Nanomaterials based optical and electrochemical sensing of histamine: Progress and perspectives.

Histamine is known to be a principal causative agent associated with marine food poisoning outbreaks worldwide, which is typically formed in the contaminated food by decarboxylation of histidine by bacterial histidine decarboxylase. Upon quantification of histamine in different food products, one can comment on the quality of the food and use it as an indicator of the good manufacturing practices and the state of preservation. The United States Food and Drug Administration (FDA) has established 50 ppm (50 mg/kg) of histamine as the chemical index for fish spoilage. Consumption of foods containing histamine higher than the permissible limit can cause serious health issues. Several methods have been developed for the determination of histamine in a variety of food products. The conventional methods for histamine detection such as thin layer chromatography, capillary zone electrophoresis, gas chromatography, colorimetry, fluorimetry, ion mobility spectrometry, high-performance liquid chromatography, and enzyme-linked immunosorbent assay (ELISA), are being used for sensitive and selective detection of histamine. However, there are a number of disadvantages associated with the conventional techniques, such as multi-step sample processing and requirement of expensive sophisticated instruments, which restrict their applications at laboratory level only. In order to address the limitations associated with the traditional methods, new approaches have been developed by various research groups. Current advances in nanomaterial-based sensing of histamine in different food products have shown significant measurement accuracy due to their high sensitivity, specificity, field deployability, cost and ease of operation. In this review, we have discussed the development of nanomaterials-based histamine sensing assays/strategies where the detection is based on optical (fluorescence, surface enhanced Raman spectroscopy (SERS), localized surface plasmon resonance) and electrochemical (impedimetric, voltammetry, potentiometric, etc.). Further, the advantages, disadvantages and future scope of the nanomaterials-based histamine sensor research are highlighted.

Ciguatera fish poisoning: First reported case in Sabah, Malaysia.

Ciguatera fish poisoning (CFP) is the most common natural marine toxin poisoning worldwide and yet under recognised in Malaysia. We report the first confirmed case of CFP in Sabah with severe neurological, cardiovascular and gastrointestinal manifestations after consumption of emperor snapper. Early recognition of CFP is important because it will result in improved patient care and public health intervention.

Trends in blood mercury concentrations and fish consumption among U.S. women of reproductive age, NHANES, 1999-2010.

BACKGROUND: Consumption of finfish and shellfish is the primary exposure pathway of methylmercury (MeHg) in the US. MeHg exposure in utero is associated with neurodevelopmental and motor function deficits. Regulations and fish advisories may contribute to decreased exposure to mercury over time. OBJECTIVES: Combine fish tissue mercury (FTHg) concentrations and 1999-2010 NHANES blood mercury concentrations and fish consumption data to investigate trends in blood mercury concentrations, fish consumption, and mercury intake in women of reproductive age. METHODS: Blood MeHg was calculated from the blood total and inorganic concentrations. Dietary datasets were combined to estimate 30-day fish consumption, then combined with FTHg concentrations to estimate mercury intake and mercury concentration in the fish consumed. Non-linear and logistic regression analyses were used to evaluate trends over time. RESULTS: Regression analysis found NHANES 1999-2000 to have higher blood MeHg concentrations than the mean of the later releases (p<0.0001) and a positive quadratic trend since 2000 (p=0.004). No trend was observed in fish consumption amount or mercury intake. A decreasing trend was found in the ratio of mercury intake to fish consumed (p=0.04). CONCLUSIONS: The analyses found blood MeHg concentrations in NHANES 1999-2000 to be significantly higher than the mean of the later releases. There was no trend in fish consumption amount across the study period. The analysis found a decreasing trend in the ratio of mercury intake to fish consumed, consistent with women shifting their consumption to fish with lower mercury concentrations.

[Study on tetrodotoxin detection and toxic puffer fish identification of roasted fish fillet at the retail in Beijing and Qingdao].

OBJECTIVE: The roasted fish fillet sample at the retail collected in Beijing and Qingdao were detected for TTX, and the TTX positive samples was analyzed for fish species identification. METHODS: TTX was tested by EUSA method and the cytochrome c oxidase I (COI) genome of TTX-positive samples was extracted and identified by DNA barcode. RESULTS: Totally, 90 samples were tested by EUSA and 58 (64.4%) samples were positive for TTX with the levels ranging from 0.10 mg/kg to 63.81 mg/kg. Among the TTX positive samples, 24 (41.3%) were identified containing toxic puffer fish and 21 (87.5%) were Lagocephalus lunaris, the highly toxic puffer fish. CONCLUSION: Some roasted fish fillet samples obtained from the retail in two cities were positive for TTX and contained toxic puffer fish. Based on these results, we suggest that roasted fish fillet producers should prevent toxic puffer fish from mixing in the raw material and the I regulators should strengthen the TTX surveillance and product labeling supervision of roasted fish fillet.

