TY - JOUR
T1 - Enterotoxicity and cytotoxicity of Vibrio parahaemolyticus thermostable direct hemolysin in in vitro systems
AU - Raimondi, Francesco
AU - Kao, Joseph P Y
AU - Fiorentini, Carla
AU - Fabbri, Alessia
AU - Donelli, Gianfranco
AU - Gasparini, Nicoletta
AU - Rubino, Armido
AU - Fasano, Alessio
PY - 2000/6
Y1 - 2000/6
N2 - Vibrio parahaemolyticus is a marine bacterium known to be a common cause of seafood gastroenteritis worldwide. The thermostable direct hemolysin (TDH) has been proposed to be a major virulence factor of V. parahaemolyticus. TDH causes intestinal fluid secretion as well as cytotoxicity in a variety of cell types. In this study, we investigated the interplay between the hemolysin's enterotoxic and cytotoxic effects by using both human and rat cell monolayers. As revealed by microspectrofluorimetry, the toxin causes a dose-dependent increase in intracellular free calcium in both Caco-2 and IEC- 6 cells. This effect was reversible only when low toxin concentrations were tested. The TDH-activated ion influx pathway is not selective for calcium but admits ions such sodium and manganese as well. Furthermore, in the same range of concentration, the hemolysin triggers a calcium-dependent chloride secretion. At high concentrations, TDH induces a dose-dependent but calcium- independent cell death as assessed by functional, biochemical, and morphological assays.
AB - Vibrio parahaemolyticus is a marine bacterium known to be a common cause of seafood gastroenteritis worldwide. The thermostable direct hemolysin (TDH) has been proposed to be a major virulence factor of V. parahaemolyticus. TDH causes intestinal fluid secretion as well as cytotoxicity in a variety of cell types. In this study, we investigated the interplay between the hemolysin's enterotoxic and cytotoxic effects by using both human and rat cell monolayers. As revealed by microspectrofluorimetry, the toxin causes a dose-dependent increase in intracellular free calcium in both Caco-2 and IEC- 6 cells. This effect was reversible only when low toxin concentrations were tested. The TDH-activated ion influx pathway is not selective for calcium but admits ions such sodium and manganese as well. Furthermore, in the same range of concentration, the hemolysin triggers a calcium-dependent chloride secretion. At high concentrations, TDH induces a dose-dependent but calcium- independent cell death as assessed by functional, biochemical, and morphological assays.
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U2 - 10.1128/IAI.68.6.3180-3185.2000
DO - 10.1128/IAI.68.6.3180-3185.2000
M3 - Article
C2 - 10816461
AN - SCOPUS:0034115690
VL - 68
SP - 3180
EP - 3185
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 6
ER -