Nature

T. putrescentiae is a common species of mite that contaminates food. T. putrescentiae is primarily found in stored products with high protein and fat contents, such as cultured cheeses, pet food and dry-cured ham, (4) and is a major pest in cheese houses, nut and grain storage, and commercial mushroom beds (5).

One study looking at contamination rates of T. putrescentiae in storage products found an overall contamination rate of 15.4% with the following contamination rates per category: farina 12.5%, beans 6.5%, rice 0%, cookies 8.8%, mushrooms 33.3%, and pet foods 53.3% (6).

Fumigants and acaricides can be used to control T. putrescentiae but have limitations in food processing. The fumigant pesticide methyl bromide was used to control mites on food but is now banned in most countries (7). Alternative pest control methods proposed include the naturally occurring fat molecules (such as thyme, lemon grass, or rose) (7), irradiation, oxygen-reduced modified atmospheres (4) and extreme temperature control (4, 5).

Taxonomy 

Tissue

Mite feces are the most relevant source of allergens (8).

Allergenic molecules

Allergens in storage mites include fatty acid-binding proteins, tropomyosin and paramyosin homologues, apoliphorine-like proteins, alfa tubulines and other allergens, such as group 2, 5 and 7 allergens (13). Studies have identified at least 14 allergenic molecules from extracts of T. putrescentiae (13). One of these molecules, Tyr p 2, is considered a major allergen which showed high IgE reactivity in 80% of serum samples from sensitized patients (13). Other antigens include: Tyr p 13, an intracellular lipid transport protein, could bind 6.4% of serum samples from sensitized patients when presented in recombinant form. A α-tubulin was cloned and the recombinant version was recognized by IgE in 29.3% of serum samples from patients sensitized to mites and/or crustaceans. Tyr p 10 in recombinant form was recognized by 12.5% of serum samples from sensitized patients (13).

Table adapted from Allergome.org (14)

Cross-reactivity

Allergenic cross-reactivity between storage mites and HDMs is well documented; in a European Community Respiratory Health Survey, 8% of people were found to be sensitized to HDMs and 10% to storage mites. Among those patients with storage mite sensitization, 26% were also sensitized to T. putrescentiae (2).

Another study reported that 88.4% (n/N=274/310) of patients sensitive to house dust mites were also sensitive to storage mites; 73% (n/N=227/310) of patients were sensitized to all three species of storage mite studied (Lepidoglyphus destructor, T. putrescentiae and Acarus. siro) (15).

Among 117 allergic rhinitis patients hypersensitive to T. putrescentiae, 97% were also sensitized to Dermatophagoides pteronyssinus. Group 2 allergens are thought to be the major cross-reactive allergens of D. pteronyssinus and T. putrescentiae (16).

Cross reactivity between the silkworm (Bombyx mori) and T. putrescentiae has also been reported (17, 18).