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PubMed1991

Risk assessment of ochratoxin A residues in food.

Ochratoxin A is a mycotoxin that has been found to occur in foods of plant origin, in edible animal tissues and in human sera and tissues. The ability of ochratoxin A to move up the food chain is associated with its long half-life in certain edible animal species. In this presentation, approaches for the evaluation of the health risks due to the presence of ochratoxin A in food products are described. The major target for ochratoxin A toxicity in all mammalian species tested is the kidney, and endemic nephropathies affecting livestock as well as humans have been attributed to ochratoxin A. Ochratoxin A is also teratogenic, and in the fetus the major target is the developing central nervous system. Recent studies have provided 'clear evidence' for the carcinogenicity of ochratoxin A in two rodent species. It was found to be non-mutagenic in various microbial and mammalian gene mutation assays, but weak genotoxic activity to mammalian cells was noted. In addition, ochratoxin A was found to suppress immune function. On the basis of a carcinogenicity study with ochratoxin A in rats, reported from the National Toxicology Program in the USA, the estimated tolerable daily intake of ochratoxin A in humans ranges from 1.5 to 5.7 ng/kg bw per day, depending on the method of extrapolation used. The worst-case estimate for daily exposure to ochratoxin A from the consumption of pork-based food products and cereal foods for young Canadian children, the highest consumption group on a body weight basis, is probably less than 1.5 ng/kg body weight per day (mean of eaters). In view of the toxic properties of ochratoxin A, it is recommended that exposure to this toxin be kept to a minimum.

Abnormalities, Drug-Induced↗
PubMed2006

Antimicrobial resistance in Irish isolates of verocytotoxigenic Escherichia coli (E. coli)--VTEC.

This study compared the antimicrobial resistance profiles of Escherichia coli O157:H7 isolates (n=257) recovered from bovine hides, minced beef and human clinical samples in Ireland, to those profiles of a range of Irish non-O157 E. coli (O111 and O26) isolates (n=31) from a variety of clinical and veterinary sources. Four multi-drug resistant (MDR) E. coli O157:H7 food isolates were identified, with resistance to 10 (1 isolate), 6 (1 isolate) and 4 (2 isolates) antimicrobial agents, respectively. Two of these isolates (resistant to 7 and 4 antimicrobial classes) were characterised further by molecular methods and found to contain class 1 integrons along with a beta-lactamase-encoding tem-1 gene. Transfer of antimicrobial resistance (ampicillin, streptomycin and sulphonamides), the tem-1 gene and markers (int1, qacEDelta1, sul1) characteristic of class 1 integrons were evident in one MDR isolate (resistant to 4 antimicrobial classes) when conjugation and transformation experiments were performed. A clinical isolate and a veterinary isolate of the O111 serotype were MDR and resistant to 4 and 3 antimicrobial classes, respectively. These data suggest that the prevalence of antimicrobial resistance among the three VTEC serotypes examined in this study is low. However, these organisms may become a public health risk should they enter the food chain.

Animals↗
PubMedDate not supplied

Avian cytokines - the natural approach to therapeutics.

While the effective use of antibiotics for the control of human disease has saved countless lives and has increased life expectancy over the past few decades, there are concerns arising from their usage in livestock. The use of antibiotic feed additives in food production animals has been linked to the emergence in the food chain of multiple drug-resistant bacteria that appear impervious to even the most powerful antimicrobial agents. Furthermore, the use of chemical antimicrobials has led to concerns involving environmental contamination and unwanted residues in food products. The imminent banning of antibiotic usage in livestock feed has intensified the search for environmentally-friendly alternative methods to control disease. Cytokines, as natural mediators and regulators of the immune response, offer exciting new alternatives to conventional chemical-based therapeutics. The utilisation of cytokines is becoming more feasible, particularly in poultry, with the recent cloning of a number of avian cytokine genes. Chickens offer an attractive small animal model system with which to study the effectiveness of cytokine therapy in the control of disease in intensive livestock. In this report we will review the status of avian cytokines and focus on our recent studies involving the therapeutic potential of chicken interferon gamma (ChIFN-gamma) as a vaccine adjuvant and a growth promoter.

Animals↗
PubMed2005

Elemental composition of Jamaican foods 1: a survey of five food crop categories.

