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      1. Author :
        Ketonis, C.; Barr, S.; Shapiro, I. M.; Parvizi, J.; Adams, C. S.; Hickok, N. J.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2011
      5. Publication :
        Bone
      6. Products :
      7. Volume :
        48
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen36, Xen 36, Staphylococcus aureus Xen36, IVIS, Adsorption/drug effects; Anti-Bacterial Agents/chemistry/*pharmacology; Biological Markers/metabolism; *Bone Transplantation; Cell Differentiation/drug effects; Cell Shape/drug effects; Cells, Cultured; Colony Count, Microbial; Drug Stability; Fetus/cytology; Fluorescence; Gene Expression Profiling; Humans; Microbial Sensitivity Tests; Osteoblasts/cytology/drug effects/metabolism; Phenotype; Time Factors; Transplantation, Homologous; Vancomycin/chemistry/*pharmacology
      12. Abstract :
        Bacterial contamination of bone allograft is a significant complication of orthopedic surgery. To address this issue, we have engineered a method for covalently modifying bone allograft tissue with the antibiotic vancomycin. The goal of this investigation was to compare the biocidal properties of this new allograft material with those of vancomycin physisorbed onto graft material. The duration of antibiotic release from the vancomycin-modified allograft matrix was determined, and no elution was observed. In contrast, the adsorbed antibiotic showed a peak elution at 24h that then decreased over several days. We next used an Staphylococcus aureus disk diffusion assay to measure the activity of the eluted vancomycin. Again we found that no active antibiotic was eluted from the covalently modified allograft. Similarly, when the vancomycin-modified allograft morsel was used in the assay, no measurable elution was observed; amounts of antibiotic released from the adsorbed samples inhibited S. aureus growth for 4-7 days. Probably the most telling property of the allograft was that after 2 weeks, the tethered allograft was able to resist bacterial colonization. Unlike the elution system in which vancomycin was depleted over the course of days-weeks, the antibiotic on the allograft was stably bound even after 300 days, while its biocidal activity remained undiminished for 60 days. This finding was in stark contrast to the antibiotic impregnated allograft, which was readily colonized by bacteria. Finally we chose to evaluate three indicators of cell function: expression of a key transcription factor, expression of selected transcripts, and assessment of cell morphology. Since the tethered antibiotic appeared to have little or no effect on any of these activities, it was concluded that the stable, tethered antibiotic prevented bacterial infection while not modifying bone cell function.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/21035576
      14. Call Number :
        PKI @ kd.modi @ 7
      15. Serial :
        10407
      1. Author :
        Penn-Barwell, J. G.; Murray, C. K.; Wenke, J. C.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2012
      5. Publication :
        J Bone Joint Surg Br
      6. Products :
      7. Volume :
        94
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen36, Xen 36, Staphylococcus aureus Xen36, IVIS
      12. Abstract :
        Most animal studies indicate that early irrigation and debridement reduce infection after an open fracture. Unfortunately, these studies often do not involve antibiotics. Clinical studies indicate that the timing of initial debridement does not affect the rate of infection but these studies are observational and fraught with confounding variables. The purpose of this study was to control these variables using an animal model incorporating systemic antibiotics and surgical treatment. We used a rat femur model with a defect which was contaminated with Staphylococcus aureus and treated with a three-day course of systemic cefazolin (5 mg/kg 12-hourly) and debridement and irrigation, both of which were initiated independently at two, six and 24 hour time points. After 14 days the bone and hardware were harvested for separate microbiological analysis. No animal that received antibiotics and surgery two hours after injury had detectable bacteria. When antibiotics were started at two hours, a delay in surgical treatment from two to six hours significantly increased the development of infection (p = 0.047). However, delaying surgery to 24 hours increase the rate of infection, but not significantly (p = 0.054). The timing of antibiotics had a more significant effect on the proportion of positive samples than earlier surgery. Delaying antibiotics to six or 24 hours had a profoundly detrimental effect on the infection rate regardless of the timing of surgery. These findings are consistent with the concept that bacteria progress from a vulnerable planktonic form to a treatment-resistant biofilm.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/22219257
