The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Gale Brightwell - One of the best experts on this subject based on the ideXlab platform.
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The spoilage characteristics of Brochothrix thermosphacta and two psychrotolerant Enterobacteriacae in vacuum packed lamb and the comparison between high and low pH cuts.
Meat science, 2014Co-Authors: Amanda Gribble, John Mills, Gale BrightwellAbstract:Abstract The spoilage potential of Brochothrix thermosphacta, Serratia proteamaculans and Rahnella aquatilis was investigated in vacuum packaged high (5.9 to 6.4) and low (5.4 to 5.8) pH lamb. Vacuum packaged fore shank (m. extensor carpi radialis) and striploins (m. longissimus dorsi) (n = 306) inoculated with ~ 100 CFU of individual bacteria were stored for twelve weeks at temperatures − 1.5, 0, 2 and 7 °C. Spoilage characteristics and bacterial numbers were recorded and analysed in comparison to un-inoculated control samples. All three bacterial species were shown to grow in vacuum packaged lamb of pH values between 5.4 and 6.4, when stored at chilled temperatures (− 1.5 to 7 °C) for up to 84 days. B. thermosphacta and S. proteamaculans caused spoilage to the meat under these conditions whilst R. aquatilis spoiled high pH meat at 7 °C. These results go against previous beef models stipulating that Brochothrix and Enterobacteriacae species cannot grow on or cause spoilage of low pH meat in the absence of oxygen.
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spoilage characteristics of Brochothrix thermosphacta and campestris in chilled vacuum packaged lamb and their detection and identification by real time pcr
Meat Science, 2013Co-Authors: Amanda Gribble, Gale BrightwellAbstract:The spoilage potential of Brochothrix campestris and Brochothrix thermosphacta was investigated in vacuum-packed lamb. Striploins (n=338) were inoculated and stored for twelve weeks at temperatures -1.5, 0, 2 and 7 °C. Growth around 5-6 log10 CFU/cm(2) was recorded after six weeks at 0, 2 and 7 °C, and ~3 log10 CFU/cm(2) after nine weeks at -1.5 °C. B. campestris was shown to cause spoilage by nine weeks at temperatures above 0 °C by the presence of green drip and unacceptable odours. Molecular based assays for the detection and differentiation of B. thermosphacta and B. campestris were developed and validated. A TaqMan assay was designed to target a unique single-nucleotide polymorphism in the Brochothrix 16s rRNA gene with a sensitivity of <7 CFU per reaction. Secondly a specific PCR was designed for B. campestris targeting the structural genes, brcA and brcB. These testing regimes offer a rapid and cost effective method for the detection and screening of Brochothrix species in meat products and processing environments.
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Spoilage characteristics of Brochothrix thermosphacta and campestris in chilled vacuum packaged lamb, and their detection and identification by real time PCR.
Meat science, 2013Co-Authors: Amanda Gribble, Gale BrightwellAbstract:The spoilage potential of Brochothrix campestris and Brochothrix thermosphacta was investigated in vacuum-packed lamb. Striploins (n=338) were inoculated and stored for twelve weeks at temperatures -1.5, 0, 2 and 7 °C. Growth around 5-6 log10 CFU/cm(2) was recorded after six weeks at 0, 2 and 7 °C, and ~3 log10 CFU/cm(2) after nine weeks at -1.5 °C. B. campestris was shown to cause spoilage by nine weeks at temperatures above 0 °C by the presence of green drip and unacceptable odours. Molecular based assays for the detection and differentiation of B. thermosphacta and B. campestris were developed and validated. A TaqMan assay was designed to target a unique single-nucleotide polymorphism in the Brochothrix 16s rRNA gene with a sensitivity of
Mark L. Tamplin - One of the best experts on this subject based on the ideXlab platform.
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Effect of glucose, pH and lactic acid on Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens within a commercial heat-shrunk vacuum-package film.
