Presentation on induced resistance to S. aureus in an environmental biofilm

1. Induced resistance to S. aureus in marine environmental biofilms John Lafleur 3/23/09

4. a) S. aureus epidemiology & MDR

5. Crum et al., 2003. The American Journal of Medicine 119:943-51

6. Crum et al., 2003. The American Journal of Medicine 119:943-51

7. Turnidge and Bell. 2000. Microbial Drug Resistance. 6(3):223-8

8. b) Common medical biofilms

9. Costerton et al.,1999. Science. 284:1318-22

10. Camargo et al., 2005. International Journal of Gynecology and Obstetrics . 90:148—9

11. von Eiff et al., Drugs 2005; 65 (2): 179-214

13. c) The problem with antibiotics

14. Bacteria in biofilms up to 1000X more resistant to antibotics Costerton et al., 1985. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY. 27(4):619-24

15. D'Costa, et al., 2006. Science. 311:374-7

18. d) Induced antibiosis in bacteria

19. Mearns-Spragg et al. 1998. Letters in Applied Microbiology 27:142–146

21. Is there evidence that a complex, multi-species environmental biofilm might amplify any antibacterial activity among individual members of its bacterial consortia?

22. Burmolle et al., 2006. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. 76(6):3916– 23

26. II. Materials and Methods

27. III. Results

28. S. aureus agar with biofilm treated with UV

29. S. aureus agar with biofilm no UV

30. Percentage of area per high-powered field covered by S. aureus micro-colonies.

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

32. Percentage of S. aureus microcolonies with less than 4 cells at baseline and after incubation by treatment type .

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

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

35. IV Australia

36. Two day incubation--Dapi stain

37. Two day incubation--live/dead stain

38. Two day incubation—live/dead stain

40. Next steps

44. Questions?