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      1. Author :
        N/A
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2007
      5. Publication :
        PLoS pathogens
      6. Products :
      7. Volume :
        3
      8. Issue :
        6
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Anthrax; Bacillus anthracis; Bioware; Disease Models, Animal; Gastrointestinal Diseases; Inhalation Exposure; Luciferases; Luminescence; Luminescent Measurements; Lymph Nodes; Mice; Mice, Inbred BALB C; Nasal Cavity; Organisms, Genetically Modified; Peyer's Patches; Pharynx; pXen-5; Skin; Spores, Bacterial
      12. Abstract :
        Bacillus anthracis causes three forms of anthrax: inhalational, gastrointestinal, and cutaneous. Anthrax is characterized by both toxemia, which is caused by secretion of immunomodulating toxins (lethal toxin and edema toxin), and septicemia, which is associated with bacterial encapsulation. Here we report that, contrary to the current view of B. anthracis pathogenesis, B. anthracis spores germinate and establish infections at the initial site of inoculation in both inhalational and cutaneous infections without needing to be transported to draining lymph nodes, and that inhaled spores establish initial infection in nasal-associated lymphoid tissues. Furthermore, we found that Peyer's patches in the mouse intestine are the primary site of bacterial growth after intragastric inoculation, thus establishing an animal model of gastrointestinal anthrax. All routes of infection progressed to the draining lymph nodes, spleen, lungs, and ultimately the blood. These discoveries were made possible through the development of a novel dynamic mouse model of B. anthracis infection using bioluminescent non-toxinogenic capsulated bacteria that can be visualized within the mouse in real-time, and demonstrate the value of in vivo imaging in the analysis of B. anthracis infection. Our data imply that previously unrecognized portals of bacterial entry demand more intensive investigation, and will significantly transform the current perception of inhalational, gastrointestinal, and cutaneous B. anthracis pathogenesis.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/17542645
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9022
      1. Author :
        Hardy, Jonathan; Chu, Pauline; Contag, Christopher H
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Disease models & mechanisms
      6. Products :
      7. Volume :
        2
      8. Issue :
        1-2
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Bioware; Bone Marrow; Bone Marrow Cells; Disease Models, Animal; Female; Host-Pathogen Interactions; Humans; Knee Joint; Listeria monocytogenes; Listeriosis; Mice; Mice, Inbred BALB C; Mutation; pXen-5; Tibia
      12. Abstract :
        Murine listeriosis is one of the most comprehensive and well-studied models of infection, and Listeria monocytogenes has provided seminal information regarding bacterial pathogenesis. However, many aspects of the mouse model remain poorly understood, including carrier states and chronic colonization which represent important features of the spectrum of host-pathogen interaction. Bone marrow has recently been shown to harbor L. monocytogenes, which spreads from this location to the central nervous system. Bone could, therefore, be an important chronic reservoir, but this infection is difficult to study because it involves only a few bacteria and the extent of infection cannot be assessed until after the animal is sacrificed. We employed in vivo bioluminescence imaging to localize L. monocytogenes bone infections over time in live mice, revealing that the bacteria grow in discrete foci. These lesions can persist in many locations in the legs of mice and are not accompanied by a histological indication such as granuloma or a neutrophil infiltratate. We demonstrate that highly attenuated hly mutants, which have defective intracellular replication, are capable of prolonged focal infection of the bone marrow for periods of up to several weeks. These results support the recently proposed hypothesis that the bone marrow is a unique niche for L. monocytogenes.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/19132117
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9018
      1. Author :
        Hardy, Jonathan; Margolis, Jeffrey J; Contag, Christopher H
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2006
      5. Publication :
        Infection and immunity
      6. Products :
      7. Volume :
        74
      8. Issue :
        3
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Bacterial Toxins; Biliary Tract; Bioware; Feces; Food Contamination; Intestines; Listeria monocytogenes; Listeriosis; Mice; Mice, Inbred BALB C; pXen-5
      12. Abstract :
