P2-223 The Complete Mitochondrial Genome of the Foodborne Parasitic Pathogen Cyclospora cayetanensis

Monday, July 27, 2015
Exhibit Hall (Oregon Convention Center)
Hediye Nese Cinar , U.S. Food and Drug Administration , Laurel , MD
Gopal Gopinath , U.S. Food and Drug Administration , Laurel , MD
Karen Jarvis , U.S. Food and Drug Administration , Laurel , MD
Dajung Choi , US Food and Drug Administration , Laurel , MD
Seulgi Lee , Food and Drug Administration , Laurel , MD
Alexandre DaSilva , U.S. Food and Drug Administration , Laurel , MD
Helen Murphy , Food and Drug Administration , Laurel , MD
Introduction: Cyclospora cayetanensis is a coccidian parasite responsible for waterborne and large scale foodborne outbreaks worldwide. In the U.S., the two most recent diarrhea outbreaks caused by C. cayetanensis were solely associated with the consumption of fresh produce and sickened 631 and 304 persons in 2013 and 2014, respectively.

Purpose: In different apicomplexan parasites multicopy organellar DNA such as mitochondrion genomes have been used for detection and genetic traceback analysis. A complete C. cayetanensis mitochondrial genome sequence was obtained in this study and it will be used to design alternative molecular methods for enhanced detection and characterization of the parasite.

Methods: We sequenced the C. cayetanensis genomic DNA obtained from stool samples from patients infected with Cyclospora in Nepal using the Illumina MiSeq platform. By the use of bioinfiormatics the metagenomic reads of non-coccidian origin sequences were filtered out and by targeted alignment, we were able to obtain contigs containing Eimeria-like mitochondrial, apicoplastic and chromosomal genomic fragments.

Results: A complete Cyclospora mitochondrial genome was assembled and confirmed by sequencing of cloned PCR amplicons obtained with primers designed on the basis of the draft assembly sequence. The results show that the C. cayetanensis mitochondrion genome is 6274 bp long, with a 33% GC content and appears to exist in concatemeric arrays, similar to Eimeria spp. mitochondrial genomes. Phylogenetic analysis of the C. cayetanensis mitochondrial genome placed this organism in closely related cluster with Eimeria species.  The mitochondrial genome of C. cayetanensis contains coding genes for Cytochrome B (cytb), Cytochrome C oxidase subunit 1(cox1), and Cytochrome C oxidase subunit 3 (cox3) in addition to 14 large subunit (LSU) and nine small subunit (SSU) fragmented rRNA genes. 

Significance: The complete mitochondrial genome sequence presented here will provide novel molecular targets for detection and characterization of C. cayetanensis during foodborne outbreaks.