The concentrations of 27 elements in Jamaican food categories consisting of fruit, legumes, leafy and root vegetables and other root crops are reported. The main analytical techniques used were neutron activation analysis and flame and graphite furnace atomic absorption spectrophotometry. The results are compared, where possible, with values from Denmark, the United Kingdom, the United States and Nigeria, and with some regulatory limits. Over 75% of the results for antimony, arsenic, barium, cerium, thorium and uranium were below the respective sample detection limits but even among these, some of the maximum values observed indicate that further examination may be useful for those foods grown in the regions of highest uptake and consumed in large amounts. The other elements reported are bromine, cadmium, calcium, caesium, cerium, chromium, copper, europium, hafnium, iron, lanthanum, lead, magnesium, manganese, phosphorus, potassium, rubidium, scandium, samarium, sodium, strontium, thorium, uranium, and zinc. Many of these elements occur at concentration levels above those reported from the other countries but it seems unlikely that most of these will contribute significantly to public health risk. However, at this stage cadmium clearly appears to be the element of greatest concern in the Jamaican food chain. The observed range of cadmium concentrations suggests that factors such as land selection, coupled perhaps where necessary, with suitably modified agricultural practices, is a feasible way to reduce the cadmium content of certain local foods.

Animals↗
PubMed2006

Temporal changes in dietary fats: role of n-6 polyunsaturated fatty acids in excessive adipose tissue development and relationship to obesity.

The importance of a high fat intake in the increasing prevalence of childhood and adult obesity remains controversial. Moreover, qualitative changes (i.e. the fatty acid composition of fats) have been largely disregarded. Herein is reviewed the role of polyunsaturated fatty acids (PUFAs) of the n-6 series in promoting adipogenesis in vitro and favouring adipose tissue development in rodents during the gestation/suckling period. Epidemiological data from infant studies as well as the assessment of the fatty acid composition of mature breast milk and infant formulas over the last decades in the Western industrialized world are revisited and appear consistent with animal data. Changes over decades in the intake of n-6 and n-3 PUFAs, with a striking increase in the linoleic acid/alpha-linolenic ratio, are observed. In adults, using a consumption model based upon production data, similar changes in the PUFA content of ingested lipids have been found for France, and are associated with an increase of fat consumption over the last 40 years. These profound quantitative and qualitative alterations can be traced in the food chain and shown to be due to changes in human dietary habits as well as in the feeding pattern of breeding stock. If prevention of obesity is a key issue for future generations, agricultural and food industry policies should be thoroughly reevaluated.

Adipogenesis↗
PubMed2006

Assuring food safety: the complementary tasks and standards of the World Organisation for Animal Health and the Codex Alimentarius Commission.

The Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organization specifically recognises the international standards developed by the World Organisation for Animal Health (OIE) and the Codex Alimentarius Commission (CAC). OIE standards focus on animal health and zoonoses and those of the CAC on food safety, but since zoonoses can affect food safety, it is vital that the two organisations cooperate closely to avoid duplication of effort, gaps and conflicting standards. The OIE has established an Animal Production Food Safety Working Group to promote cooperation with the CAC and to act as a steering committee for the OIE's work programme on the development of standards aimed at protecting consumers from foodborne hazards arising from animals at the production level of the food chain. This paper describes briefly how standards are developed by the OIE and the CAC and gives examples of how the tasks and standards of the two organisations complement each other in helping to assure food safety. The areas covered include meat hygiene, the identification and traceability of live animals, model certificates for international trade, antimicrobial resistance, veterinary drugs, animal feed, and salmonellosis.

Animal Welfare↗
PubMedDate not supplied

[The migration of radionuclides from global fallout in the trophic chains of biogeocenoses in arid zones].

Radionuclide (137Cs and 90Sr) content in soil, plants, terrestrial vertebrates and invertebrates has been studied in Kalmyk ASSR, Turkmenian SSR, and Great Gobi Reserve (Mongolia). The content of radionuclides accumulated by wild animals in arid zone biogeocenoses and the patterns of radionuclide migration along food chains have been estimated. 90Sr was found to be involved in biological cycles with participation of soil and terrestrial organisms 3-23 times more intensively than 137Cs.

Animals↗
PubMed2006

[Significance of Escherichia coli O157 in sheep at slaughter in Switzerland].