        Listeria monocytogenes is a ubiquitous gram-positive bacterium that can cause systemic and often life-threatening disease in immunocompromised hosts. This organism is largely an intracellular pathogen; however, we have determined that it can also grow extracellularly in animals, in the lumen of the gallbladder. The significance of growth in the gallbladder with respect to the pathogenesis and spread of listeriosis depends on the ability of the bacterium to leave this organ and be disseminated to other tissues and into the environment. Should this process be highly inefficient, growth in the gallbladder would have no impact on pathogenesis or spread, but if it occurs efficiently, bacterial growth in this organ may contribute to listeriosis and dissemination of this organism. Here, we use whole-body imaging to determine the efficacy and kinetics of food- and hormone-induced biliary excretion of L. monocytogenes from the murine gallbladder, demonstrating that transit through the bile duct into the intestine can occur within 5 min of induction of gallbladder contraction by food or cholecystokinin and that movement of bacteria through the intestinal lumen can occur very rapidly in the absence of fecal material. These studies demonstrate that L. monocytogenes bacteria replicating in the gallbladder can be expelled from the organ efficiently and that the released bacteria move into the intestinal tract, where they pass into the environment and may possibly reinfect the animal.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/16495556
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9024
      1. Author :
        Harms, Jerome S; Durward, Marina A; Magnani, Diogo M; Splitter, Gary A
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Journal of immune based therapies and vaccines
      6. Products :
      7. Volume :
        7
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Bioware; pXen-13
      12. Abstract :
        BACKGROUND There is no safe, effective human vaccine against brucellosis. Live attenuated Brucella strains are widely used to vaccinate animals. However these live Brucella vaccines can cause disease and are unsafe for humans. Killed Brucella or subunit vaccines are not effective in eliciting long term protection. In this study, we evaluate an approach using a live, non-pathogenic bacteria (E. coli) genetically engineered to mimic the brucellae pathway of infection and present antigens for an appropriate cytolitic T cell response. METHODS E. coli was modified to express invasin of Yersinia and listerialysin O (LLO) of Listeria to impart the necessary infectivity and antigen releasing traits of the intracellular pathogen, Brucella. This modified E. coli was considered our vaccine delivery system and was engineered to express Green Fluorescent Protein (GFP) or Brucella antigens for in vitro and in vivo immunological studies including cytokine profiling and cytotoxicity assays. RESULTS The E. coli vaccine vector was able to infect all cells tested and efficiently deliver therapeutics to the host cell. Using GFP as antigen, we demonstrate that the E. coli vaccine vector elicits a Th1 cytokine profile in both primary and secondary immune responses. Additionally, using this vector to deliver a Brucella antigen, we demonstrate the ability of the E. coli vaccine vector to induce specific Cytotoxic T Lymphocytes (CTLs). CONCLUSION Protection against most intracellular bacterial pathogens can be obtained mostly through cell mediated immunity. Data presented here suggest modified E. coli can be used as a vaccine vector for delivery of antigens and therapeutics mimicking the infection of the pathogen and inducing cell mediated immunity to that pathogen.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/19126207
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9029
      1. Author :
        Orihuela, Carlos J; Gao, Geli; McGee, Mackenzie; Yu, Jun; Francis, Kevin P; Tuomanen, Elaine
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2003
      5. Publication :
        Scandinavian journal of infectious diseases
      6. Products :
      7. Volume :
        35
      8. Issue :
        9
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Bioware; Disease Models, Animal; Female; Lung; Mice; Mice, Inbred BALB C; Pneumococcal Infections; pXen-5; Serotyping; Streptococcus pneumoniae, Xen10, Xen7, Xen35
      12. Abstract :
