Seafood-Associated Outbreak of ctx-Negative Vibrio mimicus Causing Cholera-Like Illness, Florida, USA

Area of Science:

• Microbiology
• Infectious Diseases
• Food Safety

Background:

• Vibrio mimicus is a known cause of seafood-associated gastroenteritis.
• Outbreaks highlight the public health importance of identifying and characterizing bacterial pathogens.
• Understanding virulence factors is crucial for predicting disease severity.

Purpose of the Study:

• To characterize Vibrio mimicus strains involved in a Florida seafood-associated outbreak.
• To identify virulence determinants in these strains.
• To assess the potential for cholera-like disease caused by ctx-negative strains.

Main Methods:

• Bacterial isolation and identification from clinical and food samples.
• Molecular analysis to detect virulence genes, including cholera toxin (ctx) genes.
• Clinical data review for case-patients.

Main Results:

• Vibrio mimicus was identified as the causative agent of a seafood-associated outbreak in Florida.
• All investigated strains were negative for cholera toxin (ctx) genes.
• Strains possessed genes encoding other virulence factors such as hemolysin, proteases, and various secretion systems (types I-IV and VI).
• 4 out of 6 case-patients required hospitalization, with one needing intensive care for severe diarrhea.

Conclusions:

• Vibrio mimicus can cause significant gastrointestinal illness and cholera-like disease, even in the absence of cholera toxin.
• Virulence factors beyond cholera toxin contribute to the pathogenicity of Vibrio mimicus.
• This underscores the need for vigilant surveillance and prompt clinical recognition of Vibrio infections from seafood.