Applying insights from biofilm biology to drug development-can a new approach be developed?

Nature Reviews Drug Discovery

Volumn 12, Issue 10, 2013, Pages 791-808

  Bjarnsholt, Thomas ^a,b   Ciofu, Oana ^a   Molin, Søren ^c   Givskov, Michael ^a,d   Høiby, Niels ^a,b  

^a UNIVERSITY OF COPENHAGEN   (Denmark)

^b Rigshospitalet   (Denmark)

^c TECHNICAL UNIVERSITY OF DENMARK   (Denmark)

^d NANYANG TECHNOLOGICAL UNIVERSITY   (Singapore)

Author keywords

[No Author keywords available]

Indexed keywords

ACETYLCYSTEINE; AMINOGLYCOSIDE; ANTIBIOTIC AGENT; AZITHROMYCIN; AZTREONAM; BETA LACTAM ANTIBIOTIC; BIOCIDE; CEFTAZIDIME; CHLORHEXIDINE; CIPROFLOXACIN; COLISTIN; CYCLOSPORIN A; DAPTOMYCIN; DICLOFENAC; DISINFECTANT AGENT; EDETIC ACID; FURANONE DERIVATIVE; GALLIUM NITRATE; GENTAMICIN; MEROPENEM; NIFUROXAZIDE; PATULIN; POLYPEPTIDE ANTIBIOTIC AGENT; QUINOLINE DERIVED ANTIINFECTIVE AGENT; SALICYLIC ACID; SOLENOPSIN A; THIORIDAZINE; TOBRAMYCIN; UNINDEXED DRUG; VANCOMYCIN;

ADAPTIVE IMMUNITY; ANTIBIOTIC RESISTANCE; BACTERIAL INFECTION; BIOFILM; BIOFILM INFECTION; DRUG DEVELOPMENT; DRUG TARGETING; HUMAN; INFECTION; INNATE IMMUNITY; LOBAR PNEUMONIA; NONHUMAN; PATHOGENESIS; PRIORITY JOURNAL; PSEUDOMONAS INFECTION; RESPIRATORY TRACT INFECTION; REVIEW;

ACUTE DISEASE; ADAPTIVE IMMUNITY; ANIMALS; ANTI-BACTERIAL AGENTS; BACTERIAL INFECTIONS; BIOFILMS; CHRONIC DISEASE; DRUG DESIGN; HUMANS; IMMUNITY, INNATE; MOLECULAR TARGETED THERAPY;

EID: 84885005029     PISSN: 14741776     EISSN: 14741784     Source Type: Journal    
DOI: 10.1038/nrd4000     Document Type: Review

References (245)

