Domoic Acid Poisoning: A Case Study

1. Background and Introduction Domoic acid poisoning will be disucussed in this essay. DA poisoning is not always present as the outbreak or intoxication case. The first case was recognised in 1987 in Prince Edward Island, Canada. At that moment, DA poisoning caused 3 deaths and 105 cases of acute human poisoning as the consumption of blue mussels with the marine diatom Pseudonitschia pungens. In September 1991, the deaths of pelicans and cormorants in Monterey Bay, California were due to another outbreak of DA poisoning produced by a related diatom Pseudo-nitzschia australis. This diatom was consumed by anchovies that in turn were eaten by the birds. However this case was not influenced to human. The symptoms of this toxin included diarrhea,

The method is shellfish fish samples are homogenizedand extracted the homogenate extract with solvent. The sample extracts after centrifugation are diluted to a specified concentration. Then the sample is added to the precoated Biosense ASP ELISA microtiter walls. In the direct competition of ELISA, the free DA molecules in the sample competes with DA-conjugated protein coated on the plastic walls soas to bind to anti-DA antibodies. The anti-DA antibodies also added to the wells. The equilibrium is reached after mixture is reached after the incubation for 1 h to allow the competitive binding step. After all uninteracted components are washed away, a half portion of the antibodies conjugated to the horseradish peroxidase (HRP) is bound to the fixed DA-conjugated protein. The amount of conjugate remaining bound after washing to the wall. A substrate which is a blue product measured by incubation since there are reaction with the HRP enzyme. Added acid so as to stops the reaction and changes the product color from blue to yellow. The intensity is at 450 nm, and is inversely proportional to the concentration of DA in the sample solution. The other method for detection of omoic acid toxins in shellfish is liquid chromatography- mass spectrometry. LC/MS has excellent sensitivity and can provide quantitative measurements of DA, while also providing a high degree of confidence in DA compound identification. Analysis of DA is conducted primarily with reverse phase LC. Reverse phase LC by using a low pH mobile phase have been used most commonly for DA analysis. The DA ion spectral library was constructed by getting enhanced product ion scans of [M+H]+. Separations were on a Luna C18 column using a guard column of the same phase. DA toxin at a range of collision energies and collision energy spreads. Different spectra were then saved under a