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      1. Author :
        Jenkins, D. E.; Oei, Y.; Hornig, Y. S.; Yu, S. F.; Dusich, J.; Purchio, T.; Contag, P. R.
      2. Title :
        Bioluminescent imaging (BLI) to improve and refine traditional murine models of tumor growth and metastasis
      3. Type :
        Journal Article
      4. Year :
        2003
      5. Publication :
        Clinical and Experimental Metastasis
      6. Products :
      7. Volume :
        20
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        A549-luc-C8 cells; Animals, Cell Line, Tumor, Colonic Neoplasms/pathology, Fluorouracil/therapeutic use, Humans, Image Interpretation, Computer-Assisted, Longitudinal Studies, Luciferases/diagnostic use, Luminescent Measurements, Lung Neoplasms/ secondary, Lymphatic Metastasis, Male, Mice, Mice, SCID, Mitomycin/therapeutic use, Models, Biological, Neoplasm Transplantation, Prostatic Neoplasms/drug therapy/ pathology IVIS, Xenogen
      12. Abstract :
        Bioluminescent imaging (BLI) permits sensitive in vivo detection and quantification of cells specifically engineered to emit visible light. Three stable human tumor cell lines engineered to express luciferase were assessed for their tumorigenicity in subcutaneous, intravenous and spontaneous metastasis models. Bioluminescent PC-3M-luc-C6 human prostate cancer cells were implanted subcutaneously into SCID-beige mice and were monitored for tumor growth and response to 5-FU and mitomycin C treatments. Progressive tumor development and inhibition/regression following drug treatment were observed and quantified in vivo using BLI. Imaging data correlated to standard external caliper measurements of tumor volume, but bioluminescent data permitted earlier detection of tumor growth. In a lung colonization model, bioluminescent A549-luc-C8 human lung cancer cells were injected intravenously and lung metastases were monitored in vivo by whole animal imaging. Anesthetized mice were imaged weekly allowing a temporal assessment of in vivo lung tumor growth. This longitudinal study design permitted an accurate, real-time evaluation of tumor burden in the same animals over time. End-point bioluminescence measured in vivo correlated to total lung weight at necropsy. For a spontaneous metastatic tumor model, bioluminescent HT-29-luc-D6 human colon cancer cells implanted subcutaneously produced metastases to lung and lymph nodes in SCID-beige mice. Both primary tumors and micrometastases were detected by BLI in vivo. Ex vivo imaging of excised lung lobes and lymph nodes confirmed the in vivo signals and indicated a slightly higher frequency of metastasis in some mice. Levels of bioluminescence from in vivo and ex vivo images corresponded to the frequency and size of metastatic lesions in lungs and lymph nodes as subsequently confirmed by histology. In summary, BLI provided rapid, non-invasive monitoring of tumor growth and regression in animals. Its application to traditional oncology animal models offers quantitative and sensitive analysis of tumor growth and metastasis. The ability to temporally assess tumor development and responses to drug therapies in vivo also improves upon current standard animal models that are based on single end point data.
      13. URL :
        N/A
      14. Call Number :
        139189
      15. Serial :
        5565
      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 :
        Kadurugamuwa, J. L.; Francis, K. P.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2008
      5. Publication :
        Methods in Molecular Biology
      6. Products :
      7. Volume :
        431
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Bioware, Xen29, Animals, Bacteria/chemistry/ genetics, Bacterial Infections/diagnosis/ microbiology, Biofilms/ growth & development, Diagnostic Imaging/methods, Luminescent Measurements/ methods IVIS, Xenogen, Xen5, Xen44
      12. Abstract :
        Whole body biophotonic imaging (BPI) is a technique that has contributed significantly to the way researchers study bacterial pathogens and develop pre-clinical treatments to combat their ensuing infections in vivo. Not only does this approach allow disease profiles and drug efficacy studies to be conducted non-destructively in live animals over the entire course of the disease, but in many cases, it enables investigators to observe disease profiles that could otherwise easily be missed using conventional methodologies. The principles of this technique are that bacterial pathogens engineered to express bioluminescence (visible light) can be readily monitored from outside of the living animal using specialized low-light imaging equipment, enabling their movement, expansion and treatment to be seen completely non-invasively. Moreover, because the same group of animals can be imaged at each time-point throughout the study, the overall number of animals used is dramatically reduced, saving lives, time, and money. Also, as each animal acts as its own control over time, the issues associated with animal-to-animal variation are circumvented, thus improving the quality of the biostatistical data generated. The ability to monitor infections in vivo in a longitudinal fashion is especially appealing to assess chronic infections such as those involving implanted devices. Typically, bacteria grow as biofilms on these foreign bodies and are reputably difficult to monitor with conventional methods. Because of the non-destructive and non-invasive nature of BPI, the procedure can be performed repeatedly in the same animal, allowing the biofilm to be studied in situ without detachment or disturbance. This ability not only allows unique patterns of disease relapse to be seen following termination of antibiotic therapy but also in vivo resistance development during prolonged treatment, both of which are common occurrences with device-related infections. This chapter describes the bioluminescent engineering of both Gram-positive and Gram-negative bacteria and overviews their use in device-associated infections in several anatomical sites in a variety of animal models.