Food microbiology, 2020Co-Authors: Kaniz Mohsina, Shane M Powell, David A. Ratkowsky, John P. Bowman, M Kaur, Mark L. TamplinAbstract:Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens are common spoilage organisms found within the microbiome of refrigerated vacuum-packaged (VP) beef. Extending and predicting VP beef shelf-life requires knowledge about how spoilage bacteria growth is influenced by environmental extrinsic and intrinsic factors. Multifactorial effects of pH, lactic acid (LA) and glucose on growth kinetics were quantified for C. maltaromaticum, B. thermosphacta and S. liquefaciens within a heat shrink-wrapped VP commercial film containing a simulated beef medium. LA, pH, and undissociated lactic acid (UDLA) significantly affected bacterial growth rate (p
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Effect of glucose, pH and lactic acid on Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens within a commercial heat-shrunk vacuum-package film
'Elsevier BV', 2020Co-Authors: Mohsina K, David A. Ratkowsky, Jp Bowman, Powell S, Kaur M, Mark L. TamplinAbstract:Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens are common spoilage organisms found within the microbiome of refrigerated vacuum-packaged (VP) beef. Extending and predicting VP beef shelf-life requires knowledge about how spoilage bacteria growth is influenced by environmental extrinsic and intrinsic factors. Multifactorial effects of pH, lactic acid (LA) and glucose on growth kinetics were quantified for C. maltaromaticum, B. thermosphacta and S. liquefaciens within a heat shrink-wrapped VP commercial film containing a simulated beef medium. LA, pH, and undissociated lactic acid (UDLA) significantly affected bacterial growth rate (p C. maltaromaticum, B. thermosphacta, and S. liquefaciens, respectively
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Characterisation of the Brochothrix thermosphacta sortase A enzyme
Fems Microbiology Letters, 2018Co-Authors: Tamsyn Stanborough, Stewart D Nuttall, Randy Suryadinata, Shane M Powell, Narelle Fegan, Mark L. Tamplin, P. Scott ChandryAbstract:Gram-positive bacteria utilise class A sortases to coat the surface of their cells with a diversity of proteins that facilitate interactions with their environment and play fundamental roles in cell physiology and virulence. A putative sortase A gene was identified in the genome of the poorly studied meat spoilage bacterium Brochothrix thermosphacta. To understand how this bacterium mediates interactions with its environment, an N-terminal truncated, His-tagged variant of this protein (His6-BtSrtA) was expressed and purified. Catalytic activity of recombinant His6-BtSrtA was investigated, including sorting motif recognition of target proteins and bioconjugation activity. Further, the B. thermosphacta genome was examined for the presence of sortase A (SrtA) protein substrates. His6-BtSrtA readily formed intermediate complexes with LPXTG-tagged proteins. Although the reaction was inefficient, nucleophilic attack of the resultant thioacyl intermediates by tri-glycine was observed. Genome examination identified 11 potential SrtA substrates, two of which contained protein domains associated with adherence of pathogens to host extracellular matrix proteins and cells, suggesting the B. thermosphacta SrtA may be indirectly involved in its attachment to meat surfaces. Thus, further work in this area could provide crucial insight into molecular mechanisms involved in the colonisation of meat by B. thermosphacta.
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Insight into the Genome of Brochothrix thermosphacta, a Problematic Meat Spoilage Bacterium.
Applied and environmental microbiology, 2017Co-Authors: Tamsyn Stanborough, Shane M Powell, Narelle Fegan, Mark L. Tamplin, P. Scott ChandryAbstract:Brochothrix thermosphacta is a dominant but poorly studied meat spoilage organism. It is a close relative of the foodborne pathogen Listeria monocytogenes, and Brochothrix constitutes the second genus in the Listeriaceae family. Here, the genomes of 12 B. thermosphacta strains were sequenced, assembled into draft genomes, characterized, and compared with the genomes of Brochothrix campestris and L. monocytogenes. Phenotypic properties including biogenic amine production and antibiotic and heavy metal susceptibilities were tested. Comparative genomic analyses revealed a high degree of similarity among the B. thermosphacta strains, with bacteriophage genes constituting a significant proportion of the accessory genome. Genes for the production of the malodorous compounds acetate, acetoin, butanediol, and fatty acids were found, as were stress response regulatory genes, which likely play important roles in the spoilage process. Amino acid decarboxylases were not identified in the genomes, and phenotypic testing confirmed their absence. Orthologs of Listeria virulence proteins involved in virulence regulation, intracellular survival, and surface protein anchoring were found; however, key virulence genes were absent. Analysis of antibiotic susceptibility showed that strains were sensitive to the four tested antibiotics, except for one tetracycline-resistant isolate with plasmid-mediated tetracycline resistance genes. Strains tolerated higher levels of copper and cobalt than of cadmium although not at concentrations high enough to categorize the strains as being resistant. This study provides insight into the Brochothrix genome, links previous phenotypic data and data provided here to the gene inventory, and identifies genes that may contribute to the persistence of this organism in the food chain. IMPORTANCE Despite increasing knowledge and advances in food preservation techniques, microbial spoilage of foods causes substantial losses, with negative social and economic consequences. To better control the contamination and microbial spoilage of foods, fundamental knowledge of the biology of key spoilage bacteria is crucial. As a common meat spoilage organism, B. thermosphacta contributes substantially to spoilage-associated losses. Nonetheless, this organism and particularly its genome remain largely unstudied. This study contributes to improving our knowledge of the Brochothrix genus. Spoilage-relevant pathways and genes that may play a role in the survival of this organism in a food processing environment were identified, linking previous phenotypic data and data provided here to the gene inventory of Brochothrix and establishing parallels to and differences from the closely related foodborne pathogen L. monocytogenes.
