89 research outputs found
AhrC and Eep are biofilm infection-associated virulence factors in enterococcus faecalis
Enterococcus faecalis is part of the human intestinal microbiome and is a prominent cause of health care-associated infections. The pathogenesis of many E. faecalis infections, including endocarditis and catheter-associated urinary tract infection (CAUTI), is related to the ability of clinical isolates to form biofilms. To identify chromosomal genetic determinants responsible for E. faecalis biofilm-mediated infection, we used a rabbit model of endocarditis to test strains with transposon insertions or in-frame deletions in biofilm-associated loci: ahrC, argR, atlA, opuBC, pyrC, recN, and sepF. Only the ahrC mutant was significantly attenuated in endocarditis. We demonstrate that the transcriptional regulator AhrC and the protease Eep, which we showed previously to be an endocarditis virulence factor, are also required for full virulence in murine CAUTI. Therefore, AhrC and Eep can be classified as enterococcal biofilm-associated virulence factors. Loss of ahrC caused defects in early attachment and accumulation of biofilm biomass. Characterization of ahrC transcription revealed that the temporal expression of this locus observed in wild-type cells promotes initiation of early biofilm formation and the establishment of endocarditis. This is the first report of AhrC serving as a virulence factor in any bacterial species
2002 Wild Blueberry Project Reports
The 2002 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Factors Affecting Microbial and Pesticide Residue Levels on Wild Blueberries
2. Effect of Blueberry Products on Oxidation in Meat Based Food
3. Determination of Pesticide Residue Levels in Freshly Harvested and Processed Wild Blueberries
4. Detection of Infested Wild Blueberries using Near-Infrared Spectroscopy
5. Investigation Of The Mechanism By Which Blueberry Fractions Maintain Arterial Integrity
6. Antioxidant Assessment in the Elderly
7. Water Use of Wild Blueberries and the Impact of Plant Water Stress on Yield
8. Control Tactics for Wild blueberry Pest Insects
9. IPM Strategies
10. Pest Biology
11. Wild Blueberry Pollination Research
12. Survey and Determination of Effective Control of Stem Blight and Leaf Spot Diseases in Wild Blueberry Fields
13. Effect of Foliar-applied Iron Chelate Concentration on Leaf Iron Concentration, Wild Blueberry Growth and Yield
14. Effect of Boron Application Methods on Boron Uptake in Wild Blueberries
15. Effect of Foliar N spray on Leaf N Concentration, Growth and Yield of Wild Blueberries
16. Effect of Foliar Spray (4-13-15) on Leaf Nutrient Concentration, Growth and Yield of Wild Blueberries
17. Effect of Foliar Copper Application on Growth and Yield of Wild Blueberries
18. Effect of Foliar Copper and/or Iron Application on Growth and Yield of Wild Blueberries
19. Effect of Soil pH on Nutrient Uptake
20. Assessment of Hexazinone Alternatives for Weed Control in Wild Blueberries and Weed Control
21. Evaluation of Fall Applications of Sulfonylurea Herbicides for Bunchberry Control in Wild Blueberries
22. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
23. Blueberry Extension Education Program Base
24. 2002 Pesticide Groundwater Survey
25. Cultural Weed Management using sulfur to lower the p
2005 Wild Blueberry Project Reports
The 2005 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Evaluation of Emerging Disinfections Technologies for Wild Blueberry Processing
1A. Incorporation of wild blueberry puree into a soy-based burger and its effect on sensory and chemical properties of the broiled burgers.
2. Incorporation of wild blueberry puree into a soy-based burger and its effect on sensory and chemical properties of the broiled burgers
