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At least 19 recordsLinked to original sources
PubMed1991

Testing for food-borne parasites, their metabolic products and symbionts.

Microscopic animals associated with foods include free-living and saprophytic invertebrates, parasites of hosts other than humans, and parasitic animals specifically designated as food-borne that can infect a human host by the gastrointestinal route. The first general method used to screen for food-borne species was digestion with pepsin and hydrochloric acid at 36 degrees C, based on the "artificial stomach juice" technique for recovering larvae of the nematode Trichinella spiralis from muscle. This method selects for forms capable of surviving a mammalian digestive enzyme at mammalian temperatures. It has been used successfully to recover a variety of food-borne helminths, not only from mammalian flesh but also from fish, shellfish and molluscs, and can be adapted to greatly reduce the "background of living animals" associated with soils and the crops grown in them. However, not all animal forms that survive digestion are food-borne parasites, and all that succumb are not necessarily noninfectious. Methodology to test for food-borne parasites is, in general, not as efficient as that for food-borne bacteria. Recent developments in food parasitology indicate a need to identify not only the parasite, but also its metabolic products and associated symbionts.

Animals↗
PubMed1992

Determination of the heating temperature of fishery products.

The German Fish Directive prescribes that products must be heated to the core temperature of +70 degrees C to kill existing larvae of nematodes. For subsequent determination of the heating temperature samples were extracted with water. The extracts were analysed for protein content, for protein patterns obtained by isoelectric focusing and by using the coagulation test. The suitability of these methods was investigated with heated extracts, heated minced fish flesh, and smoked herring and mackerel. Smoking was performed in the kiln of the institute at controlled temperatures. Analysis of commercial samples showed that the core temperature during smoking of herring and mackerel must have been clearly below 70 degrees C in several cases.

Animals↗
PubMedDate not supplied

Infectivity of Toxoplasma gondii in mutton following curing, smoking, freezing or microwave cooking.

To investigate the effects of curing with sodium chloride and sucrose, low temperature smoking, freezing at -20 degrees C, and cooking in a microwave oven, respectively, on the infectivity of Toxoplasma gondii encysted in mutton, meat from three experimentally and one naturally infected sheep was used. Samples of meat prepared accordingly as well as untreated, raw meat from each animal were assayed by mouse inoculation. Infective T. gondii was isolated from untreated samples from all animals used, but in no case from cured, smoked or frozen meat. However, in two of four steaks processed in a microwave oven, according to a standard household recipe, the parasite remained infective, possibly due to uneven heating of the meat.

Animals↗
PubMed1994

Parasites, animal production and sustainable development.

Ecologically sustainable development is aimed at reducing environmental degradation while enabling economic development with equity between the developed and developing worlds and between generations. Parasite control in livestock can both contribute to, and take advantage of, sustainable agriculture. This will tend towards less intensive, lower input, diversified crop and animal production with less risk of parasite-induced losses and greater opportunities for integrated control including the exploitation of grazing management. Chemotherapy will continue to play a part but the most serious problem is resistance in the target species. Except for a few isolated issues, currently used parasiticides are relatively minor contaminants of the food supply or the environment. Nevertheless, the compounds of the future will need to be narrow-spectrum, non-persistent and rapidly degraded, with convenience in the hands of the user reduced in importance. Environmentally friendly alternatives to chemotherapy, including genetic resistance of hosts, vaccines, and biological control, show considerable promise and must be pursued. Sustainable systems pose optimisation problems and more attention must be given to systems research, models and products to aid decisions. If governments are serious about sustainable development, greater support will be needed for longer-term patient, multi-disciplinary research.

Agriculture↗
PubMed2004

Food safety education: health professionals' knowledge and assessment of WIC client needs.

A written questionnaire was used to assess the opportunities and challenges for food safety education in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). The sample included directors and health professionals with nutrition counseling responsibilities in 79 WIC clinics in a midwestern state. Seventy-two percent of the clinics participated in the study. Data analysis included descriptive statistics, chi(2) analysis, and Cronbach's alpha. Seventy-two percent reported offering food safety advice to 20% or more of their clients daily. Ninety percent identified the food-safety knowledge of their WIC clients to be fair to very poor. The need for food safety handouts, targeted for WIC clients, was identified by 27% of the respondents. WIC professionals are promoting safe food handling among a high-risk population group. Expansion of current food-safety education efforts with WIC clients is encouraged with emphasis on methods to effectively overcome barriers to safe food handling.