Amanda Gribble - One of the best experts on this subject based on the ideXlab platform.
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The spoilage characteristics of Brochothrix thermosphacta and two psychrotolerant Enterobacteriacae in vacuum packed lamb and the comparison between high and low pH cuts.
Meat science, 2014Co-Authors: Amanda Gribble, John Mills, Gale BrightwellAbstract:Abstract The spoilage potential of Brochothrix thermosphacta, Serratia proteamaculans and Rahnella aquatilis was investigated in vacuum packaged high (5.9 to 6.4) and low (5.4 to 5.8) pH lamb. Vacuum packaged fore shank (m. extensor carpi radialis) and striploins (m. longissimus dorsi) (n = 306) inoculated with ~ 100 CFU of individual bacteria were stored for twelve weeks at temperatures − 1.5, 0, 2 and 7 °C. Spoilage characteristics and bacterial numbers were recorded and analysed in comparison to un-inoculated control samples. All three bacterial species were shown to grow in vacuum packaged lamb of pH values between 5.4 and 6.4, when stored at chilled temperatures (− 1.5 to 7 °C) for up to 84 days. B. thermosphacta and S. proteamaculans caused spoilage to the meat under these conditions whilst R. aquatilis spoiled high pH meat at 7 °C. These results go against previous beef models stipulating that Brochothrix and Enterobacteriacae species cannot grow on or cause spoilage of low pH meat in the absence of oxygen.
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spoilage characteristics of Brochothrix thermosphacta and campestris in chilled vacuum packaged lamb and their detection and identification by real time pcr
Meat Science, 2013Co-Authors: Amanda Gribble, Gale BrightwellAbstract:The spoilage potential of Brochothrix campestris and Brochothrix thermosphacta was investigated in vacuum-packed lamb. Striploins (n=338) were inoculated and stored for twelve weeks at temperatures -1.5, 0, 2 and 7 °C. Growth around 5-6 log10 CFU/cm(2) was recorded after six weeks at 0, 2 and 7 °C, and ~3 log10 CFU/cm(2) after nine weeks at -1.5 °C. B. campestris was shown to cause spoilage by nine weeks at temperatures above 0 °C by the presence of green drip and unacceptable odours. Molecular based assays for the detection and differentiation of B. thermosphacta and B. campestris were developed and validated. A TaqMan assay was designed to target a unique single-nucleotide polymorphism in the Brochothrix 16s rRNA gene with a sensitivity of <7 CFU per reaction. Secondly a specific PCR was designed for B. campestris targeting the structural genes, brcA and brcB. These testing regimes offer a rapid and cost effective method for the detection and screening of Brochothrix species in meat products and processing environments.
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Spoilage characteristics of Brochothrix thermosphacta and campestris in chilled vacuum packaged lamb, and their detection and identification by real time PCR.
Meat science, 2013Co-Authors: Amanda Gribble, Gale BrightwellAbstract:The spoilage potential of Brochothrix campestris and Brochothrix thermosphacta was investigated in vacuum-packed lamb. Striploins (n=338) were inoculated and stored for twelve weeks at temperatures -1.5, 0, 2 and 7 °C. Growth around 5-6 log10 CFU/cm(2) was recorded after six weeks at 0, 2 and 7 °C, and ~3 log10 CFU/cm(2) after nine weeks at -1.5 °C. B. campestris was shown to cause spoilage by nine weeks at temperatures above 0 °C by the presence of green drip and unacceptable odours. Molecular based assays for the detection and differentiation of B. thermosphacta and B. campestris were developed and validated. A TaqMan assay was designed to target a unique single-nucleotide polymorphism in the Brochothrix 16s rRNA gene with a sensitivity of
Shane M Powell - One of the best experts on this subject based on the ideXlab platform.
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Effect of glucose, pH and lactic acid on Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens within a commercial heat-shrunk vacuum-package film.
