New Insights into Vibrio parahaemolyticus Infections: A Threat to Global Shrimp Aquaculture

Strategic Insights -

Researchers from Jeonbuk National University in Iksan, South Korea, have made significant strides in understanding the Gram-negative bacteria Vibrio parahaemolyticus, which causes Acute Hepatopancreatic Necrosis Disease (AHPND) in shrimp. This devastating disease has far-reaching implications for global shrimp aquaculture, affecting millions of dollars in revenue each year. By sequencing and analyzing the genomes of five AHPND-associated V. parahaemolyticus strains, the researchers have identified a unique genetic recombination event that contributes to the bacteria's virulence and antibiotic resistance.

Key Takeaways:

  • The researchers analyzed five AHPND-associated V. parahaemolyticus genomes, referred to as CGVP strains, which were isolated during the 2016 disease outbreak in Korea.
  • The CGVP genomes average 5.3 Mbp in size, consisting of two circular chromosomes and a 69 kbp plasmid carrying pirAB toxin genes.
  • A novel 20.6 kbp insertion in the recA gene was identified, suggesting a unique genetic recombination event that contributes to the bacteria's virulence and antibiotic resistance.
  • The phylogenetic and population analyses assigned the genomes to a clonal complex (CC) named CC 917, which exhibits high intra-complex similarity but diverges significantly from strains outside this complex.
  • The study's findings contribute to improved strategies for controlling AHPND outbreaks and mitigating impacts on shrimp aquaculture.

Statistics:

  • The CGVP genomes average 5.3 Mbp in size.
  • The recA gene insertion is 20.6 kbp in size.
  • The GC content of the unique insertion is lower than in the surrounding genome.
  • The open reading frames (ORFs) in the insertion encode for 15 proteins.
  • The clonal complex (CC) 917 exhibits 1-826 SNPs and 99.62-99.98% ANI (average nucleotide identity) within the complex.
  • The divergent strains outside of CC 917 have 20,000 SNPs.

Sources:

  • Jeonbuk National University, Biosafety Research Institute and College of Veterinary Medicine, Iksan 54596, South Korea
  • Journal of Invertebrate Pathology, Academic Press Inc, 525 B St, Ste 1900, San Diego, CA 92101-4495, USA
  • Health & Medicine Week, September 5, 2025, p 4482.