Background: Manuka honey is recognized for it’s health-promoting properties and it’s use in medic... more Background: Manuka honey is recognized for it’s health-promoting properties and it’s use in medicine is well documented. However, the actions of Manuka honey are limited by rapid digestion and the inactivation of bioactive components such as methylglyoxal. Cyclodextrins are naturally occurring glucose rings that improve stability and bioactivity of products. This study investigates the tolerability and bioactivity of a-cyclodextrin-complexed Manuka honey called Manuka Honey with CycloPower TM.
Methods: The antibacterial properties of Manuka honey complexed with a-cyclodextrin (Manuka honey with CyclopowerTM) were compared to uncomplexed Manuka honey against a range of common organisms using standard measurements of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Time course growth measurements were determined using a sublethal concentration of 2% w (honey solids)/v and measuring the area under the growth curve.
Results: In tube MIC assays, Manuka honey completely inhibited Staphylococcus aureus (MSSA and MRSA), Streptococcus pyogenes, Helicobacter pylori and Moraxella catarrhalis at concentrations of 10% w/v or less, with MIC values decreasing as the methylglyoxal content of the honeys increased from 100 to 550 mg/kg. MIC values at a given methlyglyoxal level were also decreased for S. pyogenes, M. catarrhalis and H. pylori by complexing the Manuka honey with a-cyclodextrin. Pseudomonas aeruginosa was not inhibited by any of the Manuka honey or Cyclopower treatments at the concentrations tested (2-10% w/v). Manuka honey with CyclopowerTM had an increased bacteriostatic action against S. aureus, MRSA and P. aeruginosa compared with Manuka honey.
Conclusions: This study concludes that Manuka honey is an effective antibacterial agent that can be enhanced by complexing with a-cyclodextrin.
Bacterium-to-host signalling during infection is a complex process involving proteins, lipids and... more Bacterium-to-host signalling during infection is a complex process involving proteins, lipids and other diffusible signals that manipulate host cell biology for pathogen survival. Bacteria also release membrane vesicles (MV) that can carry a cargo of effector molecules directly into host cells. Supported by recent publications, we hypothesised that these MVs also associate with RNA, which may be directly involved in the modulation of the host response to infection. Using the uropathogenic Escherichia coli (UPEC) strain 536, we have isolated MVs and found they carry a range of RNA species. Density gradient centrifugation further fractionated and characterised the MV preparation and confirmed that the isolated RNA was associated with the highest particle and protein containing fractions. Using a new approach, RNA-sequencing of libraries derived from three different 'size' RNA populations (<50nt, 50-200nt and 200nt+) isolated from MVs has enabled us to now report the first e...
... Page 4. 6 SIMON SWIFT particular, restore toWollstonecraft the religious teleology which is c... more ... Page 4. 6 SIMON SWIFT particular, restore toWollstonecraft the religious teleology which is central to her thought, by reconciling Wollstonecraft's rationalism to an under standing of the Platonic eros,a sacralized form of erotic love which Woll stonecraft inherited throughthe ...
Summary The aim of this study was to review systematically the available evidence on pleurodesis ... more Summary The aim of this study was to review systematically the available evidence on pleurodesis for malignant effusion, focusing on the choice of the agents, route of delivery and other strategies to improve outcomes. Four electronic databases (MEDLINE, EMBASE, Web of Science and Cochrane Controlled Trials Register) were searched, reference lists checked and letters requesting details of unpublished trials and
In Aeromonas hydrophila, the ahyI gene encodes a protein responsible for the synthesis of the quo... more In Aeromonas hydrophila, the ahyI gene encodes a protein responsible for the synthesis of the quorum sensing signal N-butanoyl-L-homoserine lactone (C4-HSL). Inactivation of the ahyI gene on the A. hydrophila chromosome abolishes C4-HSL production. The exoprotease activity of A. hydrophila consists of both serine protease and metalloprotease activities; in the ahyI-negative strain, both are substantially reduced but can be restored by the addition of exogenous C4-HSL. In contrast, mutation of the LuxR homolog AhyR results in the loss of both exoprotease activities, which cannot be restored by exogenous C4-HSL. Furthermore, a substantial reduction in the production of exoprotease by the ahyI+ parent strain is obtained by the addition of N-acylhomoserine lactone analogs that have acyl side chains of 10, 12, or 14 carbons. The inclusion of N-(3-oxododecanoyl)-L-homoserine lactone or N-(3-oxotetradecanoyl)-L-homoserine lactone at 10 microM in overnight cultures of A. hydrophila abolishe...
