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Microbial utilization of the neurotoxin domoic acid: blue mussels (Mytilus edulis) and soft shell clams (Mya arenaria) as sources of the microorganisms.

The neurotoxin domoic acid is produced in quantity by the diatom Pseudo-nitzschia multiseries and is released to the environment directly and indirectly via food chains. Presumably there is a mechanism for the biodegradation and disposal of domoic acid and as bacteria are logical candidates for such an activity, a search for bacteria competent to carry out biodegradation of domoic acid was initiated. Extensive trials with a wide variety of bacteria isolated mainly from muds and waters taken from the marine environment showed that the ability to grow on or degrade domoic acid was rare; in fact, domoic acid was inhibitory to resting cells or growing cultures of most of these bacteria. In contrast, using enrichment techniques, it was possible to isolate from molluscan species that eliminate domoic acid readily, i.e., blue mussels (Mytilus edulis) and soft-shell clams (Mya arenaria), bacteria that exhibited growth with and biodegradation of domoic acid when supplemented with low concentrations of growth factors. The species that retain domoic acid for lengthy periods, such as sea scallops (Placopecten magellanicus) and red mussels (Modiolus modiolus), only occasionally yielded bacteria with this capability. The differences may be a result of the mechanisms used by the different shellfish in dealing with domoic acid, i.e., freely available in the blue mussels and soft-shell clams but likely sequestered in the digestive glands of sea scallops and red mussels and thus, largely unavailable for bacterial utilization. The results show that Mytilus edulis and Mya arenaria, almost uniquely, are prime and reliable sources of domoic acid utilizing bacteria. These findings suggest a strong possibility that autochthonous bacteria may be significant factors in the elimination of the neurotoxin in these two species of shellfish.

Animals↗

Manifestations of food allergy: evaluation and management.

The term "food allergy" refers to adverse immunologic reactions to food. Food allergy is usually mediated by IgE antibody directed to specific food proteins, but other immunologic mechanisms can also play a role. The primary target organs for food allergic reactions are the skin, the gastrointestinal tract and the respiratory system. Both acute reactions (hives and anaphylaxis) and chronic disease (asthma, atopic dermatitis and gastrointestinal disorders) may be caused or exacerbated by food allergy. The foods most commonly causing these reactions in children are milk, egg, peanuts, soy, wheat, tree nuts, fish and shellfish; in adults, they are peanuts, tree nuts, shellfish and fish. The diagnosis of food allergy requires a careful search for possible causes, confirmation of the cause(s) with supporting tests, including specific tests for IgE (i.e., prick skin tests, radioallergosorbent tests) and, in some cases, oral food challenges. Treatment consists of elimination of the causal food(s) along with medical treatment, including the prompt self-administration of epinephrine in the event of a serious reaction.

Diagnosis, Differential↗

First European case of gastroenteritis and bacteremia due to Vibrio hollisae.

Vibrio hollisae is a pathogenic Vibrio species known to cause gastroenteritis in humans after the consumption of shellfish. All cases of infection reported previously were restricted to the Atlantic and Pacific coasts of the United States. A case of gastroenteritis and bacteremia in a previously healthy 76-year-old man who ate cockles from the Quiberon Bay in Brittany, France, is described. This is the first report of Vibrio hollisae infection in Europe.

Aged↗

Spatial and temporal evolution of PSP toxins along the Atlantic shore of Morocco.

A monitoring program for bivalve molluscs contaminated by algal toxins was established in 1992 at different stations along the Atlantic Moroccan shore. The presence of toxicity in bivalve molluscs commercially exploited was tested fortnightly using the mouse bioassay method. Results obtained from this surveillance indicate paralytic shellfish poisoning is responsible for bivalve molluscs contamination along the Atlantic coastline of Morocco. Toxin profile was established by automated pre-column HPLC/FLD in selected contaminated tissues. The study of individual toxins in mussel during a bloom in the northern Atlantic coastline in 1994 showed a very complex profile, typical to that obtained with cultures of the toxigenic dinoflagellate Gymnodinium catenatum isolated from the Iberian region. However, toxin composition of mussels and marine beans from later blooms in the southern Atlantic coastline in 1999 showed a strong resemblance with that of Alexandrium minutum, due to dominance of gonyautoxins 1/4. A minor contamination by G. catenatum due to the presence of decarbamoyl-saxitoxin is hypothesized.

