Ciguatoxin in Hawai'i: Fisheries forecasting using geospatial and environmental analyses for the invasive Cephalopholis argus (Epinephelidae).

Invasive species can precede far-reaching environmental and economic consequences. In the Hawai'ian Archipelago Cephalopholis argus (family Serranidae) is an established invasive species, now recognized as the dominant local reef predator, negatively impacting the native ecosystem and local fishery. In this region, no official C.

Analysis of Chloramphenicol and Two Metabolites in Crab and Shrimp Following Waterborne Exposure.

The use of chloramphenicol (CAP) in aquaculture products is banned in many countries, including the United States, due to human health issues. Very few depletion and metabolism studies of CAP in seafood have been performed. Current detection methods for CAP residues in food are directed toward the parent drug molecule, but rapid elimination following treatment suggests the need for an alternative marker residue.

Performance Assessment and Comparability of a Commercial Enzyme-Linked Immunosorbent Assay Kit with Liquid Chromatography-Tandem Mass Spectrometry for Chloramphenicol Residues in Crab and Shrimp.

Monitoring for chloramphenicol (CAP) in aquaculture products is primarily performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), which requires expensive equipment and specialized training. Many laboratories prefer to screen samples with facile and high-throughput enzyme-linked immunosorbent assay (ELISA) kits for CAP residues before submitting samples for LC-MS/MS quantification and confirmation. We evaluated the performance of a Ridascreen (R-Biopharm) ELISA kit for CAP in spiked and incurred crab and shrimp muscle at levels bracketing the minimum required performance level for analysis (0.

Screening for petrochemical contamination in seafood by headspace solid-phase microextraction gas chromatography-mass spectrometry.

A headspace solid-phase microextraction gas chromatography-mass spectrometry (SPME GC-MS) method is described, to screen seafood for volatile organic compounds (VOCs) associated with petrochemical taint. VOCs are extracted from the headspace of heated sample homogenates by adsorption onto a SPME fiber and desorbed for analysis by GC-MS. Targeted compounds are determined semi-quantitatively using representative calibration standards for the various classes (alkanes, alkylbenzenes, indanes/tetralins, and naphthalenes) of VOCs analyzed.

Biomarkers of brevetoxin exposure and composite toxin levels in hard clam (Mercenaria sp.) exposed to Karenia brevis blooms.

Brevetoxins in clams (Mercenaria sp.) exposed to recurring blooms of Karenia brevis in Sarasota Bay, FL, were studied over a three-year period. Brevetoxin profiles in toxic clams were generated by ELISA and LC-MS.

Invasive lionfish (Pterois volitans): a potential human health threat for ciguatera fish poisoning in tropical waters.

Invasive Indo-Pacific lionfish (Pterois volitans) have rapidly expanded in the Western Atlantic over the past decade and have had a significant negative impact on reef fish biodiversity, habitat, and community structure, with lionfish out-competing native predators for resources. In an effort to reduce this population explosion, lionfish have been promoted for human consumption in the greater Caribbean region. This study examined whether the geographical expansion of the lionfish into a known ciguatera-endemic region can pose a human health threat for ciguatera fish poisoning (CFP).

Performance evaluation of commercial ELISA kits for screening of furazolidone and furaltadone residues in fish.

Regulatory monitoring for nitrofuran drug residues in aquaculture products has largely focused on LC-MS/MS. In addition, there is a need for facile and high-throughput screening methods for monitoring programs. We evaluated the performance of Ridascreen (R-Biopharm) ELISA kits for nitrofuran drug residues in fish muscle, with verification by LC-MS/MS.

Ciguatera fish poisoning on the West Africa Coast: An emerging risk in the Canary Islands (Spain).

Ciguatera fish poisoning (CFP) is endemic in certain tropical and subtropical regions of the world. CFP had not been described on the West Africa Coast until a 2004 outbreak in the Canary Islands. In 2008-2009, two additional outbreaks of ciguatera occurred.

Cyano metabolite as a biomarker of nitrofurazone in channel catfish.

The use of nitrofuran drugs in food-producing animals continues to attract international concern as a food safety issue. Methods for monitoring nitrofuran residues have been directed to the intact side chain of tissue-bound metabolites. Semicarbazide, the side chain of nitrofurazone (NFZ), can enter food products from non-NFZ sources, suggesting the need for an alternative biomarker for confirmatory purposes.

Biomarkers of neurotoxic shellfish poisoning.

Urine specimens from patients diagnosed with neurotoxic shellfish poisoning (NSP) were examined for biomarkers of brevetoxin intoxication. Brevetoxins were concentrated from urine by using solid-phase extraction (SPE), and analyzed by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine extracts were fractionated by LC, and fractions analyzed for brevetoxins by ELISA.

