Vibrio parahaemolyticus is an important gastrointestinal pathogen that can cause illness after the consumption of raw or undercooked contaminated seafood (Ronholm et al., 2016; Chung et al., 2018). Vibrio parahaemolyticus carries multiple virulence genes, such as thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (trh) genes (Lüdeke et al., 2015; Guin et al., 2019). These genes were considered indicators of pathogenicity for V. parahaemolyticus, which exerts an enterotoxic effect on the intestinal cells of affected mammals (Letchumanan et al., 2015; Ahn et al., 2016). This work presents the complete genome sequence of V. parahaemolyticus MFDS1020133, the causative agent of a food poisoning incident in Busan, South Korea, in 2021. The virulent strain, isolated from raw fish and detected using real-time PCR, was identified during a food poisoning investigation managed by the Ministry of Food and Drug Safety (MFDS, South Korea). MFDS1020133 isolate was then incubated on tryptic soy agar containing 2% (w/v) sodium chloride overnight at 37°C. The total genomic DNA of MFDS1020133 was extracted using a Blood and Tissue Kit (Qiagen) following manufacturer’s protocol. The genomic DNA was qualitatively and quantitatively assessed using a NanoDrop 2000 UV-visible spectrophotometer (Thermo Fisher Scientific) and a Qubit 3.0 Fluorometer (Invitrogen), respectively. The qualified genomic DNA was then sheared fragments approximately 8 to 15 kb in size using G-tube device (Covaris). Subsequently, the sheared genomic DNA was used to perform PacBio library utilizing the template preparation kit 2.0 (Pacific Biosciences). The library was sequenced using a Sequel Binding Kit 3.0 and Sequencing kit 3.0 on a single-molecule real-time (SMRT Cell 1M v3) cell. The raw sequence reads were de novo assembled using the PacBio SMRT analysis system by HGAP2 assembler (version 8; Pacific Bioscience). The total number of reads produced was 5,178,451 bp with N50 of 3,086,349. The final assembly had a coverage of 169X. The genome was annotated using Bacterial and Viral Bioinformatics Resource Center (BV-BRC, v3.32.13.a) web server (Wattam et al., 2017). Virulence –associated genes were predicted using the Virulence Factor Database (VFDB) (Liu et al., 2019) and PATRIC_VF (Snyder et al., 2007). The complete genome sequence of V. parahaemolyticus MFDS1021033 comprises three contigs of 238,675 bp, 3,086,349 bp and 1,853,427, with G + C contents 46.8%, 45.0% and 45.4, respectively. Each contig has 201, 2,941 and 1,715 CDSs. There are 131 tRNAs (28, 89, and 14) and 32 rRNAs (13, 16, and 3) in the chromosome (Table 1). Genetic virulence analysis were identified thermolabile hemolysin (tlh), flagellum-related genes, type 3 secretion system (T3SS), and type 6 secretion system (T6SS) virulence genes in MFDS1020133. The T3SS comprising 33 genes and located on contig 2, and the T6SS comprising 36 genes and located on contig 2 or 3 may play an important role in the strong pathogenicity of V. parahaemolyticus (Table 1). This strain did not have primary virulence factors associated with V. parahaemolyticus illness, such as tdh and trh, alothough tlh were identified. Complete genome information of V. parahaemolyticus MFDS1020133 will be useful for further investigation of this food-borne pathogen and provides a genetic basis for a more detailed analysis of its virulence factors.

Table 1

Genome features of V. parahaemolyticus MFDS1020133

Genomic features	Contig 1	Contig 2	Contig 3	Total
Statistics
Total genome size (bp)	238,675	3,086,349	1,853,427	5,178,451
GC contents (%)	46.8	45.0	45.4	45.3
Total number of CDSs	201	2,941	1,715	4,857
rRNA genes	13	16	3	32
tRNA genes	28	89	14	131
Virulence factor
tlh genes	-	-	1	1
T3SS	-	33	-	33
T6SS	-	17	19	36

Nucleotide sequence accession numbers

The complete genome sequence of Vibrio parahaemolyticus MFDS1021033 has been deposited in the NCBI GenBank database under the accession numbers JAZBVV000000000 (chromosome, MFDS1021033), and the strain has been deposited in the Korean Culture Collection for Foodborne Pathogens under strain number MFDS1021033.

장염비브리오균은 해산물을 날 것이나 덜 익혀서 섭취하였을 때 인체에 질병을 발생시키는 식품매개균이다. 본 연구에서는 2021년 부산에서 발생한 식중독 사고의 원인식품으로 추정되는 전어회로부터 분리된 Vibrio parahaemolyticus MFDS1021033의 유전체 분석을 수행하였다. Vibrio parahaemolyticus MFDS1021033는 병원성 관련 유전자는 열불안정성 용혈독(tlh), type Ⅲ secretion system (T3SS) 및 type Ⅵ secretion system (T6SS) 등이 확인되었다. 유전자 총 수 예측 결과, 4,857개의 CDSs, 131개의 tRNA, 32개의 rRNA를 보유한 것으로 나타났다.

This research was financially supported by the Ministry of Food and Drug Safety, Republic of Korea (23194MFDS016).

The authors have no conflict of interest to report.