Use of Fourier transform infrared spectroscopy (FTIR) spectroscopy for rapid and accurate identification of Yeasts isolated from human and animals

Abstract

Rapid and accurate identification of yeast is increasingly important to stipulate the appropriate therapy thus reducing morbidity and mortality related to yeast infections. Vibrational spectroscopic techniques (infrared (IR) and Raman) could provide potential alternatives to conventional typing methods, because they constitute a rapid, inexpensive and highly specific spectroscopic fingerprint through-which microorganism can be identified. The present study evaluate (FTIR) spectroscopy as a sensitive and effective assay for the identification of the most frequent yeast species isolated from human and animals. One hundred and twenty-eight yeasts isolated from infected human mouths/vaginas, chronic diseased cows, crop mycosis in chicken and soil contaminated with pigeon droppings were phenotypically identified. Using universal primers, ITS1/ITS4, we have amplified ITS1-5.8S-ITS2 rDNA regions for 39 yeast isolates as representative samples. The PCR products were digested with restriction enzyme MspI and examined by PCR-RFLP, which was an efficient technique for identification of Candida spp., Cryptococcus neoformans and Trichosporon asahii. Further, identification of the same 39 isolates were done by FTIR spectroscopy and considered as reference for other strains by comparison of their FTIR spectra. The current study has sharply demonstrated the significant spectral differences between the various examined species of Candida, Cryptococcus, Trichosporon, Rhodotorula and Geotrichum isolated from different sources. Decisively, our research has confirmed that FTIR spectroscopy is a promising diagnostic tool, because of its sensitivity, rapidity, high differentiation capacity and simplicity compared to conventional/molecular techniques.