Animals↗

Outbreak of Vibrio parahaemolyticus gastroenteritis associated with Alaskan oysters.

BACKGROUND: Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis in the United States, typically is associated with the consumption of raw oysters gathered from warm-water estuaries. We describe a recognized outbreak of V. parahaemolyticus infection associated with the consumption of seafood from Alaska. METHODS: After we received reports of the occurrence of gastroenteritis on a cruise ship, we conducted a retrospective cohort study among passengers, as well as active surveillance throughout Alaska to identify additional cases, and an environmental study to identify sources of V. parahaemolyticus and contributors to the outbreak. RESULTS: Of 189 passengers, 132 (70 percent) were interviewed; 22 of the interviewees (17 percent) met our case definition of gastroenteritis. In our multiple logistic-regression analysis, consumption of raw oysters was the only significant predictor of illness; the attack rate among people who consumed oysters was 29 percent. Active surveillance identified a total of 62 patients with gastroenteritis. V. parahaemolyticus serotype O6:K18 was isolated from the majority of patients tested and from environmental samples of oysters. Patterns on pulsed-field gel electrophoresis were highly related across clinical and oyster isolates. All oysters associated with the outbreak were harvested when mean daily water temperatures exceeded 15.0 degrees C (the theorized threshold for the risk of V. parahaemolyticus illness from the consumption of raw oysters). Since 1997, mean water temperatures in July and August at the implicated oyster farm increased 0.21 degrees C per year (P<0.001 by linear regression); 2004 was the only year during which mean daily temperatures in July and August at the shellfish farm did not drop below 15.0 degrees C. CONCLUSIONS: This investigation extends by 1000 km the northernmost documented source of oysters that caused illness due to V. parahaemolyticus. Rising temperatures of ocean water seem to have contributed to one of the largest known outbreaks of V. parahaemolyticus in the United States.

Adolescent↗

Acute gastroenteritis associated with seafood privately imported from the Pacific Islands.

AIMS: To investigate a potential link between consumption of food privately imported from the Pacific Islands and presentation with acute gastroenteritis to Middlemore Hospital Emergency Department. METHODS: This was a three month prospective observational case study that included patients aged greater than fifteen years presenting with acute gastroenteritis and a history of food privately imported from the Pacific Islands. Data included case demographics, symptoms, island of food origin and food type. Stool and blood samples were collected and analysed. RESULTS: Of 358 patients who presented to Middlemore Emergency Department during the study period with gastroenteritis, 34 (9.4%) had a history of consumption of food privately imported from the Pacific Islands. The seafood came from Tonga (23 cases), Samoa (10 cases) or Niue (1 case). The implicated seafood was shellfish (28 cases), jellyfish (2 cases), fish intestine (2 cases), seaweed or seaslug (1 case each). Fourteen patients (41%) provided stool samples; all were culture positive for Vibrio parahaemolyticus (VPH). CONCLUSIONS: This case series confirms a link between acute VPH gastroenteritis and consumption of seafood privately imported from the Pacific Islands. A number of public health initiatives to reduce the burden of VPH gastroenteritis among Auckland's Pacific Islanders have commenced. The Ministries of Health, Agriculture and Forestry are considering tighter controls or banning food privately imported from the Pacific Islands.

Adolescent↗

[Domoic acid and human health].

Domoic acid (DA), structurally related to glutamic and kainic acid, mainly generated by Pseudo nitzschia diatom. It often contaminates halobios such as fish and seashell and cause the Amnesic Shellfish Poisoning in human beings with the consumption of foods contaminated by DA. DA has been detected from seafoods worldwide. As the frequent occurrence of red tide and outbreak of human poisoning, more and more studies focus on DA, especially on its excitotoxicity. The producing alga, physico - chemical properties, natural contamination of seafoods, information on human poisoning, toxicity and analytical methods of DA are reviewed.