      14. Call Number :
        PKI @ kd.modi @ 10
      15. Serial :
        10404
      1. Author :
        van Staden, A. D.; Brand, A. M.; Dicks, L. M.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2012
      5. Publication :
        J Appl Microbiol
      6. Products :
      7. Volume :
        N/A
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen36, Xen 36, Staphylococcus aureus Xen36, IVIS
      12. Abstract :
        Aims: To determine if nisin F-loaded self-setting brushite cement could control the growth of Staphylococcus aureus in vivo. Methods and Results: Brushite cement was prepared by mixing equimolar concentrations of beta-tricalcium phosphate and monocalcium phosphate monohydrate. Nisin F was added at 5.0%, 2.5% and 1.0% (w/w) and the cement moulded into cylinders. In vitro antibacterial activity was determined using a delayed agar diffusion assay. Release of nisin F from the cement was determined using BCA protein assays. Based on scanning electron microscopy and X-ray diffraction analysis, nisin F did not cause significant changes in cement structure or chemistry. Cement containing 5.0% (w/w) nisin F yielded the most promising in vitro results. Nisin F-loaded cement was implanted into a subcutaneous pocket on the back of mice and then infected with S. aureus Xen 36. Infection was monitored for 7 days, using an in vivo imaging system. Nisin F prevented S. aureus infection for 7 days and no viable cells were isolated from the implants. Conclusions: Nisin F-loaded brushite cement successfully prevented in vivo growth of S. aureus. Significance and Impact of the Study: Nisin F incorporated into bone cement may be used to control S. aureus infection in vivo. (c) 2012The Authors Journal of Applied Microbiology (c) 2012 The Society for Applied Microbiology.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/22268790
      14. Call Number :
        PKI @ kd.modi @ 11
      15. Serial :
        10402
      1. Author :
        Xie, Chao; Liang, Bojian; Xue, Ming; Lin, Angela S.P.; Loiselle, Alayna; Schwarz, Edward M.; Guldberg, Robert E.; O'Keefe, Regis J.; Zhang, Xinping
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Am J Pathol
      6. Products :
      7. Volume :
        175
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen10, Xen 10, Streptococcus pneumoniae Xen10, IVIS
      12. Abstract :
        Although the essential role of cyclooxygenase (COX)-2 in fracture healing is known, the targeted genes and molecular pathways remain unclear. Using prostaglandin E2 receptor (EP)2 and EP4 agonists, we examined the effects of EP receptor activation in compensation for the lack of COX-2 during fracture healing. In a fracture-healing model, COX-2-/- mice showed delayed initiation and impaired endochondral bone repair, accompanied by a severe angiogenesis deficiency. The EP4 agonist markedly improved the impaired healing in COX-2-/- mice, as evidenced by restoration of bony callus formation on day 14, a near complete reversal of bone formation, and an approximately 70% improvement of angiogenesis in the COX-2-/- callus. In comparison, the EP2 agonist only marginally enhanced bone formation in COX-2-/- mice. To determine the differential roles of EP2 and EP4 receptors on COX-2-mediated fracture repair, the effects of selective EP agonists on chondrogenesis were examined in E11.5 long-term limb bud micromass cultures. Only the EP4 agonist significantly increased cartilage nodule formation similar to that observed during prostaglandin E2 treatment. The prostaglandin E2/EP4 agonist also stimulated MMP-9 expression in bone marrow stromal cell cultures. The EP4 agonist further restored the reduction of MMP-9 expression in the COX-2-/- fracture callus. Taken together, our studies demonstrate that EP2 and EP4 have differential functions during endochondral bone repair. Activation of EP4, but not EP2 rescued impaired bone fracture healing in COX-2-/- mice.
