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Multi-locus sequence analysis reveals profound genetic diversity among isolates of the human pathogen Bartonella bacilliformis.

Chaloner GL - PLoS Negl Trop Dis (2011)

Bottom Line: MLST identified eight sequence types among these isolates and the delineation of these was generally congruent with those of the previously described typing scheme.Phylogenetic analysis based on concatenated sequence data derived from MLST loci revealed that seven of the eight sequence types were closely related to one another; however, one sequence type, ST8, exhibited profound evolutionary divergence from the others.The extent of this divergence was akin to that observed between other members of the Bartonella genus, suggesting that ST8 strains may be better considered as members of a novel Bartonella genospecies.

View Article: PubMed Central - PubMed

Affiliation: Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom. g.chaloner@liv.ac.uk

ABSTRACT
Bartonella bacilliformis is the aetiological agent of human bartonellosis, a potentially life threatening infection of significant public health concern in the Andean region of South America. Human bartonellosis has long been recognised in the region but a recent upsurge in the number of cases of the disease and an apparent expansion of its geographical distribution have re-emphasized its contemporary medical importance. Here, we describe the development of a multi-locus sequence typing (MLST) scheme for B. bacilliformis and its application to an archive of 43 isolates collected from patients across Peru. MLST identified eight sequence types among these isolates and the delineation of these was generally congruent with those of the previously described typing scheme. Phylogenetic analysis based on concatenated sequence data derived from MLST loci revealed that seven of the eight sequence types were closely related to one another; however, one sequence type, ST8, exhibited profound evolutionary divergence from the others. The extent of this divergence was akin to that observed between other members of the Bartonella genus, suggesting that ST8 strains may be better considered as members of a novel Bartonella genospecies.

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Splits decomposition was used to detect evidence for a past history of recombination in the sequences.The extensive reticulation suggests that recombination has occurred relatively frequently. However, ST 8 remains distinct.
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pntd-0001248-g002: Splits decomposition was used to detect evidence for a past history of recombination in the sequences.The extensive reticulation suggests that recombination has occurred relatively frequently. However, ST 8 remains distinct.

Mentions: Sequence comparison not only confirmed ST8 to be outlying to the other B. bacilliformis STs, but also demonstrated the extent of dissimilarity between this and other STs (Table 3). Among STs 1–7, only 37 variable positions (1.3%) among the 2951 bp of sequence data were observed, whereas among STs 1–8 this number rose to 157 (5.3%) (Table 3). Phylogenetic analysis, inferred from alignment of concatenated sequence data for all seven loci (2951 bp) confirmed the profound divergence of isolates belonging to ST8 from all other B. bacilliformis isolates studied (Figure 2). This dendrogram, inferred using splits decomposition analysis, is also characterised by a network structure that suggests recombination has influenced the divergence of B. bacilliformis STs. This suggestion is supported by the results of a phi test, which also indicated significant evidence for recombination (P = 0.042).


Multi-locus sequence analysis reveals profound genetic diversity among isolates of the human pathogen Bartonella bacilliformis.

Chaloner GL - PLoS Negl Trop Dis (2011)

Splits decomposition was used to detect evidence for a past history of recombination in the sequences.The extensive reticulation suggests that recombination has occurred relatively frequently. However, ST 8 remains distinct.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3139668&req=5

pntd-0001248-g002: Splits decomposition was used to detect evidence for a past history of recombination in the sequences.The extensive reticulation suggests that recombination has occurred relatively frequently. However, ST 8 remains distinct.
Mentions: Sequence comparison not only confirmed ST8 to be outlying to the other B. bacilliformis STs, but also demonstrated the extent of dissimilarity between this and other STs (Table 3). Among STs 1–7, only 37 variable positions (1.3%) among the 2951 bp of sequence data were observed, whereas among STs 1–8 this number rose to 157 (5.3%) (Table 3). Phylogenetic analysis, inferred from alignment of concatenated sequence data for all seven loci (2951 bp) confirmed the profound divergence of isolates belonging to ST8 from all other B. bacilliformis isolates studied (Figure 2). This dendrogram, inferred using splits decomposition analysis, is also characterised by a network structure that suggests recombination has influenced the divergence of B. bacilliformis STs. This suggestion is supported by the results of a phi test, which also indicated significant evidence for recombination (P = 0.042).

Bottom Line: MLST identified eight sequence types among these isolates and the delineation of these was generally congruent with those of the previously described typing scheme.Phylogenetic analysis based on concatenated sequence data derived from MLST loci revealed that seven of the eight sequence types were closely related to one another; however, one sequence type, ST8, exhibited profound evolutionary divergence from the others.The extent of this divergence was akin to that observed between other members of the Bartonella genus, suggesting that ST8 strains may be better considered as members of a novel Bartonella genospecies.

View Article: PubMed Central - PubMed

Affiliation: Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom. g.chaloner@liv.ac.uk

ABSTRACT
Bartonella bacilliformis is the aetiological agent of human bartonellosis, a potentially life threatening infection of significant public health concern in the Andean region of South America. Human bartonellosis has long been recognised in the region but a recent upsurge in the number of cases of the disease and an apparent expansion of its geographical distribution have re-emphasized its contemporary medical importance. Here, we describe the development of a multi-locus sequence typing (MLST) scheme for B. bacilliformis and its application to an archive of 43 isolates collected from patients across Peru. MLST identified eight sequence types among these isolates and the delineation of these was generally congruent with those of the previously described typing scheme. Phylogenetic analysis based on concatenated sequence data derived from MLST loci revealed that seven of the eight sequence types were closely related to one another; however, one sequence type, ST8, exhibited profound evolutionary divergence from the others. The extent of this divergence was akin to that observed between other members of the Bartonella genus, suggesting that ST8 strains may be better considered as members of a novel Bartonella genospecies.

Show MeSH
Related in: MedlinePlus