Animals↗

Outbreak of Vibrio parahaemolyticus infection associated with eating raw oysters and clams harvested from Long Island Sound--Connecticut, New Jersey, and New York, 1998.

During July-September 1998, an outbreak of Vibrio parahaemolyticus infections associated with consumption of oysters and clams harvested from Long Island Sound occurred among residents of Connecticut, New Jersey, and New York. This is the first reported outbreak of V. parahaemolyticus linked to consumption of shellfish harvested from New York waters. This report summarizes the investigation of this outbreak.

Animals↗

Concentration and dispersal of a Pseudo-nitzschia bloom in Penn Cove, Washington, USA.

A bloom of the pennate diatom Pseudo-nitzschia, several species of which are associated with the production of the potent excitotoxin domoic acid, was observed in a Puget Sound, Washington embayment in July and August of 1997. Penn Cove, which receives nutrients from the nearby Skagit River and abundant sunshine during summer months due to its location in the rain shadow of the Olympic Mountains, is the home of a commercial mussel farm which supplies shellfish to many coastal areas of the USA. Levels of domoic acid in mussels increased to 3 ppm on 6 and 10 July, corresponding to the observation of a brown algal bloom in Penn Cove. Four species of Pseudo-nitzschia (P. pungens, P. multiseries, P. australis, and P. pseudodelicatissima) were present in our samples from the cove, corresponding to levels of domoic acid in seawater ranging from 0.1-0.8 mirog l(-1) as measured by a receptor binding assay. The highest Pseudo-nitzschia concentration during the time of our sampling was 13 million cells per liter on 28 July. The bloom of Pseudo-nitzschia occurred after a period of strong discharge from the Skagit River and rain accompanied by elevated south and southeasterly winds. Stratification of the cove, providing optimal bloom conditions, was facilitated by weak winds, sunshine, and a freshwater lens at the mouth of the cove. The position of the Pseudo-nitzschia bloom was influenced by buoyancy fronts caused by exchange of water within the cove with that of Saratoga Passage. The decay of this bloom in Penn Cove was accompanied by decreasing nitrate levels at all measured depths. These and future observations aid in the development of a model for prediction of toxic bloom events in the shallow embayments of Puget Sound.

Diatoms↗

Effects of nitrogen concentration and cold temperature on DSP-toxin concentrations in the dinoflagellate Prorocentrum lima (Prorocentrales, Dinophyceae).

The diarrhetic shellfish poisoning toxin-producing dinoflagellate, Prorocentrum lima, isolated from Nova Scotian waters, contained both okadaic acid (OA) and dinophysistoxin-1 (DTX-1) throughout its growth cycle in culture; maximum concentrations of toxins and highest OA/DTX-1 ratios occurred during the stationary phase. Cells of P. lima survived 0 degrees C for 5 weeks and recovered when brought to a higher temperature. During the cold period, some cell damage probably occurred with concomitant losses of toxins to the medium. Nitrogen concentration in the medium was used to limit growth or stress the cells physiologically, and when growth was limited, increases in toxin associated with the cells were recorded. The relative amounts of okadaic acid were always greater than dinophysistoxin-1, but the significance of these ratios remains to be determined.

Animals↗

The effect of psychological stress on neutrophil superoxide release.

Stress has long been suggested to exacerbate symptom expression in people with chronic inflammatory disorders. The release of oxidative metabolites from activated PMN plays a significant role in the pathophysiology of inflammation. Thus, we examined the effects of psychological stress on release of superoxide anions from PMN of rats with or without an inflammation induced by injection of shellfish glycogen (SFG). Psychological stress was found to significantly increase PMN superoxide release in both healthy and SFG-injected animals. Total amounts of superoxide release were similar between the two groups, suggesting that PMN from animals with a mild inflammatory condition were not more susceptible to the effects of stress than PMN from healthy animals. However, this study should be repeated using an animal model of chronic inflammation, such as airway hyperactivity or rheumatoid arthritis.