      13. URL :
        http://ajp.amjpathol.org/cgi/content/abstract/175/2/772
      14. Call Number :
        PKI @ kd.modi @ 2
      15. Serial :
        10401
      1. Author :
        Kadioglu, A.; Brewin, H.; Hartel, T.; Brittan, J. L.; Klein, M.; Hammerschmidt, S.; Jenkinson, H. F.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Mol Oral Microbiol
      6. Products :
      7. Volume :
        25
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen10, Xen 10, Streptococcus pneumoniae Xen10, IVIS, Animals; Bacterial Adhesion; Bacterial Processes; Bacterial Proteins/*physiology; *Carrier State; Colony Count, Microbial; Female; Host-Pathogen Interactions; Lung/microbiology; Meningitis, Pneumococcal/microbiology; Mice; Models, Animal; Mutation; Nasopharynx/*microbiology; Pneumonia, Pneumococcal/complications; Sepsis/*microbiology; Streptococcus pneumoniae/*pathogenicity; Virulence Factors/physiology
      12. Abstract :
        Summary The pneumococcal cell surface protein PavA is a virulence factor associated with adherence and invasion in vitro. In this study we show in vivo that PavA is necessary for Streptococcus pneumoniae D39 colonization of the murine upper respiratory tract in a long-term carriage model, with PavA-deficient pneumococci being quickly cleared from nasopharyngeal tissue. In a pneumonia model, pavA mutants were not cleared from the lungs of infected mice and persisted to cause chronic infection, whereas wild-type pneumococci caused systemic infection. Hence, under the experimental conditions, PavA-deficient pneumococci appeared to be unable to seed from lung tissue into blood, although they survived in blood when administered intravenously. In a meningitis model of infection, levels of PavA-deficient pneumococci in blood and brain following intercisternal injection were significantly lower than wild type. Taken collectively these results suggest that PavA is involved in successful colonization of mucosal surfaces and in translocation of pneumococci across host barriers. Pneumococcal sepsis is a major cause of mortality worldwide so identification of factors such as PavA that are necessary for carriage and for translocation from tissue to blood is of clinical and therapeutic importance.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/20331793
      14. Call Number :
        PKI @ kd.modi @ 1
      15. Serial :
        10400
      1. Author :
        Barman, T. K.; Rao, M.; Bhati, A.; Kishore, K.; Shukla, G.; Kumar, M.; Mathur, T.; Pandya, M.; Upadhyay, D. J.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2011
      5. Publication :
        Indian J Med Res
      6. Products :
      7. Volume :
        134
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen10, Xen 10, Streptococcus pnuemoniae Xen10, IVIS,
      12. Abstract :
        Background & objectives: In vivo imaging system has contributed significantly to the understanding of bacterial infection and efficacy of drugs in animal model. We report five rapid, reproducible, and non invasive murine pulmonary infection, skin and soft tissue infection, sepsis, and meningitis models using Xenogen bioluminescent strains and specialized in vivo imaging system (IVIS). Methods: The progression of bacterial infection in different target organs was evaluated by the photon intensity and target organ bacterial counts. Genetically engineered bioluminescent bacterial strains viz. Staphylococcus aureus Xen 8.1, 29 and 31; Streptococcus pneumoniae Xen 9 and 10 and Pseudomonas aeruginosa Xen-5 were used to induce different target organs infection and were validated with commercially available antibiotics. Results: The lower limit of detection of colony forming unit (cfu) was 1.7-log10 whereas the lower limit of detection of relative light unit (RLU) was 4.2-log10 . Recovery of live bacteria from different target organs showed that the bioluminescent signal correlated to the live bacterial count. Interpretation & conclusions: This study demonstrated the real time monitoring and non-invasive analysis of progression of infection and pharmacological efficacy of drugs. These models may be useful for pre-clinical discovery of new antibiotics.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/22199109
      14. Call Number :
        PKI @ kd.modi @ 3
      15. Serial :
        10399
      1. Author :
        Yan, J.; Meng, X.; Wancket, L. M.; Lintner, K.; Nelin, L. D.; Chen, B.; Francis, K. P.; Smith, C. V.; Rogers, L. K.; Liu, Y.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2012
      5. Publication :
        J Immunol
      6. Products :
      7. Volume :
        188
