Red Foxes (<i>Vulpes vulpes</i>) Are Exposed to High Diversity of <i>Borrelia burgdorferi</i> Sensu Lato Species Infecting Fox-Derived <i>Ixodes</i> Ticks in West-Central Poland

The role of red fox, Vulpes vulpes, and its associated ticks in maintaining Borrelia burgdorferi sensu lato (s.l.) was studied. A total of 1583 ticks were removed from ears of 120 infested animals and were identified as species using a nested PCR targeting the ITS2 and coxI fragments of Ixodes DNA. Ixodes kaiseri prevailed (76%), followed by I. canisuga, I. ricinus, and I. hexagonus. In total, 32.4% of 943 ticks revealed Borrelia DNA and 10 species of B. burgdorferi s.l. complex were identified. Borrelia garinii and B. afzelii comprised 70% of all infections. The other eight species included B. americana, B. bissettiae, B. burgdorferi sensu stricto (s.s.), B. californiensis, B. carolinensis, B. lanei, B. spielmanii, and B. valaisiana. Analysis of tissues from 243 foxes showed that 23.5% were infected with B. burgdorferi s.l. Borrelia garinii was detected in 91% of the infected animals, including 31% of mixed infections with B. afzelii, the second most prevalent species, followed by B. spielmanii. The predominance of B. garinii in PCR-positive animals and infected larval ticks (38.1%), suggests that this spirochete and B. afzelii are preferentially associated with foxes. Although red foxes are exposed to a high diversity of B. burgdorferi s.l. species found in engorged Ixodes ticks, their reservoir competence for most of them appears to be low

The YJL185C, YLR376C and YJR129C genes of Saccharomyces cerevisiae are probably involved in regulation of the glyoxylate cycle

The ER24 aci (acidification) mutant of Saccharomyces cerevisiae excreting protons in the absence of glucose was transformed with a multicopy yeast DNA plasmid library. Three different DNA fragments restored the wild-type phenotype termed Aci- because it does not acidify the complete glucose medium under the tested conditions. Molecular dissection of the transforming DNA fragments identified two multicopy suppressor genes YJL185C, YJR129C and one allelic YLR376C. Disruption of either of the three genes in wild-type yeast strain resulted in acidification of the medium (Aci+ phenotype) similarly to the original ER24 mutant. These data indicate the contribution of the ER24 gene product Ylr376Cp and of the two suppressor gene products Yjl185Cp and Yjr129Cp to a complex regulation of the glyoxylate cycle in yeast