1. Murray, C. J. & Lopez, A. D. Alternative projections of mortality and disability by cause 1990-2020: Global Burden of Disease Study. Lancet 349, 1498-1504 (1997).
2. Costerton, J. W., Lewandowski, Z., Caldwell, D. E., Korber, D. R. & Lappin-Scott, H. M. Microbial biofilms. Annu. Rev. Microbiol. 49, 711-745 (1995).
3. Potera, C. Studying slime. Environ. Health Perspect. 106, A604-A606 (1998).
4. Martinez, J. L. The role of natural environments in the evolution of resistance traits in pathogenic bacteria. Proc. Biol. Sci. 276, 2521-2530 (2009).
5. Høiby, N. Pseudomonas aeruginosa infection in cystic fibrosis. Diagnostic and prognostic significance of Pseudomonas aeruginosa precipitins determined by means of crossed immunoelectrophoresis. A survey. Acta. Pathol. Microbiol. Scand. Suppl. 262, 1-96 (1977).
6. McCoy, W. F., Bryers, J. D., Robbins, J. & Costerton, J. W. Observations of fouling biofilm formation. Can. J. Microbiol. 27, 910-917 (1981).
7. Marrie, T. J. & Costerton, J. W. Scanning and transmission electron microscopy of in situ bacterial colonization of intravenous and intraarterial catheters. J. Clin. Microbiol. 19, 687-693 (1984).
8. Costerton, J. W. How bacteria stick - a citation classic commentary on how bacteria stick by Costerton, J. W., Geesey, G. G., and Cheng, K. J. Citation classics 48, 18 (1989).
9. Islam, M. S., Richards, J. P. & Ojha, A. K. Targeting drug tolerance in mycobacteria: a perspective from mycobacterial biofilms. Expert. Rev. Anti. Infect. Ther. 10, 1055-1066 (2012).
10. Muller, F. M., Seidler, M. & Beauvais, A. Aspergillus fumigatus biofilms in the clinical setting. Med. Mycol. 49 (Suppl. 1), 96-100 (2011).
11. Cuellar-Cruz, M., Lopez-Romero, E., Villagomez- Castro, J. C. & Ruiz-Baca, E. Candida species: new insights into biofilm formation. Future. Microbiol. 7, 755-771 (2012).
12. Donlan, R. M. & Costerton, J. W. Biofilms: survival mechanisms of clinically relevant microorganisms. Clin. Microbiol. Rev. 15, 167-193 (2002).
13. Parsek, M. R. & Singh, P. K. Bacterial biofilms: an emerging link to disease pathogenesis. Annu. Rev. Microbiol. 57, 677-701 (2003).
14. Hall-Stoodley, L., Costerton, J. W. & Stoodley, P. Bacterial biofilms: from the natural environment to infectious diseases. Nature Rev. Microbiol. 2, 95-108 (2004).
15. Burmolle, M. et al. Biofilms in chronic infections - a matter of opportunity - monospecies biofilms in multispecies infections. FEMS Immunol. Med. Microbiol. 59, 324-336 (2010).
16. Jensen, P. O., Givskov, M., Bjarnsholt, T. & Moser, C. The immune system versus Pseudomonas aeruginosa biofilms. FEMS Immunol. Med. Microbiol. 59, 292-305 (2010).
17. Pamp, S. J., Gjermansen, M., Johansen, H. K. & Tolker-Nielsen, T. Tolerance to the antimicrobial peptide colistin in Pseudomonas aeruginosa biofilms is linked to metabolically active cells, and depends on the pmr and mexAB-oprM genes. Mol. Microbiol. 68, 223-240 (2008).
18. Hall-Stoodley, L. et al. Towards diagnostic guidelines for biofilm-associated infections. FEMS Immunol. Med. Microbiol. 65, 127-145 (2012).
19. Costerton, J. W., Geesey, G. G. & Cheng, K. J. How bacteria stick. Sci. Am. 238, 86-95 (1978).
20. Li, H. et al. Antibacterial activity of antibiotic coated silicone grafts. J. Urol. 160, 1910-1913 (1998).
21. Darouiche, R. O. Treatment of infections associated with surgical implants. N. Engl. J. Med. 350, 1422-1429 (2004).
22. Safdar, N. & Maki, D. G. Use of vancomycin-containing lock or flush solutions for prevention of bloodstream infection associated with central venous access devices: a meta-analysis of prospective, randomized trials. Clin. Infect. Dis. 43, 474-484 (2006).
23. Bjarnsholt, T., Tolker-Nielsen, T., Givskov, M., Janssen, M. & Chrsitensen, L. Detection of bacteria by FISH in culture-negative soft tissue filler lesions. Dermatol. Surg. 35, 1620-1624 (2009).
24. Bjarnsholt, T. et al. Pseudomonas aeruginosa tolerance to tobramycin, hydrogen peroxide and polymorphonuclear leukocytes is quorum-sensing dependent. Microbiology 151, 373-383 (2005).
25. Bjarnsholt, T. et al. Why chronic wounds will not heal: a novel hypothesis. Wound Repair Regen. 16, 2-10 (2008).
26. Bjarnsholt, T. et al. Pseudomonas aeruginosa biofilms in the respiratory tract of cystic fibrosis patients. Pediatr. Pulmonol. 44, 547-558 (2009).
27. Fexby, S. et al. Biological Trojan horse: Antigen 43 provides specific bacterial uptake and survival in human neutrophils. Infect. Immun. 75, 30-34 (2007).
28. Fux, C. A., Costerton, J. W., Stewart, P. S. & Stoodley, P. Survival strategies of infectious biofilms. Trends Microbiol. 13, 34-40 (2005).
29. Stewart, P. S. New ways to stop biofilm infections. Lancet 361, 97 (2003).
30. Stewart, P. S. & Costerton, J. W. Antibiotic resistance of bacteria in biofilms. Lancet 358, 135-138 (2001).
31. Kim, J., Hahn, J. S., Franklin, M. J., Stewart, P. S. & Yoon, J. Tolerance of dormant and active cells in Pseudomonas aeruginosa PA01 biofilm to antimicrobial agents. J. Antimicrob. Chemother. 63, 129-135 (2009).
32. Walters, M. C. et al. Contributions of antibiotic penetration, oxygen limitation, and low metabolic activity to tolerance of Pseudomonas aeruginosa biofilms to ciprofloxacin and tobramycin. Antimicrob. Agents Chemother. 47, 317-323 (2003).
33. Hentzer, M., Eberl, L. & Givskov, M. Transcriptome analysis of Pseudomonas aeruginosa biofilm development: anaerobic respiration and iron limitation. Biofilms 2, 37-61 (2005).
34. Marvig, R. L. et al. Mutations in 23S rRNA confer resistance against azithromycin in Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 56, 4519-4521 (2012).
35. Imamura, Y. et al. Azithromycin exhibits bactericidal effects on Pseudomonas aeruginosa through interaction with the outer membrane. Antimicrob. Agents Chemother. 49, 1377-1380 (2005).
36. Saiman, L. The use of macrolide antibiotics in patients with cystic fibrosis. Curr. Opin. Pulm. Med. 10, 515-523 (2004).
37. Gillis, R. J. & Iglewski, B. H. Azithromycin retards Pseudomonas aeruginosa biofilm formation. J. Clin. Microbiol. 42, 5842-5845 (2004).
38. Ciofu, O., Giwercman, B., Pedersen, S. S. & Høiby, N. Development of antibiotic resistance in Pseudomonas aeruginosa during two decades of antipseudomonal treatment at the Danish CF Center. APMIS 102, 674-680 (1994).
