The occurrence of mite-containing wheat flour

Effects of gaseous ozone treatment on the mite pest control and qualitative properties during ripening storage of pecorino cheese

BACKGROUND

Ripened cheeses, such as pecorino, are susceptible to mites and molds contamination on the crust area that must be removed before the product can be marketed. This study investigates the effectiveness of gaseous ozone treatment in the control of microbiological and mite growth without negatively affecting product quality.

RESULTS

Cheese samples were treated with gaseous ozone at 200 and 300 ppb for 8 h per day (overnight) for 150 days in storage rooms under controlled conditions (12 °C and 85% relative humidity). The results showed that ozone at 200 ppb limits the growth of mites starting from 25 days of storage and significantly reduced bacteria, molds, and yeasts counts starting from 75 days of storage. Concerning the physicochemical and qualitative parameters evaluated during ripening (weight loss, moisture content, dry weight, ash, fat, protein, total nitrogen, color, non-destructive firmness), no significant differences were shown between the control samples and ozone treatment at 200 ppb. Sensory analysis (consumer test) also showed no specific defects with the ozone-treated samples. It was observed that the ozone treatment at 300 ppb had limited microbiological growth and no alteration of sensory aspects but did not have the same positive impact on some aspects of overall quality, compared with ozone treatment at 200 ppb.

CONCLUSION

The use of gaseous ozone treatments during ripening of pecorino cheese can potentially offer an excellent solution for the control of mite growth, while preserving the quality and sensory characteristics of the product. For this reason, this technique could be very useful for commercial purposes. © 2022 Society of Chemical Industry.

Oral mite anaphylaxis: who, when, and how?

PURPOSE OF REVIEW

To present an update on the recent advances in the understanding of the mechanisms and practical management of oral mite anaphylaxis (OMA, pancake syndrome).

RECENT FINDINGS

Among novel observations regarding OMA, this review highlights the increased prevalence of aspirin/NSAID hypersensitivity inpatients affected by OMA, the association of OMA with exercise-induced anaphylaxis, the presentation of OMA simulating acute asthma, the occurrence of OMA in childhood, the high severity and lethal potential of OMA, the contamination of other foods, such as oat and corn flour with mites, and the simultaneous induction of OMA symptoms in more than one individual exposed to the same food source.

SUMMARY

OMA is a severe, potentially lethal, acute allergic condition that should be suspected whenever symptoms begin soon after the intake of mite-contaminated foods. Physician awareness on this clinical picture is of paramount importance to establish a correct diagnosis and to implement adequate preventive measures to help patients at risk to avoid its occurrence.

The Role of Dust Mites in Allergy

House dust mites are an unsurpassed cause of atopic sensitization and allergic illness throughout the world. The major allergenic dust mites Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, and Blomia tropicalis are eight-legged members of the Arachnid class. Their approximately 3-month lifespan comprises egg, larval, protonymph, tritonymph, and adult stages, with adults, about one fourth to one third of a millimeter in size, being at the threshold of visibility. The geographic and seasonal distributions of dust mites are determined by their need for adequate humidity, while their distribution within substrates is further determined by their avoidance of light. By contacting the epithelium of the eyes, nose, lower airways, skin, and gut, the allergen-containing particles of dust mites can induce sensitization and atopic symptoms in those organs. Various mite allergens, contained primarily in mite fecal particles but also in shed mite exoskeletons and decaying mite body fragments, have properties that include proteolytic activity, homology with the lipopolysaccharide-binding component of Toll-like receptor 4, homology with other invertebrate tropomyosins, and chitin-cleaving and chitin-binding activity. Mite proteases have direct epithelial effects including the breaching of tight junctions and the stimulation of protease-activated receptors, the latter inducing pruritus, epithelial dysfunction, and cytokine release. Other components, including chitin, unmethylated mite and bacterial DNA, and endotoxin, activate pattern recognition receptors of the innate immune system and act as adjuvants promoting sensitization to mite and other allergens. Clinical conditions resulting from mite sensitization and exposure include rhinitis, sinusitis, conjunctivitis, asthma, and atopic dermatitis. Systemic allergy symptoms can also occur from the ingestion of cross-reacting invertebrates, such as shrimp or snail, or from the accidental ingestion of mite-contaminated foods. Beyond their direct importance as a major allergen source, an understanding of dust mites leads to insights into the nature of atopy and of allergic sensitization in general.

Oral mite anaphylaxis after ingestion of Korean pancake

Background

Oral mite anaphylaxis (OMA) is a syndrome characterized by severe allergic manifestations occurring in atopic patients shortly after the intake of foods made with mite-contaminated wheat flour. A history of atopic disease has been identified as one of risk factors for the development of OMA. This is the report that OMA was induced by the ingestion of Korean pancake prepared with commercial mixed wheat flour contaminated with mites.

