Microbial keratitis is an infection of the cornea that can be severe since it leads, in some cases, to blindness. One of the most important prognostic factors is the microbiological diagnosis which determines the rapid use of the appropriate treatment. Therefore we sought a faster and more efficient diagnosis method by using mass spectrometry.Methods
This study is the analysis of corneal samples with MALDI-TOF MS as a new approach, undeveloped in the literature, without preparation nor culture of infected epithelia. All together 18 human corneal epithelia were studied to characterize the healthy human corneal spectra. An animal experimentation was also conducted on 45 Balb/c mice for comparison of their left healthy corneas and their right infected corneas by two difficult diagnosis seeds: Mycobacterium chelonae or Acanthamoeba polyphaga.Results
Corneal protein spectra can be obtained quickly, in less than ten minutes, and easily by simple deposit on a mass-spectrometry target. The study of healthy corneas gives reproducible and specific spectra compared to other human tissues available in our database. In animal model, the MALDI-TOF MS detects an inflammatory response secondary to wound healing corneal and an infectious response to Mycobacterium chelonae.Conclusion
This original work consists in using MALDI-TOF MS for a microbial keratitis analyze directly on infected epithelium. This technique permits, to differentiate easily and quickly, a healthy cornea from an ulcerated or infected one in mice. After the development of microbiologic recognition algorithms, mass-spectrometry could be used, in the future, for a “minute” diagnosis of infectious keratitis.Diagnosis of infectious keratitis by mass spectrometry.