Comparative Ribosome Analysis of Pseudomonas aeruginosa Planktonic and Biofilm Cells

Caleb Smith, Adam Corcoran, Rawan Eleshy, Savanna Waddle, Erika Lutter, Kevin Wilson

Abstract


Pseudomonas aeruginosa is an opportunistic pathogen commonly found in the lungs of cystic fibrosis patients. P. aeruginosa is notable for its ability to form biofilms within the lungs. Biofilms exhibit incredible antibiotic tolerance. Tolerance differs from resistance: while resistant cells may actively grow in the presence of antibiotics, tolerant cells slow their metabolic rates, preventing most antibiotics from taking effect. The tolerance of P. aeruginosa biofilms is the cause of recalcitrant infections in cystic fibrosis infections. In this project, we sought to characterize the ribosomes of P. aeruginosa planktonic and biofilm cells in samples which either have or have not been exposed to tobramycin. Tobramycin is an aminoglycoside commonly used in P. aeruginosa infections. Recent studies have shown environmental stressors including antibiotic exposure cause ribosome degradation, remodeling, and dimerization in E. coli, leading to translational inhibition and in turn, antibiotic tolerance. We hypothesized similar events occur in tolerant cells of P. aeruginosa. We isolated ribosomes of planktonic and biofilm cells through sucrose gradient centrifugation. Following this, we qualified the relative distributions of ribosome fractions and analyzed the protein makeup of these ribosomes by mass spectrophotometry. We expect to observe a difference between the protein makeup of ribosomes from biofilm cells and those from planktonic cells. We expect similar results between samples treated with/without tobramycin. The results of this project may mediate future research on how to target cells exhibiting antibiotic tolerance.

Full Text:

PDF

References


Anderson, M., R. Gregory, S. Thompson, D. Souza, S. Paul, R. Mulligan, A. Smith, and M. Welsh. 1991. Demonstration that CFTR is a chloride channel by alteration of its anion selectivity. Science 253:202-205.

Bjarnsholt, T., P. Ø. Jensen, M. J. Fiandaca, J. Pedersen, C. R. Hansen, C. B. Andersen, T. Pressler, M. Givskov, and N. Høiby. 2009. Pseudomonas aeruginosa biofilms in the respiratory tract of cystic fibrosis patients. Pediatric Pulmonology 44:547-558.

Cho, J., J. Rogers, M. Kearns, M. Leslie, S. D. Hartson, and K. S. Wilson. 2015. Escherichia coli persister cells suppress translation by selectively disassembling and degrading their ribosomes. Molecular Microbiology 95:352-364.

Drenkard, E. 2003. Antimicrobial resistance of Pseudomonas aeruginosa biofilms. Microbes Infect 5:1213-1219.

Folkesson, A., L. Jelsbak, L. Yang, H. K. Johansen, O. Ciofu, N. Hoiby, and S. Molin. 2012. Adaptation of Pseudomonas aeruginosa to the cystic fibrosis airway: an evolutionary perspective. Nature Reviews Micro 10:841-851.

Fosso, M. Y., H. Zhu, K. D. Green, S. Garneau‐Tsodikova, and K. Fredrick. 2015. Tobramycin Variants with Enhanced Ribosome‐Targeting Activity. ChemBioChem 16:1565-1570.

Govan, J. R., and V. Deretic. 1996. Microbial pathogenesis in cystic fibrosis: mucoid Pseudomonas aeruginosa and Burkholderia cepacia. Microbiological Reviews 60:539-574.

Hall-Stoodley, L., J. W. Costerton, and P. Stoodley. 2004. Bacterial biofilms: from the Natural environment to infectious diseases. Nature Reviews Micro 2:95-108.

Hoffman, L. R., D. A. D'Argenio, M. J. MacCoss, Z. Zhang, R. A. Jones, and S. I. Miller. 2005. Aminoglycoside antibiotics induce bacterial biofilm formation. Nature 436:1171-1175.

O'Sullivan, B. P., and S. D. Freedman. 2009. Cystic fibrosis. The Lancet 373:1891-1904.

Potrykus, K., and M. Cashel. 2008. (p)ppGpp: still magical? Annual Review of Microbiology 62:35-51.

Ramsey, B. W., H. L. Dorkin, J. D. Eisenberg, R. L. Gibson, I. R. Harwood, R. M. Kravitz, D. V. Schidlow, R. W. Wilmott, S. J. Astley, and M. A. McBurnie. 1993. Efficacy of aerosolized tobramycin in patients with cystic fibrosis. New England Journal of Medicine 328:1740-1746.

Ratjen, F., G. Döring, and W. H. Nikolaizik. 2001. Effect of inhaled tobramycin on early Pseudomonas aeruginosa colonisation in patients with cystic fibrosis. The Lancet 358:983-984.

Walters, M. C., F. Roe, A. Bugnicourt, M. J. Franklin, and P. S. Stewart. 2003. Contributions of antibiotic penetration, oxygen limitation, and low metabolic activity to tolerance of Pseudomonas aeruginosa biofilms to ciprofloxacin and tobramycin. Antimicrobial Agents And Chemotherapy 47:317-323.

Yoshida, H., Y. Maki, H. Kato, H. Fujisawa, K. Izutsu, C. Wada, and A. Wada. 2002. The ribosome modulation factor (RMF) binding site on the 100S ribosome of Escherichia coli. Journal of Biochemistry 132:983-989.


Refbacks

  • There are currently no refbacks.