Adult↗
PubMed1998

Viability of metacercariae of Clonorchis sinensis in frozen or salted freshwater fish.

Metacercariae of Clonorchis sinensis were collected from freshwater fish (Pseudorasbora parva) after storage in a freezer at -12 degrees C for 10-20 days, in a freezer at -20 degrees for 3-7 days, or treating with heavy salt (fish/salt = 10 gm/3 gm) at 26 degrees for 5-15 days. The metacercariae from the frozen fish were inoculated into 30 rats and eight rabbits, and those from the salted fish into 33 rats. Metacercariae from freshwater fish stored at -12 degrees for 10-18 days or -20 degrees for 3-7 remained viable and infective. Moreover, those kept at the heavy salt concentration for 5-7 days remained viable and infective. These findings indicate that freezing or storing infected freshwater fish in heavy salt may not be effective in the prevention of clonorchiasis. However, it appears that refrigeration, or keeping the fish in salt for longer periods, may be suitable for prevention of the infection.

Animals↗
PubMed2004

State of the art and future prospects of the biological control of postharvest fruit diseases.

Synthetic fungicides are the primary means to control postharvest diseases of fruits. Biological control has emerged as one of the most promising alternatives to chemicals. During the last 20 years, several biological control agents have been widely investigated for use on different pathogens and fruit crops. Many biological control mechanisms have been suggested for use on fruit including antibiosis, parasitism, induced resistance in the host tissue and competition. With the aim of extending the use of the biofungicides, there have been many studies on the application of various combinations of control agents, and on the application integrated with chemical and physical means of protection. The formulation and application methods are key issues for the efficacy and successful outcome of the commercial product. Genetic engineering may provide a useful tool in the enhancement of the biological control efficacy. Since biofungicides are usually not as effective as pesticides, this approach should be viewed as an important component of an integrated disease management scheme given that a significant and permanent reduction of pesticide use is our goal.

Antibiosis↗
PubMedDate not supplied

Dietary recommendations for patients allergic to Anisakis simplex.

BACKGROUND: Anisakis simplex, a fish parasite, causes allergic urticaria, angioedema and anaphylactic shock through an IgE-mediated hypersensitivity mechanism. Consensus on the dietary recommendations that should be given to allergic patients is lacking. Our objective was to evaluate the usefulness of different types of diets in preventing further reactions in patients allergic to A. simplex. METHODS: Twenty-eight adult patients, who had suffered an allergic episode caused by A. simplex were asked to follow one of the following three diets for a mean period of 13.16 months: a fish-free diet (diet 1; n = 19), a diet including fish frozen for more than 48 hours (diet 2; n = 9) and a diet with fresh fish (diet 3; n = 12). In all patients raw fish was excluded. Relapse rates and changes in total serum IgE and specific IgE to A. simplex were studied during the follow up. RESULTS: During the 13-month follow-up none of the patients developed anaphylaxis. Urticaria symptoms were present in 5.8 %, 11.1 % (n.s) and 33.3 % (p = 0.016) of patients following diets 1, 2 and 3, respectively. Total IgE decreased by 64 % (p < 0.05), 48 % (p < 0.05) and 39.4 % (p < 0.05), respectively. Specific IgE to A. simplex decreased by 50.7 % (p < 0.05), 54.1 % (p < 0.05) and 23.6 % (p < 0.05) after diets 1, 2 and 3, respectively. No statistically significant differences were found among the groups in variations in total and specific IgE. CONCLUSIONS: Patients allergic to A. simplex can eat fish that has been frozen at -20 C for 48 hours without risk of a severe allergic reaction. Long term decreases in specific and total IgE may not be good markers of eventual contact with A. simplex.

Adult↗
PubMedDate not supplied

[Anisakis and anisakiosis].

The nematode Anisakis simplex (AS) is a world wide distributed parasite that infects consumers of raw or undercoocked parasitized fish. The clinical manifestation of Anisakiosis depend on the site in the digestive tract in which larva lodges. The symptoms develops as a result of the inflammation when the larvae penetrates the gastric mucous. Most of asymptomatic subjects show high levels of specific IgE to AS. Diagnosis of AS allergy is not simple, due to cross-reactivity with other allergens. In childhood is more difficult to make a right diagnosis than in adult population. Most of positive prick test to AS correspond to children with positive prick tests to other allergens. Cross-reactivity between this parasite and other parasites with a higher prevalence in childhood, is the cause of a false diagnosis. The secretor-excretory antigen shows a better specificity, recognizing the true parasitized patients. This antigen could be used as indicator of parasitization. To follow prevention rules AS, avoid consumption of raw fish unless frozen for 48 hours or ingestion of fresh fish always cooked for more than 20 minutes at least at 60 C.