Analysis of Variance↗

Analysis of uranium and isotopic ratio measurement in fish and marine invertebrates from the North Adriatic Sea by inductively coupled plasma mass spectrometry.

Uranium analysis in fish, echinoderms and shellfish samples collected in the north part of the Adriatic Sea is presented. The aim of the work was to evaluate uranium concentrations in samples of this kind, and also to investigate possible contamination from depleted uranium (DU) in consequence of the war operations previously conducted in that area. DU contamination was checked by measuring the (235)U/(238)U isotope ratio. The samples were dissolved according to the EPA 3052 procedure, and the determinations were performed by inductively coupled plasma mass spectrometry (ICP-MS), optimized in order to perform isotope ratio measurements with good precision. The method was validated by evaluating the recovery from spiked samples; results in the range 93-107% were obtained. The isotope ratio measurement was evaluated in terms of accuracy and precision by analyzing the certified reference materials IAEA 326 and GBW 07305, and good agreement with the certified values was obtained here also. The concentration of uranium was higher in invertebrate samples than in fish (0.3-2 microg/g of U vs. 0.05-0.1 microg/g, respectively). The isotope ratio measurements for all the samples gave values very similar to the natural ratio, permitting exclusion of the presence of DU.

Animals↗

Determinants of cadmium burden levels in a population of children living in the vicinity of nonferrous smelters.

This report covers part of the assessment of a site in northern France polluted by industrial metal emissions. Our objectives were to assess the cadmium burden in children aged 8 to 11 years and look for factors that affected it. A cross-sectional population-based study took place in 1996-1997 and included 400 children (200 in the metal-polluted area). The geometric mean of the blood cadmium (CdB) levels of children living on the polluted site was 0.51 microg/L (95% CI=[0.49-0.53]); that of the nonexposed children was 0.47 microg/L (95% CI=[0.45-0.49]) (P<0.01). The geometric mean of the urinary cadmium (CdU) levels of children living on the polluted site was 1.16 microg/g creatinine (95% CI=[1.01-1.34]); that of the nonexposed children was 0.99 microg/g creatinine (95% CI=[0.86-1.14]) (P=0.10). Mean CdB was higher among children within 4 km of a zinc smelter and consuming > or =500 ml of tap water daily (x1.34; 95% CI=[1.14-1.51]) compared with children living more than 4 km away and consuming <500 ml of tap water daily. Independently of this association, consumption of fish and shellfish (> or =once a week vs. or =once daily vs. <once daily) was associated with higher mean CdB levels, respectively: x 1.14; 95% CI=[1.07-1.21] and x 1.25; 95% CI=[1.04-1.50]. Neither sex nor age was associated with CdB. Mean CdU was associated with paternal occupational cadmium exposure.

Animals↗

Presence of phospholipase-D (dly) gene coding for damselysin production is not a pre-requisite for pathogenicity in Photobacterium damselae subsp. damselae.

The presence of the phospholipase-D (dly) gene as pre-requisite for virulence of Photobacterium damselae subsp. damselae for poikilotherm and homoiotherm animals was investigated in a total of 17 strains isolated from fish, shellfish, mammals and seawater. With this aim, we developed two PCR protocols. A simple PCR using primers flanking the almost complete dly gene, and a multiplex-PCR using two sets of primers directed to internal fragments of the dly and 16S rRNA genes. Only six of the 17 Ph. damselae subsp. damselae strains studied harboured the dly gene regardless of their haemolytic activity against sheep or rabbit erythrocytes as well as their virulence for mammals and marine fish. In fact, all strains but one were pathogenic for one or both animals, with LD(50)values ranging from 1x10(3)and 3x10(5)bacteria for turbot, and 2x10(6)and 8x10(7)cells for mice. The PCR results were corroborated in dot blot hybridization experiments employing a DNA probe directed to an internal region of the dly gene. From the data obtained in this work, we can conclude that the presence of the dly gene is not an indicative of the pathogenicity of Ph. damselae subsp. damselae and, therefore, the role of damselysin as the main virulence factor of this marine bacterium for poikilotherm and homoiotherm hosts should be re-evaluated.

