly increased relative gizzard weights. 4. Overall, WGF generated profound responses in AME, ME:GE ratios, N retention and AMEn that were highly correlated with relative gizzard weights. In general, WGF improved starch and protein (N) digestibilities and again there were some correlations with these outcomes and relative gizzard weights. 5. Post-pellet WG inclusions where WG and pelleted concentrate were offered separately provided chickens with the opportunity to choice feed. Birds showed a preference for the relatively high-protein pelleted concentrate and at 30% WG, this resulted in an improvement in FCR of 7.69% (1.260 versus 1.365 P < 0.001) relative to the ground-grain control diet.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.3382/PS/PEZ200
Abstract: Off-sex, male Ross 308 chickens were offered maize-soy diets without and with 3.5 g/kg lysine monohydrochloride (HCl), which contained 10.0 or 12.8 g/kg digestible lysine, from 7 to 28 D post-hatch. Birds were permitted access to diets at intervals of 12, 16, and 20 h/day. Lysine HCl improved weight gain (1,465 vs. 1,417 g/bird P < 0.025) and feed conversion ratios (1.351 vs. 1.382 P < 0.005). Extending feed access intervals increased weight gain (1,542 vs. 1,303 g/bird P < 0.001) and feed intake (2,142 vs. 1,748 g/bird P < 0.001) but compromised feed conversion ratios (1.390 vs. 1.342 P < 0.001). Extending feed access intervals increased (P < 0.001) both relative crop and gizzard weights and amounts of digesta retained in these organs. Effective lysine HCl utilization in poultry irrespective of feeding frequency, as opposed to pigs, may stem from anticipatory feeding behavior, crop and gizzard functionality, and increased episodes of reverse peristalsis. Collectively, these properties appear to modulate the relative intestinal uptakes of unbound lysine and protein-bound amino acids including lysine. Instructively, extending daily feed access intervals from 12 to 20 h increased average ileal digestibility coefficients of 16 amino acids by 12.8% (0.830 vs. 0.736 P < 0.001), which was linearly related (r = -0.834 P 0.35) between lysine HCl and feed access intervals for parameters of growth performance were not observed, it was concluded that feed access intervals do not influence lysine utilization. The implications of these findings are discussed.
Publisher: Springer Science and Business Media LLC
Date: 05-04-2019
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 05-2005
DOI: 10.1053/J.GASTRO.2005.01.050
Abstract: We have developed a therapeutic strategy for gastrointestinal infections that is based on molecular mimicry of host receptors for bacterial toxins on the surface of harmless gut bacteria. The aim of this study was to apply this to the development of a recombinant probiotic for treatment and prevention of diarrheal disease caused by enterotoxigenic Escherichia coli strains that produce heat-labile enterotoxin. This was achieved by expressing glycosyltransferase genes from Neisseria meningitidis or C ylobacter jejuni in a harmless Escherichia coli strain (CWG308), resulting in the production of a chimeric lipopolysaccharide capable of binding heat-labile enterotoxin with high avidity. The strongest heat-labile enterotoxin binding was achieved with a construct (CWG308:pLNT) that expresses a mimic of lacto-N-neotetraose, which neutralized > or = 93.8% of the heat-labile enterotoxin activity in culture lysates of erse enterotoxigenic Escherichia coli strains of both human and porcine origin. When tested with purified heat-labile enterotoxin, it was capable of adsorbing approximately 5% of its own weight of toxin. Weaker toxin neutralization was achieved with a construct that mimicked the ganglioside GM2. Preabsorption with, or coadministration of, CWG308:pLNT also resulted in significant in vivo protection from heat-labile enterotoxin-induced fluid secretion in rabbit ligated ileal loops. Toxin-binding probiotics such as those described here have considerable potential for prophylaxis and treatment of enterotoxigenic Escherichia coli-induced travelers' diarrhea.
Publisher: Microbiology Society
Date: 03-2019
Abstract: Pandoraea species have been isolated from erse environmental s les and are emerging important respiratory pathogens, particularly in people with cystic fibrosis (CF). In the present study, two bacterial isolates initially recovered from consecutive sputum s les collected from a CF patient and identified as Pandoraea pnomenusa underwent a polyphasic taxonomic analysis. The isolates were found to be Gram-negative, facultative anaerobic motile bacilli and subsequently designated as strains 6399
Publisher: Elsevier BV
Date: 03-2020
Publisher: CSIRO Publishing
Date: 2017
Publisher: Springer Science and Business Media LLC
Date: 23-05-2017
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/PP00107
Abstract: The nodulation failure resulting from the interaction between Rhizobium leguminosarum biovar trifolii strain ANU794 and the Trifolium subterraneum cv. Woogenellup was examined by transposon mutagenesis to resolve whether multiple determinants were involved in cultivar-specificity. Three new transposon-induced mutants of ANU794 (W72, W78 and W710) with significantly enhanced nodulation ability on cv. Woogenellup were identified. The W72 and W78 mutations are chromosomally-located, whereas the W710 mutation isplasmid-located. The ethylene synthesis inhibitor, aminoethoxyvinylglycine, fails to enhance the nodulation ability of ANU794, ANU7943 (csn1::Tn5) and W78 on cv. Woogenellup, but enhances the nodulation ability of W72,W710 and ANU7941 (nodM::Tn5). DNA sequencing of the W78 locus reveals strong homology to an unknown Mycobacterium open reading frame, and to several bacterial non-haem chloroperoxidases. The previously identified csn1 locus showed homology to the 50S ribosomal protein, L9, with the Tn5 insertion being located in the 5′-untranslated region. The results suggest that cultivar-specificity is mediated by at least two independent mechanisms or determinants, and not by a simple gene-for-gene interaction. The role of ethylene in cultivar specificity is discussed. Cultivar-specific interactions may prove useful in identifying pathways involved in efficient nodule formation and plant-microbe interactions.
Publisher: American Society for Microbiology
Date: 26-02-2015
Abstract: Pandoraea is an emerging respiratory pathogen capable of causing chronic lung infections in people with cystic fibrosis (CF), but the clinical significance of this infection is ambiguous. We have sequenced and annotated the genomes of two multidrug-resistant Pandoraea pnomenusa isolates recovered 11 months apart from the same CF patient.
Publisher: Hindawi Limited
Date: 04-03-2011
Start Date: 2015
End Date: 2015
Funder: Royal Hobart Hospital Research Foundation
View Funded ActivityStart Date: 2013
End Date: 2013
Funder: Clifford Craig Medical Research Trust
View Funded ActivityStart Date: 2014
End Date: 2016
Funder: Australian Cystic Fibrosis Research Trust
View Funded ActivityStart Date: 2010
End Date: 2010
Funder: Royal Hobart Hospital Research Foundation
View Funded ActivityStart Date: 2011
End Date: 2012
Funder: Royal Hobart Hospital Research Foundation
View Funded ActivityStart Date: 2007
End Date: 2007
Funder: Clifford Craig Medical Research Trust
View Funded ActivityStart Date: 2005
End Date: 2005
Funder: Clifford Craig Medical Research Trust
View Funded ActivityStart Date: 2009
End Date: 2009
Funder: Rebecca L Cooper Medical Research Foundation
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: Marinova Pty Ltd
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: Department of Industry, Innovation and Science
View Funded Activity