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/18287760
      14. Call Number :
        139321
      15. Serial :
        5568
      1. Author :
        Kadurugamuwa, J. L.; Sin, L.; Albert, E.; Yu, J.; Francis, K.; DeBoer, M.; Rubin, M.; Bellinger-Kawahara, C.; Jr, T. R. Parr; Contag, P. R.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2003
      5. Publication :
        Infection and Immunity
      6. Products :
      7. Volume :
        71
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Bioware, Xen29, Xen5, Biofilms/ growth & development, Catheterization, Central Venous/adverse effects, Chemiluminescent Measurements, Colony Count, Microbial, Disease Models, Animal, Female, Humans, Luciferases/genetics/metabolism, Mice, Mice, Inbred BALB C, Pseudomonas Infections/ microbiology, Pseudomonas aeruginosa/genetics/ growth & development, Staphylococcal Infections/ microbiology, Staphylococcus aureus/genetics/ growth & development IVIS, Xenogen
      12. Abstract :
        We have developed a rapid, continuous method for real-time monitoring of biofilms, both in vitro and in a mouse infection model, through noninvasive imaging of bioluminescent bacteria colonized on Teflon catheters. Two important biofilm-forming bacterial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, were made bioluminescent by insertion of a complete lux operon. These bacteria produced significant bioluminescent signals for both in vitro studies and the development of an in vivo model, allowing effective real-time assessment of the physiological state of the biofilms. In vitro viable counts and light output were parallel and highly correlated (S. aureus r = 0.98; P. aeruginosa r = 0.99) and could be maintained for 10 days or longer, provided that growth medium was replenished every 12 h. In the murine model, subcutaneous implantation of the catheters (precolonized or postimplant infected) was well tolerated. An infecting dose of 10 (3) to 10 (5) CFU/catheter for S. aureus and P. aeruginosa resulted in a reproducible, localized infection surrounding the catheter that persisted until the termination of the experiment on day 20. Recovery of the bacteria from the catheters of infected animals showed that the bioluminescent signal corresponded to the CFU and that the lux constructs were highly stable even after many days in vivo. Since the metabolic activity of viable cells could be detected directly on the support matrix, nondestructively, and noninvasively, this method is especially appealing for the study of chronic biofilm infections and drug efficacy studies in vivo.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/12540570
      14. Call Number :
        139339
      15. Serial :
        5926
      1. Author :
        Engelsman, A. F.; Mei, H. C. van der; Francis, K. P.; Busscher, H. J.; Ploeg, R. J.; Dam, G. M. van
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        J Biomed Mater Res B Appl Biomater
      6. Products :
      7. Volume :
        88
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Bioware; IVIS, Xenogen; Xen29
      12. Abstract :
        Infection is the main cause of biomaterials-related failure. A simple technique to test in-vivo new antimicrobial and/or nonadhesive implant coatings is unavailable. Current in vitro methods for studying bacterial adhesion and growth on biomaterial surfaces lack the influence of the host immune system. Most in vivo methods to study biomaterials-related infections routinely involve implant-removal, preventing comprehensive longitudinal monitoring. In vivo imaging circumvents these drawbacks and is based on the use of noninvasive optical imaging of bioluminescent bacteria. Staphylococcus aureus Xen29 is genetically modified to be stably bioluminescent, by the introduction of a modified full lux operon onto its chromosome. Surgical meshes with adhering S. aureus Xen29 were implanted in mice and bacterial growth and spread into the surrounding tissue was monitored longitudinally from bioluminescence with a highly sensitive CCD camera. Distinct spatiotemporal bioluminescence patterns, extending beyond the mesh area into surrounding tissues were observed. After 10 days, the number of living organisms isolated from explanted meshes was found to correlate with bioluminescence prior to sacrifice of the animals. Therefore, it is concluded that in vivo imaging using bioluminescent bacteria is ideally suited to study antimicrobial coatings taking into account the host immune system. In addition, longitudinal monitoring of infection in one animal will significantly reduce the number of experiments and animals.
