Publication details
Detekce Borrelia burgdorferi sensu lato v klíštěti obecném (Ixodes ricinus)
| Title in English | Detection of Borrelia burgdorferi sensu lato in the tick Ixodes ricinus |
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| Authors | |
| Year of publication | 2007 |
| Type | Article in Proceedings |
| Conference | Tomáškovy dny 2007 XVI. konference mladých mikrobiologů, sborník abstraktů |
| MU Faculty or unit | |
| Citation | |
| Field | Microbiology, virology |
| Keywords | Borrelia burgdorferi; Lyme disease; genomospecies; Ixodes ricinus; PCR detection; dark-field microscopy; ticks |
| Description | Lyme disease (LD) is one of the most widespread tick borne infections in the northern hemisphere. In the Czech Republic, the mean annual incidence of LD was 32 cases per 100,000 inhabitants during the years 1990 2006 (the range, 14-61). The causative agent of LD, Borrelia burgdorferi, was isolated in the U.S.A as late as 1982. Subsequently many other isolates were reported from various sources and countries. Analyses have demonstrated a high degree of their biological heterogeneity. There are 12 genomic groups (also called genomospecies, genospecies etc.) of B. burgdorferi s.l. at present:they differ ecologically, epidemiologically, and in their potential to cause various clinical forms of LD. Three genomospecies are considered pathogenic for humans: B. burgdorferi sensu stricto, B. afzelii and B. garinii. One of the indicators, that enables us to estimate the LD risk for humans in the natural foci, is the estimation of borrelial prevalence in the tick vector. Ixodes ricinus ticks were collected by flagging at approximately monthly periods from May to November 2006 and in March 2007 on three localities in southern Moravia (Czech Republic). All the localities represent popular recreational sites. The ticks were examined by dark-field microscopy (DFM) and PCR with primers specific for the whole complex Borrelia burgdorferi s.l. One of the aims of the work was to compare these two methods. The tick population density decreased from spring to autumn. The density peaked (up to 189 ticks/100 m2) in May and June and the minimum (2,6 ticks/100 m2) was observed in August to October. The localities differed in the density of ticks. A part of the nymphs (280) was examined by DFM and another part (236) by PCR in pools of three or five individuals. The adults (100) were longitudinally dissected with a sterile lancet and a half of each individual was examined by DFM, the other half by PCR. The prevalence of borreliae in nymphal I. ricinus detected by DFM reached 10 % whereas by PCR ..%. In the case of adults the prevalence in ticks reached 18 % by DFM and 27 % by PCR. 14 % of the samples were positive by both methods, 4 % were positive by DFM and negative by PCR, 13 % were negative by DFM and positive by PCR, and 69 % were negative by both methods. The PCR positive samples will be further confirmed and the genomic groups will be identified, using the PCR-RFLP method of Postic et al. (1994). |