Induced Resistance To S

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Induced Resistance To S

  1. 1. Induced resistance to S. aureus in marine environmental biofilms John Lafleur 3/23/09
  2. 2. <ul><li>I. Background </li></ul><ul><li>a) S. aureus epidemiology & MDR </li></ul><ul><li>b) Common medical biofilms </li></ul><ul><li>c) The problem with antibiotics </li></ul><ul><li>d) Induced antibiosis in bacteria </li></ul><ul><li>e) Putting it together </li></ul><ul><li>II. Materials and methods </li></ul><ul><li>III. Results </li></ul><ul><li>IV. Australia </li></ul>
  3. 4. a) S. aureus epidemiology & MDR
  4. 5. Crum et al., 2003. The American Journal of Medicine 119:943-51
  5. 6. Crum et al., 2003. The American Journal of Medicine 119:943-51
  6. 7. Turnidge and Bell. 2000. Microbial Drug Resistance. 6(3):223-8
  7. 8. b) Common medical biofilms
  8. 9. Costerton et al.,1999. Science. 284:1318-22
  9. 10. Camargo et al., 2005. International Journal of Gynecology and Obstetrics . 90:148—9
  10. 11. von Eiff et al., Drugs 2005; 65 (2): 179-214
  11. 12. von Eiff et al., Drugs 2005; 65 (2): 179-214 <ul><li>Central venous catheter related infections in the US: </li></ul><ul><li>¼ million per year </li></ul><ul><li>¼ die </li></ul><ul><li>$25,000 each incident </li></ul>
  12. 13. c) The problem with antibiotics
  13. 14. Bacteria in biofilms up to 1000X more resistant to antibotics Costerton et al., 1985. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY. 27(4):619-24
  14. 15. D'Costa, et al., 2006. Science. 311:374-7
  15. 17. <ul><li>Bacteria have been around long enough to develop every possible kind of resistance to each other </li></ul>
  16. 18. d) Induced antibiosis in bacteria
  17. 19. Mearns-Spragg et al. 1998. Letters in Applied Microbiology 27:142–146
  18. 20. <ul><li>If antibacterial activity can be induced in individual strains of bacteria, can it also be induced in whole biofilms? </li></ul>
  19. 21. Is there evidence that a complex, multi-species environmental biofilm might amplify any antibacterial activity among individual members of its bacterial consortia?
  20. 22. Burmolle et al., 2006. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. 76(6):3916– 23
  21. 23. e) Putting it together <ul><li>Multi-drug resistant biofilms on implantable medical devices are a growing problem with no obvious solution </li></ul><ul><li>a) antibiotics don’t work on biofilms </li></ul><ul><li>b) even if they did, there’s growing resistance </li></ul>
  22. 24. <ul><li>Existing natural models show that nature has solutions to the problem of unwanted biofilm formation, and some of them involves preexisting (‘friendly) biofilms. </li></ul>
  23. 25. <ul><li>If it is possible to induce resistance in an environmental biofilm to a problematic, biofilm-forming human pathogen, perhaps it would be possible to learn how this could also be done for an inanimate surface—such as the surface of an implantable medical device. </li></ul>
  24. 26. II. Materials and Methods
  25. 27. III. Results
  26. 28. S. aureus agar with biofilm treated with UV
  27. 29. S. aureus agar with biofilm no UV
  28. 30. Percentage of area per high-powered field covered by S. aureus micro-colonies.
  29. 31. Comparison of percentages of area of S. aureus biofilm growth with associated P values . <0.001 S. aureus agar with biofilm no UV (0.07%) vs. S. aureus agar with biofilm, pos. UV (1.56%) 0.14** S. aureus agar with biofilm pos. UV (1.56%) vs. Plain agar with biofilm, pos. UV (1.30%) <0.001 S. aureus agar with biofilm no UV (0.07%) vs. Plain agar with biofilm, no UV (0.13%) <0.001 Baseline (0.05%) vs. S. aureus agar with biofilm, no UV (0.07%) P value
  30. 32. Percentage of S. aureus microcolonies with less than 4 cells at baseline and after incubation by treatment type .
  31. 33. Percentage of S. aureus microcolonies with less than 4 cells at baseline and after incubation by treatment types (Sd =standard deviation). nd nd Plain agar no biofilm nd nd S. aureus agar no biofilm +/-29% 53% Plainagar with biofilm, UV exposed +/-14% 5% S. aureus agar with biofilm, UV exposed +/-37% 68% Plain agar with biofilm +/-24% 91% S. aureus spent medium agar with biofilm +/-31% 78% Baseline Sd Percent <4 cells per microcolony
  32. 34. Table 2. Comparison of percentages of microcolonies with fewer than 4 cells per micrcolony with associated p values <0.001 S. aureus agar with biofilm no UV (91%) vs. S. aureus agar with biofilm, pos. UV (5%) <0.001 S. aureus agar with biofilm no UV (91%) vs. Plain agar with biofilm, no UV (68%) 0.10 ** Baseline (78%) vs. Plain agar with biofilm, no UV (68%) 0.02 Baseline (78%) vs. S. aureus agar with biofilm, no UV (91%) P value
  33. 35. IV Australia
  34. 36. Two day incubation--Dapi stain
  35. 37. Two day incubation--live/dead stain
  36. 38. Two day incubation—live/dead stain
  37. 39. P values for comparison S. aureus area coverage S. aureus agar versus plain agar: <ul><li>#1: P=0.001 </li></ul><ul><li>#2: P=0.01 </li></ul><ul><li>#3: P=0.02 </li></ul>
  38. 40. Next steps
  39. 41. <ul><li>DGGE to get an idea of differences in biofilm consortia between S. aureus and plain agar </li></ul><ul><li>Isolate members of consortia and attempt to recreate induced S. aureus inhibition in lab-based biofilm culture </li></ul>
  40. 43. <ul><li>Many thanks to Professors S. Kjelleberg and S. Rice, and to all the kind people on the sixth floor </li></ul><ul><li>Prof. M. Shiaris </li></ul><ul><li>Dr. M. Yasuda </li></ul><ul><li>Prof. G. Burgess </li></ul>
  41. 44. Questions?

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