Animals↗

Viral infections transmitted by food of animal origin: the present situation in the European Union.

The goal of this presentation was to clarify which foods are involved in viral diseases, which viruses are transmitted via food and how to evaluate the risk of a foodborne viral infection. Food items frequently identified as cause of viral disease outbreaks were shellfish harvested in sewage-contaminated water. Another common source of foodborne viral illness was cold food contaminated by infected food handlers. In the European Union the viruses most frequently associated with foodborne illness were hepatitis A virus and the SRSV's. A few isolated cases of foodborne hepatitis E were reported in Mediterranean countries. Compared to other foodborne diseases, those caused by viruses are less severe and seldom fatal. This might be a reason why the problem of viral contamination of food has been neglected. Yet, because many foodborne viral diseases are not recognized either as foodborne or as caused by viruses, the actual number of cases must be assumed to be significantly higher than the reported number. Consequently, food associated diseases of viral origin should be granted more attention.

Animals↗

An epidemiologic study of thyroid cancer in Hawaii.

A population-based case-control interview study was designed to test the hypothesis that dietary iodine or the consumption of goitrogenic vegetables increases the risk of thyroid cancer. A total of 191 histologically confirmed cases (64 percent female) and 441 matched controls from five ethnic groups in Hawaii were available for analysis. Among women, intake of seafood (especially shellfish), harm ha (a fermented fish sauce), and dietary iodine were associated with an increased risk of cancer, whereas consumption of goitrogenic (primarily cruciferous) vegetables was associated with a decreased risk. Non-dietary risk factors included miscarriage (especially at first pregnancy), use of fertility drugs, family history of thyroid disease, obesity, and work as a farm laborer. The odds ratio for the combined effect of a high iodine intake and a first-pregnancy miscarriage was 4.8 (95 percent confidence interval [CI] = 1.2-19.2); and for high iodine intake and use of fertility drugs 7.3 (95 percent CI = 1.5-34.5). Among men, positive associations were found for obesity, work as a farm laborer, and a past history of benign thyroid disease. Although this study identified several dietary and non-dietary risk factors for thyroid cancer, it could not fully explain the exceptionally high incidence rates among Filipino women in Hawaii.

Adult↗

Diarrhetic mussel poisoning in the Netherlands related to the dinoflagellate Dinophysis acuminata.

In 1961, 1971, 1976, 1979 and 1981 several cases of mussel poisoning have been recorded in the Netherlands. During the outbreak of this phenomenon, consumers of raw or cooked mussels, Mytilus edulis, obtained from the Dutch shellfish-growing areas, showed gastrointestinal disorders. Investigations revealed that phytoplankton bloom of the dinoflagellate Dinophysis acuminata Claparède & Lachman preceded the mussel poisoning. After the disappearance of these dinoflagellates, the toxicity of mussels was slowly diminishing and no longer detectable after a cleansing period of about 4 weeks at 14-15 degrees C. Toxicity of mussels could easily be detected by the rat bioassay. The chemical structure of the toxin, isolated in 1981 from toxic mussels from the Dutch Waddensea has been determined in Japan as a dinophysis-type toxin.

Bivalvia↗

Integrated epidemiological system for acute viral hepatitis in Italy (SEIEVA): description and preliminary results.

An integrated epidemiological system for the surveillance of acute viral hepatitis SEIEVA which linked notifications to available serology results and used a standard risk factor questionnaire is described. Results of over 1300 cases reported by 35 participating local health units (USL's) during the first 18 months of the programme are presented. Overall the annual reported incidence of acute viral hepatitis was 70 per 100,000. There were marked regional and age specific differences in the incidence of each type of viral hepatitis. The annual incidence per 100,000 of hepatitis A in southern children was 133 while in northern young adults the incidence of hepatitis B was 88 and hepatitis non-A non-B was 43. The possible roles of shellfish consumption in the transmission of non-A non-B hepatitis at all ages were highlighted.

Acute Disease↗