Host races in Ixodes ricinus, the European vector of Lyme borreliosis

• Published in: Infection, genetics and evolution genetics and evolution, 2011-12, Vol.11 (8), p.2043-2048
• Main Authors: Kempf, Florent, De Meeûs, Thierry, Vaumourin, Elise, Noel, Valérie, Taragel’ová, Veronika, Plantard, Olivier, Heylen, Dieter J.A., Eraud, Cyril, Chevillon, Christine, McCoy, Karen D.
• Format: Article
• Language: English
• Subjects: Animals; Animals, Wild - microbiology; Animals, Wild - parasitology; Arachnid Vectors - genetics; Arachnid Vectors - microbiology; bacteria; Bacterial diseases; Biodiversity; Biological and medical sciences; birds; Borrelia burgdorferi; Borrelia burgdorferi - genetics; Borrelia infections; Capreolus capreolus; Epidemiology. Vaccinations; Europe - epidemiology; General aspects; Generalist–specialist; Genetic Markers; genetic variation; Genotype; Host specialization; host specificity; Human bacterial diseases; Humans; Infectious diseases; Ixodes - genetics; Ixodes - microbiology; Ixodes ricinus; Life Sciences; lizards; Lyme disease; Lyme Disease - epidemiology; Lyme Disease - genetics; Lyme Disease - microbiology; Lyme Disease - transmission; Medical sciences; Microsatellite Repeats; Microsatellites; pathogens; Polymorphism, Genetic; races; rodents; Systematics, Phylogenetics and taxonomy; Ticks; Tropical bacterial diseases; Vector-borne diseases; wild boars
• ISSN: 1567-1348; 1567-7257
• DOI: 10.1016/j.meegid.2011.09.016

► We genetically characterize 598 Ixodes ricinus ticks from diverse host species. ► We test for genetic structure among host types and individuals within populations. ► Host-associated races are evident, but structure varies among populations. ► The presence of local vector races has notable implications for disease epidemiology. Ixodes ricinus is a European tick that transmits numerous pathogenic agents, including the bacteria that cause Lyme disease (some genospecies of Borrelia burgdorferi sensu lato complex). This tick has been considered as a classic example of an extreme generalist vector. However, host-associations in such vector species are difficult to determine from field observations alone and recent work suggests that host specificity may be more frequent in ticks than previously thought. The presence of host-associated vector groups can significantly alter the circulation and evolutionary pathway of associated pathogens. In this paper, we explicitly test for host-associated genetic structure in I. ricinus. We analyzed genetic variability at 11 microsatellite markers in a large sample of ticks collected directly from trapped wild animals (birds, rodents, lizards, wild boar and roe deer) at five sites in Western and Central Europe. We found significant levels of genetic structure both among host individuals and among host types within local populations, suggesting that host use is not random in I. ricinus. These results help explain previous patterns of structure found in off-host tick samples, along with epidemiological observations of Lyme disease.