LC-MS early warning mechanism offers significant advantage in shellfish harvesting
Food Standards Agency in Scotland (FSAS) announced the 2012 biotoxin, phytoplankton and microbiological monitoring programme annual reports for shellfish harvesting areas last week.
These reports, which have been produced for the FSAS by the Centre for Environment, Fisheries and Aquaculture Science (Cefas), describe the results of shellfish and water sampling undertaken as part of the official control monitoring programme in Scotland.
A total of 2425 bivalve shellfish samples were submitted to Cefas for toxin analyses in the reporting period. They comprised: common mussels (1711), Pacific oysters (438), razors (131), common cockles (108), surf clams (36) and wedge clams (1) from 101 inshore sampling locations.
Analysis method
Monitoring was conducted using a LC-MS method, with the exception of April 2012 when surf clams and processed king scallops were tested by the biological assay (MBA).
MBA was replaced by the LC-MS method on 1 May 2012, following a period of validation of the replacement method and approval by the FSA.
The LC-MS method is able to characterise and quantify the following lipophilic toxins (LT) groups; Okadaic Acid (OA)/Dinophysis Toxins (DTXs) and Pectenotoxins (PTXs)/kg shellfish flesh.
OA/DTX/PTX group toxins were detected in 355 samples, comprising of mussels (314 samples), surf clams (28), razors (11) and Pacific oyster (2) samples.
Ninety nine samples comprising of mussels (91 samples), surf clams (6) and razors (2) recorded results above the maximum permitted limits (MPL) (>160μg OA eq./kg).
The highest level recorded was 2009μg OA eq./kg, more than twelve times the regulatory limit, in a sample from Loch Inchard in late July 2012.
AZAs toxins by LC-MS
Azaspiracid toxins (AZAs) – reported as μg AZA1 eq./kg shellfish flesh and Yessotoxins (YTXs) reported as mg YTX eq./kg shellfish flesh.
AZA group toxins were detected in 175 samples, comprising of Pacific oysters (94 samples), mussels (35), surf clams (26), cockles (17) and razors (3).
Four mussel samples and one surf clam sample from two separate sites recorded results above the MPL (>160μg AZA1 eq./kg) between August and September 2012.
The highest level recorded during this reporting period was 595μg AZA1 eq./kg, almost four times the regulatory limit, in a sample from Loch Bay: Loch Bay Indicator in late August 2012.
Campylobacter call
Meanwhile, the UK Food Standards Agency is inviting tenders to sequence the whole genome for campylobacter isolates archived from early studies.
Campylobacter is the most commonly reported bacterial cause of infectious intestinal disease in the UK and the leading cause of bacterial food poisoning.
The majority of infection is caused by Campylobacter jejuni while the remainder is caused by Campylobacter coli and other minor species with risk factors including handling or consuming raw or undercooked chicken.
Researchers will be expected to characterise selected human isolates in detail by next generation sequencing, using an appropriate platform. The resulting data will be placed in the public domain for use by other researchers.