        The variability of the course of infection by Streptococcus pneumoniae is well known but poorly understood. Most animal models of pneumonia, sepsis or meningitis have been forced to use site-specific bacterial inoculation to mimic localized human infection. This study examined the differences in the progression of disease-causing strains D39 (serotype 2), A66.1 (serotype 3) and TIGR4 (serotype 4) using isolates transformed with the Gram-positive lux transposon cassette, Tn4001 luxABCDE Km(r). Expression of the lux operon results in bioluminescence, permitting the detection of the bacteria within a living animal while using a CCD camera. Mice infected intranasally with A66.1 developed only pneumonia, those challenged with D39 experienced high-grade sepsis, while TIGR4 infection resulted in low-grade pneumonia and bacteremia ultimately progressing to meningitis. Quantitative analysis of bacterial titers confirmed these patterns, which were consistent across different lineages of mice. Mice anesthetized with ketamine and xylazine developed more severe forms of the disease compared with isoflurane. These studies unambiguously characterize 3 distinct models of the natural course of pneumococcal infection. Mapping these models provides a framework for detailed molecular modeling of pneumococcal virulence determinants at specific stages of disease.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/14620149
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9026
      1. Author :
        Park, Hae-Sun; Francis, Kevin P; Yu, Jun; Cleary, P Patrick
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2003
      5. Publication :
        Journal of immunology (Baltimore, Md.: 1950)
      6. Products :
      7. Volume :
        171
      8. Issue :
        5
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Administration, Intranasal; Animals; Bioware; Disease Models, Animal; Female; Humans; Immunohistochemistry; Intracellular Fluid; Lymphoid Tissue; Mice; Mice, Inbred BALB C; Nasal Mucosa; Nasopharynx; Palatine Tonsil; pXen-5; Streptococcal Infections; Streptococcus pyogenes
      12. Abstract :
        Human tonsils are suspected to be an antibiotic-impervious human reservoir for group A streptococcus. An intranasal infection model in mice and a bioluminescent-tagged strain were used to investigate this possibility. Viable streptococci were predominantly found both intra- and extracellularly in nasal-associated lymphoid tissue (NALT), a human tonsil homologue. Ulex europaeus-1, a membranous (M) cell-specific lectin, identified cells harboring streptococci at the epithelial surface of NALT and blocked bacterial colonization of this tissue. These results suggest that M cells in NALT transport this Gram-positive pathogen across the epithelial layers in a manner similar to those in Peyer's patches, which permit enteric pathogens to invade deeper tissues from the gastrointestinal tract.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/12928403
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9025
      1. Author :
        Rambow-Larsen, Amy A; Rajashekara, Gireesh; Petersen, Erik; Splitter, Gary
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2008
      5. Publication :
        Journal of bacteriology
      6. Products :
      7. Volume :
        190
      8. Issue :
        9
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Amino Acid Sequence; Animals; Bioware; Brucella melitensis; Brucellosis; Disease Models, Animal; Flagella; Gene Deletion; Gene Expression Regulation, Bacterial; Interferon Regulatory Factor-1; Macrophages; Mice; Mice, Mutant Strains; Molecular Sequence Data; Oligonucleotide Array Sequence Analysis; pXen-13; Quorum Sensing; Repressor Proteins; Trans-Activators; Virulence Factors
      12. Abstract :
        Brucella melitensis is an intracellular pathogen that establishes a replicative niche within macrophages. While the intracellular lifestyle of Brucella is poorly understood and few virulence factors have been identified, components of a quorum-sensing pathway in Brucella have recently been identified. The LuxR-type regulatory protein, VjbR, and an N-acylhomoserine lactone signaling molecule are both involved in regulating expression of the virB-encoded type IV secretion system. We have identified a second LuxR-type regulatory protein (BlxR) in Brucella. Microarray analysis of a blxR mutant suggests that BlxR regulates the expression of a number of genes, including those encoding the type IV secretion system and flagella. Confirming these results, deletion of blxR in B. melitensis reduced the transcriptional activities of promoters for the virB operon, flagellar genes, and another putative virulence factor gene, bopA. Furthermore, our data suggested that both BlxR and VjbR are positively autoregulated and cross-regulate the expression of each other. The blxR deletion strain exhibited reduced growth in macrophages, similar to that observed for a vjbR deletion strain. However, unlike the vjbR deletion, the blxR deletion did not fully attenuate virulence in mice. More strikingly, bioluminescent imaging revealed that dissemination of the blxR mutant was similar to that of wild-type B. melitensis, while the vjbR mutant was defective for systemic spread in IRF-1(-/-) mice, suggesting that these regulators are not functionally redundant but that they converge in a common pathway regulating bacterial processes.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/18310341