39. Roveta, S., Marchese, A. & Schito, G. C. Activity of daptomycin on biofilms produced on a plastic support by Staphylococcus spp. Int. J. Antimicrob. Agents 31, 321-328 (2008).
40. Mascio, C. T., Alder, J. D. & Silverman, J. A. Bactericidal action of daptomycin against stationary-phase and nondividing Staphylococcus aureus cells. Antimicrob. Agents Chemother. 51, 4255-4260 (2007).
41. De Rosa, F. G. et al. Early experience with high-dosage daptomycin for prosthetic infections. Clin. Infect. Dis. 49, 1772-1773 (2009).
42. Hansen, C. R., Pressler, T. & Hoiby, N. Early aggressive eradication therapy for intermittent Pseudomonas aeruginosa airway colonization in cystic fibrosis patients: 15 years experience. J. Cyst. Fibros. 7, 523-530 (2008).
43. Hurdle, J. G., O'Neill, A. J., Chopra, I. & Lee, R. E. Targeting bacterial membrane function: an underexploited mechanism for treating persistent infections. Nature Rev. Microbiol. 9, 62-75 (2011).
44. Palmer, R. J. et al. in Biofilm Infections (eds Bjarnsholt, T., Moser, C., Jensen, P. O. & Høiby, N.) 35-60 (Springer, 2010).
45. Zimmerli, W. & Trampuz, A. in Biofilm Infections (eds Bjarnsholt, T., Moser, C., Jensen, P. O. & Høiby, N.) 91-110 (Springer, 2010).
46. Flemming, H. C., Neu, T. R. & Wozniak, D. J. The EPS matrix: the "house of biofilm cells". J. Bacteriol. 189, 7945-7947 (2007).
47. Madsen, J. S., Burmolle, M., Hansen, L. H. & Sorensen, S. J. The interconnection between biofilm formation and horizontal gene transfer. FEMS Immunol. Med. Microbiol. 65, 183-195 (2012).
48. Christensen, B. B. et al. Molecular tools for study of biofilm physiology. Methods Enzymol. 310, 20-42 (1999).
49. Pamp, S. J., Sternberg, C. & Tolker-Nielsen, T. Insight into the microbial multicellular lifestyle via flow-cell technology and confocal microscopy. Cytometry A 75, 90-103 (2009).
50. Klausen, M. et al. Biofilm formation by Pseudomonas aeruginosa wild type, flagella and type IV pili mutants. Mol. Microbiol. 48, 1511-1524 (2003).
51. Klausen, M., aes-Jorgensen, A., Molin, S. & Tolker- Nielsen, T. Involvement of bacterial migration in the development of complex multicellular structures in Pseudomonas aeruginosa biofilms. Mol. Microbiol. 50, 61-68 (2003).
52. Schleheck, D. et al. Pseudomonas aeruginosa PAO1 preferentially grows as aggregates in liquid batch cultures and disperses upon starvation. PLoS ONE 4, e5513 (2009).
53. Oliver, J. D. Recent findings on the viable but nonculturable state in pathogenic bacteria. FEMS Microbiol. Rev. 34, 415-425 (2010).
54. Werner, E. et al. Stratified growth in Pseudomonas aeruginosa biofilms. Appl. Environ. Microbiol. 70, 6188-6196 (2004).
55. Folsom, J. P. et al. Physiology of Pseudomonas aeruginosa in biofilms as revealed by transcriptome analysis. BMC Microbiol. 10, 294 (2010).
56. Alhede, M. et al. Phenotypes of non-attached Pseudomonas aeruginosa aggregates resemble surface attached biofilm. PLoS ONE 6, e27943 (2011).
57. Worlitzsch, D. et al. Effects of reduced mucus oxygen concentration in airway Pseudomonas infections of cystic fibrosis patients. J. Clin. Invest. 109, 317-325 (2002).
58. Aanaes, K. et al. Decreased mucosal oxygen tension in the maxillary sinuses in patients with cystic fibrosis. J. Cyst. Fibros. 10, 114-120 (2011).
59. Yang, L. et al. In situ growth rates and biofilm development of Pseudomonas aeruginosa populations in chronic lung infections. J. Bacteriol. 190, 2767-2776 (2008).
60. Lee, B. et al. Heterogeneity of biofilms formed by nonmucoid Pseudomonas aeruginosa isolates from patients with cystic fibrosis. J. Clin. Microbiol. 43, 5247-5255 (2005).
61. Lee, B. et al. Mucoid Pseudomonas aeruginosa isolates maintain the biofilm formation capacity and the gene expression profiles during the chronic lung infection of CF patients. Acta. Pathol. Microbiol. Scand. Suppl. 119, 263-274 (2011).
62. Ciofu, O., Mandsberg, L. F., Bjarnsholt, T., Wassermann, T. & Hoiby, N. Genetic adaptation of Pseudomonas aeruginosa during chronic lung infection of patients with cystic fibrosis: strong and weak mutators with heterogeneous genetic backgrounds emerge in mucA and/or lasR mutants. Microbiology 156, 1108-1119 (2010).
63. Folkesson, A. et al. Adaptation of Pseudomonas aeruginosa to the cystic fibrosis airway: an evolutionary perspective. Nature Rev. Microbiol. 10, 841-851 (2012).
64. Moscoso, J. A., Mikkelsen, H., Heeb, S., Williams, P. & Filloux, A. The Pseudomonas aeruginosa sensor RetS switches type III and type VI secretion via c-di-GMP signalling. Environ. Microbiol. 13, 3128-3138 (2011).
65. Hickman, J. W., Tifrea, D. F. & Harwood, C. S. A chemosensory system that regulates biofilm formation through modulation of cyclic diguanylate levels. Proc. Natl Acad. Sci. USA 102, 14422-14427 (2005).
66. Mikkelsen, H., Sivaneson, M. & Filloux, A. Key two-component regulatory systems that control biofilm formation in Pseudomonas aeruginosa. Environ. Microbiol. 13, 1666-1681 (2011).
67. Sivaneson, M., Mikkelsen, H., Ventre, I., Bordi, C. & Filloux, A. Two-component regulatory systems in Pseudomonas aeruginosa: an intricate network mediating fimbrial and efflux pump gene expression. Mol. Microbiol. 79, 1353-1366 (2011).
68. Borlee, B. R. et al. Pseudomonas aeruginosa uses a cyclic-di-GMP- regulated adhesin to reinforce the biofilm extracellular matrix. Mol. Microbiol. 75, 827-842 (2010).
69. Meissner, A. et al. Pseudomonas aeruginosa cupA-encoded fimbriae expression is regulated by a GGDEF and EAL domain-dependent modulation of the intracellular level of cyclic diguanylate. Environ. Microbiol. 9, 2475-2485 (2007).
70. Petrova, O. E. & Sauer, K. SagS contributes to the motile-sessile switch and acts in concert with BfiSR to enable Pseudomonas aeruginosa biofilm formation. J Bacteriol. 193, 6614-6628 (2011).
71. Banin, E., Vasil, M. L. & Greenberg, E. P. Iron and Pseudomonas aeruginosa biofilm formation. Proc. Natl Acad. Sci. USA 102, 11076-11081 (2005).
72. Smith, D. J., Lamont, I. L., Anderson, G. J. & Reid, D. W. Targeting iron uptake to control Pseudomonas aeruginosa infections in cystic fibrosis. Eur. Respir. J. http://dx.doi. org/10.1183/09031936.00124012 (2012).
