MALDI-TOF mass spectrometry: a new tool for rapid identification of cercariae (Trematoda, Digenea)

Abstract

Identification of cercariae was long based on morphological and morphometric features, but these approaches remain difficult to implement and require skills that have now become rare. Molecular tools have become the reference even though they remain relatively time-consuming and expensive. We propose a new approach for the identification of cercariae using MALDI-TOF mass spectrometry. Snails of different genera (Radix, Lymnaea, Stagnicola, Planorbis, and Anisus) were collected in the field to perform emitting tests in the laboratory. The cercariae they emitted (Trichobilharzia anseri, Diplostomum pseudospathaceum, Alaria alata, Echinostoma revolutum, Petasiger phalacrocoracis, Tylodelphys sp., Australapatemon sp., Cotylurus sp., Posthodiplostomum sp., Parastrigea sp., Echinoparyphium sp. and Plagiorchis sp.) were characterized by sequencing the D2, ITS2 and ITS1 domains of rDNA, and by amplification using specific Alaria alata primers. A sample of each specimen, either fresh or stored in ethanol, was subjected to a simple preparation protocol for MALDI-TOF analysis. The main spectral profiles were analyzed by Hierarchical Clustering Analysis. Likewise, the haplotypes were analyzed using the maximum likelihood method. Analytical performance and the log-score value (LSV) cut-off for species identification were then assessed by blind testing. The clusters obtained by both techniques were congruent, allowing identification at a species level. MALDI-TOF enables identification at an LSV cut-off of 1.7 without false-positives; however, it requires more data on closely related species. The development of a “high throughput” identification system for all types of cercariae would be of considerable interest in epidemiological surveys of trematode infections.

Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

“…Regarding the ITS2 fragment, our isolates presented the highest similarity with sequences of Australapatemon sp. (MK168687 and MK168688) from France [ 25 ]. Based on the COI locus, an isolate of Australapatemon sp.…”

“…Importantly, a detailed molecular analysis of cercariae and adult specimens of Australapatemon sampled across North America clearly indicates the existence of several distinct lineages within this taxon and indisputably illustrates the hidden species diversity [ 13 , 15 ]. In Europe, Huguenin et al [ 25 ] identified another lineage within Australapatemon cercariae using Matrix-Assisted Laser Desorption-Ionisation–Time of Flight (MALDI-TOF) mass spectrometry, but the taxonomic position and molecular diversity of larval stages of Australapatemon collected from a wide range of intermediate hosts (snails and leeches) have not been the subject of extensive studies. The genetic variability and species richness within the genus Australapatemon from various geographical regions thus remain relatively unknown.…”

No limit in interspecific hybridization in schistosomes: observation from a case report

“…The use of new low-cost and high throughput tools like MALDI-TOF MS [14] to detect such hybrids could be helpful to explore this challenge.…”

MALDI-TOF Mass Spectroscopy Applications in Clinical Microbiology

“…An essential feature of MALDI-TOF MS is that in addition to detecting bacteria, it can be used to detect microbial toxins [ 44 ], study antibiotic resistance [ 45 – 47 ], detect viruses [ 48 , 49 ], parasites [ 50 , 51 ], fungi [ 52 , 53 ], and study of human [ 54 – 56 ] and plant cells [ 57 , 58 ], which makes us more familiar with the creatures in our environment.…”