Raman microspectroscopy analysis in the treatment of acanthamoeba keratitis

PLoS One. 2013 Aug 20;8(8):e72127. doi: 10.1371/journal.pone.0072127. eCollection 2013.


Acanthamoeba keratitis is a rare but serious corneal disease, often observed in contact lens wearers. Clinical treatment of infected patients frequently involves the use of polyhexamethylene biguanide (PHMB), a polymer used as a disinfectant and antiseptic, which is toxic also for the epithelial cells of the cornea. Prompt and effective diagnostic tools are hence highly desiderable for both starting early therapy and timely suspension of the treatment. In this work we use Raman microspectroscopy to analyse in vitro a single Acanthamoeba cell in cystic phase. In particular, we investigate the effect of PHMB at the single-cell level, providing useful information on both the underlying biochemical mechanism and the time frame for Acanthamoeba eradication in ocular infections. Furthermore, we demonstrate that Raman spectroscopy, in conjunction with standard multivariate analysis methods, allows discriminating between live and dead Acanthamoebas, which is fundamental to optimizing patients' treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acanthamoeba / drug effects*
  • Acanthamoeba / metabolism
  • Acanthamoeba Keratitis / drug therapy
  • Acanthamoeba Keratitis / parasitology*
  • Amebicides / pharmacology*
  • Biguanides / pharmacology*
  • Contact Lenses / parasitology
  • Cytoplasm / metabolism
  • Humans
  • Models, Biological
  • Multivariate Analysis
  • Principal Component Analysis
  • Single-Cell Analysis
  • Spectrum Analysis, Raman


  • Amebicides
  • Biguanides
  • polihexanide

Grant support

This work was funded by MIUR (Ministero dell'Istruzione, dell'Università e della Ricerca). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.