DNA-based identification of fish species implicated in Puffer fish poisoning.

A method for identification of fish species using three different mitochondrial DNA regions, 16S rRNA, cytochrome b and cytochrome c gene fragments, was investigated. The combined use of all three regions enabled reliable species identification in not only raw fish, but also dried, seasoned and boiled fish, products. Furthermore, the method was applicable even to vomitus from a patient involved in a puffer fish poisoning incident. However, further improvement is necessary to discriminate between closely related species such as Takifugu rubripes and T. chinensis, because they showed close similarity in the nucleotide sequences in the three gene fragments analyzed in this study.

Scombroid poisoning: a review.

Scombroid poisoning, also called histamine fish poisoning, is an allergy-like form of food poisoning that continues to be a major problem in seafood safety. The exact role of histamine in scombroid poisoning is not straightforward. Deviations from the expected dose-response have led to the advancement of various possible mechanisms of toxicity, none of them proven. Histamine action levels are used in regulation until more is known about the mechanism of scombroid poisoning. Scombroid poisoning and histamine are correlated but complicated. Victims of scombroid poisoning respond well to antihistamines, and chemical analyses of fish implicated in scombroid poisoning generally reveal elevated levels of histamine. Scombroid poisoning is unique among the seafood toxins since it results from product mishandling rather than contamination from other trophic levels. Inadequate cooling following harvest promotes bacterial histamine production, and can result in outbreaks of scombroid poisoning. Fish with high levels of free histidine, the enzyme substrate converted to histamine by bacterial histidine decarboxylase, are those most often implicated in scombroid poisoning. Laboratory methods and screening methods for detecting histamine are available in abundance, but need to be compared and validated to harmonize testing. Successful field testing, including dockside or on-board testing needed to augment HACCP efforts will have to integrate rapid and simplified detection methods with simplified and rapid sampling and extraction. Otherwise, time-consuming sample preparation reduces the impact of gains in detection speed on the overall analysis time.

[Histamine food poisonings in Japan and other countries].

Histamine food poisonings are allergy-like food poisonings caused by the ingestion of spoiled fish containing markedly elevated histamine levels. We examined histamine food poisonings in Japan from 1998 to 2008. In average 8 food poisonings and 150 cases were reported annually and there was no fatality case. In more than 80% of remaining food samples, histamine content exceeded 20 mg/100 g. These poisonings were caused by tuna, billfish (marlin) and mackerel, which contained higher level of histamine than other fishes in histamine food poisonings in Japan. Cooking methods of these fishes were mainly "broiled". We also studied histamine food poisonings in other countries. Tuna was the main fish in histamine food poisonings reported to Centers for the Disease Control and Prevention (CDC) in the US and Ozfoodnet in Australia from 2000 to 2006. In the US, histamine food poisonings were also caused by mahimahi and escolar fish. Our review will be useful for in taking measures to reduce risk of histamine food poisonings.

Three successive cases of enteric anisakiasis.

Enteric anisakiasis is relatively rare, and the preoperative diagnosis is difficult. We report 3 cases of enteric anisakiasis: 1 was confirmed by operation, and the other 2 cases were suspected by the patient history. The 1st patient was a 48-year-old female presenting with abdominal pain. An abdominal computed tomography scan showed a dilated small intestine and accumulation of ascites. We performed partial resection of the small intestine, and an Anisakis nematode was found on the wall of the resected bowel. After surgery, the detailed history revealed that the patient consumed a raw sardine with vinegar and miso, fermented soybean paste. Three days after her operation, 2 men presenting with abdominal pain visited the hospital, and computed tomography scans of the patients showed dilated small intestines and accumulation of ascites. By taking patient histories, we found that both of them consumed sardines with vinegar and miso, and both were given conservative treatment with fasting and transfusion. By the experience of the 1st case, we could diagnose the following 2 cases as having enteric anisakiasis. In conclusion, the possibility of anisakiasis should be considered in patients with abdominal pain after ingesting raw fish, especially when intestinal obstruction is suspected.

Emergence of imported ciguatera in Europe: report of 18 cases at the Poison Control Centre of Marseille.

BACKGROUND: Ciguatera is a disease caused by the ingestion of fish containing the toxins of Gambierdiscus toxicus. This dinoflagellate is frequently found in damaged coral reef systems. Previously rare in Europe, this disease entity is now seen in tourists returning from tropical countries. CASE SERIES: Eighteen patients were examined between 1997 and 2002. Nine poisonings occurred in Atlantic Ocean islands, eight in Pacific Ocean islands, and one in the Egyptian Red Sea coast. Gastrointestinal signs were always present in the Atlantic areas, but were less severe or absent in the Pacific areas. All patients had sensory disturbances, and two of them had motor disturbances affecting the respiratory muscles and leading to the death of a 73-year-old man in Cuba. The 17 surviving patients returned to France and for 2 to 18 months suffered from arthralgias, myalgias, or pruritus. CONCLUSION: Ciguatera is a newly imported intoxication in Europe. As the number of international tourists grows each year, this type of poisoning will be seen more frequently. Furthermore, as the condition of coral reefs declines around the world and the prevalence of G. toxicus increases, physicians in non-tropical countries should be prepared to manage such poisoned patients.