Food microbiology, 2020Co-Authors: Kaniz Mohsina, Shane M Powell, David A. Ratkowsky, John P. Bowman, M Kaur, Mark L. TamplinAbstract:Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens are common spoilage organisms found within the microbiome of refrigerated vacuum-packaged (VP) beef. Extending and predicting VP beef shelf-life requires knowledge about how spoilage bacteria growth is influenced by environmental extrinsic and intrinsic factors. Multifactorial effects of pH, lactic acid (LA) and glucose on growth kinetics were quantified for C. maltaromaticum, B. thermosphacta and S. liquefaciens within a heat shrink-wrapped VP commercial film containing a simulated beef medium. LA, pH, and undissociated lactic acid (UDLA) significantly affected bacterial growth rate (p
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Characterisation of the Brochothrix thermosphacta sortase A enzyme
Fems Microbiology Letters, 2018Co-Authors: Tamsyn Stanborough, Stewart D Nuttall, Randy Suryadinata, Shane M Powell, Narelle Fegan, Mark L. Tamplin, P. Scott ChandryAbstract:Gram-positive bacteria utilise class A sortases to coat the surface of their cells with a diversity of proteins that facilitate interactions with their environment and play fundamental roles in cell physiology and virulence. A putative sortase A gene was identified in the genome of the poorly studied meat spoilage bacterium Brochothrix thermosphacta. To understand how this bacterium mediates interactions with its environment, an N-terminal truncated, His-tagged variant of this protein (His6-BtSrtA) was expressed and purified. Catalytic activity of recombinant His6-BtSrtA was investigated, including sorting motif recognition of target proteins and bioconjugation activity. Further, the B. thermosphacta genome was examined for the presence of sortase A (SrtA) protein substrates. His6-BtSrtA readily formed intermediate complexes with LPXTG-tagged proteins. Although the reaction was inefficient, nucleophilic attack of the resultant thioacyl intermediates by tri-glycine was observed. Genome examination identified 11 potential SrtA substrates, two of which contained protein domains associated with adherence of pathogens to host extracellular matrix proteins and cells, suggesting the B. thermosphacta SrtA may be indirectly involved in its attachment to meat surfaces. Thus, further work in this area could provide crucial insight into molecular mechanisms involved in the colonisation of meat by B. thermosphacta.
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Insight into the Genome of Brochothrix thermosphacta, a Problematic Meat Spoilage Bacterium.
Applied and environmental microbiology, 2017Co-Authors: Tamsyn Stanborough, Shane M Powell, Narelle Fegan, Mark L. Tamplin, P. Scott ChandryAbstract:Brochothrix thermosphacta is a dominant but poorly studied meat spoilage organism. It is a close relative of the foodborne pathogen Listeria monocytogenes, and Brochothrix constitutes the second genus in the Listeriaceae family. Here, the genomes of 12 B. thermosphacta strains were sequenced, assembled into draft genomes, characterized, and compared with the genomes of Brochothrix campestris and L. monocytogenes. Phenotypic properties including biogenic amine production and antibiotic and heavy metal susceptibilities were tested. Comparative genomic analyses revealed a high degree of similarity among the B. thermosphacta strains, with bacteriophage genes constituting a significant proportion of the accessory genome. Genes for the production of the malodorous compounds acetate, acetoin, butanediol, and fatty acids were found, as were stress response regulatory genes, which likely play important roles in the spoilage process. Amino acid decarboxylases were not identified in the genomes, and phenotypic testing confirmed their absence. Orthologs of Listeria virulence proteins involved in virulence regulation, intracellular survival, and surface protein anchoring were found; however, key virulence genes were absent. Analysis of antibiotic susceptibility showed that strains were sensitive to the four tested antibiotics, except for one tetracycline-resistant isolate with plasmid-mediated tetracycline resistance genes. Strains tolerated higher levels of copper and cobalt than of cadmium although not at concentrations high enough to categorize the strains as being resistant. This study provides insight into the Brochothrix genome, links previous phenotypic data and data provided here to the gene inventory, and identifies genes that may contribute to the persistence of this organism in the food chain. IMPORTANCE Despite increasing knowledge and advances in food preservation techniques, microbial spoilage of foods causes substantial losses, with negative social and economic consequences. To better control the contamination and microbial spoilage of foods, fundamental knowledge of the biology of key spoilage bacteria is crucial. As a common meat spoilage organism, B. thermosphacta contributes substantially to spoilage-associated losses. Nonetheless, this organism and particularly its genome remain largely unstudied. This study contributes to improving our knowledge of the Brochothrix genus. Spoilage-relevant pathways and genes that may play a role in the survival of this organism in a food processing environment were identified, linking previous phenotypic data and data provided here to the gene inventory of Brochothrix and establishing parallels to and differences from the closely related foodborne pathogen L. monocytogenes.
Kaniz Mohsina - One of the best experts on this subject based on the ideXlab platform.
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Effect of glucose, pH and lactic acid on Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens within a commercial heat-shrunk vacuum-package film.
Food microbiology, 2020Co-Authors: Kaniz Mohsina, Shane M Powell, David A. Ratkowsky, John P. Bowman, M Kaur, Mark L. TamplinAbstract:Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens are common spoilage organisms found within the microbiome of refrigerated vacuum-packaged (VP) beef. Extending and predicting VP beef shelf-life requires knowledge about how spoilage bacteria growth is influenced by environmental extrinsic and intrinsic factors. Multifactorial effects of pH, lactic acid (LA) and glucose on growth kinetics were quantified for C. maltaromaticum, B. thermosphacta and S. liquefaciens within a heat shrink-wrapped VP commercial film containing a simulated beef medium. LA, pH, and undissociated lactic acid (UDLA) significantly affected bacterial growth rate (p
