Pathogenic Vibrio parahaemolyticus indiarrhoeal patients, fish and aquatic environments and their potential for...

Area of Science:

• Microbiology
• Food Safety
• Environmental Science

Background:

• Vibrio parahaemolyticus is a known cause of diarrheal disease.
• Detailed investigation of phenotypic and genetic traits of V. parahaemolyticus from diverse sources is lacking.
• Understanding pathogen reservoirs is crucial for public health.

Purpose of the Study:

• To screen clinical, fish, and environmental samples for V. parahaemolyticus.
• To identify pathogenic strains using virulence genes like tdh.
• To analyze pandemic strain markers, serovars, and genetic relatedness across different sources.

Main Methods:

• Screening of 2603 diarrheal cases, 301 brackish water fish, and 115 aquatic environment samples.
• Detection of virulence (tdh) and pandemic strain marker (toxRS, PGS-sequences) genes.
• Serotyping and Pulsed Field Gel Electrophoresis (PFGE) for genetic relatedness analysis.

Main Results:

• V. parahaemolyticus identified in 1.1% of clinical, 56.8% of fish, and 37.4% of water samples.
• Pathogenic V. parahaemolyticus with tdh gene more prevalent in fish (19.3%) and water (15.6%) than clinical samples (1.04%).
• Classical (O3:K6) and new pandemic serovars identified; PFGE showed 60-85% clonal relatedness between sources.

Conclusions:

• Brackish water fish and aquatic environments serve as significant reservoirs for pathogenic V. parahaemolyticus.
• The emergence of new pandemic serovars indicates evolving phenotypic characteristics of the pathogen.
• Findings highlight the need for integrated surveillance of V. parahaemolyticus in food and environmental sources.