Detection of ciguatoxin in fish tissue using sandwich ELISA and neuroblastoma cell bioassay

Abstract

The applicability of a new enzyme-linked immunoassay (ELISA) for detecting ciguatoxin (CTX) in fish tissue was evaluated by testing three fish species commonly implicated in ciguatera fish poisoning in Hawaii. A total of 164 individual almaco jack (Seriola rivoliana) and greater amberjack (S. dumerili) and a total of 175 individuals of the blue-spotted grouper (Cephalopholis argus) were caught at various locations in the Hawaiian Islands. Muscle tissue from each individual was assessed for the presence of CTX using two methods: a semi-quantitative ELISA that was recently developed for detecting picogram levels of CTX in fish extract and a neuroblastoma (NB) cell assay commonly used to screen for marine toxins in fish. Results of the tests were highly correlated, with the ELISA indicating the presence of CTX in 9.4% of all fish samples, and the NB assay indicating toxicity in 6.8% of the fish samples. We conclude that the ELISA produces reliable and accurate results that are consistent with those provided by the accepted NB assay and that the ELISA has potential for future applications in screening fish populations for CTX.

Evaluating the Risk of Ciguatera Fish Poisoning from Reef Fish Grown at Marine Aquaculture Facilities in Hawai'i

“…Differences between the ELISA and NB assay results imply that 2.1% of results are false positives when assessing the aquacultured fish using the ELISA alone, and show that 1.2% of results are false positives when screening the wild-caught kahala compared to the NB results. In addition, the wild kahala data (Table 2) imply that 1.7% of results are false negatives, confirming a previous study which indicated that 1.2% of results were considered false negatives when using the ELISA (Campora et al 2008b).…”

“…As a tool for CTX screening, the ELISA shows promise for its capabilities of efficiently and economically screening a large number of fish samples using a unique two-site antibody configuration. However, cross-reactivity of extraneous lipids and the establishment of a somewhat arbitrary positive threshold may inadvertently score fish as positive or borderline that are truly negative, leading to an overall estimated 2.7% false-positive rate when using the ELISA (Campora et al 2008b).…”

Ciguatera in the Introduced Fish Cephalopholis argus (Serranidae) in Hawai‘i and Implications for Fishery Management

“…The specific Neuroblastoma cell assay methodology followed Campora et al (2008). In short, the presence of ciguatoxin in muscle tissue was determined by comparing the survival rate of neuroblastoma cells in treatment wells containing fish extract with that in control wells without extract, with lowered survival in treatment wells indicating cytotoxicity.…”

Gambierdiscus and Ostreopsis: Reassessment of the state of knowledge of their taxonomy, geography, ecophysiology, and toxicology

“…Antibodies have been prepared for CTX and used in different formats over the years including immunobead assay, radioimmunoassay, or ELISA (Hokama et al, 1990(Hokama et al, , 1998Campora et al, 2008), yet the accuracy of the results has been questioned (Dickey et al, 1994;Lehane and Lewis, 2000;EFSA, 2009a;Bienfang et al, 2011). Monoclonal antibodies specific to Pacific ciguatoxins CTX-3C and 51-hydroxyCTX3C (Tsumuraya et al, 2006) have been prepared using synthetic haptens and used to develop a sandwich ELISA.…”