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9030
      1. Author :
        Schwan, William R; Lehmann, Lynn; McCormick, James
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2006
      5. Publication :
        Infection and immunity
      6. Products :
      7. Volume :
        74
      8. Issue :
        1
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Amino Acid Transport Systems, Neutral; Animals; Bacterial Proteins; Bioware; Blotting, Northern; Disease Models, Animal; Gene Expression Regulation, Bacterial; Humans; Lac Operon; Mice; Osmolar Concentration; Proline; pXen-5; Recombinant Fusion Proteins; Staphylococcal Infections; Staphylococcus aureus; Symporters; Transcriptional Activation
      12. Abstract :
        Staphylococcus aureus can grow virtually anywhere in the human body but needs to import proline through low- and high-affinity proline transporters to survive. This study examined the regulation of the S. aureus putP gene, which encodes a high-affinity proline permease. putP::lacZ and putP::lux transcriptional fusions were constructed and integrated into the genomes of several S. aureus strains. Enzyme activity was measured after growth in media with various osmolyte concentrations. As osmolarity rose, putP expression increased, with a plateau at 2 M for NaCl in strain LL3-1. Proline concentrations as low as 17.4 muM activated expression of the putP gene. The putP::lux fusion was also integrated into the genomes of S. aureus strains that were either SigB inactive (LL3-1, 8325-4, and SH1003) or SigB active (Newman and SH1000). SigB inactive strains showed increased putP gene expression as NaCl concentrations rose, whereas SigB active strains displayed a dramatic decrease in putP expression, suggesting that the alternative sigma factor B plays a negative role in putP regulation. Mice inoculated with S. aureus strains containing the putP::lux fusion exhibited up to a 715-fold increase in putP expression, although levels in the various murine organs differed. Moreover, urine from human patients infected with S. aureus showed elevated putP levels by use of a PCR procedure, whereas blood and some abscess material had no significant increase. Thus, putP is transcriptionally activated by a low-proline and high osmotic environment both in growth media and in murine or human clinical specimens.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/16368996
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9023
      1. Author :
        N/A
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2007
      5. Publication :
        PloS one
      6. Products :
      7. Volume :
        2
      8. Issue :
        2
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Adhesins, Bacterial; Animals; Antigens, CD46; Bacteremia; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacterial Translocation; Bioware; Blood-Brain Barrier; Central Nervous System; Disease Progression; Female; Luminescent Measurements; Luminescent Proteins; Male; Meningitis, Meningococcal; Meningococcal Infections; Mice; Mice, Transgenic; Nasal Cavity; pXen-13; Recombinant Fusion Proteins; Respiratory System; Sepsis; Thyroid Gland
      12. Abstract :
        Neisseria meningitidis is a human pathogen that causes septicemia and meningitis with high mortality. The disease progression is rapid and much remains unknown about the disease process. The understanding of disease development is crucial for development of novel therapeutic strategies and vaccines against meningococcal disease. The use of bioluminescent imaging combined with a mouse disease model allowed us to investigate the progression of meningococcal sepsis over time. Injection of bacteria in blood demonstrated waves of bacterial clearance and growth, which selected for Opa-expressing bacteria, indicating the importance of this bacterial protein. Further, N. meningitidis accumulated in the thyroid gland, while thyroid hormone T4 levels decreased. Bacteria reached the mucosal surfaces of the upper respiratory tract, which required expression of the meningococcal PilC1 adhesin. Surprisingly, PilC1 was dispensable for meningococcal growth in blood and for crossing of the blood-brain barrier, indicating that the major role of PilC1 is to interact with mucosal surfaces. This in vivo study reveals disease dynamics and organ targeting during meningococcal disease and presents a potent tool for further investigations of meningococcal pathogenesis and vaccines in vivo. This might lead to development of new strategies to improve the outcome of meningococcal disease in human patients.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/17311106
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9032
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