Veterinary/zoology session

Borrelia burgdorferi sensu lato is maintained in nature through enzootic cycles, which involve ticks of the Ixodes ricinus species complex and a variety of vertebrate reservoir hosts. In Europe several mammal and bird species have been shown to contain the Lyme disease spirochetes. The role of some lizard species in maintaining borreliae has also recently been demonstrated. Our aim was to investigate the involvement of lizard species in the natural cycle of B. burgdorferi s.l. in Hungary.

We captured a total of 186 reptiles belonging to the species green lizard (Lacerta viridis), sand lizard (Lacerta agilis) and Balkan wall lizard (Podarcis taurica) in 2007 and 2008 at our study site near Gödöllő. Altogether 472 ticks (324 larvae and 148 nymphs) were removed from lizards. All collected specimens were later identified as Ixodes ricinus. More than half (52.4%) of green lizard individuals were infested by I. ricinus ticks and the prevalence of ticks on the other two species was 35%.

A total of 472 Ixodes ricinus ticks, 134 collar scales and 62 toe clips were collected from lizards and further analysed for the presence of B. burgdorferi sensu lato with polymerase chain reaction. Borrelial infection was detected in 10% of L. agilis, 6.38% of P. taurica and 5.76% of L. viridis tissue samples. In total 6.57% of ticks from lizards tested positive for borreliae. Prevalence of B. burgdorferi s.l. in ticks collected from L. viridis, P. taurica and L. agilis was 7.56%; 1.82% and 0%, respectively. In 2008 we had the opportunity to genotype positive samples. Restriction fragmenth length polymorphism genotyping identified B. lusitaniae in all lizard tissue samples. Most of the infected ticks carried Borrelia lusitaniae, however, B. afzelii was detected in a larva removed from a green lizard and Borrelia burgdorferi sensu stricto was found in nymphs and a larva from green lizards and in a larva from a Balkan wall lizard.

We conclude that lizards, particularly Lacerta viridis are important hosts for Ixodes ricinus larvae and nymphs, thus can be regarded as “reservoirs” of these important pathogen vectors. The role of green lizards has been confirmed and the implication of Balkan wall lizards and sand lizards can be suggested in the natural cycle of Borrelia lusitaniae at our study site.