3. Wild blueberries and Arterial Functional Properties
4. Practical Microbial Control Approach and Antimicrobial Properties Study for Wild Blueberries
5. Wild Blueberries Reduce Risks for Cardiovascular Disease –No Report at this time, data is still under analysis.
6. Irrigation Water Use in Wild Blueberry Production
7. Control Tactics for Blueberry Pest Insects, 2005
8. Integrated Pest Management (IPM) strategies, 2005
9. Control Tactics for Blueberry Pest Insects, 2005
10. The Effect of Fungicides and Cultural Treatments on Monilinia Blight, Yield and Post-Harvest Disease in Wild Blueberries
11. Effect of Soil pH on Nutrient Uptake
12. Effect of Manganese on Growth and Yield of Wild Blueberry
13. Raising Foliar Nitrogen by Application of CoRoN
14. Effects of Summer Foliar Fertilization to Increase Branch Length and Flower Bud Formation in the Prune Year
15. Assessment of Hexazinone Alternatives for Weed Control in Wild Blueberries and Field Cover Program Base
16. Evaluation of Fall Applications of Tribenuron Methyl for Bunchberry Control in Wild Blueberries
17. Evaluation of spot treatments of Tribenuron Methyl for weed control in Wild Blueberries
18. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
19. Assessment of Evitol and Kerb for Sedge Control in Wild Blueberrie
2004 Wild Blueberry Project Progress Reports
The 2004 edition of the Wild Blueberry Project Progress Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Determination of Pesticide Residue Levels in Freshly Harvested and Processed Lowbush Blueberries
2. Effect of Wild Blueberry Products on Physical, Chemical, Microbiological and Sensory Quality of Soy-Based and Ground Beef Patties
3. Evaluation of Emerging Disinfection Technologies for Wild Blueberry Processing
4. Detection of Infested Blueberries using Near-Infrared Spectroscopy-Spectra Collection
5. Health Claims for Wild Blueberries
6. Wild blueberries and Arterial Functional Properties
7. Irrigation Water Use in Wild Blueberry Production
8. Insect Control Tactics for Blueberry Pest Insects & Program Base
9. Integrated Pest Management (IPM) Strategies
10. Biology and Ecology of Blueberry Insect Pests
11. Stem Blight/Dieback and Leaf Spot Diseases in Lowbush Blueberry Fields
12. . Evaluation of fungicide control of mummy berry blight in wild blueberries: a) ground application and b) aerial application
13. Effect of Foliar Copper Application on Growth and Yield of Wild Blueberries
14. Effect of Soil pH on Nutrient Uptake
15. Effect of Fertilizer Timing (prune year vs. crop year) on Wild Blueberry Growth and Productivity
16. Raising Foliar Nitrogen by Application of CoRoN
17. Effect of Manganese on Growth and Yield of Wild Blueberry
18. Assessment of Hexazinone Alternatives for Weed Control in Wild Blueberries and Field Cover Program Base
19. Evaluation of Fall Applications of Sulfonylurea Herbicides for Bunchberry Control in Wild Blueberries
20. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
21. Assessment of Evitol for Sedge Control in Wild Blueberries
22. Cultural Weed Management Using pH
23. 2004 Pesticide Groundwater Survey
24. Wild Blueberry Extension Education Program in 200
2003 Wild Blueberry Project Reports
The 2003 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Factors Affecting the Microbial and Pesticide Residues Levels on Lowbush Blueberries
2. Effect of Blueberry Products on Oxidation in Ground Beef Patties
3. Infestation Detection using Near-Infrared Spectroscopy
4. Whole Wild Blueberries and Arterial Functional Properties
5. Irrigation Water use in Wild Blueberry Production
7. Control Tactics for Blueberry Pest Insects
8. IPM Strategies
9. Biology and Ecology of Blueberry Pest Insects, 2003
10. Wild Blueberry Pollination Research
11. Stem Blight/Dieback and Leaf Spot Diseases in Wild Blueberry Fields
12. Effect of Foliar N spray on Leaf N Concentration, Growth and Yield of Wild Blueberries
13. Effect of Foliar Spray (4-13-15) on Leaf Nutrient Concentration, Growth and Yield of Wild Blueberries
14. Effect of Foliar Copper Application on Growth and Yield of Wild Blueberries
15. Effect of Foliar Copper and/or Iron Application on Growth and Yield of Wild Blueberries
16. Effect of Soil pH on Nutrient Uptake.
17. Effect of Gibberellic Acid (GA3) and CPPU on Fruit Set and Yield of Wild Blueberry after low temperature flower stress
