Sustainable food systems are those in which diverse foods are produced in close proximity to a market. A dynamic, adaptive knowledge base that is grounded in local culture and geography and connected to outside knowledge resources is essential for such food systems to thrive. Sustainable food systems are particularly important to remote and Aboriginal communities, where extensive transportation makes food expensive and of poorer nutritional value. The Learning Garden program was developed and run with two First Nation communities in northwestern Ontario. With this program, the team adopted a holistic and experiential model of learning to begin rebuilding a knowledge base that would support a sustainable local food system. The program involved a series of workshops held in each community and facilitated by a community-based coordinator. Topics included cultivated gardening and forest foods. Results of survey data collected from 20 Aboriginal workshop participants are presented, revealing a moderate to low level of baseline knowledge of the traditional food system, and a reliance on the mainstream food system that is supported by food values that place convenience, ease, and price above the localness or cultural connectedness of the food. Preliminary findings from qualitative data are also presented on the process of learning that occurred in the program and some of the insights we have gained that are relevant to future adaptations of this program.
Bath treatment pharmaceuticals used to control sea lice infestations in the salmonid industry, such as hydrogen peroxide (H2O2), are released directly into the environment where non-target organisms are at risk of exposure. The aim of this study was to determine the threshold concentrations for mortality of the Northern krill, Meganyctiphanes norvegica, a major component of the north Atlantic marine ecosystem. To assess the lethal effects of H2O2, we carried out a series of 1 h acute toxicity tests and assessed mortality through a 48 h post-exposure period. One-hour exposure to 170 mg/L, corresponding to 10% of the recommended H2O2 treatment, caused 100% mortality and a subsequent acute median-lethal concentration LC50 value of 32.5 mg/L. Increased mortality was observed with time in all exposed groups, resulting in successively lower LC50 values during the post-exposure period. The suggested H2O2 concentrations have the potential of causing negative effects to the Northern krill.
We aim to investigate the prevalence, putative virulence factors and antimicrobial resistance of mesophilic Aeromonas isolated from ready-to-eat (RTE) seafood available on the Norwegian market, and to assess the potential risks by consuming RTE seafood to consumers.
The prevalence of mesophilic Aeromonas in 148 RTE seafood was investigated and the highest prevalence was found in retail sushi (17%), followed by oysters (10%), fresh salmon loins (10%) and scallops (4%). Among 43 Aeromonas isolates, 75% of them were identified as A. media, 23% as A. salmonicida and 2% as A. bestiarum based on partial gryB gene sequencing. Aeromonas isolates were potentially pathogenic due to the presence of four virulence genes: alt (73%), hylA (22%), aerA (17%) and act (6%). In addition, all isolates were resistant to ampicillin and erythromycin. Most of the isolates (98%) were multidrug resistant.
The occurrence of potentially pathogenic and multidrug-resistant Aeromonas strains in RTE seafood implies a potential risk to consumers. Our finding suggests that RTE seafood could be a potential vehicle for the transfer of virulent and multidrug-resistant Aeromonas.
To our knowledge, this is the first study to report multiple antibiotic resistance in Aeromonas associated with RTE seafood in Norway.
In an ongoing study of the hypothesised association between consumption of fish contaminated with persistent organochlorine compounds and low birth weight, a relevant measure of exposure is the accumulated fish consumption over long time periods. An issue of concern in this study is the quality of the retrospective exposure assessments. The present investigation was undertaken to determine the agreement between reported fish consumption in two interviews with approximately one year in between. in order to evaluate its impact on the effect estimates. The agreement decreased with increasing retrospective time interval between interview and focused time period of fish consumption. Furthermore, the exposure assessments based on the two interviews led to considerably different effect estimates.
During the last decade, cases of the fish parasite Anisakis simplex infection and allergy in human have increased in countries with high fish consumption. Our aim was to perform an extended seroprevalence study of anti-IgE antibodies against this parasite in Norway, one of the high fish-consuming countries. At the Department of Immunology and Transfusion Medicine and the Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway, two main groups of anonymized serum samples were collected; the first (n = 993) from recently recruited blood donors (designated 'BDO') and the second (n = 414) from patient with total IgE levels =1000 kU/l (designated 'IGE+'). The sera were analysed by the ImmunoCAP(®) method for total IgE and IgE antibodies against A. simplex, house dust mite (HDM), shrimp, cod, crab, brine shrimp and shrimp tropomyosin. The A. simplex positive sera were further tested by an enzyme-linked immunosorbent assay (ELISA) method, which uses 2 recombinant (r) major allergens, rAni s 1 and rAni s 7 as target antigens. SDS-PAGE and Western immunoblotting analyses were also performed. Whereas the prevalences by ImmunoCAP(®) were 0.4% and 16.2% in the BDO and IGE+ groups, respectively, analyses with recombinant allergens showed only 0.0% and 0.2%. Cross-reactivity and immunoblotting analyses suggested that most of the ImmunoCAP(®) positive sera were probably false-positive due to cross-sensitization to shrimp and HDM. However, positivity due to other A. simplex antigens should also be considered. Compared with other high fish-consuming countries, we observed a very low seroprevalence of anti-Anisakis IgE antibodies in a Norwegian population.