73. Bagge, N. et al. Pseudomonas aeruginosa biofilms exposed to imipenem exhibit changes in global gene expression and beta-lactamase and alginate production. Antimicrob. Agents Chemother. 48, 1175-1187 (2004).
74. Hoffman, L. R. et al. Aminoglycoside antibiotics induce bacterial biofilm formation. Nature 436, 1171-1175 (2005).
75. Rybtke, M. T. et al. The implication of Pseudomonas aeruginosa biofilms in infections. Inflamm. Allergy Drug Targets. 10, 141-157 (2011).
76. Taga, M. E. & Bassler, B. L. Chemical communication among bacteria. Proc. Natl Acad. Sci. USA 100, 14549-14554 (2003).
77. Zhu, J. et al. Quorum-sensing regulators control virulence gene expression in Vibrio cholerae. Proc. Natl Acad. Sci. USA 99, 3129-3134 (2002).
78. Gilligan, P. H. Microbiology of airway disease in patients with cystic fibrosis. Clin. Microbiol. Rev. 4, 35-51 (1991).
79. Whiteley, M., Lee, K. M. & Greenberg, E. P. Identification of genes controlled by quorum sensing in Pseudomonas aeruginosa. Proc. Natl Acad. Sci. USA 96, 13904-13909 (1999).
80. Eberl, L., Molin, S. & Givskov, M. Surface motility of serratia liquefaciens MG1. J. Bacteriol. 181, 1703-1712 (1999).
81. Eberl, L. et al. Involvement of N-acyl-l-homoserine lactone autoinducers in controlling the multicellular behaviour of Serratia liquefaciens. Mol. Microbiol. 20, 127-136 (1996).
82. Kohler, T., Curty, L. K., Barja, F., van Delden, C. & Pechere, J. C. Swarming of Pseudomonas aeruginosa is dependent on cell-to-cell signaling and requires flagella and pili. J. Bacteriol. 182, 5990-5996 (2000).
83. Huber, B. et al. The cep quorum-sensing system of Burkholderia cepacia H111 controls biofilm formation and swarming motility. Microbiology 147, 2517-2528 (2001).
84. Magnuson, R., Solomon, J. & Grossman, A. D. Biochemical and genetic characterization of a competence pheromone from B. subtilis. Cell 77, 207-216 (1994).
85. Qin, X., Singh, K. V., Weinstock, G. M. & Murray, B. E. Effects of Enterococcus faecalis fsr genes on production of gelatinase and a serine protease and virulence. Infect. Immun. 68, 2579-2586 (2000).
86. Hengzhuang, W., Wu, H., Ciofu, O., Song, Z. & Hoiby, N. Pharmacokinetics/pharmacodynamics of colistin and imipenem on mucoid and nonmucoid Pseudomonas aeruginosa biofilms. Antimicrob. Agents Chemother. 55, 4469-4474 (2011).
87. Bink, A. et al. The non-steroidal anti-inflammatory drug diclofenac potentiates the in vivo activity of caspofungin against Candida albicans biofilms. J. Infect. Dis. 206, 1790-1797 (2012).
88. Costerton, J. W., Stewart, P. S. & Greenberg, E. P. Bacterial biofilms: a common cause of persistent infections. Science 284, 1318-1322 (1999).
89. Costerton, J. W. et al. Bacterial biofilms in nature and disease. Annu. Rev. Microbiol. 41, 435-464 (1987).
90. Alipour, M., Suntres, Z. E. & Omri, A. Importance of DNase and alginate lyase for enhancing free and liposome encapsulated aminoglycoside activity against Pseudomonas aeruginosa. J. Antimicrob. Chemother. 64, 317-325 (2009).
91. Stewart, P. S. Theoretical aspects of antibiotic diffusion into microbial biofilms. Antimicrob. Agents Chemother. 40, 2517-2522 (1996).
92. Herrmann, G. et al. Colistin-tobramycin combinations are superior to monotherapy concerning the killing of biofilm Pseudomonas aeruginosa. J. Infect. Dis. 202, 1585-1592 (2010).
93. Borriello, G. et al. Oxygen limitation contributes to antibiotic tolerance of Pseudomonas aeruginosa in biofilms. Antimicrob. Agents Chemother. 48, 2659-2664 (2004).
94. Yoon, S. S. et al. Anaerobic killing of mucoid Pseudomonas aeruginosa by acidified nitrite derivatives under cystic fibrosis airway conditions. J. Clin. Invest. 116, 436-446 (2006).
95. Borriello, G., Richards, L., Ehrlich, G. D. & Stewart, P. S. Arginine or nitrate enhances antibiotic susceptibility of Pseudomonas aeruginosa in biofilms. Antimicrob. Agents Chemother. 50, 382-384 (2006).
96. Fernandez, L. & Hancock, R. E. Adaptive and mutational resistance: role of porins and efflux pumps in drug resistance. Clin. Microbiol. Rev. 25, 661-681 (2012).
97. Dibdin, G. H., Assinder, S. J., Nichols, W. W. & Lambert, P. A. Mathematical model of β-lactam penetration into a biofilm of Pseudomonas aeruginosa while undergoing simultaneous inactivation by released β-lactamases. J. Antimicrob. Chemother. 38, 757-769 (1996).
98. Bagge, N. et al. Dynamics and spatial distribution of beta-lactamase expression in Pseudomonas aeruginosa biofilms. Antimicrob. Agents Chemother. 48, 1168-1174 (2004).
99. Gillis, R. J. et al. Molecular basis of azithromycin-resistant Pseudomonas aeruginosa biofilms. Antimicrob. Agents Chemother. 49, 3858-3867 (2005).
100. Chiang, W. C., Pamp, S. J., Nilsson, M., Givskov, M. & Tolker-Nielsen, T. The metabolically active subpopulation in Pseudomonas aeruginosa biofilms survives exposure to membrane-targeting antimicrobials via distinct molecular mechanisms. FEMS Immunol. Med. Microbiol. 65, 245-256 (2012).
101. Poole, K. Bacterial stress responses as determinants of antimicrobial resistance. J. Antimicrob. Chemother. 67, 2069-2089 (2012).
102. Kvist, M., Hancock, V. & Klemm, P. Inactivation of efflux pumps abolishes bacterial biofilm formation. Appl. Environ. Microbiol. 74, 7376-7382 (2008).
103. Drenkard, E. & Ausubel, F. M. Pseudomonas biofilm formation and antibiotic resistance are linked to phenotypic variation. Nature 416, 740-743 (2002).
104. Hengzhuang, W. et al. High β-lactamase levels change the pharmacodynamics of β-lactam antibiotics in Pseudomonas aeruginosa biofilms. Antimicrob. Agents Chemother. 57, 196-204 (2012).
105. Driffield, K., Miller, K., Bostock, J. M., O'Neill, A. J. & Chopra, I. Increased mutability of Pseudomonas aeruginosa in biofilms. J. Antimicrob. Chemother. 61, 1053-1056 (2008).
106. Ciofu, O., Riis, B., Pressler, T., Poulsen, H. E. & Hyiby, N. Occurrence of hypermutable Pseudomonas aeruginosa in cystic fibrosis patients is associated with the oxidative stress caused by chronic lung inflammation. Antimicrob. Agents Chemother. 49, 2276-2282 (2005).
107. Xu, K. D., Franklin, M. J., Park, C. H., McFeters, G. A. & Stewart, P. S. Gene expression and protein levels of the stationary phase sigma factor, RpoS, in continuously-fed Pseudomonas aeruginosa biofilms. FEMS Microbiol. Lett. 199, 67-71 (2001).
108. Bjedov, I. et al. Stress-induced mutagenesis in bacteria. Science 300, 1404-1409 (2003).