Case presentation

A 15-year-old Japanese girl with a history of atopic asthma and dermatitis was admitted to the emergency department with the anaphylactic symptoms of urticaria, skin flushing, throat discomfort, acute dyspnea and severe wheezing that developed shortly after the ingestion of home-cooked buchimgae (Korean pancake) prepared with commercial mixed wheat flour. The ingredients in the buchimgae were eggs, shrimps and chopped Chinese chives, but the girl had previously consumed these individual ingredients without incident. Microscopic examination of the mixed wheat flour revealed the presence of large numbers of live dust mites. The patient's serum specific IgE analysis was positive for antibodies to dust mite allergens. From these findings, the anaphylactic episode in this patient was concluded to be the result of ingestion of mixed wheat flour contaminated with mites.

Conclusions

OMA was induced by the ingestion of wheat flour contaminated with mites. Physicians should be aware of this clinical picture, particularly in the case with risk factors, and recommend that wheat flour should be stored in a refrigerator to prevent mite proliferation and the development of OMA.

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Oral mite anaphylaxis (OMA) is a syndrome characterized occurring after the intake of foods made with mite-contaminated wheat flour.

Influence of storage conditions on the infestation of Tyrophagus putrescentiae and prevalence of mite hypersensitivity in Taiwan

Sensitization to mites is a considerable factor in the development of allergic diseases. Because of its abundance, Tyrophagus putrescentiae (Tp) is the predominant storage mite found in home storage rooms, kitchens, and bakeries. Patients allergic to mites might exhibit a severely hypersensitive reaction upon ingesting Tp-contaminated food. The objective of this study was to investigate the rates of Tp contamination in commercial storage products from various areas, storage conditions, and environments in Taiwan. A specific antibody against Tyr p 3, the allergen on Tp, could be used as an indicator to monitor the contamination condition in storage foods. The microscopic mite examination, allergen detection by ELISA and cultured mite chemotaxis were used to evaluate the prevalence of T. putrescentiae contamination. Moreover, the IgE responses of patients allergic to mites were examined. We found that pet food and mushrooms were commonly contaminated with Tp, and this was validated through Tyr p 3 concentration and chemotaxis experiments. Tp contamination rates decreased significantly when samples were sealed and stored at a low temperature (<  4 °C), low relative humidity (RH < 60%), or for longer periods at a low temperature. The results of the clinical study indicated that the mites that elicited major positive IgE responses in allergic subjects were Dermatophagoides pteronyssinus and D. farinae. Thus, people who are sensitized to D. pteronyssinus or D. farinae might be at risk of a second anaphylactic reaction due to cross-reactivity upon ingestion of Tp-contaminated food. Accordingly, Tp contamination can be prevented by keeping food packages sealed and stored at a low temperature. This prevents the severe allergic reaction caused by the inadvertent ingestion of contaminated food-borne Tp.

Health Hazards Associated with Arthropod Infestation of Stored Products

Insects and mites are common inhabitants and accidental invaders of food, including durable commodities, and their presence can have both direct and indirect effects on human health. The most common direct effect is contamination of food with arthropod fragments and related contaminants, which may be allergenic or even carcinogenic. The most important indirect effect is that their presence can change the storage microenvironment, making durable products suitable for the rapid development of fungi and other microorganisms. Some of these fungi can produce toxins (e.g., aflatoxins) that endanger human health. Insects may actively or passively contribute to the spread of microorganisms, increasing product contamination, and they may host bacteria that have developed antibiotic resistance, contributing to their spread in food. Several species also may host, attract, or transmit tapeworms, predators, or parasitoids that may affect health. This review synthesizes research on these topics and suggests directions for future research.

A case of mite-ingestion-associated exercise- induced anaphylaxis mimicking wheat-dependent exercise-induced anaphylaxis

We present a case of mite-ingestion-associated exercise-induced anaphylaxis mimicking wheat-dependent exercise-induced anaphylaxis (WDEIA). A 17-year-old boy was referred for an episode of anaphylaxis while jogging, 1.5 h after having eaten okonomiyaki (a Japanese pancake). Laboratory measures revealed a slightly elevated specific immunoglobulin E (IgE) antibody against omega-5 gliadin (0.41 kUA/l) and a marked elevation of specific IgE antibody against house-dust mite, Dermatophagoides farinae (142 kUA/l). A detailed interview revealed that, in spite of the referring doctor's advice to discontinue postprandial exercises, he continued his jogging routine after consuming foods containing wheat and also that his younger brother, who had mild intermittent asthma, had suffered a mild asthma attack 2 h after eating the same food. We therefore examined the okonimiyaki mix, which had been stored for several months after opening the package until this episode, under a microscope, and we found an abundant number of live mites, D. farinae. Finally, a diagnosis of mite-ingestion-associated exercise-induced anaphylaxis was made. This clinical entity should be excluded when making a diagnosis of WDEIA.