      13. URL :
        http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18618733
      14. Call Number :
        137698
      15. Serial :
        7462
      1. Author :
        Xiong, Y. Q.; Willard, J.; Kadurugamuwa, J. L.; Yu, J.; Francis, K. P.; Bayer, A. S.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2005
      5. Publication :
        Antimicrobial Agents and Chemotherapy
      6. Products :
      7. Volume :
        49
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        IVIS, Xenogen; Bioware; Xen29
      12. Abstract :
        Therapeutic options for invasive Staphylococcus aureus infections have become limited due to rising antimicrobial resistance, making relevant animal model testing of new candidate agents more crucial than ever. In the present studies, a rat model of aortic infective endocarditis (IE) caused by a bioluminescently engineered, biofilm-positive S. aureus strain was used to evaluate real-time antibiotic efficacy directly. This strain was vancomycin and cefazolin susceptible but gentamicin resistant. Bioluminescence was detected and quantified daily in antibiotic-treated and control animals with IE, using a highly sensitive in vivo imaging system (IVIS). Persistent and increasing cardiac bioluminescent signals (BLS) were observed in untreated animals. Three days of vancomycin therapy caused significant reductions in both cardiac BLS (>10-fold versus control) and S. aureus densities in cardiac vegetations (P < 0.005 versus control). However, 3 days after discontinuation of vancomycin therapy, a greater than threefold increase in cardiac BLS was observed, indicating relapsing IE (which was confirmed by quantitative culture). Cefazolin resulted in modest decreases in cardiac BLS and bacterial densities. These microbiologic and cardiac BLS differences during therapy correlated with a longer time-above-MIC for vancomycin (>12 h) than for cefazolin (?4 h). Gentamicin caused neither a reduction in cardiac S. aureus densities nor a reduction in BLS. There were significant correlations between cardiac BLS and S. aureus densities in vegetations in all treatment groups. These data suggest that bioluminescent imaging provides a substantial advance in the real-time monitoring of the efficacy of therapy of invasive S. aureus infections in live animals.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/15743898
      14. Call Number :
        144577
      15. Serial :
        7474
      1. Author :
        Kadurugamuwa, J. L.; Sin, L. V.; Yu, J.; Francis, K. P.; Kimura, R.; Purchio, T.; Contag, P. R.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2003
      5. Publication :
        Antimicrobial Agents and Chemotherapy
      6. Products :
      7. Volume :
        47
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Anti-Bacterial Agents/ pharmacology, Bacterial Infections/drug therapy/microbiology, Biofilms/ drug effects/growth & development, Bioware; Catheterization/adverse effects, Chemiluminescent Measurements, Ciprofloxacin/pharmacology, Colony Count, Microbial, Disease Models, Animal, Dose-Response Relationship, Drug, Drug Monitoring/methods, Mice, Rifampin/pharmacology, Staphylococcus aureus/drug effects/genetics/growth & development, Tobramycin/pharmacology IVIS, Xenogen; Xen29
      12. Abstract :
        We have developed a rapid, continuous method for monitoring the effectiveness of several antibacterial agents in real time, noninvasively, by using a recently described mouse model of chronic biofilm infection (J. L. Kadurugamuwa et al., Infect. Immun. 71:882-890, 2003), which relies on biophotonic imaging of bioluminescent bacteria. To facilitate real-time monitoring of infection, we used a Staphylococcus aureus isolate that was made bioluminescent by inserting a modified lux operon into the bacterial chromosome. This bioluminescent reporter bacterium was used to study the antimicrobial effects of several antibiotics belonging to different molecular families. Treatment with rifampin, tobramycin, and ciprofloxacin was started 7 days after subcutaneous implantation of catheters precolonized with 10(4) CFU of S. aureus. Three different doses of antibiotics were administered twice a day for 4 consecutive days. The number of metabolically active bacteria in untreated mice and the tobramycin- and ciprofloxacin-treated groups remained relatively unchanged over the 4-week observation period, indicating poor efficacies for tobramycin and ciprofloxacin. A rapid dose-dependent decline in metabolic activity in rifampin-treated groups was observed, with almost a 90% reduction after two doses and nearly undetectable levels after three doses. The disappearance of light emission correlated with colony counts. After the final treatment, cell numbers rebounded as a function of concentration in a time-dependent manner. The staphylococci isolated from the catheters of mice treated with rifampin were uniformly resistant to rifampin but retained their in vitro susceptibilities to tobramycin and ciprofloxacin. Since the metabolic activities of viable cells and a postantibiotic effect could be detected directly on the support matrix nondestructively and noninvasively, the methodology is specifically appealing for investigating the effects of antibiotics on biofilms in vivo. Moreover, our study points to the possible use of biophotonic imaging for the detection of the development of resistance to therapeutic agents during treatment of chronic infections in vivo.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/14506020