The importance of latent zoonoses has increased in recent years in view of foodborne diseases: (i) the "healthy" animal repesents a reservoir for specific pathogens; () no pathological-anatomical changes in the carcass and its organs show the presence of these pathogens; and (iii) these pathogens may enter the food chain via hygienic weak points in the slaughtering process. To estimate the risks involved and to take appropriate measures, analysis of the slaughtering process should be complemented by collecting data relating to the carriage of the animals of latent zoonotic pathogens. From October 2004 to June 2005, fecal samples from 630 slaughtered sheep were enriched and then examied by IMS technique and by PCR to assess the prevalence of E. coli O157 (OE). Seven samples (1.1%), distributed throughout the whole examination period, were found to be positive. To assess the potential pathogenicity for humans, E. coli O157 strains were isolated by colony hybridization and further characterized. The isolated strains fermented Sorbitol, showed four different H tys (H7, H12, H38, H48), and were all negative for stx. One O157:H7 strain harbored the gene for intimin (eae) in combination with ehxA, and paa. In consequence, the potential health hazard from sheep meat related to O157 STEC seems current not to be of particular importance in Switzerland. Results emphasize the fact that E. coli O157 are not always STEC but may belong to other pathotypes as nontraditional EPEC.

Abattoirs↗
PubMed2003

Detection of Shiga toxin-producing Escherichia coli in food.

Shiga toxin-producing Escherichia coli are emerging as a significant source of food-borne infectious disease all over the world. Illness caused by Shiga toxin-producing E. coli can range from self limited, watery diarrhea to life-threatening manifestations such as hemorrhagic colitis, hemolytic uremic syndrome or thrombotic thrombocytopenic purpura and death. Shiga toxin-producing E. coli can potentially enter the human food chain from a number of animal sources, most commonly by contamination of meat with feces or intestinal contents after slaughter or cross-contamination of unpasteurized milk products. Because of the low infectious dose of the O157:H7 Shiga toxin-producing E. coli strain, laboratory diagnosis of Shiga toxin-producing E. coli in food samples has developed a great importance. This review will focus on the microorganism, giving priority to illness prevention and Shiga toxin-producing E. coli detection in food.

Animals↗
PubMed1997

Potential for secondary poisoning and biomagnification in marine organisms.

For selected priority pollutants, like organochlorine pesticides, PAHs and PCBs, and mercury and cadmium, the transfer along marine food chains was assessed based on monitoring data. Comparison of the acquired body burden for marine fish and the toxicity thresholds for predating marine birds and mammals provides evidence for the relevance of contaminant uptake with the food and the liability for secondary poisoning. As a consequence, contaminant residues in prey organisms (critical body burden) should be used for marine hazard and risk assessments. Evaluations solely from aquatic exposure concentrations are not adequate to account for potential secondary effects in marine ecosystems.

Animals↗
PubMed1999

Shiga toxin-producing Escherichia coli in sheep and pre-slaughter lambs in eastern Australia.

Sheep and lambs from 14 farms in southern Queensland and one from central New South Wales were surveyed to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC). STEC, isolated from 45% of 144 sheep faeces collected on the farms and 36% of 72 lamb faeces from abattoir yards, were tested for the presence of genes encoding virulence factors. Most (64%) of the 117 STEC isolates contained Shiga toxin 1 and 2 genes, 22% contained those encoding Shiga toxin 1, and 14% contained genes encoding Shiga toxin 2. The genes encoding the E. coli attaching and effacing factor were present in 2.6% of STEC and 26% contained the enterohaemolysin gene. The isolates that contained the E. coli attaching and effacing gene were serotype O157:H. This study has shown that STEC are widely distributed in eastern Australian sheep and lambs and are shed in their faeces prior to slaughter. Thus, there is potential for contamination of carcasses and entry of STEC into the human food chain.

Adhesins, Bacterial↗
PubMed2001

Comparison of different digestive tract models for estimating bioaccessibility of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) from red slag 'Kieselrot'.

'Kieselrot' (red slag), a highly PCDD/F-contaminated leaching residue from a copper production process, has been used as surface layer for more than 1,000 sports fields, playgrounds and pavements in Germany and neighbouring countries. Children can ingest this material directly by hand-to-mouth activities or soil-pica behaviour. Furthermore secondary contamination of farm land or kitchen gardens by drift of red slag dust may lead to an enrichment of PCDD/F within the food-chain. PCDD/F can be mobilized from contaminated materials by digestive juices and thus become bioaccessible for intestinal absorption. Two different digestive tract models were used to estimate the bioaccessibility of PCDD/F from red slag and to study the influence of food material on the mobilization of the contaminants. The bioaccessibility of PCDD/F from red slag depends on the charge of red slag material used, the bile content of the intestinal juice and on the presence of lipophilic foodstuffs. A low bioaccessibility of less than 5% was found when using a digestive tract model with a low bile content and in absence of food material. The bioaccessibility was estimated to be more than 60% when using a model with a higher bile content and in the presence of whole milk powder. A low bioaccessibility of PCDD/F from red slag in general--as assumed until now and mentioned in legal provision--was not confirmed by our study. Considering observations for the different homologue groups it is obvious that bioaccessibility is the first of several important steps to estimate human health risks arising from contaminated materials. In case red slag contaminated with PCDD/F their absorption rate in the digestive tract and/or metabolism might be at least just like important.