Epidemiological studies suggest that fish consumption may be a protective factor against the development of prostate cancer. We investigated the association between prostate cancer risk and fresh and preserved fish consumption among participants of a population-based case-control study (1,534 cases, 1,607 controls). Fish intake was measured using a dietary questionnaire that collected both frequency of consumption of a given portion size. Logistic regression analysis demonstrated an inverse association between preserved fish and prostate cancer risk for all levels of consumption, but reductions only reached statistical significance for the category of 1 to 3 servings of preserved fish per month (odds ratio = 0.78, confidence interval = 0.64-0.95). Consumption of any fat or energy from preserved fish was also associated with reduced risk. There was no suggestion of reduced prostate cancer risk with consumption of fresh and canned fish. Our results suggest that consumption of preserved fish may reduce the risk of developing prostate cancer.
The natural microflora of cold-smoked fish at the end of shelf-life are lactic acid bacteria (LAB). Some of these display a capacity to inhibit spoilage as well as several strains of pathogenic micro-organisms, e.g. Listeria monocytogenes which is isolated frequently from cold-smoked salmon (CSS). Eight batches of sliced vacuum-packed CSS from Norway, Scotland and Spain were collected at retail. Packs were stored at 5 degrees C and examined for chemical and microbiological characteristics, at purchase date and at expiration date. pH, water activity and salt content were similar to available data on lightly preserved fish products. There was a consistent pattern in the development of the microflora on CSS; the initial level of LAB was low on freshly produced CSS (10(2) cfu g(-1)); however, storage in vacuum packaging at refrigeration temperature was elective for LAB. At the end of the stated shelf-life these micro-organisms, represented mainly by Lactobacillus spp., attained ca.10(7) cfu g(-1) while Enterobacteriaceae counts were consistently lower (10(5) cfu g(-1)), which indicates the ability of LAB to grow and compete with few carbohydrates available and in the presence of moderate salt concentrations. L. monocytogenes was not found in any sample. Forty-one percent of LAB strains isolated exhibited inhibitory capacity against Listeria innocua, in a plate assay. A majority of the inhibitory effects were non-bacteriocinogenic, but nevertheless were very competitive cultures which may provide an additional hurdle for improved preservation by natural means.
Vibrio vulnificus is a bacterium indigenous to estuarine waters and is known to be a significant human pathogen. Infections are generally associated with the consumption of raw oyster. In an attempt to identify possible antimicrobial agents against this organism that might be used in foods, ten compounds that are generally recognized as safe (GRAS) by the FDA were tested against both the opaque and translucent morphotypes of V. vulnificus. Eight of those compounds had a lethal effect for both morphotypes of this bacterium. Diacetyl had the lowest lethal concentration (50 ppm) of the GRAS compounds tested within 24 h. Lactic acid and butylated hydroxyanisole possessed lethal activities at 300 ppm and 400 ppm, respectively, within 3 h. The mode of action of lactic acid against V. vulnificus appears to be an effect primarily of pH, while the antimicrobial activities of diacetyl and BHA appeared not to be affected by pH. No significant differences were found for opaque to translucent, or from translucent to opaque switching, in examining the possible effects of the GRAS compounds on colonial morphology.
World Health Organization (WHO), in cooperation with the Consortium to Perform Human Biomonitoring on a European Scale (COPHES), has developed a standardized methodology for human biomonitoring (HBM) surveys in maternities in order to assess prenatal exposure to mercury. To test this standard methodology and adapt it to Russian settings, a cross-sectional HBM survey involving 120 parturient women was conducted in six maternities of the Moscow Region. Levels of total mercury in maternal hair (geometric mean: 0.21 µg/g, 95th percentile: 0.54 µg/g), cord blood (0.89 µg/L and 2.38 µg/L, respectively) and maternal urine (0.27 µg/L and 0.94 µg/L) in this population were similar to those in other European countries with relatively low fish consumption. Consumption of all types of fish at least once per week during the third trimester of pregnancy compared to fish consumption less than once per month was associated with the increase of geometric mean level of total mercury: in hair by 31% (95% confidence interval: 4%, 66%) higher, in cord blood--by 38% (9%, 74%) and in maternal urine--by 36% (2%, 81%). No biomarker values exceeded levels recommended by WHO or national agencies in the USA and Germany. However; at the population level, adverse effects of prenatal exposures to mercury can still be substantial.