Monitoring of brevetoxins in the Karenia brevis bloom-exposed Eastern oyster (Crassostrea virginica).

Brevetoxin uptake and elimination were examined in Eastern oyster (Crassostrea virginica) exposed to recurring blooms of the marine alga Karenia brevis in Sarasota Bay, FL, over a three-year period. Brevetoxins were monitored by in vitro assays (ELISA, cytotoxicity assay, and receptor binding assay) and LC-MS, with in vivo toxicity of shellfish extracts assessed by the traditional mouse bioassay. Measurements by all methods reflected well the progression and magnitude of the blooms.

Saxitoxin puffer fish poisoning in the United States, with the first report of Pyrodinium bahamense as the putative toxin source.

Background: From January 2002 to May 2004, 28 puffer fish poisoning (PFP) cases in Florida, New Jersey, Virginia, and New York were linked to the Indian River Lagoon (IRL) in Florida. Saxitoxins (STXs) of unknown source were first identified in fillet remnants from a New Jersey PFP case in 2002.

Methods: We used the standard mouse bioassay (MBA), receptor binding assay (RBA), mouse neuroblastoma cytotoxicity assay (MNCA), Ridascreen ELISA, MIST Alert assay, HPLC, and liquid chromatography-mass spectrometry (LC-MS) to determine the presence of STX, decarbamoyl STX (dc-STX), and N-sulfocarbamoyl (B1) toxin in puffer fish tissues, clonal cultures, and natural bloom samples of Pyrodinium bahamense from the IRL.

Characterization of polar brevetoxin derivatives isolated from Karenia brevis cultures and natural blooms.

Several novel brevetoxin derivatives were isolated and identified in Karenia brevis cultures and natural blooms by using solid phase extraction (SPE) and LC/MS(MS) techniques. These analogs were more polar compared with previously described brevetoxins, and were poorly extractable by conventional non-polar solvent (chloroform) partitioning. Brevetoxin analogs were structurally confirmed as hydrolyzed (open A-ring) forms of brevetoxins PbTx-1, PbTx-7, PbTx-2, and PbTx-3, and of oxidized PbTx-1 and PbTx-2.

Brevetoxin metabolism and elimination in the Eastern oyster (Crassostrea virginica) after controlled exposures to Karenia brevis.

The metabolism and elimination of brevetoxins were examined in the Eastern oyster (Crassostrea virginica) following controlled exposures to Karenia brevis cultures in the laboratory. After a 2-day exposure period ( approximately 62 million cells/oyster), elimination of brevetoxins and their metabolites was monitored by using liquid chromatography/mass spectrometry (LC/MS). Composite toxin in oyster extracts was measured by in vitro assay (i.

LC/MS analysis of brevetoxin metabolites in the Eastern oyster (Crassostrea virginica).

Brevetoxin (PbTx) metabolism was examined in the Eastern oyster (Crassostrea virginica) following exposure to a Karenia brevis red tide, by using LC/MS(/MS) and cytotoxicity assay. Metabolites observed in field-exposed oysters were confirmed in oysters exposed to K. brevis cultures in the laboratory.

Multi-Laboratory Study of Five Methods for the Determination of Brevetoxins in Shellfish Tissue Extracts.

A thirteen-laboratory comparative study tested the performance of four methods as alternatives to mouse bioassay for the determination of brevetoxins in shellfish. The methods were N2a neuroblastoma cell assay, two variations of the sodium channel receptor binding assay, competitive ELISA, and LC/MS. Three to five laboratories independently performed each method using centrally prepared spiked and naturally incurred test samples.

A rapid assay for the brevetoxin group of sodium channel activators based on fluorescence monitoring of synaptoneurosomal membrane potential.

A functional pharmacologically-based assay for the brevetoxin group of sodium channel activators was developed using synaptoneurosomes isolated from the brains of CD1 mice. The assay can detect the depolarizing effect of brevetoxin congeners PbTx-2 and PbTx-3 as enhancements of the veratridine-dependent increase in fluorescence of the voltage-sensitive fluorescent probe rhodamine 6G. The assay is relatively rapid and can detect brevetoxin activity in the nanomolar range.

Confirmation of brevetoxin metabolism in the Eastern oyster (Crassostrea virginica) by controlled exposures to pure toxins and to Karenia brevis cultures.

Previously, we analyzed Eastern oysters (Crassostrea virginica) naturally exposed to a Karenia brevis red tide and found that brevetoxins (PbTx) are rapidly accumulated and metabolized. Several metabolites were isolated and later identified, including a cysteine-PbTx conjugate (MH(+): m/z 1018) and its sulfoxide product (m/z 1034). In the present study, we confirm and extend those findings by examining PbTx metabolism and elimination in oysters exposed to pure toxins (PbTx-2 and -3) under controlled conditions.