Benzofurans↗
PubMed1992

The effect of potassium on the uptake of 137Cs in food crops grown on coral soils: coconut at Bikini Atoll.

The soils of Bikini Atoll (11 degrees 35'N, 165 degrees 25'E) were contaminated by fallout from a thermonuclear explosion in 1954. Today, in the absence of any treatment, intake of 137Cs via the terrestrial food chain could account for 70% of the radiological dose received by a returning population. Therefore, we examined the effectiveness of potassium applications, alone and combined with nitrogen and phosphorus, in reducing 137Cs uptake by coconut (Cocos nucifera L.), a major food crop. Mean pretreatment concentrations of 137Cs in "drinking-nut" meat of approximately 17-y palms ranged from approximately 0.5 to 7.0 kBq kg-1 (approximately 14 to 190 pCi g-1) (wet mass) in the seven primary experiments reported. These values were reduced to approximately 0.06 to approximately 1.0 kBq kg-1 (approximately 1.6 to approximately 27 pCi g-1) following soil additions of potassium-chloride at rates from 670 to 6270 kg potassium ha-1. Major reductions were complete within 9-12 mo after single large applications and persisted for at least 3 y. Proportional reductions in associated drinking-nut fluid and in mature "copra nut" meat from the same palm also occurred. Comparable but shorter-lived reductions occurred in grass and herbaceous species beneath the palms. A combined nitrogen-phosphorus treatment had no additive effect in the presence of potassium but, by itself, reduced plant uptake by about 50%. The persistence of this effect suggested that phosphorus alone was the major factor. Periodic addictions of potassium at rates of approximately 1000 kg ha-1 would provide a feasible and highly effective means of reducing 137Cs in coconut food products.

Cesium Radioisotopes↗
PubMed2005

Return of the cycad hypothesis - does the amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) of Guam have new implications for global health?

Recently published work provides evidence in support of the cycad hypothesis for Lytico--Bodig, the Guamanian amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC), based on a new understanding of Chamorro food practices, a cyanobacterial origin of beta-methylaminoalanine (BMAA) in cycad tissue, and a possible mechanism of biomagnification of this neurotoxic amino acid in the food chain. BMAA is one of two cycad chemicals with known neurotoxic properties (the other is cycasin, a proven developmental neurotoxin) among the many substances that exist in these highly poisonous plants, the seeds of which are used by Chamorros for food and medicine. The traditional diet includes the fruit bat, a species that feeds on cycad seed components and reportedly bioaccumulates BMAA. Plant and animal proteins provide a previously unrecognized reservoir for the slow release of this toxin. BMAA is reported in the brain tissue of Guam patients and early data suggest that some Northern American patients dying of Alzheimer's disease (AD) have detectable brain levels of BMAA. The possible role of cyanobacterial toxicity in sporadic neurodegenerative disease is therefore worthy of consideration. Recent neuropathology studies of ALS/PDC confirm understanding of this disorder as a 'tangle' disease, based on variable anatomical burden, and showing biochemical characteristics of 'AD-like' combined 3R and 4R tau species. This model mirrors the emerging view that other neurodegenerative disease spectra comprise clusters of related syndromes, owing to common molecular pathology, with variable anatomical distribution in the nervous system giving rise to different clinical phenotypes. Evidence for 'ubiquitin-only' inclusions in ALS/PDC is weak. Similarly, although there is evidence for alpha-synucleinopathy in ALS/PDC, the parkinsonian component of the disease is not caused by Lewy body disease. The spectrum of sporadic AD includes involvement of the substantia nigra and a high prevalence of 'incidental'alpha-synucleinopathy in sporadic AD is reported. Therefore the pathogenesis of Lytico-Bodig appears still to have most pertinence to the ongoing investigation of the pathogenesis of AD and other tauopathies.