Iron is an essential micronutrient for microbial life. At the start of an infection the host envi... more Iron is an essential micronutrient for microbial life. At the start of an infection the host environment will normally restrict available iron, and innate immune responses will aim to further reduce iron, thus inhibiting growth of potential pathogens. Successful pathogens have developed a variety of mechanisms to acquire iron from the available in vivo sources, using remote and direct capture, to render their environment iron replete. Iron restriction, and the presence of host iron sources like haem, are important drivers of gene regulation controlling the expression of numerous virulence factors. As an infection progresses the changing iron environment will therefore influence pathogen gene expression and trigger new activities. Understanding how bacteria acquire iron, and how iron acquisition affects the bacteria, has identified vaccine and antibiotic drug targets and is now suggesting novel approaches to control and treat infection.
Spent culture supernatants from both Aeromonas hydrophila and Aeromonas salmonicida activate a ra... more Spent culture supernatants from both Aeromonas hydrophila and Aeromonas salmonicida activate a range of biosensors responsive to N-acylhomoserine lactones (AHLs). The genes for a quorum sensing signal generator and a response regulator were cloned from each Aeromonas species and termed ahyRI and asaRI, respectively. Protein sequence homology analysis places the gene products within the growing family of LuxRI homologs. ahyR and asaR are transcribed divergently from ahyI and asaI, respectively, and in both Aeromonas species, the genes downstream have been identified by DNA sequence and PCR analysis. Downstream of both ahyI and asaI is a gene with close homology to iciA, an inhibitor of chromosome replication in Escherichia coli, a finding which implies that in Aeromonas, cell division may be linked to quorum sensing. The major signal molecule synthesized via both AhyI and AsaI was purified from spent culture supernatants and identified as N-(butanoyl)-L-homoserine lactone (BHL) by th...
Two different representative recombinant clones encoding Aeromonas hydrophila lipases were found ... more Two different representative recombinant clones encoding Aeromonas hydrophila lipases were found upon screening on tributyrin (phospholipase A1) and egg yolk agar (lecithinase-phospholipase C) plates of a cosmid-based genomic library of Aeromonas hydrophila AH-3 (serogroup O34) introduced into Escherichia coli DH5alpha. Subcloning, nucleotide sequencing, and in vitro-coupled transcription-translation experiments showed that the phospholipase A1 (pla) and C (plc) genes code for an 83-kDa putative lipoprotein and a 65-kDa protein, respectively. Defined insertion mutants of A. hydrophila AH-3 defective in either pla or plc genes were defective in phospholipase A1 and C activities, respectively. Lecithinase (phospholipase C) was shown to be cytotoxic but nonhemolytic or poorly hemolytic. A. hydrophila AH-3 plc mutants showed a more than 10-fold increase in their 50% lethal dose on fish and mice, and complementation of the plc single gene on these mutants abolished this effect, suggestin...
Background: Manuka honey is recognized for it’s health-promoting properties and it’s use in medic... more Background: Manuka honey is recognized for it’s health-promoting properties and it’s use in medicine is well documented. However, the actions of Manuka honey are limited by rapid digestion and the inactivation of bioactive components such as methylglyoxal. Cyclodextrins are naturally occurring glucose rings that improve stability and bioactivity of products. This study investigates the tolerability and bioactivity of a-cyclodextrin-complexed Manuka honey called Manuka Honey with CycloPower TM.
Methods: The antibacterial properties of Manuka honey complexed with a-cyclodextrin (Manuka honey with CyclopowerTM) were compared to uncomplexed Manuka honey against a range of common organisms using standard measurements of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Time course growth measurements were determined using a sublethal concentration of 2% w (honey solids)/v and measuring the area under the growth curve.
Results: In tube MIC assays, Manuka honey completely inhibited Staphylococcus aureus (MSSA and MRSA), Streptococcus pyogenes, Helicobacter pylori and Moraxella catarrhalis at concentrations of 10% w/v or less, with MIC values decreasing as the methylglyoxal content of the honeys increased from 100 to 550 mg/kg. MIC values at a given methlyglyoxal level were also decreased for S. pyogenes, M. catarrhalis and H. pylori by complexing the Manuka honey with a-cyclodextrin. Pseudomonas aeruginosa was not inhibited by any of the Manuka honey or Cyclopower treatments at the concentrations tested (2-10% w/v). Manuka honey with CyclopowerTM had an increased bacteriostatic action against S. aureus, MRSA and P. aeruginosa compared with Manuka honey.