18. Effect of Fertilizer Timing (prune year vs. crop year) on Wild Blueberry Growth and Productivity.
19. Assessment of Hexazinone Alternatives for Weed Control in Wild Blueberries and Weed Control and Field Cover Program Base
20. Evaluation of Fall Applications of Sulfonylurea Herbicides for Bunchberry Control in Wild Blueberries
21. Assessment of clean-cut adapter on hand clippers for weed control in wild blueberries
22. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
23. Blueberry Extension Education Program in 2003
24. 2003 Pesticide Groundwater Survey
25. Cultural Weed Management using Sulfur to lower the p
2006 Lowbush Blueberry Project Reports
The 2006 edition of the Lowbush Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Evaluation of Emerging Disinfection Technologies for Wild Blueberry Processing
2. Incorporation of wild blueberry puree into a soy-based burger and its effect on sensory and chemical properties of the broiled burgers
3. Infestation Detection using NIRS
4. Mechanism of Action through which Wild Blueberries affect Arterial Functional Properties in Normotensive and Spontaneously Hypertensive Rats
5. Practical Microbial Control Approach for Wild Blueberries and their Antimicrobial Property
6. Wild Blueberry Consumption and Risks for Cardiovascular Disease
7. Irrigation Water use in Wild Blueberry Production
8. Control Tactics for Blueberry Pest Insects & Program Base
9. Integrated Pest Management (IPM) Strategies
10. Biology and Ecology of Blueberry Insect Pests, 2006
11. Research on Wild Blueberry Diseases for 2006-2007
12. Effect of Soil pH on Nutrient Uptake
13. Effect of Manganese on Growth and Yield of Wild Blueberry
14. Effects of Summer Foliar Fertilization to Increase Branch Length and Flower Bud Formation in the Prune Year
15. Effects of Phosphite Foliar Fertilizers on disease control and fruit set of wild blueberry
16. Assessment of Hexazinone Alternatives for Weed Control in Wild Blueberries
17. Evaluation of Fall Applications of Tribenuron Methyl for Bunchberry Control in Wild Blueberries
18. Evaluation of spot treatments of Tribenuron Methyl, Ultim and Roundup for weed control in Wild Blueberries
19. Blueberry Extension Education Program
20. Cultural Weed Management Using p
2001 Wild Blueberry CSREES Project Reports
The 2001 edition of the Wild Blueberry CSREES Progress Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Effect of Wild Blueberry Products on Oxidation in Meat Based Food Systems
2. Factors Affecting the Microbial and Pesticide Residues Levels on Wild Blueberries
3. Determination of Pesticide Residue Levels in Fresh and Processed Wild Blueberries
4. Separation of Maggot-Infested Wild Blueberries in the IQF Processing Line
5. Water Use of Wild Blueberries and the Impact of Plant Water Stress on Yields
6. Survey of Stem Blight and Leaf Spot Diseases in Wild Blueberry Fields
7. IPM Strategies
8. Control Tactics for Wild Blueberry Pest Insects, 2001
9. Biology and Ecology of Blueberry Pest Insects
10. Diurnal Bee Activity and Measurement of Honeybee Field Strength
11. Effect of Foliar-applied Iron (Fe) Chelate Concentration on Leaf Iron Concentration, Wild Blueberry Growth and Yield
12. Effect of Boron Application Methods on Boron Uptake in Wild Blueberries
13. Effect of Foliar Iron and Copper Application on Growth and Yield of Wild Blueberries
14. Effect of Fertilizer Timing on Wild Blueberry Growth and Productivity
15. Effect of Foliar Copper Application on Growth and Yield of Wild Blueberries
16. Effect of Prune-year Applications of Nutri-Phitetm P or Nutri-Phitetm P+K on Growth and Yield of Wild Blueberry (Vaccinium angustifolium Ait.)
