[Show abstract][Hide abstract] ABSTRACT: 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.
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.
We found STXs in 516 IRL southern (Sphoeroides nephelus), checkered (Sphoeroides testudineus), and bandtail (Sphoeroides spengleri) puffer fish. During 36 months of monitoring, we detected STXs in skin, muscle, and viscera, with concentrations up to 22,104 microg STX equivalents (eq)/100 g tissue (action level, 80 microg STX eq/100 g tissue) in ovaries. Puffer fish tissues, clonal cultures, and natural bloom samples of P. bahamense from the IRL tested toxic in the MBA, RBA, MNCA, Ridascreen ELISA, and MIST Alert assay and positive for STX, dc-STX, and B1 toxin by HPLC and LC-MS. Skin mucus of IRL southern puffer fish captive for 1-year was highly toxic compared to Florida Gulf coast puffer fish. Therefore, we confirm puffer fish to be a hazardous reservoir of STXs in Florida's marine waters and implicate the dinoflagellate P. bahamense as the putative toxin source.
Associated with fatal paralytic shellfish poisoning (PSP) in the Pacific but not known to be toxic in the western Atlantic, P. bahamense is an emerging public health threat. We propose characterizing this food poisoning syndrome as saxitoxin puffer fish poisoning (SPFP) to distinguish it from PFP, which is traditionally associated with tetrodotoxin, and from PSP caused by STXs in shellfish.
Full-text · Article · Nov 2006 · Environmental Health Perspectives
[Show abstract][Hide abstract] ABSTRACT: This study evaluated magnetic resonance (MR) as a nondestructive method for detection of bacterial contamination in shelf-stable soymilk and cheese sauce. To accomplish this, individual 355-ml polymeric trays filled with soymilk and inoculated with Bacillus stearothermophilus and Bacillus subtilis (10(3) CFU) were incubated for up to 28 h at 55 degrees C and 62 h at 37 degrees C, respectively. MR relaxation times (T2) of these samples were then correlated with the bacterial growth as well as viscosity and pH changes caused by the bacteria in the packaged soymilk. In addition, this study investigated the ability of MR to differentiate between regularly processed cheese sauce and cheese sauce that was modified with alpha-amylase as a spoilage simulation. Results showed increased MR T2 relaxation times after the bacterial populations reached 10(8) CFU/ml (after 18 h) and 10(7) CFU/ml (after 44 h) for B. stearothermophilus and B. subtilis, respectively. B. subtilis had an undetectable influence on viscosity but a profound influence on pH. B. stearothermophilus, in comparison, significantly lowered the pH and increased the viscosity of the soymilk. MR was able to distinguish between regularly processed 85-g pouches of cheese sauce and other pouches with sauce that were modified with 0.5 ml of 1% alpha-amylase solution. These results showed that MR has the potential to be used for nondestructive detection of physical changes insoymilk and cheese sauce induced by bacterial growth and enzymatic activities, respectively.
No preview · Article · Aug 2006 · Journal of food protection