      14. Call Number :
        139345
      15. Serial :
        7448
      1. Author :
        De Kwaadsteniet, Michele
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        N/A
      6. Products :
      7. Volume :
        N/A
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Antibiotics -- Therapeutic use; Bacteriocins; Bioware; Dissertations -- Microbiology; Drug resistance in microorganisms; Nisin; Respiratory infections -- Treatment; Skin -- Infections -- Treatment; Staphylococcus aureus; Theses -- Microbiology; Xen29
      12. Abstract :
        Multidrug resistant strains of Staphylococcus aureus is presenting an increasing threat, especially immune compromised individuals. Many of these strains have developed resistance to newly approved drugs such as quinupristin-dalfopristin, linezolid and daptomycin. The search for alternative treatment, including bacteriocins (ribosomally synthesized antimicrobial peptides) of lactic acid bacteria is increasing . Lactococcus lactis subsp. lactis F10, isolated from freshwater catfish, produced a new nisin variant active against clinical strains of S. aureus. The operon encoding nisin F is located on a plasmid and the structural gene has been sequenced. The lantibiotic is closely related to nisin Z, except at position 30 where valine replaced isoleucine. The antimicrobial activity of nisin F against S. aureus was tested in the respiratory tract of Wistar rats. Non-immunosuppressed and immunosuppressed rats were intranasally infected with S. aureus K and then treated with either nisin F or sterile physiological saline. Nisin F protected immunosuppressed rats against S. aureus, as symptoms of an infection were only detected in the trachea and lungs of immunosuppressed rats treated with saline. The safety of intranasally administered nisin F was also evaluated and proved to have no adverse side effects. The potential of nisin F as an antimicrobial agent to treat subcutaneous skin infections was evaluated by infecting C57BL/6 mice with a bioluminescent strain of S. aureus (Xen 36). Immunosuppressed mice were treated with either nisin F or sterile physiological saline 24 h and 48 h after infection with subcutaneously injected S. aureus Xen 36. Histology and bioluminescence flux measurements revealed that nisin F was ineffective in the treatment of deep dermal staphylococcal infections. Non-infected and infected mice treated with nisin F had an influx of polymorphonuclear cells in the deep stroma of the skin tissue. This suggested that nisin F, when injected subcutaneously, may have modulated the immune system. Nisin F proved an effective antimicrobial agent against S. aureus-related infections in the respiratory tract, but not against subcutaneous infections. The outcome of nisin F treatment thus depends on the route of administration and site of infection.
      13. URL :
        http://scholar.sun.ac.za/handle/10019.1/1285
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9042
      1. Author :
        N/A
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Annals of the New York Academy of Sciences
      6. Products :
      7. Volume :
        1192
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Biofilms; Bioware; Bone Density Conservation Agents; Chronic Disease; Cytokines; Drug Evaluation, Preclinical; Humans; Immunity; Incidence; Jaw Diseases; Mice; Neovascularization, Physiologic; Osteoclasts; Osteomyelitis; Osteonecrosis; Staphylococcal Infections; Xen29
      12. Abstract :
        The effects of antiresorptive agents (e.g., alendronate [Aln], osteoprotegerin [OPG]) on bone infection are unknown. Thus, their effects on implant-associated osteomyelitis (OM) were investigated in mice using PBS (placebo), gentamycin, and etanercept (TNFR:Fc) controls. None of the drugs affected humoral immunity, angiogenesis, or chronic infection. However, the significant (P < 0.05 vs. PBS) inhibition of cortical osteolysis and decreased draining lymph node size in Aln- and OPG-treated mice was associated with a significant (P < 0.05) increase in the incidence of high-grade infections during the establishment of OM. In contrast, the high-grade infections in TNFR:Fc-treated mice were associated with immunosuppression, as evidenced by the absence of granulomas and presence of Gram(+) biofilm in the bone marrow. Collectively, these findings indicate that although antiresorptive agents do not exacerbate chronic OM, they can increase the bacterial load during early infection by decreasing lymphatic drainage and preventing the removal of necrotic bone that harbors the bacteria.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/20392222
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        9034
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