title: Identification of Ixodes ricinus blood meals using an automated protocol with high resolution melting analysis (HRMA) reveals the importance of domestic dogs as larval tick hosts in Italian alpine forests.
abstract: In Europe, Ixodes ricinus L. is the main vector of a variety of zoonotic pathogens, acquired through blood meals taken once per stage from a vertebrate host. Defining the main tick hosts in a given area is important for planning public health interventions; however, until recently, no robust molecular methods existed for blood meal identification from questing ticks. Here we improved the time- and cost-effectiveness of an HRMA protocol for blood meal analysis and used it to identify blood meal sources of sheep tick larvae from Italian alpine forests.
  
  
  
  Nine hundred questing nymphs were collected using blanket-dragging in 18 extensive forests and 12 forest patches close to rural villages in the Province of Trento. Total DNA was either extracted manually, with the QIAamp DNA Investigator kit, or automatically using the KingFisher™ Flex Magnetic Particle Processors (KingFisher Cell and Tissue DNA Kit). Host DNA was amplified with six independent host group real-time PCR reactions and identified by means of HRMA. Statistical analyses were performed in R to assess the variables important for achieving successful identification and to compare host use in the two types of forest.
  
  
  
  Automating DNA extraction improved time- and cost-effectiveness of the HRMA protocol, but identification success fell to 22.4% (KingFisher™) from 55.1% (QIAamp), with larval hosts identified in 215 of 848 questing nymphs; 23 mixed blood meals were noted. However, the list of hosts targeted by our primer sets was extended, improving the potential of the method. Host identification to species or genus level was possible for 137 and 102 blood meals, respectively. The most common hosts were Rodentia (28.9%) and, unexpectedly, Carnivora (28.4%), with domestic dogs accounting for 21.3% of all larval blood meals. Overall, Cetartiodactyla species fed 17.2% of larvae. Passeriformes (14.6%) fed a significantly higher proportion of larvae in forest patches (22.3%) than in extensive forest (9.6%), while Soricomorpha (10.9%) were more important hosts in extensive forest (15.2%) than in forest patches (4.3%).
  
  
  
  The HRMA protocol for blood meal analysis is a valuable tool in the study of feeding ecology of sheep ticks, especially with the cost- and time- reductions introduced here. To our knowledge, we show for the first time that domestic dogs are important larval hosts in the Alps, which may have possible implications for tick-borne disease cycles in urbanized areas.
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy. collini.margherita@gmail.com.|Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy. collini.margherita@gmail.com.
authors.forename: Margherita
authors.initials: M
authors.lastname: Collini
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.|Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Albonico
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rosà
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Tagliapietra
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Arnoldi
authors.affiliation: Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Lorenza
authors.initials: L
authors.lastname: Conterno
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Rossi
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Mortarino
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Annapaola
authors.initials: A
authors.lastname: Rizzoli
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
authors.forename: Heidi Christine
authors.initials: HC
authors.lastname: Hauffe
mesh_terms: D000818:Animals; D057205:Automation, Laboratory / Q000379:methods*; D002335:Carnivora; D004285:Dogs; D005247:Feeding Behavior; D065928:Forests; D007558:Italy; D018884:Ixodes / Q000502:physiology*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D046109:Passeriformes; D012377:Rodentia; D012756:Sheep; D044366:Transition Temperature
keywords: Blood meal analysis; Canis lupus familiaris; Feeding ecology; Ixodes ricinus; Nymphs; Tick-borne disease; Vertebrate hosts