Detection of tetrodotoxins in juvenile pufferfish Lagocephalus sceleratus (Gmelin, 1789) from the North Aegean Sea (Greece) by an electrochemical magnetic bead-based immunosensing tool

Abstract

Two small Lagocephalus sceleratus juveniles were captured in picarel targeting catches from North Aegean Sea (Greece) in the autumn of 2017. An electrochemical immunosensing tool using magnetic beads as immobilisation support was developed and applied to the rapid 2 screening of tetrodotoxins (TTXs), potent neurotoxins that constitute a food safety hazard when present in seafood. This tool revealed the presence of TTXs in both individuals. Results were compared with those provided by mELISA and LC-HRMS, the latter confirming the presence of TTX. Some of the tissues contained TTX contents close to or above 2 mg/kg. L. sceleratus juveniles had been considered as non-toxic and, to our knowledge, this is the first report of high TTX levels in small L. sceleratus individuals. Such specimens can be mistaken with other edible species, posing a threat to consumers. The availability of low-cost and user-friendly tools for TTXs detection will contribute to guarantee seafood safety.

Public Health Risks Associated with Tetrodotoxin and Its Analogues in European Waters: Recent Advances after The EFSA Scientific Opinion

“…Antibody-based methods, such as competitive inhibition enzymatic immunoassay (ELISA) or surface plasmon resonance biosensor (SPR), are potentially useful for qualitative identification, but not ideal for routine screening at present, due to fact that there is no cross reactivity for all the known TTX analogues. Recent developments in TTXs detection in this type of methods comprise a nanoarray planar waveguide biosensor, initially tested on pufferfish samples [32] and the modification of a self-assembled monolayer-based Immunoassay (mELISA) previously developed for TTX detection in pufferfish [43], which has now been adapted to the analysis of oyster and mussel samples [30]. As regards the biosensor method, TTX detection was possible at levels of 0.4–3.29 μg/g puffer fish tissue in 10 min; repeatability and reproducibility were assessed at 0.4 and 0.8 μg/g, showing relative standard deviation (RSD) values below 15% and toxin recoveries within 85–115%.…”

“…As regards the biosensor method, TTX detection was possible at levels of 0.4–3.29 μg/g puffer fish tissue in 10 min; repeatability and reproducibility were assessed at 0.4 and 0.8 μg/g, showing relative standard deviation (RSD) values below 15% and toxin recoveries within 85–115%. Cross-reactivity with some of the known TTX analogues was indicated by the quantitative results, when compared to the mouse bioassay results and the concentrations obtained by LC-MS/MS but no cross-reactivity factors were established [32]. Concerning the mELISA technique, the modifications introduced significantly improved the effective detection limits (eLOD) of the assay, with the lowest values obtained being 20 and 50 μg TTX/kg for oyster extracts without and with SPE cleanup, respectively, and about 30 μg TTX/kg for mussel extracts with both protocols, substantially below the eLOD obtained by the previous mELISA for puffer fish (230 μg TTX/kg).…”

Magnetic Beads in Marine Toxin Detection: A Review

“…Diverse toxins cause different intoxications, which are grouped according to their effects: diarrheic shellfish poisoning (DSP), paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), neurologic shellfish poisoning (NSP), ciguatera fish poisoning (CFP) and pufferfish poisoning [3]. The marine toxins responsible for these intoxications are produced by microalgae, except for pufferfish poisoning, in which the toxin producer is a bacterium [4].…”

“…Consumption of this contaminated animal may cause intoxication and even death, and the rapid and reliable detection of TTX in pufferfish is thus of enormous importance. Recently, an electrochemical MB-based immunosensor has been developed for the detection of TTX [4]. Oriented and stable TTX immobilization was achieved through the formation of a cysteine monolayer on maleimide-activated MBs, for the subsequent covalent biding of TTX.…”

Can bioactive peptides of Lagocephalus sceleratus be evaluated in the functional food industry

“…The Mediterranean Sea is under threat of introduction of invasive species due to the Suez Channel and also heavy maritime traffic (Galil, 2009). Although Lagocephalus sceleratus (Gmelin, 1789) is a very common species in the tropical waters such as Indian and Pacific Ocean, it is being one of the well invaded species in the Mediterranean Sea via Suez Channel (Leonardo et al, 2019). This alien fish has been commonly observed in almost all the Mediterranean Sea region (Akyol et al, 2005;Kasapidis et al, 2007;Kalogirou, 2013).…”