Identifying the last supper: utility of the DNA barcode library for bloodmeal identification in ticks

Abstract

Ticks are among the most important vectors of disease in the Northern Hemisphere, and a better understanding of their feeding behaviour and life cycle is critical to the management and control of tick‐borne zoonoses. DNA‐based tools for the identification of residual bloodmeals in hematophagous arthropods have proven useful in the investigation of patterns of host use in nature. Using a blind test approach, we challenged the utility of the DNA barcode library for the identification of vertebrate bloodmeals in engorged, field‐collected Ixodes scapularis. Universal vertebrate primers for the COI barcode region successfully amplified DNA from the host bloodmeal and only rarely amplified tick DNA. Of the 61 field‐collected ticks, conclusive genus‐ and species‐level identification was possible for 72% of the specimens. In all but two cases, barcode‐based identification of the bloodmeal was consistent with the morphological identification of the vertebrate host the ticks were collected from. Possible explanations for mismatches or ambiguities are presented. This study validates the utility of the DNA barcode library as a valuable and reliable resource for the identification of unknown bloodmeals in arthropod vectors of disease. Future directions aimed at the refinement of these techniques to gain additional information and to improve the amplification success of digested vertebrate DNA in tick bloodmeals are discussed.

A comparative test of ixodid tick identification by a network of European researchers

“…Dieme et al, 2014;Yssouf et al, 2013). Examples of this approach to ticks so far cover the use of DNA-barcoding for the detection of the blood meal source (Gariepy et al, 2012). Nevertheless, the morphological identification of ticks is routinely used in laboratories around the world, more commonly than molecular methods, mainly in large sample sets, which simplify the flow of work and reduces the costs.…”

When bugs reveal biodiversity

“…Only recently, however, has the use of such invertebrates been proposed as a method for assaying vertebrate presence itself (Gariepy et al 2012;Schnell et al 2012). Although in hindsight a remarkably obvious proposition (as many of the best ideas always are), in this issue of Molecular Ecology, Calvignac-Spencer et al (2013) demonstrate an exciting new addition to the iDNA sampling platter, to include the 'carrion' flies (defined as the blow and flesh flies of the Calliphoridae and Sarcophagidae families, respectively) that feed on the live flesh of open wounds, carrion or faeces (Fig.…”

“…Vigilant et al 2009), to the less obvious, including environmental DNA extracted from sediments, soil or water samples (e.g. Taberlet et al 2012), and as recently demonstrated, the dietary content of blood-sucking invertebrates (Gariepy et al 2012;Schnell et al 2012) Globally, biodiversity is declining at an unprecedented rate, and unless vigorous conservation initiatives are urgently implemented, much of our diversity may soon be lost forever (Butchart et al 2010). Acknowledging the key role played by biodiversity-related information in feeding decision-making processes, 'Parties to the Convention on Biological Diversity' made the improvement of 'knowledge, the science base and technologies relating to biodiversity' one of the Aichi Biodiversity Targets (CoP10 2010).…”

Survival of Host Blood Proteins in <I>Ixodes scapularis</I> (Acari: Ixodidae) Ticks: A Time Course Study

“…These include the comparatively rapid degradation of the target nucleic acids, dependence on DNA primers that may vary in their speciÞcities, and the susceptibility of PCR to contaminating DNA from previous ampliÞcations from different species in the laboratory. These shortcomings arise even when using the more advanced methods, such as DNA barcoding for host identiÞcation (Gariepy et al 2012). …”