109. Lewis, K. Persister cells. Annu. Rev. Microbiol. 64, 357-372 (2010).
110. Macia, M. D., Perez, J. L., Molin, S. & Oliver, A. Dynamics of mutator and antibiotic-resistant populations in a pharmacokinetic/ pharmacodynamic model of Pseudomonas aeruginosa biofilm treatment. Antimicrob. Agents Chemother. 55, 5230-5237 (2011).
111. Boles, B. R. & Singh, P. K. Endogenous oxidative stress produces diversity and adaptability in biofilm communities. Proc. Natl Acad. Sci. USA 105, 12503-12508 (2008).
112. Kohanski, M. A., Dwyer, D. J., Hayete, B., Lawrence, C. A. & Collins, J. J. A common mechanism of cellular death induced by bactericidal antibiotics. Cell 130, 797-810 (2007).
113. Zhang, Q. et al. Acceleration of emergence of bacterial antibiotic resistance in connected microenvironments. Science 333, 1764-1767 (2011).
114. Hausner, M. & Wuertz, S. High rates of conjugation in bacterial biofilms as determined by quantitative in situ analysis. Appl. Environ. Microbiol. 65, 3710-3713 (1999).
115. Gristina, A. Biomaterial-centered infection: microbial adhesion versus tissue integration. 1987. Clin. Orthop. Relat. Res. 427, 4-12 (2004).
116. Wahlig, H. & Buchholz, H. W. [Experimental and clinical studies on the release of gentamicin from bone cement]. Chirurg 43, 441-445 (1972).
117. Stensballe, J. et al. Infection risk with nitrofurazone-impregnated urinary catheters in trauma patients: a randomized trial. Ann. Intern. Med. 147, 285-293 (2007).
118. O'Grady, N. P. et al. Guidelines for the prevention of intravascular catheter-related infections. Am. J. Infect. Control 39, S1-34 (2011).
119. Berra, L. et al. Internally coated endotracheal tubes with silver sulfadiazine in polyurethane to prevent bacterial colonization: a clinical trial. Intensive Care Med. 34, 1030-1037 (2008).
120. Kittinger, C. et al. Antimicrobial activity of gentamicin palmitate against high concentrations of Staphylococcus aureus. J. Mater. Sci. Mater. Med. 22, 1447-1453 (2011).
121. Crnich, C. J. & Maki, D. G. Are antimicrobial-impregnated catheters effective? When does repetition reach the point of exhaustion? Clin. Infect. Dis. 41, 681-685 (2005).
122. Cho, Y. H. et al. Prophylactic efficacy of a new gentamicin-releasing urethral catheter in short-term catheterized rabbits. BJU Int. 87, 104-109 (2001).
123. Gaonkar, T. A., Sampath, L. A. & Modak, S. M. Evaluation of the antimicrobial efficacy of urinary catheters impregnated with antiseptics in an in vitro urinary tract model. Infect. Control Hosp. Epidemiol. 24, 506-513 (2003).
124. Johnson, J. R., Kuskowski, M. A. & Wilt, T. J. Systematic review: antimicrobial urinary catheters to prevent catheter-associated urinary tract infection in hospitalized patients. Ann. Intern. Med. 144, 116-126 (2006).
125. Siddiq, D. M. & Darouiche, R. O. New strategies to prevent catheter-associated urinary tract infections. Nature Rev. Urol. 9, 305-314 (2012).
126. Pickard, R. et al. Antimicrobial catheters for reduction of symptomatic urinary tract infection in adults requiring short-term catheterisation in hospital: a multicentre randomised controlled trial. Lancet 380, 1927-1935 (2012).
127. Vasilev, K., Cook, J. & Griesser, H. J. Antibacterial surfaces for biomedical devices. Expert. Rev. Med. Devices 6, 553-567 (2009).
128. Bak, J., Begovic, T., Bjarnsholt, T. & Nielsen, A. A UVC device for intra-luminal disinfection of catheters: in vitro tests on soft polymer tubes contaminated with Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans. Photochem. Photobiol. 87, 1123-1128 (2011).
129. Polo, A. et al. Effects of photoactivated titanium dioxide nanopowders and coating on planktonic and biofilm growth of Pseudomonas aeruginosa. Photochem. Photobiol. 87, 1387-1394 (2011).
130. Brady, R. A., O'May, G. A., Leid, J. G., Costerton, J. W. & Shirtliff, M. E. Resolution of Staphylococcus aureus biofilm infection using vaccination and antibiotic treatment. Infect. Immun. 79, 1797-1803 (2011).
131. Doring, G., Meisner, C. & Stern, M. A double-blind randomized placebo-controlled phase III study of a Pseudomonas aeruginosa flagella vaccine in cystic fibrosis patients. Proc. Natl Acad. Sci. USA 104, 11020-11025 (2007).
132. Nilsson, E., Larsson, A., Olesen, H. V., Wejaker, P. E. & Kollberg, H. Good effect of IgY against Pseudomonas aeruginosa infections in cystic fibrosis patients. Pediatr. Pulmonol. 43, 892-899 (2008).
133. Frederiksen, B., Pressler, T., Hansen, A., Koch, C. & Hoiby, N. Effect of aerosolized rhDNase (Pulmozyme) on pulmonary colonization in patients with cystic fibrosis. Acta Paediatr. 95, 1070-1074 (2006).
134. Bjarnsholt, T. et al. Quorum sensing and virulence of Pseudomonas aeruginosa during lung infection of cystic fibrosis patients. PLoS ONE 5, e10115 (2010).
135. Alhede, M. et al. Pseudomonas aeruginosa recognizes and responds aggressively to the presence of polymorphonuclear leukocytes. Microbiology 155, 3500-3508 (2009).
136. Jensen, P. O. et al. Rapid necrotic killing of polymorphonuclear leukocytes is caused by quorum-sensing-controlled production of rhamnolipid by Pseudomonas aeruginosa. Microbiology 153, 1329-1338 (2007).
137. van Gennip, M. et al. Interactions between polymorphonuclear leukocytes and Pseudomonas aeruginosa biofilms on silicone implants in vivo. Infect. Immun. 80, 2601-2607 (2012).
138. Jackson, G. G., Dowling, H. F. & Lepper, M. H. Pathogenicity of staphylococci; a comparison of alpha-hemolysin production with the coagulase test and clinical observations of virulence. N. Engl. J. Med. 252, 1020-1025 (1955).
139. van Gennip, M. et al. Inactivation of the rhlA gene in Pseudomonas aeruginosa prevents rhamnolipid production, disabling the protection against polymorphonuclear leukocytes. APMIS 117, 537-546 (2009).
140. Bjarnsholt, T. et al. Garlic blocks quorum sensing and promotes rapid clearing of pulmonary Pseudomonas aeruginosa infections. Microbiology 151, 3873-3880 (2005).
141. Ciofu, O., Bagge, N. & Hyiby, N. Antibodies against beta-lactamase can improve ceftazidime treatment of lung infection with beta-lactam-resistant Pseudomonas aeruginosa in a rat model of chronic lung infection. APMIS 110, 881-891 (2002).