17. Effect of Soil pH on Nutrient Uptake
18. Assessment of Azafenidin for Weed Control in Wild Blueberries
19. Assessment of Rimsulfuron for Weed Control in Wild Blueberries
20. Assessment of Pendimethalin for Weed Control in Wild Blueberries
21. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
22. Assessment of Sprout-less Weeder for Hardwood Control in Wild Blueberries
23. Wild Blueberry Extension Education Program in 2001
24. Evaluation of Fungicide Efficacy in Wild Blueberry Fields
25. 2001 Pesticide Groundwater Survey
26. Cultural Weed Management Using Sulfur to Lower the pH
27. Wild Blueberry Web Sit
Ecto-5′-Nucleotidase: A Candidate Virulence Factor in Streptococcus sanguinis Experimental Endocarditis
Streptococcus sanguinis is the most common cause of infective endocarditis (IE). Since the molecular basis of virulence of this oral commensal bacterium remains unclear, we searched the genome of S. sanguinis for previously unidentified virulence factors. We identified a cell surface ecto-5′-nucleotidase (Nt5e), as a candidate virulence factor. By colorimetric phosphate assay, we showed that S. sanguinis Nt5e can hydrolyze extracellular adenosine triphosphate to generate adenosine. Moreover, a nt5e deletion mutant showed significantly shorter lag time (P<0.05) to onset of platelet aggregation than the wild-type strain, without affecting platelet-bacterial adhesion in vitro (P = 0.98). In the absence of nt5e, S. sanguinis caused IE (4 d) in a rabbit model with significantly decreased mass of vegetations (P<0.01) and recovered bacterial loads (log10CFU, P = 0.01), suggesting that Nt5e contributes to the virulence of S. sanguinis in vivo. As a virulence factor, Nt5e may function by (i) hydrolyzing ATP, a pro-inflammatory molecule, and generating adenosine, an immunosuppressive molecule to inhibit phagocytic monocytes/macrophages associated with valvular vegetations. (ii) Nt5e-mediated inhibition of platelet aggregation could also delay presentation of platelet microbicidal proteins to infecting bacteria on heart valves. Both plausible Nt5e-dependent mechanisms would promote survival of infecting S. sanguinis. In conclusion, we now show for the first time that streptococcal Nt5e modulates S. sanguinis-induced platelet aggregation and may contribute to the virulence of streptococci in experimental IE
Phylogenomics of the Reproductive Parasite Wolbachia pipientis wMel: A Streamlined Genome Overrun by Mobile Genetic Elements
The complete sequence of the 1,267,782 bp genome of Wolbachia pipientis wMel, an obligate intracellular bacteria of Drosophila melanogaster, has been determined. Wolbachia, which are found in a variety of invertebrate species, are of great interest due to their diverse interactions with different hosts, which range from many forms of reproductive parasitism to mutualistic symbioses. Analysis of the wMel genome, in particular phylogenomic comparisons with other intracellular bacteria, has revealed many insights into the biology and evolution of wMel and Wolbachia in general. For example, the wMel genome is unique among sequenced obligate intracellular species in both being highly streamlined and containing very high levels of repetitive DNA and mobile DNA elements. This observation, coupled with multiple evolutionary reconstructions, suggests that natural selection is somewhat inefficient in wMel, most likely owing to the occurrence of repeated population bottlenecks. Genome analysis predicts many metabolic differences with the closely related Rickettsia species, including the presence of intact glycolysis and purine synthesis, which may compensate for an inability to obtain ATP directly from its host, as Rickettsia can. Other discoveries include the apparent inability of wMel to synthesize lipopolysaccharide and the presence of the most genes encoding proteins with ankyrin repeat domains of any prokaryotic genome yet sequenced. Despite the ability of wMel to infect the germline of its host, we find no evidence for either recent lateral gene transfer between wMel and D. melanogaster or older transfers between Wolbachia and any host. Evolutionary analysis further supports the hypothesis that mitochondria share a common ancestor with the α-Proteobacteria, but shows little support for the grouping of mitochondria with species in the order Rickettsiales. With the availability of the complete genomes of both species and excellent genetic tools for the host, the wMel–D. melanogaster symbiosis is now an ideal system for studying the biology and evolution of Wolbachia infections
Partial Meal Replacement Plan and Quality of the Diet at 1 Year: Action for Health in Diabetes (Look AHEAD) Trial
Little is known about diet quality with a reduced-energy, low-fat, partial meal replacement (PMR) plan, especially in individuals with type 2 diabetes. The Action for Health in Diabetes (Look AHEAD) trial implemented a PMR plan in the intensive lifestyle intervention (ILI)
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