Multilocus Sequence Typing Tool for Cyclospora cayetanensis

Abstract

Because the lack of typing tools for Cyclospora cayetanensis has hampered outbreak investigations, we sequenced its genome and developed a genotyping tool. We observed 2 to 10 geographically segregated sequence types at each of 5 selected loci. This new tool could be useful for case linkage and infection/contamination source tracking.

Keywords: Cyclospora cayetanensis; molecular epidemiology; multilocus sequence typing; parasites; protozoa; whole genome sequencing.

Figure 1

Phylogenetic relationships among sequence types of Cyclospora cayetanensis at 5 microsatellite loci: A) CYC3, B) CYC13, C) CYC15, D) CYC21, and E) CYC22. Tree was constructed on the basis of neighbor-joining analyses of the nucleotide sequences, using genetic distances calculated by the Kimura 2-parameter model. Numbers on branches are bootstrap values from 1,000 replicate analyses. Only values >50% are displayed on the left of each node. Scale bars indicate substitution rates per nucleotide. HN, Henan.

Figure 2

Phylogenetic relationships among concatenated multilocus sequence types of Cyclospora cayetanensis as assessed by a neighbor-joining analysis of the nucleotide sequences, using genetic distances calculated by the Kimura 2-parameter model. Numbers on branches are bootstrap values from 1,000 replicate analyses. Only values >50% are displayed on the left of each node. Scale bar indicates substitution rates per nucleotide. HN, Henan.