142. Ciofu, O. Pseudomonas aeruginosa chromosomal beta-lactamase in patients with cystic fibrosis and chronic lung infection. Mechanism of antibiotic resistance and target of the humoral immune response. APMIS Suppl. 116, 1-47 (2003).
143. Ciofu, O. et al. Antibodies against Pseudomonas aeruginosa chromosomal beta-lactamase in patients with cystic fibrosis are markers of the development of resistance of P. aeruginosa to beta-lactams. J. Antimicrob. Chemother. 35, 295-304 (1995).
144. Ciofu, O., Petersen, T. D., Jensen, P. & Hoiby, N. Avidity of anti-P aeruginosa antibodies during chronic infection in patients with cystic fibrosis. Thorax 54, 141-144 (1999).
145. Bjarnsholt, T. & Givskov, M. Quorum sensing inhibitory drugs as next generation antimicrobials: worth the effort? Curr. Infect. Dis. Rep. 10, 22-28 (2008).
146. Boles, B. R. & Horswill, A. R. agr-mediated dispersal of Staphylococcus aureus biofilms. PLoS. Pathog. 4, e1000052 (2008).
147. Bjarnsholt, T. et al. In vitro screens for quorum sensing inhibitors and in vivo confirmation of their effect. Nature Protoc. 5, 282-293 (2010).
148. Wu, H. et al. Synthetic furanones inhibit quorum-sensing and enhance bacterial clearance in Pseudomonas aeruginosa lung infection in mice. J. Antimicrob. Chemother. 53, 1054-1061 (2004).
149. Hentzer, M. et al. Inhibition of quorum sensing in Pseudomonas aeruginosa biofilm bacteria by a halogenated furanone compound. Microbiology 148, 87-102 (2002).
150. Skindersoe, M. E. et al. Quorum sensing antagonism from marine organisms. Mar. Biotechnol. 10, 56-63 (2008).
151. Rasmussen, T. B. & Givskov, M. Quorum-sensing inhibitors as anti-pathogenic drugs. Int. J. Med. Microbiol. 296, 149-161 (2006).
152. Rasmussen, T. B. et al. Identity and effects of quorum sensing inhibitors produced by Penicillum species. Microbiology 151, 1325-1340 (2005).
153. Rasmussen, T. B. et al. Screening for quorum-sensing inhibitors (QSI) by use of a novel genetic system, the QSI selector. J. Bacteriol. 187, 1799-1814 (2005).
154. Camara, M., Williams, P. & Hardman, A. Controlling infection by tuning in and turning down the volume of bacterial small-talk. Lancet Infect. Dis. 2, 667-676 (2002).
155. Hentzer, M. & Givskov, M. Pharmacological inhibition of quorum sensing for the treatment of chronic bacterial infections. J. Clin. Invest. 112, 1300-1307 (2003).
156. Jakobsen, T. H. et al. Ajoene, a sulfur-rich molecule from garlic, inhibits genes controlled by quorum sensing. Antimicrob. Agents Chemother. 56, 2314-2325 (2012).
157. Hentzer, M. et al. Attenuation of Pseudomonas aeruginosa virulence by quorum sensing inhibitors. EMBO J. 22, 3803-3815 (2003).
158. Christensen, L. D. et al. Synergistic antibacterial efficacy of early combination treatment with tobramycin and quorum-sensing inhibitors against Pseudomonas aeruginosa in an intraperitoneal foreign-body infection mouse model. J. Antimicrob. Chemother. 67, 1198-1206 (2012).
159. Givskov, M. et al. Eukaryotic interference with homoserine lactone-mediated prokaryotic signalling. J. Bacteriol. 178, 6618-6622 (1996).
160. Ankri, S. & Mirelman, D. Antimicrobial properties of allicin from garlic. Microbes. Infect. 1, 125-129 (1999).
161. Song, Z. et al. Panax ginseng has anti-infective activity against opportunistic pathogen Pseudomonas aeruginosa by inhibiting quorum sensing, a bacterial communication process critical for establishing infection. Phytomedicine 17, 1040-1046 (2010).
162. Wu, H. et al. Effects of ginseng on Pseudomonas aeruginosa motility and biofilm formation. FEMS Immunol. Med. Microbiol. 62, 49-56 (2011).
163. Choi, K. T. Botanical characteristics, pharmacological effects and medicinal components of Korean Panax ginseng C A Meyer. Acta Pharmacol. Sin. 29, 1109-1118 (2008).
164. Skindersoe, M. E. et al. Effects of antibiotics on quorum sensing in Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 52, 3648-3663 (2008).
165. Kohler, T., Guanella, R., Carlet, J. & van Delden, C. Quorum sensing-dependent virulence during Pseudomonas aeruginosa colonisation and pneumonia in mechanically ventilated patients. Thorax 65, 703-710 (2010).
166. Patriquin, G. M. et al. Influence of quorum sensing and iron on twitching motility and biofilm formation in Pseudomonas aeruginosa. J. Bacteriol. 190, 662-671 (2008).
167. Banin, E., Brady, K. M. & Greenberg, E. P. Chelator-induced dispersal and killing of Pseudomonas aeruginosa cells in a biofilm. Appl. Environ. Microbiol. 72, 2064-2069 (2006).
168. Budzikiewicz, H. Siderophore-antibiotic conjugates used as Trojan horses against Pseudomonas aeruginosa. Curr. Top. Med. Chem. 1, 73-82 (2001).
169. Ghosh, A. et al. Iron transport-mediated drug delivery using mixed-ligand siderophore-beta-lactam conjugates. Chem. Biol. 3, 1011-1019 (1996).
170. Reid, D. W. et al. Iron chelation directed against biofilms as an adjunct to conventional antibiotics. Am. J. Physiol. Lung Cell. Mol. Physiol. 296, L857-L858 (2009).
171. Moreau-Marquis, S., O'Toole, G. A. & Stanton, B. A. Tobramycin and FDA-approved iron chelators eliminate Pseudomonas aeruginosa biofilms on cystic fibrosis cells. Am. J. Respir. Cell. Mol. Biol. 41, 305-313 (2009).
172. Banin, E. et al. The potential of desferrioxamine-gallium as an anti-Pseudomonas therapeutic agent. Proc. Natl Acad. Sci. USA 105, 16761-16766 (2008).
173. Kaneko, Y., Thoendel, M., Olakanmi, O., Britigan, B. E. & Singh, P. K. The transition metal gallium disrupts Pseudomonas aeruginosa iron metabolism and has antimicrobial and antibiofilm activity. J. Clin. Invest. 117, 877-888 (2007).
174. Pichon, C. & Felden, B. Small RNA gene identification and mRNA target predictions in bacteria. Bioinformatics 24, 2807-2813 (2008).
175. Kint, G., De, C. D., Marchal, K., Vanderleyden, J. & De Keersmaecker, S. C. The small regulatory RNA molecule MicA is involved in Salmonella enterica serovar Typhimurium biofilm formation. BMC Microbiol. 10, 276 (2010).
176. Bordi, C. & de Bentzmann, S. Hacking into bacterial biofilms: a new therapeutic challenge. Ann. Intensive Care 1, 19 (2011).
177. Achermann, Y., Vogt, M., Leunig, M., Wust, J. & Trampuz, A. Improved diagnosis of periprosthetic joint infection by multiplex PCR of sonication fluid from removed implants. J. Clin. Microbiol. 48, 1208-1214 (2010).