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Escherichia coli/immunology; Escherichia coli Infections/enzymology/immunology/*prevention & control; Extracellular Space/genetics/*immunology/metabolism; Glutathione Reductase/deficiency/genetics/*physiology; Humans; Mice; Mice, Inbred C3H; Mice, Knockout; Neutrophils/*immunology/*metabolism/microbiology; Oxidative Stress/genetics/*immunology; Phagocytosis/genetics/*immunology; Staphylococcal Infections/enzymology/immunology/*prevention & control; Staphylococcus aureus/immunology
      12. Abstract :
        Glutathione reductase (Gsr) catalyzes the reduction of glutathione disulfide to glutathione, which plays an important role in the bactericidal function of phagocytes. Because Gsr has been implicated in the oxidative burst in human neutrophils and is abundantly expressed in the lymphoid system, we hypothesized that Gsr-deficient mice would exhibit marked defects during the immune response against bacterial challenge. We report in this study that Gsr-null mice exhibited enhanced susceptibility to Escherichia coli challenge, indicated by dramatically increased bacterial burden, cytokine storm, striking histological abnormalities, and substantially elevated mortality. Additionally, Gsr-null mice exhibited elevated sensitivity to Staphylococcus aureus. Examination of the bactericidal functions of the neutrophils from Gsr-deficient mice in vitro revealed impaired phagocytosis and defective bacterial killing activities. Although Gsr catalyzes the regeneration of glutathione, a major cellular antioxidant, Gsr-deficient neutrophils paradoxically produced far less reactive oxygen species upon activation both ex vivo and in vivo. Unlike wild-type neutrophils that exhibited a sustained oxidative burst upon stimulation with phorbol ester and fMLP, Gsr-deficient neutrophils displayed a very transient oxidative burst that abruptly ceased shortly after stimulation. Likewise, Gsr-deficient neutrophils also exhibited an attenuated oxidative burst upon encountering E. coli. Biochemical analysis revealed that the hexose monophosphate shunt was compromised in Gsr-deficient neutrophils. Moreover, Gsr-deficient neutrophils displayed a marked impairment in the formation of neutrophil extracellular traps, a bactericidal mechanism that operates after neutrophil death. Thus, Gsr-mediated redox regulation is crucial for bacterial clearance during host defense against massive bacterial challenge.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/22279102
      14. Call Number :
        PKI @ kd.modi @ 3
      15. Serial :
        10398
      1. Author :
        Sjollema, J.; Sharma, P. K.; Dijkstra, R. J.; van Dam, G. M.; van der Mei, H. C.; Engelsman, A. F.; Busscher, H. J.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Biomaterials
      6. Products :
      7. Volume :
        31
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen14, Xen 14, E. coli Xen14, IVIS, Animals; Anti-Infective Agents/*pharmacology/therapeutic use; Bacteria/*drug effects/pathogenicity; Bacterial Infections/drug therapy/*etiology; Biocompatible Materials/*adverse effects/chemistry; Biofilms; Coated Materials, Biocompatible/chemistry; Fluorescent Dyes/chemistry/metabolism; Humans; Image Enhancement/methods; Light; Luminescent Measurements/instrumentation/*methods; Luminescent Proteins/metabolism; Microscopy, Fluorescence/instrumentation/*methods; Prosthesis-Related Infections/drug therapy/microbiology; Sensitivity and Specificity
      12. Abstract :
        This review presents the current state of Bioluminescence and Fluorescent Imaging technologies (BLI and FLI) as applied to Biomaterial-Associated Infections (BAI). BLI offers the opportunity to observe the in vivo course of BAI in small animals without the need to sacrifice animals at different time points after the onset of infection. BLI is highly dependent on the bacterial cell metabolism which makes BLI a strong reporter of viable bacterial presence. Fluorescent sources are generally more stable than bioluminescent ones and specifically targeted, which renders the combination of BLI and FLI a promising tool for imaging BAI. The sensitivity and spatial resolution of both imaging tools are, however, dependent on the imaging system used and the tissue characteristics, which makes the interpretation of images, in terms of the location and shape of the illuminating source, difficult. Tomographic reconstruction of the luminescent source is possible in the most modern instruments, enabling exact localization of a colonized implant material, spreading of infecting organisms in surrounding tissue and immunological tissue reactions. BLI studies on BAI have successfully distinguished between different biomaterials with respect to the development and clearance of BAI in vivo, simultaneously reducing animal use and experimental variation. It is anticipated that bio-optical imaging will become an indispensable technology for the in vivo evaluation of antimicrobial coatings.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/19969345
