Abstract:
Objective This study aims to investigate the pathogenicity of Vibrio parahaemolyticus serotype O4: KUT in BALB/c mice, with specific focus on the induced pathological damage and host immune responses during acute infection.
Methods The virulence genes of the strain (ICDC-VP01716) were identified using PCR. Subsequently, BALB/c mice were infected with 1.0×109 colony forming unit of the strain via oral gavage. After 4 hours of infection, the mice were euthanized to observe pathological changes in the colon, and transcriptional analysis was performed on the colonic tissue to study the host's immune response.
Results The ICDC-VP01716 carries two toxin genes, tdh and tlh, as well as some effector genes of T3SS1 and T3SS2, and adhesion-related virulence genes such as mam7 and vpadF. After high-dose infection for 4 hours, BALB/c mice exhibited mild colonic swelling and intestinal fluid accumulation. Transcriptional analysis indicated that the host rapidly activated immune-related pathways and signaling molecules, as well as pathways involved in cellular interactions, within 4 hours of infection.
Conclusion The ICDC-VP01716 possesses a virulence gene profile similar to other clinical isolates. High-dose infection with this strain induces clinical manifestations in mice that resemble human diarrhea, further confirming its pathogenic potential as a clinical isolate.