Vector Competence of Ixodes scapularis and Ixodes ricinus (Acari: Ixodidae) for Three Genospecies of Borrelia burgdorferi

Abstract

The vector competence of 2 tick species, Ixodes ricimis (L.) and Ixodes scapularis Say, was determined and compared for 3 genospecies of Borrelia burgdorferi. The 3 genospecies of B. burgdorferi used in the following experiments were Borrelia burgdorferi sensu stricto (B-31 and B-31.D1 clone), Borrelia afzelii (strain Pgau.C3), and Borrelia garinii (strain VS286 and VSBP). Spirochetes from all 5 strains were inoculated intradermally into outbred mice; larval ticks of both species were subsequently fed on those mice and replete larvae were assayed for infection by culture in BSK-H media every 7 d for 4 wk. Infection frequencies in I. scapularis exposed to the 5 strains were as follows: B-31 (90%), B-31.D1 (83%), Pgau.C3 (87%), VS286 (10%), and VSBP (5%). The comparable infection frequencies for /. ricinus were B-31 (3%), B-31.D1 (3%), Pgau.C3 (90%), VS286 (5%), and VSBP (3%). Resultant nymphal /. scapularis successfully transmitted B-31, B-31.D1, Pgau.C3, and VS286 to outbred mice. /. ricinus nymphs transmitted Pgau.C3 and VS286. Both species failed to transmit strain VSBP.

Comparative genetic diversity of Lyme disease bacteria in Northern Californian ticks and their vertebrate hosts

“…genospecies such as western fence lizards (S. occidentalis) that are refractory to B. burgdorferi (Kurtenbach et al, 2002b). Similarly, there is evidence that compatibility and transmission efficiency can also vary with vector-pathogen associations (Dolan et al, 1998). Particular B. burgdorferi s.s. outer surface protein C (OspC) or rrs-rrl genotypes that are found only in certain vertebrate hosts may reflect the presence of host-specific pathogen compatibility as well (Brisson, 2004;Girard et al, 2009).…”

Coinfections Acquired from Ixodes Ticks

“…On the West Coast of the United States, the primary vector is a morphologically similar species, Ixodes pacificus (107,163,164). In Europe, including the British Isles, I. ricinus is the primary vector for LD, HA, and probably babesiosis (43,56,68,71,77,188,208), but it is largely replaced by I. persulcatus in Eastern Europe and Asia (6,37,203).…”

Identification of Three Clinically Relevant Borrelia burgdorferi Sensu Lato Genospecies by PCR-Restriction Fragment Length Polymorphism Analysis of 16S-23S Ribosomal DNA Spacer Amplicons

“…The principal vectors of B. burgdorferi sensu lato are ticks of the Ixodes ricinus complex (2). Two tick species, I. ricinus and Ixodes persulcatus, are present in Latvia, and vector competence for these two species has been experimentally confirmed (3,5,8,10,24,28). Identification of the pathogenic B. burgdorferi species in ticks has epidemiological importance, since they are prime factors in determining the risk of acquiring LB and its clinical presentation.…”