      14. Call Number :
        PKI @ kd.modi @ 8
      15. Serial :
        10397
      1. Author :
        Sharma, P. K.; Engels, E.; Van Oeveren, W.; Ploeg, R. J.; van Henny der Mei, C.; Busscher, H. J.; Van Dam, G. M.; Rakhorst, G.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Surgery
      6. Products :
      7. Volume :
        147
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen14, Xen 14, E. coli Xen14, IVIS, Animals; Bacteroides fragilis/*isolation & purification; Diagnostic Imaging/methods; Disease Progression; Escherichia coli/*isolation & purification; Luciferases, Bacterial/*diagnostic use; Luminescent Agents/*diagnostic use; Male; Peritoneal Lavage; Peritonitis/*microbiology/pathology/therapy; Rats; Rats, Wistar
      12. Abstract :
        BACKGROUND: Bacterial peritonitis is a life-threatening abdominal infection associated with high morbidity and mortality. The rat is a popular animal model for studying peritonitis and its treatment, but longitudinal monitoring of the progression of peritonitis in live animals has been impossible until now and thus required a large number of animals. Our objective was to develop a noninvasive in vivo imaging technique to monitor the spatiotemporal spread of bacterial peritonitis. METHODS: Peritonitis was induced in 8 immunocompetent male Wistar rats by placing fibrin clots containing 5x10(8) cells of both Bacteroides fragilis (American Type Tissue Culture [ATCC)] 25,285 and bioluminescent Escherichia coli Xen14. After 1 or 2 days, infected clots were removed and open abdomen lavage was performed. In vivo bioluminescent imaging was used to monitor the spread of peritonitis. RESULTS: Bioluminescent in vivo imaging showed an increase in the area of spread, and the number of E. coli tripled into the rat's abdominal cavity on day 1 after clot insertion; however, on day 2, encapsulation of the clot confined bacterial spread. Bioluminescent E. coli respread over the peritoneal cavity after lavage; within 10 days, however, in vivo imaging showed a decrease of 3-4 orders of magnitude in bacterial load. CONCLUSION: Bioluminescent in vivo imaging can be effectively used to monitor the spatiotemporal behavior of the peritonitis during 3 different stages of the disease process: initiation, treatment, and follow-up. Imaging allows researchers to repeatedly image the same animal, thereby reducing variability and providing greater confidence in determining treatment efficacies for therapeutic interventions using a small number of animals.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/19733882
      14. Call Number :
        PKI @ kd.modi @ 7
      15. Serial :
        10396
      1. Author :
        Ryan, P. L.; Christiansen, D. L.; Hopper, R. M.; Walters, F. K.; Moulton, K.; Curbelo, J.; Greene, J. M.; Willard, S. T.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2011
      5. Publication :
        J Anim Sci
      6. Products :
      7. Volume :
        89
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Xen14, Xen 14, E. coli Xen14, IVIS, Horse, bioluminescence
      12. Abstract :
        Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacteria transformed with lux genes of Xenorhabdus luminescens or Photorhabdus luminescens origin and biophotonic imaging are utilized to better understand pathogen-induced preterm birth in late-term pregnant mares. This technology uses highly sensitive bioluminescence imaging camera systems to localize and monitor pathogen progression during tissue invasion by measuring the bioluminescent signatures emitted by the lux-modified pathogens. This method has an important advantage in that it allows for the potential tracking of pathogens in vivo in real time and over time, which was hitherto impossible. Although the application of this technology in domestic animals is in its infancy, investigators were successful in identifying the fetal lungs, sinuses, nares, urinary, and gastrointestinal systems as primary tissues for pathogen invasion after experimental infection of pregnant mares with lux-modified Escherichia coli. It is important that pathogens were not detected in other vital organs, such as the liver, brain, and cardiac system. Such precision in localizing sites of pathogen invasion provides potential application for this novel approach in the development of more targeted therapeutic interventions for pathogen-related diseases in the equine and other domestic species.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/21239661
      14. Call Number :
        PKI @ kd.modi @ 1
      15. Serial :
        10395
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