Animals↗
PubMed2005

Impact of food disinfection on beneficial biothiol contents in vegetables.

In this work we investigated the impact of food disinfection on the beneficial biothiol contents in a suite of vegetables consumed daily, including spinach, green bean, asparagus, cucumber, and red pepper. Four disinfection technologies commonly studied and/or used in food processing and preservation, including hydrogen peroxide, free chlorine, and gaseous- and aqueous-phase ozone, were examined with common dosages and contact times. Results indicate that the common disinfection technologies may result in significant loss of beneficial biothiols in vegetables which are essentially important to human health. For example, as much as 70% of biothiols were lost when spinach was treated with hydrogen peroxide (5.0 wt %) for 30 min. Approximately 48-54% of biothiols were destroyed by free chlorine and gaseous- and aqueous-phase ozone under typical contacting conditions. In red pepper, about 60-71% of reduced glutathione was oxidized by the disinfectants. The potential decrease in biothiols during disinfection was dependent upon the biothiol type, the disinfectant, and the vegetable. The effectiveness of total bacterial inactivation by the four disinfection technologies was concurrently evaluated. Results show that free chlorine is most effective, achieving disinfection efficiencies of greater than 4 log for all study vegetables. This study may provide important information for the food industry to design optimum contacting methods for vegetables to simultaneously achieve sufficient bacterial disinfection while minimizing loss of beneficial biothiols.

Disinfection↗
PubMed1996

Outbreak of trichinellosis associated with eating cougar jerky.

There has been a decline in the number of human trichinellosis cases associated with consumption of commercial pork in the United States, while the relative importance of trichinellosis from game meats has increased. An investigation of an outbreak of trichinellosis in Idaho occurring after consumption of improperly prepared cougar jerky is described. Ten cases of trichinellosis were identified among 15 persons who ate the implicated meat. Viable Trichinella larvae were recovered from frozen cougar tissue. Polymerase chain reaction on parasite DNA yielded results consistent with genotypes T. nativa and Trichinella type T6. This report of cougar meat as a source of human trichinellosis and the finding of freeze-resistant Trichinella organisms in wildlife in Idaho extends the range of this genotype. Consumers of game need to cook the meat thoroughly, since even frozen meat may harbor viable Trichinella that can cause illness.

Adolescent↗
PubMed2000

[Mite contamination in polished rice and beans sold at markets].

OBJECTIVE: To evaluate mite contamination rate in grains commercialized in nine municipal markets of the city of São Paulo, in the period from November 1989 to November 1990. METHODS: 23 samples of polished rice and 53 samples of beans were microscopically examined after sieving, once a week and during 42 days at air temperature. Other sample fractions were kept in an incubator at 25 degrees C and 75% Relative Humidity (RH) during 28 days. RESULTS: Samples were negative for mites in the first day of analysis and were detected after incubation. Samples incubated revealed a higher percentage of positive examinations for mites (incidence): 31.7% (and 1,845 mites); while samples kept at air temperature showed only 6.9% (and 45 mites). Samples of polished rice were more contaminated in comparison to the ones of beans. There was a larger amount of mites when the mean monthly temperature of the laboratory was between 21.5 degrees C to 22.5 degrees C (37. 8%) and humidity between 73.5% to 74.5% (31.1%). CONCLUSIONS: The predominant species was Tyrophagus putrescentiae and other identified species were Blomia tropicalis, Cheyletus spp., Blattisocius tarsalis, and others. Mite population had a higher proliferation rate during spring, summer and in the beginning of autumn, due to highest temperature and humidity. These results confirm the importance of improving grains storage, to avoid mites proliferation.

Animals↗
PubMedDate not supplied

[Detection of transmissible forms of enteroparasites in water and vegetables consumed at schools in Sorocaba, São Paulo state, Brazil].