The toxic effect of chitosan/metal-impregnated textile to synanthropic mites

BACKGROUND

Plasma treatment enables effective binding of chitosan film to textile fibres. Heavy metal ions such as Ag(+) adsorbed onto the chitosan coating are known to enhance toxicity to microorganisms. The acaricidal effect of chitosan and chitosan/metal adducts with Ag(+) , Zn(2+) and Cu(2+) was tested in laboratory experiments. Tested species Acarus siro, Dermatophagoides farinae, D. pteronyssinus and Tyrophagus putrescentiae are allergen producers and important pests in house dust, stored food and feed. The mortality was compared after 24 h of exposure of mites to plasma-treated textiles.

RESULTS

Chitosan/Ag(+) textile caused at least 80% mortality of all species tested. Chitosan/Zn(2+) and chitosan/Cu(2+) textiles had a smaller effect on mite mortality than chitosan/Ag(+) . The conversion of chitosan/Ag(+) finishing to chitosan/Ag2 O did not influence the mortality of mites in biotests, except that of Tyrophagus putrescentiae, where the mortality decreased from 86 to 64%.

CONCLUSION

The results support a great potential of chitosan/Ag(+) fibres in acaricidal materials and/or mite protective food packages.

Food allergy in Asia: how does it compare?

Asia is a populous and diverse region and potentially an important source of information on food allergy. This review aims to summarize the current literature on food allergy from this region, comparing it with western populations. A PubMed search using strategies "Food allergy AND Asia", "Food anaphylaxis AND Asia", and "Food allergy AND each Asian country" was made. Overall, 53 articles, published between 2005 and 2012, mainly written in English were reviewed. The overall prevalence of food allergy in Asia is somewhat comparable to the West. However, the types of food allergy differ in order of relevance. Shellfish is the most common food allergen from Asia, in part due to the abundance of seafood in this region. It is unique as symptoms vary widely from oral symptoms to anaphylaxis for the same individual. Data suggest that house dust mite tropomysin may be a primary sensitizer. In contrast, peanut prevalence in Asia is extremely low compared to the West for reasons not yet understood. Among young children and infants, egg and cow's milk allergy are the two most common food allergies, with prevalence data comparable to western populations. Differences also exist within Asia. Wheat allergy, though uncommon in most Asian countries, is the most common cause of anaphylaxis in Japan and Korea, and is increasing in Thailand. Current food allergy data from Asia highlights important differences between East and West, and within the Asian region. Further work is needed to provide insight on the environmental risk factors accounting for these differences.

[House dust mites and their allergens]

The taxonomy, anatomy, life cycle and ecology of Pyroglyphidae mites and storage mites (Acaridae, Glycyphagidae, B. tropicalis) are described. Pyroglyphidae and storage mites have similar morphologies: they are octopods, with characteristic gnathosoma and sensory hairs. Salivary glands and the mid gut produce most of the allergens excreted, which are enzymatic proteins. Biological cycles and development are similar, although fecundity is superior in storage mites compared to the Pyroglyphides. Relative humidity is the main parameter, which regulates mite development, with a higher degree of temperature and humidity required for storage mites. Bedding is the ecological niche of Pyroglyphidae, which feed on human skin. Moulds and food products are the storage mite biotope from which they spread in the dwelling. Initially considered as rural mites, storage mites are also present in urban dwellings. B. tropicalis, in tropical regions is a true domestic mite. Because of this, it is justified to denominate Pyroglyphidae "house dust mites" and storage mites "domestic mites". In addition to the respiratory allergic symptoms, the storage mites can also cause occupational contact dermatoses.

Dust mite infestation of flour samples

BACKGROUND

Ingestion of flour contaminated with dust mite may trigger severe anaphylaxis in tropical and sub-tropical regions.

AIMS

This study aimed to evaluate environmental factors that affect dust mite propagation in the tropics.

MATERIALS & METHODS

Dust mites were introduced to a variety of flour samples and incubated at two different environmental conditions.

RESULTS

It was found that dust mites populations flourished best in wheat flour compared to other varieties of flour, and at ambient temperatures with high humidity instead of the air conditioned environment.

CONCLUSION

Dust mite infestation of flour is dependent on the presence of wheat and high ambient temperature in the tropics.

Oral mite anaphylaxis by Thyreophagus entomophagus in a child: a case report

Sensitization to Thyreophagus entomophagus, a storage mite, is uncommon and might produce occupational respiratory disorders in farmers. We present the first case of a child suffering anaphylaxis produced by ingestion of contaminated flour with Thyreophagus entomophagus.