Local variations in the distribution and prevalence of Borrelia burgdorferi sensu lato genomospecies in Ixodes ricinus ticks

Abstract

Unfed nymphal and adult Ixodes ricinus ticks were collected from five locations within the 10,000-ha Killarney National Park, Ireland. The distribution and prevalence of the genomospecies of Borrelia burgdorferi sensu lato in the ticks were investigated by PCR amplification of the intergenic spacer region between the 5S and 23S rRNA genes and by reverse line blotting with genomospecies-specific oligonucleotide probes. The prevalence of ticks infected with B. burgdorferi sensu lato was significantly variable between the five locations, ranging from 11.5 to 28.9%. Four genomospecies were identified as B. burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, and VS116. Additionally, untypeable B. burgdorferi sensu lato genomospecies were identified in two nymphs. VS116 was the most prevalent of the genomospecies and was identified in 50% of the infected ticks. Prevalences of B. garinii and B. burgdorferi sensu stricto were similar (17 and 18%, respectively); however, significant differences were observed in the prevalence of these genomospecies in mixed infections (58.8 and 23.5%, respectively). Notably, the prevalence of B. afzelii was low, comprising 9.6 and 7.4%, respectively, of single and mixed infections. Significant variability was observed in the distribution and prevalence of B. burgdorferi sensu lato genomospecies between locations in the park, and the diversity and prevalence of B. burgdorferi sensu lato genomospecies was typically associated with woodland. The distributions of B. burgdorferi sensu lato genomospecies were similar in wooded areas and in areas bordering woodland, although the prevalence of B. burgdorferi sensu lato infection was typically reduced. Spatial distributions vegetation composition, and host cenosis of the habitats were identified as factors which may affect the distribution and prevalence of B. burgdorferi sensu lato genomospecies within the park.

Diversity within sensu lato genospecies in Switzerland by gene sequence

“…However, it is in contrast with other reports showing that B. garinii is the most common genospecies in a number of countries of Central Europe and South Western Europe [2,24]. In addition, according to Kirsten et al [25], B. valaisiana is the most abundant species in Ireland, and B. lusitaniae in Tunisia [26], in Morocco [27] as well as in Portugal [28]. Summarising these different studies, B. afzelii and B. garinii appear be the most abundant genospecies in Europe, while the presence of the other genospecies differs according to the study area and are in any case less abundant.…”

The importance of passerine birds as tick hosts and in the transmission of Borrelia burgdorferi, the agent of Lyme disease: a case study from Scotland

“…Although we found no B. valaisiana , it would seem highly likely that this genospecies could occur in birds in Scotland. Borrelia valaisiana is the most commonly found genospecies in questing nymphs in Ireland (Kirstein et al. 1997), and therefore it would be possible for a bird migrating from Ireland to mainland UK to introduce infected ticks.…”

Diversity of Ixodes ricinus tick-associated bacterial communities from different forests

“…This, in combination with the fact that Borrelia species have different transmission rates in different reservoir hosts (Kurtenbach et al, 1998a), indicates that transmission of Borrelia species between ticks and reservoir hosts in nature is highly complex. Geographic differences in tick bacterial composition have been observed before (Kirstein et al, 1997;Wielinga et al, 2006). In the study by Wielinga et al, ticks were collected from four different habitats in the Netherlands during two to four successive years.…”

“…Borrelia afzelii, for example, is often the most prevalent species found in I. ricinus (Rijpkema et al, 1995;Schouls et al, 1999;Jenkins et al, 2001;Fraenkel et al, 2002;Maetzel et al, 2005;Kipp et al, 2006;Wielinga et al, 2006). However, in some studies prevalence is lower or this species is even absent (Nohlmans et al, 1995;Kirstein et al, 1997;Kurtenbach et al, 1998a, b;De Michelis et al, 2000;Lenčková et al, 2006;Fingerle et al, 2007).…”