Article
Feasibility of near-infrared spectroscopy for species identification and parasitological diagnosis of freshwater snails of the genus Biomphalaria (Planorbidae)
Registro en:
VALLADARES, Vanessa et al. Feasibility of near-infrared spectroscopy for species identification and parasitological diagnosis of freshwater snails of the genus Biomphalaria (Planorbidae). Plos One, v. 16, n. 11. e0259832, p. 1 - 10, Nov. 2021.
1932-6203
10.1371/journal. pone.0259832
Autor
Valladares, Vanessa
Pasquini, Célio
Thiengo, Silvana Carvalho
Silva, Clélia Christina Mello
Resumen
Near Infrared Spectroscopy (NIRS) has been applied in epidemiological surveillance studies
of insect vectors of parasitic diseases, such as the Dengue’s mosquitoes. However, regarding
mollusks, vectors of important worldwide helminth diseases such as schistosomiasis,
fascioliasis and angiostrongyliasis, NIRS studies are rare. This work proposes to establish
and standardize the procedure of data collection and analysis using NIRS applied to medical
malacology, i.e., to mollusk vectors identifications. Biomphalaria shells and live snails were
analyzed regarding several operational aspects, such as: moisture, shell side and position
of the live animal for acquisition of NIR spectra. Representative spectra of Biomphalaria
shells and live snails were collected using an average of 50 scans per sample and resolution
of 16 cm-1. For shells, the sample should first be dried for a minimum of 15 days at an average
temperature of 26±1˚C, and then placed directly in the equipment measurement window
with its left side facing the light beam. Live animals should be dried with absorbent paper;
placed into a glass jar, and analyzed similarly to the shells. Once standardized, the technique
was applied aiming at two objectives: identification of Biomphalaria using only the
shells and parasitological diagnosis for Schistosoma mansoni infection. The discrimination
of the three Biomphalaria species intermediate hosts of S. mansoni only by shell has technical
limit due to the scarcity of organic material. Nevertheless, it was possible to differentiate
B. straminea from B. tenagophila and B. glabrata with 96% accuracy. As for the parasitological
diagnosis, it was possible to differentiate infected mollusks shedding S. mansoni cercariae
from the non-infected ones with 82, 5% accuracy. In conclusion, the Near Infrared
Spectroscopy (NIR’s) technique has proven to be an innovative and sound tool to detect
infection by S. mansoni in the different species of Biomphalaria intermediate hosts.