A NewBorreliaSpecies Defined by Multilocus Sequence Analysis of Housekeeping Genes

Abstract

Analysis of Lyme borreliosis (LB) spirochetes, using a novel multilocus sequence analysis scheme, revealed that OspA serotype 4 strains (a rodent-associated ecotype) of Borrelia garinii were sufficiently genetically distinct from bird-associated B. garinii strains to deserve species status. We suggest that OspA serotype 4 strains be raised to species status and named Borrelia bavariensis sp. nov. The rooted phylogenetic trees provide novel insights into the evolutionary history of LB spirochetes.Multilocus sequence typing (MLST) and multilocus sequence analysis (MLSA) have been shown to be powerful and pragmatic molecular methods for typing large numbers of microbial strains for population genetics studies, delineation of species, and assignment of strains to defined bacterial species (4,13,27,40,44). To date, MLST/MLSA schemes have been applied only to a few vector-borne microbial populations (1,6,30,37,40,41,47).Lyme borreliosis (LB) spirochetes comprise a diverse group of zoonotic bacteria which are transmitted among vertebrate hosts by ixodid (hard) ticks. The most common agents of human LB are Borrelia burgdorferi (sensu stricto), Borrelia afzelii, Borrelia garinii, Borrelia lusitaniae, and Borrelia spielmanii (7,8,12,35). To date, 15 species have been named within the group of LB spirochetes (6,31,32,37,38,41). While several of these LB species have been delineated using whole DNA-DNA hybridization (3, 20, 33), most ecological or epidemiological studies have been using single loci (5, 9-11, 29, 34, 36, 38, 42, 51, 53). Although some of these loci have been convenient for species assignment of strains or to address particular epidemiological questions, they may be unsuitable to resolve evolutionary relationships among LB species, because it is not possible to define any outgroup. For example, both the 5S-23S intergenic spacer (5S-23S IGS) and the gene encoding the outer surface protein A (ospA) are present only in LB spirochete genomes (36, 43). The advantage of using appropriate housekeeping genes of LB group spirochetes is that phylogenetic trees can be rooted with sequences of relapsing fever spirochetes. This renders the data amenable to detailed evolutionary studies of LB spirochetes.

Do the level of energy reserves, hydration status andBorreliainfection influence walking byIxodes ricinus(Acari: Ixodidae) ticks?

“…The percentage of high-fat fully hydrated (H&F), low-fat fully hydrated (L&F), and low-fat moderately hydrated (L&M) Ixodes ricinus ticks that walked towards the wet (light grey bars) or the dry end (white bars) of the arena after 2 h. common one (Casati et al 2004;Jouda et al 2004;Morán Cadenas et al 2007;Gern et al 2010;Herrmann and Gern, 2010). B. bavariensis (6·8%), formerly B. garinii OspA serotype 4, a newly described genospecies (Margos et al 2009), is reported for the first time in the area, although it was already described in Switzerland (Staatswald) (Hu et al 2001;Huegli et al 2002;Pérez et al manuscript submitted ).…”

Borrelia bavariensis sp. nov. is widely distributed in Europe and Asia

“…Phylogenetic analysis was conducted using maximum-likelihood (Tamura et al, 2011). Consistent with previous analyses (Margos et al, 2009;Scholz et al, 2013;Takano et al, 2011), European and Asian B. bavariensis sp. nov. formed a sister clade to B. garinii In this context, it is important to emphasize that giving species status to ecotypes of bacteria that form phylogenetically divergent sequence clusters (Koeppel et al, 2008) would have the advantage of being ecologically, epidemiologically and clinically predictive.…”

“…In the initial study, 10 ospA type 4 strains were included (Table 1). Here, we performed MLSA typing of additional strains isolated from human patients in Europe (Table 1) as described previously (Margos et al, 2009). This typing scheme is based on eight chromosomally located housekeeping genes, clpA, clpX, nifS, pepX, pyrG, recG, rplB and uvrA (Margos et al, 2008).…”

“…bavariensis sp. nov. was proposed as an independent species in 2009 using MLSA (Margos et al, 2009). This was based on genotypic and phenotypic differences between European ospA type 4 strains and B. garinii strains.…”

Multilocus Sequence Typing and DNA Similarity Analysis Implicates that a <i>Borrelia valaisiana</i>–related sp. Isolated in Japan is Distinguishable from European <i>B. valaisiana</i>

“…Borrelia burgdorferi (B. burgdorferi) [14] is found in North America and Europe and is pathogenic to humans. B. garinii [1], B. afzelii [5] and B. bavariensis [20] are found in Europe and East Asian countries and are also pathogenic [45]. kurtenbachii, B. finlandensis and B. yangtze) have also been reported, but the pathogenecity of these Borrelia spp.…”