Raman-based identification of tick species (Ixodidae) by spectroscopic analysis of their feces

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Apr 15:271:120966. doi: 10.1016/j.saa.2022.120966. Epub 2022 Jan 29.

Abstract

Ticks are blood-feeding parasites that vector a large number of pathogens of medical and veterinary importance. There are strong connections between tick and pathogen species. Timely detection of certain tick species on cattle can cease the spread of numerous devastating diseases such as Bovine babiesiosis and anaplasmosis. Detection of ticks is currently performed by slow and laborious scout-based inspection of cattle. In this study, we investigated the possibility of identification of tick species (Ixodidae) based on spectroscopic signatures of their feces. We collected Raman spectra from individual grains of feces of seven different species of ticks. Our results show that Raman spectroscopy (RS) allows for highly accurate (above 90%) differentiation between tick species. Furthermore, RS can be used to predict the tick developmental stage and differentiate between nymphs, meta-nymphs and adult ticks. We have also demonstrated that diagnostics of tick species present on cattle can be achieved using a hand-held Raman spectrometer. These findings show that RS can be used for non-invasive, non-destructive and confirmatory on-site analysis of tick species present on cattle.

Keywords: Confocal Raman spectroscopy; Hand-held Raman; Ixodidae Tick species differentiation; Partial least square discriminant analysis (PLS-DA); Tick feces.

MeSH terms

  • Animals
  • Cattle
  • Cattle Diseases* / diagnosis
  • Cattle Diseases* / parasitology
  • Feces
  • Ixodidae* / parasitology
  • Tick Infestations* / parasitology
  • Tick Infestations* / veterinary
  • Ticks*