Water and raw vegetables consumed in ten nursery schools were evaluated for the presence of transmissible forms of enteroparasites. The water was submitted to filtration through membranes. The washed membrane water was submitted to the Faust method. The in natura and washed vegetables were washed and the water analyzed by the sedimentation method. Contamination was not detected in one school; in two schools, all the materials were contaminated; in four schools, two items were contaminated and in three, one material presented contamination. The water presented a contamination index of 0.7% contamination (Hymenolepis diminuta, Strongyloides stercoralis and Ancylostomatidae); the vegetables in natura, 3.9% (Strongyloides stercoralis, Ancylostomatidae, Ascaris lumbricoides and Giardia lamblia) and the washed samples 1.3% (Strongyloides stercoralis, Ascaris lumbricoides and Giardia lamblia). The water and vegetables are enteroparasites vehicles. The larval form predominated. The vegetables in natura presented higher contamination than those that were washed. Elimination of these forms in vegetables was not guaranteed by washing.

Brazil↗
PubMed2001

Occurrence of cattle Sarcocystis species in raw kibbe from Arabian food establishments in the city of São Paulo, Brazil, and experimental transmission to humans.

Fifty samples of raw kibbe from 25 Arabian restaurants in the city of São Paulo, Brazil, were examined for the presence of bovine Sarcocystis species, using light and electron microscopy, and for infectivity to humans. Sarcocysts were found in all 50 samples. Based on cyst wall structure, S. hominis (94%), S. hirsuta (70%), and S. cruzi (92%) were identified (mostly as mixed infections). Different raw kibbe samples, positive for S. hominis in fresh preparations, were offered as a meal for 7 human volunteers. Six volunteers (85.7%), 2 of whom developed diarrhea, excreted sporocysts in feces. The prepatent period lasted 10-14 (12 +/- 1.8) days and the patent period lasted 5-12 (8.8 +/- 1.1) days.

Adult↗
PubMedDate not supplied

Emerging foodborne diseases.

The epidemiology of foodborne diseases is rapidly changing. Recently described pathogens, such as Escherichia coli O157:H7 and the epidemic strain of Salmonella serotype Typhimurium Definitive Type 104 (which is resistant to at least five antimicrobial drugs), have become important public health problems. Well-recognized pathogens, such as Salmonella serotype Enteritidis, have increased in prevalence or become associated with new vehicles. Emergence in foodborne diseases is driven by the same forces as emergence in other infectious diseases: changes in demographic characteristics, human behavior, industry, and technology; the shift toward a global economy; microbial adaptation; and the breakdown in the public health infrastructure. Addressing emerging foodborne diseases will require more sensitive and rapid surveillance, enhanced methods of laboratory identification and subtyping, and effective prevention and control.

Adaptation, Physiological↗
PubMed2005

Survival of Anisakis simplex in arrowtooth flounder (Atheresthes stomia) during frozen storage.

Survival of naturally occurring larvae of Anisakis simplex in fresh arrowtooth flounder (Atheresthes stomia) was determined after storage for specified periods at four freezing temperatures. All larvae were killed by 96, 60, 12, and 9 h at temperatures of -15, -20, -30, and -40 degrees C, respectively. The average percentages of live larvae per fillet at the next shortest holding time were as follows: 72 h at -15 degrees C, 0 to 3%; 48 h at -20 degrees C, 11 to 30%; 9 h at -30 degrees C, 5%; and 6 h at -40 degrees C, 0 to 3%. Larval survival was directly related to fillet thickness or weight (P < or = 0.05). Larval death was directly correlated to freezing temperatures. Holding time necessary to kill larval nematodes decreased as storage temperature decreased.

Animals↗
PubMed2006

Microwave inactivation of Cyclospora cayetanensis sporulation and viability of Cryptosporidium parvum oocysts.

The efficacy of microwave heating on the viability of Cryptosporidium parvum oocysts and on the sporulation of Cyclospora cayetanensis oocysts for various periods of cooking times (0, 10, 15, 20, 30, and 45 s) at 100% power was determined. Cyclospora oocysts were stored in 2.5% dichromate at 23 degrees C for 2 weeks, and sporulation rates were then determined. The 4',6-diamidino-2-phenylindole and propidium iodide vital stain and the neonate animal infectivity assay determined Cryptosporidium oocyst viability. Cryptosporidium oocysts could be completely inactivated with as little as 20 s of cooking time, whereas Cyclospora sporulation was observed up to 45 s. Two of the examined microwave ovens were more effective at reducing sporulation and viability than the third one. Because of the variability of temperature achieved by the various ovens, cooking time was not an accurate parameter for parasite inactivation. Cryptosporidium oocysts could be inactivated only when temperatures of 80 degrees C or higher were reached in the microwave ovens.

Animals↗