An internal transcribed spacer (ITS2) sequence between the 5.8S and 28S rRNA genes was used to estimate the phyletic relationships among Ixodes spp. tick vectors of Lyme disease-causing Borrelia spirochetes. Analysis indicates that Borrelia burgdorferi sensu lato species associated with Lyme disease are found mainly in ticks of the Ixodes ricinus species complex. Other closely related tick species are not known to transmit the Borrelia-that cause Lyme disease in humans, but they appear to have a specific association with other closely related Borrelia species. There is a high degree of concordance in the phylogenetics of Borrelia taxa and the phylogenetic relationships among Ixodes ticks.

An internal transcribed spacer (ITS2) sequence between the 5.8S and 28S rRNA genes was used to estimate the phyletic relationships among Ixodes spp. tick vectors of Lyme disease-causing Borrelia spirochetes. Analysis indicates that Borrelia burgdorferi sensu lato species associated with Lyme disease are found mainly in ticks of the Ixodes ricinus species complex. Other closely related tick species are not known to transmit the Borrelia-that cause Lyme disease in humans, but they appear to have a specific association with other closely related Borrelia species. There is a high degree of concordance in the phylogenetics of Borrelia taxa and the phylogenetic relationships among Ixodes ticks.

We report a case of Lyme borreliosis. Culture of skin biopsy was positive for Borrelia garinii, despite repeated prior treatment with antibiotics. The patient had travelled in Europe 17 months before the onset of symptoms, but the clinical details indicate that the organism could have been acquired in Australia. The results of conventional serological and histopathological tests were negative, despite an illness duration of at least two years. (MJA 1998; 168: 500-502)

Sequences of two internally transcribed spacer regions between 18S and 28S rRNA genes were determined to assess the phylogenetic relationship in the strains belonging to the genus Saccharomyces. The sequences of S. bayanus and S. pastorianus were quite similar, but not identical. Two phylogenetic trees constructed by the neighbor‐joining method showed that all the species examined were distinguished from one another. The Saccharomyces sensu stricto species: S. cerevisiae, S. bayanus, S. paradoxus and S. pastorianus, were closely related and far from the Saccharomyces sensu lato species including S. barnetti, S. castellii, S. dairensis, S. exiguus, S. servazzii, S. spencerorum and S. unisporus, and an outlying species, S. kluyveri. © 1997 John Wiley & Sons, Ltd.

The seabird tick Ixodes uriae (Acari: Ixodidae) has a bi- and circumpolar distribution and is commonly infected with Lyme disease Borrelia. Identical Borrelia flagellin gene sequences have been detected in I. uriae from both the Northern and Southern Hemispheres, suggesting a transequatorial transport of Borrelia. Parsimony analysis of the internal transcribed spacer 2 (ITS2) and a part of 16S rDNA of I. uriae from the Northern and Southern Hemispheres indicated that northern and southern I. uriae might be reproductively separated. We hypothesize that Borrelia is probably not dispersed from one hemisphere to the other by ticks attached to seabirds.