178. Rohacek, M. et al. Bacterial colonization and infection of electrophysiological cardiac devices detected with sonication and swab culture. Circulation 121, 1691-1697 (2010).
179. Sampedro, M. F. et al. A biofilm approach to detect bacteria on removed spinal implants. Spine 35, 1218-1224 (2010).
180. Bjerkan, G., Witso, E. & Bergh, K. Sonication is superior to scraping for retrieval of bacteria in biofilm on titanium and steel surfaces in vitro. Acta Orthop. 80, 245-250 (2009).
181. Kobayashi, N., Bauer, T. W., Tuohy, M. J., Fujishiro, T. & Procop, G. W. Brief ultrasonication improves detection of biofilm-formative bacteria around a metal implant. Clin. Orthop. Relat. Res. 457, 210-213 (2007).
182. Young, D., Morton, R. & Bartley, J. Therapeutic ultrasound as treatment for chronic rhinosinusitis: preliminary observations. J. Laryngol. Otol. 124, 495-499 (2010).
183. Cui, H., Thomee, E., Noble, J. G., Reynard, J. M. & Turney, B. W. Efficacy of the lithotripsy in treating lower pole renal stones. Urolithiasis 41, 231-234 (2013).
184. Kaplan, J. B. Therapeutic potential of biofilm-dispersing enzymes. Int. J. Artif. Organs 32, 545-554 (2009).
185. Alkawash, M. A., Soothill, J. S. & Schiller, N. L. Alginate lyase enhances antibiotic killing of mucoid Pseudomonas aeruginosa in biofilms. APMIS 114, 131-138 (2006).
186. Sauer, K. et al. Characterization of nutrient-induced dispersion in Pseudomonas aeruginosa PAO1 biofilm. J. Bacteriol. 186, 7312-7326 (2004).
187. Duoll, I. et al. An in vitro study of the rheology of cystic fibrosis sputum following treatment with oligoG alginate oligosaccharide. 23rd Annual North American Cystic Fibrosis Congress [online], http://algipharma.
188. Davies, D. G. & Marques, C. N. A fatty acid messenger is responsible for inducing dispersion in microbial biofilms. J. Bacteriol. 191, 1393-1403 (2009).
189. Barraud, N. et al. Involvement of nitric oxide in biofilm dispersal of Pseudomonas aeruginosa. J. Bacteriol. 188, 7344-7353 (2006).
190. Gjermansen, M., Ragas, P. & Tolker-Nielsen, T. Proteins with GGDEF and EAL domains regulate Pseudomonas putida biofilm formation and dispersal. FEMS Microbiol. Lett. 265, 215-224 (2006).
191. Ma, Q., Yang, Z., Pu, M., Peti, W. & Wood, T. K. Engineering a novel c-di-GMP-binding protein for biofilm dispersal. Environ. Microbiol. 13, 631-642 (2011).
192. Antoniani, D., Bocci, P., Maciag, A., Raffaelli, N. & Landini, P. Monitoring of diguanylate cyclase activity and of cyclic-di-GMP biosynthesis by whole-cell assays suitable for high-throughput screening of biofilm inhibitors. Appl. Microbiol. Biotechnol. 85, 1095-1104 (2010).
193. Heijerman, H., Westerman, E., Conway, S., Touw, D. & Doring, G. Inhaled medication and inhalation devices for lung disease in patients with cystic fibrosis: a European consensus. J. Cyst. Fibros. 8, 295-315 (2009).
194. Mermel, L. A. et al. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 update by the Infectious Diseases Society of America. Clin. Infect. Dis. 49, 1-45 (2009).
195. Broom, J. et al. Ethanol lock therapy to treat tunnelled central venous catheter-associated blood stream infections: results from a prospective trial. Scand. J. Infect. Dis. 40, 399-406 (2008).
196. Barbaric, D., Curtin, J., Pearson, L. & Shaw, P. J. Role of hydrochloric acid in the treatment of central venous catheter infections in children with cancer. Cancer 101, 1866-1872 (2004).
197. Goss, C. H. et al. Phase 1 pharmacokinetic and safety study of intravenous ganiteTM (Gallium nitrate) in cystic fibrosis. (Abstract 230) Pediatr. Pulmonol. 46 (Suppl. 34), 294 (2011).
198. Hill, D. et al. Antibiotic susceptabilities of Pseudomonas aeruginosa isolates derived from patients with cystic fibrosis under aerobic, anaerobic, and biofilm conditions. J. Clin. Microbiol. 43, 5085-5090 (2005).
199. Kohler, T., Dumas, J. L. & van Delden, C. Ribosome protection prevents azithromycin-mediated quorum-sensing modulation and stationary-phase killing of Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 51, 4243-4248 (2007).
200. Allison, K. R., Brynildsen, M. P. & Collins, J. J. Heterogeneous bacterial persisters and engineering approaches to eliminate them. Curr. Opin. Microbiol. 14, 593-598 (2011).
201. Shinde, R. B., Chauhan, N. M., Raut, J. S. & Karuppayil, S. M. Sensitization of Candida albicans biofilms to various antifungal drugs by cyclosporine A. Ann. Clin. Microbiol. Antimicrob. 11, 27 (2012).
202. Alem, M. A. & Douglas, L. J. Prostaglandin production during growth of Candida albicans biofilms. J. Med. Microbiol. 54, 1001-1005 (2005).
203. Alem, M. A. & Douglas, L. J. Effects of aspirin and other nonsteroidal anti-inflammatory drugs on biofilms and planktonic cells of Candida albicans. Antimicrob. Agents Chemother. 48, 41-47 (2004).
204. Ghalehnoo, Z. R., Rashki, A., Najimi, M. & Dominguez, A. The role of diclofenac sodium in the dimorphic transition in Candida albicans. Microb. Pathog. 48, 110-115 (2010).
205. Marquez, B. Bacterial efflux systems and efflux pumps inhibitors. Biochimie 87, 1137-1147 (2005).
206. Liu, Y., Yang, L. & Molin, S. Synergistic activities of an efflux pump inhibitor and iron chelators against Pseudomonas aeruginosa growth and biofilm formation. Antimicrob. Agents Chemother. 54, 3960-3963 (2010).
207. Tirouvanziam, R. et al. High-dose oral N-acetylcysteine, a glutathione prodrug, modulates inflammation in cystic fibrosis. Proc. Natl Acad. Sci. USA 103, 4628-4633 (2006).
208. Hughes, K. A., Sutherland, I. W. & Jones, M. V. Biofilm susceptibility to bacteriophage attack: the role of phage-borne polysaccharide depolymerase. Microbiology 144, 3039-3047 (1998).
209. Webb, J. S. et al. Cell death in Pseudomonas aeruginosa biofilm development. J. Bacteriol. 185, 4585-4592 (2003).
210. Morello, E. et al. Pulmonary bacteriophage therapy on Pseudomonas aeruginosa cystic fibrosis strains: first steps towards treatment and prevention. PLoS ONE 6, e16963 (2011).
211. Alemayehu, D. et al. Bacteriophages phiMR299-2 and phiNH-4 can eliminate Pseudomonas aeruginosa in the murine lung and on cystic fibrosis lung airway cells. MBio. 3, e00029-e00012 (2012).
212. Merabishvili, M. et al. Quality-controlled small-scale production of a well-defined bacteriophage cocktail for use in human clinical trials. PLoS ONE 4, e4944 (2009).
