Paralytic Shellfish Poisoning (PSP) is a syndrome caused by the consumption of shellfish contaminated with neurotoxins produced by the marine dinoflagellate genus Alexandrium. A. minutum is one of the toxic species most widespread in the Western Mediterranean basin. The standard monitoring of shellfish farms for the presence of harmful algae and related toxins usually requires the microscopic examination of phytoplankton, bioassays and toxin determination by HPLC. The microscopy procedures are time-consuming and require taxonomic expertise and experience, thus limiting the number of specimens that can be analysed. Molecular biology techniques have great potential in the detection of target microorganisms in field samples. In this study, a PCR-based assay was developed for the detection of A. minutum, in seawater samples and in contaminated mussels, using primers designed based on the ITS1-5.8S-ITS2 rDNA regions. Two primers specific for the genus Alexandrium were designed based on the conserved 5.8S rDNA region, while a primer specific for A. minutum species was designed based on the variable ITS1 region. The assay was validated using several fixed seawater samples from the Mediterranean basin, which were analyzed using PCR along with standard microscopy procedures. The results showed that PCR is a valid, rapid alternative procedure for the detection of target phytoplankton species either in seawater or directly in mussels, where accumulation of PSP toxins may cause serious problems for human health.
Development of a PCR-based method for the detection of the dinoflagellate Alexandrium minutum in contaminated Mytilus galloprovincialis mussels
2006
Abstract
Paralytic Shellfish Poisoning (PSP) is a syndrome caused by the consumption of shellfish contaminated with neurotoxins produced by the marine dinoflagellate genus Alexandrium. A. minutum is one of the toxic species most widespread in the Western Mediterranean basin. The standard monitoring of shellfish farms for the presence of harmful algae and related toxins usually requires the microscopic examination of phytoplankton, bioassays and toxin determination by HPLC. The microscopy procedures are time-consuming and require taxonomic expertise and experience, thus limiting the number of specimens that can be analysed. Molecular biology techniques have great potential in the detection of target microorganisms in field samples. In this study, a PCR-based assay was developed for the detection of A. minutum, in seawater samples and in contaminated mussels, using primers designed based on the ITS1-5.8S-ITS2 rDNA regions. Two primers specific for the genus Alexandrium were designed based on the conserved 5.8S rDNA region, while a primer specific for A. minutum species was designed based on the variable ITS1 region. The assay was validated using several fixed seawater samples from the Mediterranean basin, which were analyzed using PCR along with standard microscopy procedures. The results showed that PCR is a valid, rapid alternative procedure for the detection of target phytoplankton species either in seawater or directly in mussels, where accumulation of PSP toxins may cause serious problems for human health.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