Amyotrophic Lateral Sclerosis↗
PubMed2006

Development and assessment of a rapid method to detect Escherichia coli O26, O111 and O157 in retail minced beef.

A molecular-based detection method was developed to detect Escherichia coli O26, O111 and O157 in minced (ground) beef samples. This method consists of an initial overnight enrichment in modified tryptone soya broth (mTSB) and novobiocin prior to DNA extraction and subsequent serogrouping using a triplex PCR. This method has a low limit of detection and results are available within 24 hours of receipt of samples. Once optimized, this rapid method was utilized to determine the prevalence of these E. coli serogroups in six hundred minced beef samples all of which were previously examined by immunomagnetic separation (IMS) and selective plating for E. coli O26 and O111. Using IMS, two E. coli O26 isolates were detected. No E. coli O111 were recovered. The multiplex PCR technique described here did not detect E. coli O111 nor O157 in any of the samples, however six minced beef samples were positive for E. coli O26 using our method, only two of these were previously detected by IMS and culture. Application of molecular methods are useful to support culture-based approaches thereby further contributing to risk reduction along the food chain.

Animals↗
PubMed1998

Antimicrobial drug residues in milk and meat: causes, concerns, prevalence, regulations, tests, and test performance.

This paper presents a historical review of antimicrobial use in food animals, the causes of residues in meat and milk, the types of residues found, their regulation in Canada, tests used for their detection, and test performance parameters, with an emphasis on immunoassay techniques. The development of residue detection methods began shortly after the introduction of antimicrobials to food animal production in the late 1940s. From initial technical concerns expressed by the dairy industry to the present public health and international trade implications, there has been an ongoing need for reliable, sensitive, and economical methods for the detection of antimicrobial residues in food animal products such as milk and meat. Initially there were microbial growth inhibition tests, followed by more sensitive and specific methods based on receptor binding, immunochemical, and chromatographic principle. An understanding of basic test performance parameters and their implications is essential when choosing an analytical strategy for residue testing. While each test format has its own attributes, none test will meet all the required analytical needs. Therefore the use of a tiered or integrated system employing assays designated for screening and confirmation is necessary to ensure that foods containing violative residues are not introduced into the food chain.

Animals↗
PubMed1995

[Listeriosis 1985-1995: microbiologic and epidemiologic aspects].

Listeriosis is an emerging foodborne infection caused by L. monocytogenes (L. m.), mainly identified in industrialized countries. It is a severe disease (meningitis, septicaemia, abortion) which preferentially affects individuals whose immune system is perturbed (pregnant women, newborns, immunocompromized patients and the elderly). Epidemiology is characterized by a background of sporadic cases on which may be surimposed outbreaks. Progresses in microbiology during the last decade (detection and typing of L. m., better understanding of L.m. ecology...) and epidemiological investigations (increased use of case-control studies) demonstrated that all kind of foods, at each step of the food chain, can transmit the disease. In many respects, L.m. differs from most recognized foodborne pathogens: it is ubiquitously present in nature, resistant to various kind of environments, microaerophilic and psychrophilic. Its tenacity in industrial environment and its capability to survive in food over extended period of time under adverse conditions made this bacterium the hottest topic for industrials during the last decade.

Food Microbiology↗
PubMed2004

PCR detection assay of fumonisin-producing Fusarium verticillioides strains.

Fusarium verticillioides is considered to be the main source of fumonisins, a group of toxins that contaminate commodities and result in chronic and acute diseases affecting humans and animals. The detection and control of this species is crucial to prevent fumonisins from entering the food chain. The objective of the present research was to develop a specific, sensitive, and robust PCR assay to detect F. verticillioides strains using two pairs of specific primers for F. verticillioides, which have been designed on the basis of the intergenic spacer region of the rDNA units. The first pair of primers was F. verticillioides species specific, whereas the second pair of primers detected fumonisin-producing F. verticillioides strains. This second pair of primers allowed for the discrimination between the major group of F. verticillioides strains, fumonisin-producing strains that are mainly associated with crops, and a minor group of strains, non-fumonisin-producing strains that are associated with bananas. Fifty-four strains of F. verticillioides from different geographical regions and hosts were tested using both sets of primers. Sixteen additional Fusarium species were examined. The specificity of the primer sequences provides the basis for a simple, rapid, accurate, and sensitive detection and identification method of this fungal species that represents a risk for human and animal health.

Consumer Product Safety↗