Conclusions: This study concludes that Manuka honey is an effective antibacterial agent that can be enhanced by complexing with a-cyclodextrin.
Bacterium-to-host signalling during infection is a complex process involving proteins, lipids and... more Bacterium-to-host signalling during infection is a complex process involving proteins, lipids and other diffusible signals that manipulate host cell biology for pathogen survival. Bacteria also release membrane vesicles (MV) that can carry a cargo of effector molecules directly into host cells. Supported by recent publications, we hypothesised that these MVs also associate with RNA, which may be directly involved in the modulation of the host response to infection. Using the uropathogenic Escherichia coli (UPEC) strain 536, we have isolated MVs and found they carry a range of RNA species. Density gradient centrifugation further fractionated and characterised the MV preparation and confirmed that the isolated RNA was associated with the highest particle and protein containing fractions. Using a new approach, RNA-sequencing of libraries derived from three different 'size' RNA populations (<50nt, 50-200nt and 200nt+) isolated from MVs has enabled us to now report the first e...
... Page 4. 6 SIMON SWIFT particular, restore toWollstonecraft the religious teleology which is c... more ... Page 4. 6 SIMON SWIFT particular, restore toWollstonecraft the religious teleology which is central to her thought, by reconciling Wollstonecraft's rationalism to an under standing of the Platonic eros,a sacralized form of erotic love which Woll stonecraft inherited throughthe ...
Summary The aim of this study was to review systematically the available evidence on pleurodesis ... more Summary The aim of this study was to review systematically the available evidence on pleurodesis for malignant effusion, focusing on the choice of the agents, route of delivery and other strategies to improve outcomes. Four electronic databases (MEDLINE, EMBASE, Web of Science and Cochrane Controlled Trials Register) were searched, reference lists checked and letters requesting details of unpublished trials and
In Aeromonas hydrophila, the ahyI gene encodes a protein responsible for the synthesis of the quo... more In Aeromonas hydrophila, the ahyI gene encodes a protein responsible for the synthesis of the quorum sensing signal N-butanoyl-L-homoserine lactone (C4-HSL). Inactivation of the ahyI gene on the A. hydrophila chromosome abolishes C4-HSL production. The exoprotease activity of A. hydrophila consists of both serine protease and metalloprotease activities; in the ahyI-negative strain, both are substantially reduced but can be restored by the addition of exogenous C4-HSL. In contrast, mutation of the LuxR homolog AhyR results in the loss of both exoprotease activities, which cannot be restored by exogenous C4-HSL. Furthermore, a substantial reduction in the production of exoprotease by the ahyI+ parent strain is obtained by the addition of N-acylhomoserine lactone analogs that have acyl side chains of 10, 12, or 14 carbons. The inclusion of N-(3-oxododecanoyl)-L-homoserine lactone or N-(3-oxotetradecanoyl)-L-homoserine lactone at 10 microM in overnight cultures of A. hydrophila abolishe...
Iron is an essential micronutrient for microbial life. At the start of an infection the host envi... more Iron is an essential micronutrient for microbial life. At the start of an infection the host environment will normally restrict available iron, and innate immune responses will aim to further reduce iron, thus inhibiting growth of potential pathogens. Successful pathogens have developed a variety of mechanisms to acquire iron from the available in vivo sources, using remote and direct capture, to render their environment iron replete. Iron restriction, and the presence of host iron sources like haem, are important drivers of gene regulation controlling the expression of numerous virulence factors. As an infection progresses the changing iron environment will therefore influence pathogen gene expression and trigger new activities. Understanding how bacteria acquire iron, and how iron acquisition affects the bacteria, has identified vaccine and antibiotic drug targets and is now suggesting novel approaches to control and treat infection.
