Isolation and characterization of a novel Borrelia group of tick‐borne borreliae from imported reptiles and their associated ticks

Abstract

The members of the genus Borrelia are transmitted by arthropods and known to be infectious to vertebrates. Here we found isolates and DNAs belonging to the Borrelia turcica and unknown Borrelia species from imported reptiles and their ectoparasites. The Borrelia strains were isolated from blood and multiple organs of exotic tortoises, and were experimentally infectious to captive-bred tortoises. These findings suggest that these tortoises may be a candidate as the reservoir host of the Borrelia species. In this study, the Borrelia strains were also isolated from and/or detected in hard-bodied ticks, Amblyomma ticks and Hyalomma ticks. In some of these ticks, immunofluorescence imaging analysis revealed that the Borrelia had also invaded into the tick salivary glands. Accordingly, these ticks were expected to be a potential vector of the Borrelia species. Sequencing analyses of both housekeeping genes (flaB gene, gyrB gene and 16S rDNA gene) and 23S rRNA gene-16S rRNA gene intergenic spacer region revealed that these Borrelia strains formed a monophyletic group that was independent from two other Borrelia groups, Lyme disease Borrelia and relapsing fever Borrelia. From these results, the novel group of Borrelia comprises the third major group of arthropod-transmitted borreliae identified to date.

There is inadequate evidence to support the division of the genus Borrelia

“…A major omission in the study published by Adeolu and Gupta [1] is the exclusion of a Borrelia clade containing RF-like species that utilize hard ticks as vectors and reptiles as reservoir hosts [3,4].…”

Division of the genus Borrelia into two genera (corresponding to Lyme disease and relapsing fever groups) reflects their genetic and phenotypic distinctiveness and will lead to a better understanding of these two groups of microbes (Margos et al. (2016) There is inadequate evidence to support the division of the genus Borrelia. Int. J. Syst. Evol. Microbiol. doi: 10.1099/ijsem.0.001717)

“…2) in the Adeolu and Gupta [4] article in fact includes B. turcica, which constitutes the species from this group with a validly published name and its position was indicated to be indeterminate based on the presented results. However, in the phylogenetic tree presented by Margos et al [7], which includes B. turcica and other related reptile-associated strains of Borreliaceae without taxonomic standing, these species/strains exhibit the same pattern of branching as described by Takano et al [8], which was acknowledged by Adeolu and Gupta [4]. It should be noted, however, that in other recent studies [9,10], the position of the reptile-associated Borrelia species with respect to its branching position was found to be variable.…”

Detection and characterization of zoonotic pathogens of free-ranging non-human primates from Zambia

“…All the primer sets employed in this study and PCR conditions can be found in Table 1 [8][9][10][11][12][13][14][15]. The PCR products were electrophoresed in a 1.5% agarose gel stained with Gel-Red ™ (Biotium, Hayward, CA) and were visualized under UV light.…”