Whole-Genome Sequence of Borrelia garinii Strain 935T Isolated from Ixodes persulcatus in South Korea.

We report here the genome sequence of Borrelia garinii strain 935T isolated from Ixodes persulcatus in South Korea. The 1,176,739 bp (G+C content, 27.73%) genome consists of 1,194 coding regions, 4 rRNA genes, and 33 aminoacyl-tRNA synthetase genes. This is the first whole-genome report of a Korean Borrelia species isolate.

GENOME ANNOUNCEMENT

Lyme disease is a tick-borne zoonotic disease caused by members of the Borrelia burgdorferi sensu lato complex. The group is composed of approximately 20 species, including B. burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, Borrelia valaisiana, and Borrelia lusitaniae (1–4). The Borrelia species are mainly transmitted by Ixodes species, including I. ricinus and I. persulcatus in Europe, I. persulcatus and I. nipponensis in Asia, and I. scapularis and I. pacificus in North America (5–7). In South Korea, the Borrelia species were isolated in 1993 from I. persulcatus and Apodemus agrarius (8, 9).

The Korean B. garinii 935T strain was isolated from I. persulcatus in the northern part of South Korea (9). The strain was analyzed by Western blotting using monoclonal antibodies directed to various outer surface protein A (OspA) of other strains and the OspA of the Korean B. garinii 935T strain. Compared to the OspA of other isolates, that of the Korean B. garinii 935T strain was smaller and reacted with a unique antibody. These results indicate that the Korean B. garinii 935T strain is distinct in antigenicity from other Borrelia species strains (9, 10). In this study, the whole-genome sequencing of the Korean B. garinii 935T strain was performed for genetic characterization.

Total genomic DNA was purified using the G-spin total DNA extraction kit (iNtRON, South Korea) and sequenced using PacBio CLR sequencing technology on the PacBio RSII machine. The sequencing read quality was 0.8. The de novo assembly results for preassembly, scaffolding, and consensus polishing were analyzed by SMRT 2.1. Gene prediction was performed using Glimmer 3.02. During preassembly, 565.5 Mbp were filtered from a total of 772.6 Mbp of PacBio CLR reads. The mean read length for the genome was 10,349 bp. The genome was sequenced to 330× genome coverage.

The draft genome, comprising 1,176,739 bp with 27.73% G+C content, was annotated by the Rapid Annotations using Subsystems Technology (RAST) system server (11). A total of 1,194 coding regions were found in the genome, of which 830 (70%) were functionally annotated. The genome contains 4 rRNA genes and 33 aminoacyl-tRNA synthetase genes. The genome coding density is 86%, with an average gene length of 851 bp; 589 genes are transcribed from the positive strand and 605 from the negative strand. The annotated genome has 22 genes involved in virulence, disease, and defense, including eight genes for resistance to antibiotics and toxic compounds. Twenty genes are involved in the bacterial stress response, including five genes for oxidative stress and four genes that function to protect against osmotic stress.

RAST annotation indicated that strains B. garinii PBi (score, 520), B. afzelii PKo (score, 451), and B. burgdorferi B31 (score, 412) are the closest neighbors of the Korean B. garinii 935T strain.

This genome sequence will be a useful data set for understanding B. burgdorferi diversity and provide a functional platform for investigating the pathogenesis of Lyme disease.

Nucleotide sequence accession numbers.

The whole-genome sequence of the B. garinii 935T strain has been deposited in GenBank under the accession number JJNU00000000 (scaffold4/0, JJNU01000001; scaffold4/1, JJNU01000002; scaffold4/2, JJNU01000003; scaffold4/3, JJNU01000004; scaffold4/4, JJNU01000005; scaffold4/5, JJNU01000006; scaffold4/6, JJNU01000007).