Comparative Survival and the Cold-Induced Gene Expression of Pathogenic and Nonpathogenic Vibrio Parahaemolyticus from Tropical Eastern Oysters during Cold Storage.

Francisco Alarcón Elvira,Argel Flores Primo,Rodolfo Quintana Castro,David Martínez Herrera,Karen Ramírez Elvira,Rosa María Oliart Ros,Karla López Hernández,Violeta T Pardío Sedas

doi:10.3390/ijerph17061836

Francisco Alarcón Elvira, Argel Flores Primo + Show 6 more

Open Access

https://doi.org/10.3390/ijerph17061836

Copy DOI

Abstract

Expression of the regulatory stress rpoS gene controls the transcription of cspA genes, which are involved in survival and adaptation to low temperatures. The purpose of this study was to assess the growth kinetics of naturally occurring V. parahaemolyticus in shellstock oysters and in vitro and the cold-shock-induced expression of the rpoS and cspA gene response in vitro during postharvest refrigeration. Naturally contaminated eastern oysters (Crassostrea virginica) and pathogenic (Vp-tdh) and nonpathogenic (Vp-tlh) isolates were stored at 7 ± 1 °C for 168 h and 216 h, respectively. The regulatory stress (rpos) and cold-shock (cspA) gene expressions were determined by reverse transcription PCR. At 24 h, the (Vp-tdh) strain grew faster (p < 0.05) than the (Vp-tlh) strain in oysters (λ = 0.33, 0.39, respectively) and in vitro (λ = 0.89, 37.65, respectively), indicating a better adaptation to cold shock for the (Vp-tdh) strain in live oysters and in vitro. At 24 h, the (Vp-tdh) strain rpoS and cspA gene expressions were upregulated by 1.9 and 2.3-fold, respectively, but the (Vp-tlh) strain rpoS and cspA gene expressions were repressed and upregulated by −0.024 and 1.9-fold, respectively. The V. parahaemolyticus strains that were isolated from tropical oysters have adaptive expression changes to survive and grow at 7 °C, according to their virulence.

Highlights

Vibrio parahaemolyticus is a gram-negative halophilic bacterium that commonly inhabits marine and estuarine waters worldwide
To better understand the V. parahaemolyticus response to refrigeration temperatures, the aim of our study was to assess the survival kinetics of nonpathogenic and pathogenic V. parahaemolyticus strains in live shellstock oysters, the in vitro survival kinetics of nonpathogenic and pathogenic V. parahaemolyticus strains isolated from the tropical eastern oyster (C. virginica), and the in vitro expression levels of the related to the expression of stress (rpoS) and cspA genes that are induced by cold shock at the shellstock temperature refrigeration storage conditions recommended under the
For up to 7 days (168 h) to study the effect of temperature downshift on V. parahaemolyticus strains growth, imitating the time-of-harvest and time-of-refrigeration conditions in accordance with those currently mandated by the Mexican Minister of Health NOM-242-SSA1-2009 [20]

Summary

Introduction

Vibrio parahaemolyticus is a gram-negative halophilic bacterium that commonly inhabits marine and estuarine waters worldwide. Infections caused by V. parahaemolyticus have increased in different parts of the world in recent years [1]. This pathogen is the leading cause of gastroenteritis associated with the consumption of raw, undercooked, or poorly marinated seafood, including fish, crustaceans, and, oysters [2]. Thermolabile hemolysin (TLH), encoded by the tlh gene, is used to identify both clinical and environmental strains of V. parahaemolyticus [3]. Res. Public Health 2020, 17, 1836; doi:10.3390/ijerph17061836 www.mdpi.com/journal/ijerph

Objectives

Methods

Results

Conclusion