Detection of Paralytic Shellfish Toxins in Mussels and Oysters Using the Qualitative Neogen Lateral-Flow Immunoassay: An Interlaboratory Study

Abstract

Paralytic shellfish toxins (PSTs) in bivalve molluscs represent a public health risk and are controlled via compliance with a regulatory limit of 0.8 mg saxitoxin (STX)⋅2HCl equivalents per kilogram of shellfish meat (eq/kg). Shellfish industries would benefit from the use of rapid immunological screening tests for PSTs to be used for regulation, but to date none have been fully validated. An interlaboratory study involving 16 laboratories was performed to determine the suitability of the Neogen test to detect PSTs in mussels and oysters. Participants performed the standard protocol recommended by the manufacturer and a modified protocol with a conversion step to improve detection of gonyautoxin 1&4. The statistical analysis showed that the protocols had good homogeneity across all laboratories, with satisfactory repeatability, laboratory, and reproducibility variation near the regulatory level. The mean probability of detection (POD) at 0.8 mg STX⋅2HCl eq/kg using the standard protocol in mussels and oysters was 0.966 and 0.997, respectively, and 0.968 and 0.966 using the modified protocol. The estimated LOD in mussels was 0.316 mg STX⋅2HCl eq/kg with the standard and 0.682 mg STX⋅2HCl eq/kg with the modified protocol, and 0.710 and 0.734 mg STX⋅2HCl eq/kg for oysters, respectively. The Neogen test may be acceptable for regulatory purposes for oysters in accordance with European Commission directives in which the standard protocol provides, at the regulatory level, a probability of a negative response of 0.033 on 95% of occasions. Its use for mussels is less consistent at the regulatory level due to the wide prediction interval around the POD.

Lobster Supply Chains Are Not at Risk from Paralytic Shellfish Toxin Accumulation during Wet Storage

“…The toxin profiles of the A. catenella cells were predominantly di-sulfated carbomoyl (C) 1,2 and gonyautoxin (GTX) 1,4, with minor levels of C3,4, neosaxitoxin (Neo), GTX2,3, STX, decarbamyolated gonyautoxin (dcGTX) 2,3, and GTX5,6 (see Section 4.2 below). These analogues are the same as those found in toxic shellfish from the east coast of Tasmania [36,37] and are thus considered representative of the Tasmanian A. catenella blooms. The same PST analogues are also found in New Zealand A. pacificum, A. minutum and G. catenatum isolates, although toxin proportions vary [5,38].…”

Hyphenating paper-based biosensors with smartphones

“…However, the production industry is in desperate need of portable tools for in field testing for product release systems as the turnaround time of these regulatory methods can be detrimental to their industry in an ever-changing tidal environment. Lateral flow immunoassays are available commercially [119] and are also now being considered in different parts of the world as regulatory tools for shellfish toxin analysis or as part of end product release systems for shellfish harvest [120]. Some of these devices are already available and used in tandem with reader devices for the three main groups of toxins [47][48][49] and in development as multiplex tools [51], but the added immediate connectivity a smartphone could offer could be beneficial in a harvesting season for predictive monitoring in a network.…”