Analysis of Four Human Microsporidian Isolates by MALDI‐TOF Mass Spectrometry

Abstract

Spores of four species of microsporidia isolated from humans were analyzed by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and specific biomarkers were found for each. The microsporidia analyzed included three species, Encephalitozoon cuniculi, Encephalitozoon hellem, and Encephalitozoon intestinalis and the fourth organism is the recently described Brachiola algerae. Whole spores, spore shells, and soluble fractions were applied directly to the MALDI target without further purification steps. MALDI-TOF MS analysis of both whole spores and soluble fractions of the four isolates revealed a group of unique, characteristic, and reproducible spectral markers in the mass range of 2,000-8,000 Da. Statistical analysis of the averaged centroided masses uncovered two distinct sets of unique peptides or biomarkers, one originated from whole spores and the other from soluble fractions, that can differentiate the four microsporidian species studied. MALDI-TOF MS analysis of whole organisms is a rapid, sensitive, and specific option to characterize microsporidian isolates and has the potential for several applications in parasitology.

Differentiation of Streptococcus pneumoniae Conjunctivitis Outbreak Isolates by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

“…Additionally, Shaw et al reported the identification of biomarkers in unfractionated C. burnetii cells phase I purified from embryonic egg yolk sac preparations (24). Furthermore, spectral markers in the mass range of 2,000 to 8,000 Da were obtained from MALDI-TOF MS analysis of four human microsporidian isolates (16). Biomarkers for Mycobacterium species have also been detected by MALDI primarily in the 500-to 2,000-Da range, most likely representing lipid molecules or small polypeptides (18).…”

Discrimination of freshwater fish species by Matrix-Assisted Laser Desorption/Ionization- Time Of Flight Mass Spectrometry (MALDI-TOF MS): a pilot study

“…The results of MALDI-TOF MS analysis provide similar to those obtained by genetic molecular analysis and the outcome of MALDI-TOF MS identification is comparable to and as reliable as that originating from established genetic methods (e.g., Caldwell, and Caprioli 2005). These advantages did stimulate a number of studies addressed to improve the effectiveness of this application on whole microorganisms (Claydon et al 1996;Demirev et al 2001;Moura et al 2003;Hettick et al 2004) and on target organs and tissues of animals in ecotoxicology, neurophysiology and food control (e.g., Neupert, and Predel 2005;Mezhoud et al 2008;Keyvanshokooh et al 2009;Lu et al 2010).…”

MALDI-TOF MS Profiling-Advances in Species Identification of Pests, Parasites, and Vectors

“…Later, it was shown that incubation of intact oocytes and purified sporozoites for 45 min with the matrix was critical for generating mass spectra with a large number of reproducible peaks for C. parvum oocysts (Glassmeyer et al, 2007). Subsequently, direct application of whole spores, spore shells, and soluble fractions of spore-forming unicellular parasites such as microsporidia, Encephalitozoon cuniculi, Encephalitozoon hellem, Encephalitozoon intestinalis , and Brachiola algerae isolated from humans and propagated on monolayers of Vero monkey kidney (E6) cells, displayed species-specific markers in the mass range of 2,000–8,000 Da (Moura et al, 2003). Later, species-specific peaks in the range of m/z 3,000–19,000 was reported for the water-borne protozoan parasite, Giardia spp., the causative agent of giardiasis.…”