Spent culture supernatants from both Aeromonas hydrophila and Aeromonas salmonicida activate a ra... more Spent culture supernatants from both Aeromonas hydrophila and Aeromonas salmonicida activate a range of biosensors responsive to N-acylhomoserine lactones (AHLs). The genes for a quorum sensing signal generator and a response regulator were cloned from each Aeromonas species and termed ahyRI and asaRI, respectively. Protein sequence homology analysis places the gene products within the growing family of LuxRI homologs. ahyR and asaR are transcribed divergently from ahyI and asaI, respectively, and in both Aeromonas species, the genes downstream have been identified by DNA sequence and PCR analysis. Downstream of both ahyI and asaI is a gene with close homology to iciA, an inhibitor of chromosome replication in Escherichia coli, a finding which implies that in Aeromonas, cell division may be linked to quorum sensing. The major signal molecule synthesized via both AhyI and AsaI was purified from spent culture supernatants and identified as N-(butanoyl)-L-homoserine lactone (BHL) by th...
Two different representative recombinant clones encoding Aeromonas hydrophila lipases were found ... more Two different representative recombinant clones encoding Aeromonas hydrophila lipases were found upon screening on tributyrin (phospholipase A1) and egg yolk agar (lecithinase-phospholipase C) plates of a cosmid-based genomic library of Aeromonas hydrophila AH-3 (serogroup O34) introduced into Escherichia coli DH5alpha. Subcloning, nucleotide sequencing, and in vitro-coupled transcription-translation experiments showed that the phospholipase A1 (pla) and C (plc) genes code for an 83-kDa putative lipoprotein and a 65-kDa protein, respectively. Defined insertion mutants of A. hydrophila AH-3 defective in either pla or plc genes were defective in phospholipase A1 and C activities, respectively. Lecithinase (phospholipase C) was shown to be cytotoxic but nonhemolytic or poorly hemolytic. A. hydrophila AH-3 plc mutants showed a more than 10-fold increase in their 50% lethal dose on fish and mice, and complementation of the plc single gene on these mutants abolished this effect, suggestin...
Uploads
Papers
Methods: The antibacterial properties of Manuka honey complexed with a-cyclodextrin (Manuka honey with CyclopowerTM) were compared to uncomplexed Manuka honey against a range of common organisms using standard measurements of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Time course growth measurements were determined using a sublethal concentration of 2% w (honey solids)/v and measuring the area under the growth curve.
Results: In tube MIC assays, Manuka honey completely inhibited Staphylococcus aureus (MSSA and MRSA), Streptococcus pyogenes, Helicobacter pylori and Moraxella catarrhalis at concentrations of 10% w/v or less, with MIC values decreasing as the methylglyoxal content of the honeys increased from 100 to 550 mg/kg. MIC values at a given methlyglyoxal level were also decreased for S. pyogenes, M. catarrhalis and H. pylori by complexing the Manuka honey with a-cyclodextrin. Pseudomonas aeruginosa was not inhibited by any of the Manuka honey or Cyclopower treatments at the concentrations tested (2-10% w/v). Manuka honey with CyclopowerTM had an increased bacteriostatic action against S. aureus, MRSA and P. aeruginosa compared with Manuka honey.
Conclusions: This study concludes that Manuka honey is an effective antibacterial agent that can be enhanced by complexing with a-cyclodextrin.
Methods: The antibacterial properties of Manuka honey complexed with a-cyclodextrin (Manuka honey with CyclopowerTM) were compared to uncomplexed Manuka honey against a range of common organisms using standard measurements of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Time course growth measurements were determined using a sublethal concentration of 2% w (honey solids)/v and measuring the area under the growth curve.
Results: In tube MIC assays, Manuka honey completely inhibited Staphylococcus aureus (MSSA and MRSA), Streptococcus pyogenes, Helicobacter pylori and Moraxella catarrhalis at concentrations of 10% w/v or less, with MIC values decreasing as the methylglyoxal content of the honeys increased from 100 to 550 mg/kg. MIC values at a given methlyglyoxal level were also decreased for S. pyogenes, M. catarrhalis and H. pylori by complexing the Manuka honey with a-cyclodextrin. Pseudomonas aeruginosa was not inhibited by any of the Manuka honey or Cyclopower treatments at the concentrations tested (2-10% w/v). Manuka honey with CyclopowerTM had an increased bacteriostatic action against S. aureus, MRSA and P. aeruginosa compared with Manuka honey.
Conclusions: This study concludes that Manuka honey is an effective antibacterial agent that can be enhanced by complexing with a-cyclodextrin.