Identification of species and measurement of tetrodotoxin in dried dressed fillets of the puffer fish, Lagocephalus lunaris.

The toxicity and species of dried dressed fish fillets were investigated. Three of seven dried dressed fish fillets were found to be toxic, with their levels of toxicity ranging from 9 to 18 mouse units per g. The toxin preparation was further purified and identified as tetrodotoxin and anhydrotetrodotoxin by high-performance liquid chromatography and gas chromatography-mass spectroscopy. The species of these fillets could not be distinguished from Lagocephalus lunaris by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis or restriction site and sequence analysis of a polymerase chain reaction amplicon of the cytochrome b gene. These fish fillets were identified as L. lunaris on the basis of their protein patterns and gene characteristics. Furthermore, the toxic samples contained low levels of tetrodotoxin and its derivative.

Identification of tetrodotoxin and fish species in a dried dressed fish fillet implicated in food poisoning.

There were five victims of neurotoxic food poisoning from a dried dressed fish fillet in Changhua County, Taiwan, in February 2000. The toxicity of the dried dressed fish fillets was 243 mouse units per g according to a tetrodotoxin bioassay. The partially purified toxin was identified as tetrodotoxin and anhydrotetrodotoxin. The sequence of the 376-nucleotide region in the cytochrome b gene of the mitochondrial DNA exhibited the same genotype as that of the toxic puffer fish Lagocephalus lunaris. The same single restriction site for Hinfl was found in the polymerase chain reaction (PCR) products from the dried dressed fish fillet and the muscle of L. lunaris, yielding two DNA fragments of 170 and 206 bp. However, no restriction site for Hinfl was found in the PCR products from other toxic puffer fishes, including Takifugu niphobles, Takifugu oblongus, and Takifugu rubripes. Therefore, the species of the dried dressed fish fillet was identified as L. lunaris and its causative agent was identified as tetrodotoxin.

Escombrointoxicación por consumo de bonito / Mackerel poisoning (Scomber intoxication) due to ingestion

La escombrointoxicación es un cuadro clínico consistente en náuseas, vómitos, diarrea, abdominalgia, quemazón oral, urticaria, eritema facial, cefalea, palpitaciones, hipotensión arterial y, excepcionalmente, distrés respiratorio y shock. Estas manifestaciones aparecen desde pocos minutos a horas tras la ingesta de pescado de la familia de los escómbridos (atún, bonito, caballa...), que no ha sido mantenido en óptimas condiciones de conservación, dando lugar a la proliferación de enterobacterias que transforman la histidina del músculo del pescado en histamina, sustancia responsable del cuadro. El diagnóstico de confirmación precisa determinar la concentración de histamina en las muestras del pescado sospechoso, pudiendo también realizarse en la orina y sangre de los pacientes. Es importante establecer un diagnóstico diferencial con una reacción alérgica alimentaria e identificar precozmente la fuente de intoxicación. El tratamiento básico consiste en antihistamínicos H1 y H2. Está por clarificar la eficacia de los corticoides. Presentamos cinco casos que atendimos recientemente (AU)

A small outbreak of listeriosis potentially linked to the consumption of imitation crab meat.

A small outbreak of listeriosis involving two previously healthy adults occurred in Ontario. Food samples obtained from the refrigerator of the patients included imitation crab meat, canned black olives, macaroni and vegetable salad, spaghetti sauce with meatballs, mayonnaise and water. All of the samples except the water contained Listeria monocytogenes. The three most heavily contaminated samples were the imitation crab meat, the olives and the salad which contained 2.1 x 109, 1.1 x 107 and 1.3 x 106 cfu g-1, respectively. L. monocytogenes serotype 1/2b was isolated from the patients, as well as from the opened and unopened imitation crab meat. Molecular typing of the isolates by both randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) typing demonstrated the imitation crab meat and clinical strains to be indistinguishable. Challenge studies performed with a pool of L. monocytogenes strains showed that imitation crab meat, but not olives, supported growth of the organism. In this study we have shown for the first time the potential involvement of imitation crab meat in a small outbreak of listeriosis. In terms of disease prevention, temperature control is critical to prevent or reduce the growth of this foodborne pathogen. In addition, with refrigerated products having a long (> 30 d) shelf life, additional safety factors must be used to prevent the growth of foodborne pathogens such as L. monocytogenes.