213. Moons, P., Werckx, W., Van Houdt, R., Aertsen, A. & Michiels, C. W. Resistance development of bacterial biofilms against bacteriophage attack. Commun. Agr. Appl. Biol. Sci. 71, 297-300 (2006).
214. Fu, W. et al. Bacteriophage cocktail for the prevention of biofilm formation by Pseudomonas aeruginosa on catheters in an in vitro model system. Antimicrob. Agents Chemother. 54, 397-404 (2010).
215. Domenech, M., Garcia, E. & Moscoso, M. In vitro destruction of Streptococcus pneumoniae biofilms with bacterial and phage peptidoglycan hydrolases. Antimicrob. Agents Chemother. 55, 4144-4148 (2011).
216. Meng, X. et al. Application of a bacteriophage lysin to disrupt biofilms formed by the animal pathogen Streptococcus suis. Appl. Environ. Microbiol. 77, 8272-8279 (2011).
217. Rolain, J. M., Fancello, L., Desnues, C. & Raoult, D. Bacteriophages as vehicles of the resistome in cystic fibrosis. J. Antimicrob. Chemother. 66, 2444-2447 (2011).
218. Ojeniyi, B., Birch-Andersen, A., Mansa, B., Rosdahl, V. T. & Hoiby, N. Morphology of Pseudomonas aeruginosa phages from the sputum of cystic fibrosis patients and from the phage typing set. An electron microscopy study. APMIS 99, 925-930 (1991).
219. Willner, D. et al. Metagenomic analysis of respiratory tract DNA viral communities in cystic fibrosis and non-cystic fibrosis individuals. PLoS ONE 4, e7370 (2009).
220. Parracho, H. M., Burrowes, B. H., Enright, M. C., McConville, M. L. & Harper, D. R. The role of regulated clinical trials in the development of bacteriophage therapeutics. J. Mol. Genet. Med. 6, 279-286 (2012).
221. Wright, A., Hawkins, C. H., Anggard, E. E. & Harper, D. R. A controlled clinical trial of a therapeutic bacteriophage preparation in chronic otitis due to antibiotic-resistant Pseudomonas aeruginosa; a preliminary report of efficacy. Clin. Otolaryngol. 34, 349-357 (2009).
222. Brussow, H. Pseudomonas biofilms, cystic fibrosis, and phage: a silver lining? MBio 3, e00061-e00112 (2012).
223. Hoffmann, N. et al. Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary growth phase killing of P. aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr-/- mice. Antimicrob. Agents Chemother. 51, 3677-3687 (2007).
224. Song, Z. et al. Effects of intratracheal administration of novispirin G10 on a rat model of mucoid Pseudomonas aeruginosa lung infection. Antimicrob. Agents Chemother. 49, 3868-3874 (2005).
225. Brinch, K. S. et al. Plectasin shows intracellular activity against Staphylococcus aureus in human THP-1 monocytes and in a mouse peritonitis model. Antimicrob. Agents Chemother. 53, 4801-4808 (2009).
226. Payne, D. J., Gwynn, M. N., Holmes, D. J. & Pompliano, D. L. Drugs for bad bugs: confronting the challenges of antibacterial discovery. Nature Rev. Drug Discov. 6, 29-40 (2007).
227. Hassett, D. J. et al. Anaerobic metabolism and quorum sensing by Pseudomonas aeruginosa biofilms in chronically infected cystic fibrosis airways: rethinking antibiotic treatment strategies and drug targets. Adv. Drug Deliv. Rev. 54, 1425-1443 (2002).
228. Lu, C. D., Winteler, H., Abdelal, A. & Haas, D. The ArgR regulatory protein, a helper to the anaerobic regulator ANR during transcriptional activation of the arcD promoter in Pseudomonas aeruginosa. J. Bacteriol. 181, 2459-2464 (1999).
229. Stover, C. K. et al. Complete genome sequence of Pseudomonas aeruginosa PA01, an opportunistic pathogen. Nature 406, 959-964 (2000).
230. O'Toole, G. A. & Kolter, R. Initiation of biofilm formation in Pseudomonas fluorescens WCS365 proceeds via multiple, convergent signalling pathways: a genetic analysis. Mol. Microbiol. 28, 449-461 (1998).
231. Ceri, H. et al. The Calgary Biofilm Device: new technology for rapid determination of antibiotic susceptibilities of bacterial biofilms. J. Clin. Microbiol. 37, 1771-1776 (1999).
232. Anderl, J. N., Franklin, M. J. & Stewart, P. S. Role of antibiotic penetration limitation in Klebsiella pneumoniae biofilm resistance to ampicillin and ciprofloxacin. Antimicrob. Agents Chemother. 44, 1818-1824 (2000).
233. Goeres, D. M. et al. A method for growing a biofilm under low shear at the air-liquid interface using the drip flow biofilm reactor. Nature Protoc. 4, 783-788 (2009).
234. Zelver, N. et al. Measuring antimicrobial effects on biofilm bacteria: from laboratory to field. Methods Enzymol. 310, 608-628 (1999).
235. Werthen, M. et al. An in vitro model of bacterial infections in wounds and other soft tissues. APMIS 118, 156-164 (2010).
236. Merritt, J. H., Kadouri, D. E. & O'Toole, G. A. Growing and analyzing static biofilms. Curr. Protoc. Microbiol. http://dx.doi.org/10.1002/ 9780471729259. mc01b01s00 (2005).
237. Kirketerp-Moller, K. et al. Distribution, organization, and ecology of bacteria in chronic wounds. J. Clin. Microbiol. 46, 2717-2722 (2008).
238. Bjarnsholt, T., Tolker-Nielsen, T., Hoiby, N. & Givskov, M. Interference of Pseudomonas aeruginosa signalling and biofilm formation for infection control. Expert. Rev. Mol. Med. 12, e11 (2010).
239. Tanaka, G. et al. Effect of the growth rate of Pseudomonas aeruginosa biofilms on the susceptibility to antimicrobial agents: beta-lactams and fluoroquinolones. Chemotherapy 45, 28-36 (1999).
240. Vrany, J. D., Stewart, P. S. & Suci, P. A. Comparison of recalcitrance to ciprofloxacin and levofloxacin exhibited by Pseudomonas aeruginosa biofilms displaying rapid-transport characteristics. Antimicrob. Agents Chemother. 41, 1352-1358 (1997).
241. Zhang, L. & Mah, T. F. Involvement of a novel efflux system in biofilm-specific resistance to antibiotics. J. Bacteriol. 190, 4447-4452 (2008).
242. Anwar, H., Strap, J. L. & Costerton, J. W. Establishment of aging biofilms: possible mechanism of bacterial resistance to antimicrobial therapy. Antimicrob. Agents Chemother. 36, 1347-1351 (1992).
243. Mulcahy, H., Charron-Mazenod, L. & Lewenza, S. Extracellular DNA chelates cations and induces antibiotic resistance in Pseudomonas aeruginosa biofilms. PLoS. Pathog. 4, e1000213 (2008).
244. Hocquet, D. et al. MexXY-OprM efflux pump is necessary for a adaptive resistance of Pseudomonas aeruginosa to aminoglycosides. Antimicrob. Agents Chemother. 47, 1371-1375 (2003).
245. Mah, T. F. et al. A genetic basis for Pseudomonas aeruginosa biofilm antibiotic resistance. Nature 426, 306-310 (2003).