title: MALDI-TOF mass spectrometry for the detection and differentiation of Entamoeba histolytica and Entamoeba dispar.
abstract: Detection of Entamoeba histolytica and its differentiation from Entamoeba dispar is an important goal of the clinical parasitology laboratory. The aim of this study was the identification and differentiation of E. histolytica and E. dispar by MALDI-TOF MS, in order to evaluate the application of this technique in routine diagnostic practice. MALDI-TOF MS was applied to 3 amebic reference strains and to 14 strains isolated from feces that had been differentiated by molecular methods in our laboratory. Protein extracts from cultures of these strains (axenic cultures for the 3 reference strains and monoxenic cultures for the 14 field isolates) were analyzed by MALDI-TOF MS and the spectra obtained were analyzed by statistical software. Five peaks discriminating between E. histolytica and E. dispar reference strains were found by protein profile analysis: 2 peaks (8,246 and 8,303 Da) specific for E. histolytica and 3 (4,714; 5,541; 8,207 Da) for E. dispar. All clinical isolates except one showed the discriminating peaks expected for the appropriate species. For 2 fecal samples from which 2 strains (1 E. histolytica and 1 E. dispar) out of the 14 included in this study were isolated, the same discriminating peaks found in the corresponding isolated amebic strains were detected after only 12h (E. histolytica) and 24h (E. dispar) of incubation of the fecal samples in Robinson's medium without serum. Our study shows that MALDI-TOF MS can be used to discriminate between E. histolytica and E. dispar using in vitro xenic cultures and it also could have potential for the detection of these species in clinical samples.
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Adriana
authors: A
authors: Calderaro
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Maddalena
authors: M
authors: Piergianni
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Mirko
authors: M
authors: Buttrini
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Sara
authors: S
authors: Montecchini
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Giovanna
authors: G
authors: Piccolo
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Chiara
authors: C
authors: Gorrini
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Sabina
authors: S
authors: Rossi
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Carlo
authors: C
authors: Chezzi
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Maria Cristina
authors: MC
authors: Arcangeletti
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Maria Cristina
authors: MC
authors: Medici
authors: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors: Flora
authors: F
authors: De Conto
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003937:Diagnosis, Differential; D004591:Electrophoresis, Polyacrylamide Gel; D004747:Entamoeba / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004748:Entamoeba histolytica / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004749:Entamoebiasis / Q000175:diagnosis / Q000469:parasitology; D005243:Feces / Q000469:parasitology; D006790:Host-Parasite Interactions; D006801:Humans; D016133:Polymerase Chain Reaction; D025341:Principal Component Analysis; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D015800:Protozoan Proteins / Q000378:metabolism*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012372:ROC Curve; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D020543:Proteome; D015800:Protozoan Proteins; D012337:RNA, Ribosomal, 18S