Genetic and virulence characterisation of Vibrio parahaemolyticus isolated from Indian coast

Abstract

Background: V. parahaemolyticus is autochthonous to the marine environment and causes seafood-borne gastroenteritis in humans. Generally, V. parahaemolyticus recovered from the environment and/or seafood is thought to be non-pathogenic and the relationship between environmental isolates and acute diarrhoeal disease is poorly understood. In this study, we explored the virulence potential of environmental V. parahaemolyticus isolated from water, plankton and assorted seafood samples collected from the Indian coast. Results: Twenty-two V. parahaemolyticus isolates from seafood harboured virulence associated genes encoding the thermostable-direct haemolysin (TDH), TDH-related haemolysin (TRH), and Type 3 secretion systems (T3SS) and 95.5% of the toxigenic isolates had pandemic strain attributes (toxRS/new + ). Nine serovars, with pandemic strain traits were newly identified and an O4:K36 tdh − trh + V. parahaemolyticus bearing pandemic marker gene was recognised for the first time. Results obtained by reverse transcription PCR showed trh, T3SS1 and T3SS2β to be functional in the seafood isolates. Moreover, the environmental strains were cytotoxic and could invade Caco-2 cells upon infection as well as induce changes to the tight junction protein, ZO-1 and the actin cytoskeleton. Conclusion:Our study provides evidence that environmental isolates of V. parahaemolyticus are potentially invasive and capable of eliciting pathogenic characteristics typical of clinical strains and present a potential health risk. We also demonstrate that virulence of this pathogen is highly complex and hence draws attention for the need to investigate more reliable virulence markers in order to distinguish the environmental and clinical isolates, which will be crucial for the pathogenomics and control of this pathogen.

Prophage-encoded gene VpaChn25_0734 amplifies ecological persistence of Vibrio parahaemolyticus CHN25

“…It was estimated that more than 50% of foodborne gastrointestinal-Vibriosis cases were caused by V. parahaemolyticus in the United States (Karan et al 2021 ), which led to 45,000 illnesses each year ( https://www.cdc.gov/Vibrio/ , accessed on 26 April 2021). Sporadic outbreaks have also been reported in coastal European nations (Meparambu Prabhakaran et al 2020 ). China is one of the 15 countries with high incidence of diarrhea disease (Walker et al 2013 ).…”

“…The bacterium was first identified from semidried juvenile sardines in 1950 in Japan, which caused 272 cases of acute diarrhea and 20 death (Fujino et al 1953 ). Afterward, outbreaks of human gastroenteritis caused by V. parahaemolyticus occurred in many Asian nations and consequently around the world (Elmahdi et al 2016 ; Meparambu Prabhakaran et al 2020 ). It was estimated that more than 50% of foodborne gastrointestinal-Vibriosis cases were caused by V. parahaemolyticus in the United States (Karan et al 2021 ), which led to 45,000 illnesses each year ( https://www.cdc.gov/Vibrio/ , accessed on 26 April 2021).…”

“…Afterward, outbreaks of human gastroenteritis caused by V. parahaemolyticus occurred in many Asian nations and consequently around the world (Elmahdi et al 2016;Meparambu Prabhakaran et al 2020). It was estimated that more than 50% of foodborne gastrointestinal-Vibriosis cases were caused by V. parahaemolyticus in the United States (Karan et al 2021), which led to 45,000 illnesses each year (https:// www.…”

Distribution and expression of virulence genes in potentially pathogenic bacteria isolated from seafood in Thailand

“…Although the tlh gene is considered species-specific for V. parahaemolyticus, it is also widespread in other vibrios including Vibrio alginolyticus, Vibrio anguillarum, Vibrio diabolicus, Vibrio fischeri, Vibrio harveyi, Vibrio mimicus, Vibrio natriegens, Vibrio proteolyticus, and Vibrio vulnificus (Wang et al, 2007;Xie et al, 2005;Yanez et al, 2015). The tlh gene was employed for molecular confirmation of 22 V. parahaemolyticus isolates from seafood in the south-west coast of India (Meparambu Prabhakaran et al, 2020) and 104 V. parahaemolyticus isolates from seafood in Polish market (Lopatek et al, 2018). The association of virulence genes with outbreaks caused by V. parahaemolyticus Table 3.…”

Genotypic Diversity and Pathogenic Potential of Clinical and Environmental Vibrio parahaemolyticus Isolates From Brazil

“…Moreover, these genes have also been detected in nonclinical isolates of the bacterium worldwide (Robert-Pillot et al, 2004;Johnson et al, 2012;Gutierrez West et al, 2013;Prabhakaran and Ramamurthy, 2020). Therefore, the pathogenesis of V. parahaemolyticus has not been fully elucidated, and other as yet unidentified virulence-related factors might be required for the establishment of infection.…”