Population Growth and Allergen Content of Cultured Euroglyphus maynei House Dust Mites.

BACKGROUND: The house dust mite, Euroglyphus maynei, occurs in homes worldwide and is an important source of many allergens. Many patients sensitive to Dermatophagoides farinae and D. pteronyssinus are also sensitive to E. maynei. Extracts to detect sensitivity to E. maynei and reagents to detect E. maynei allergens in the environment or in cultures are not readily available. Information for the culture of E. maynei and for the determination of allergen and endotoxin levels in cultures is limited. METHOD: We mass cultured E. maynei at 23 and 30°C and determined the population growth profiles from inoculation until cultures could be harvested for the production of extracts. We also developed an ELISA to measure Eur m 1 and Eur m 2 allergens using mouse monoclonal antibodies directed at cross-reacting epitopes of group 1 and group 2 allergens of D. farinae and D. pteronyssinus. RESULTS: The E. maynei populations grew exponentially at both 23 and 30°C; however, the cultures matured more rapidly at 23°C. The Eur m 1 and Eur m 2 allergen concentrations in culture extracts changed independently as the cultures grew and matured. At both temperatures, the Eur m 1 concentrations increased as the cultures matured, while the Eur m 2 concentrations did not. The endotoxin levels in these cultures were low. CONCLUSION: We report here that E. maynei can be cultured at 23 and 30°C. Monoclonal antibodies directed at cross-reacting epitopes on Dermatophagoides allergens can be used to measure the associated E. maynei allergen levels in these cultures.

Cross-reactivity between storage and dust mites and between mites and shrimp.

Many patients have sensitivities to multiple species of storage and house dust mites. It is not clear if this is because patients have multiple sensitivities to species-specific mite allergens or if these mites share many cross-reacting allergens. Our objective was to further define the cross-allergenicity between several species of storage and house dust mites using crossed-immunoelectrophoresis (CIE), crossed-radioimmunoelectrophoresis (CRIE), immunoblotting, and ELISA. CIE and CRIE reactions revealed that storage mites shared two cross-antigenic molecules and one of these bound IgE in a serum pool from mite allergic patients. Antibody in anti-sera built to each species of mite recognized many SDS-PAGE resolved proteins of other mite species and this suggested the potential for other cross-reactive allergens. Among patient sera, IgE bound to many different proteins but few had IgE that bound to a protein with common molecular weights across the mite species and this suggested mostly species-specific allergens. Antiserum built to each mite species precipitated one protein in shrimp extracts that bound anti-Der p 10 (tropomyosin) and IgE in the serum pool. Anti-Der p 10 showed strong binding to shrimp tropomyosin but very little to any of the mite proteins. ELISA showed the mite extracts contained very little tropomyosin. The storage and dust mites investigated contain mostly species-specific allergens and very small amounts of the pan-allergen tropomyosin compared to shrimp and snail.

Prevalence of serum IgE to storage mites in a southwestern Ohio population.

BACKGROUND: Storage mites of the families Chortoglyphidae, Glycyphagidae, Echimyopodidae, and Acaridae are commonly found in agricultural and nonagricultural environments. The prevalence of sensitization to these storage mites in the general population in the United States is unknown. OBJECTIVE: To determine the prevalence of serum IgE to the storage mites Lepidoglyphus destructor and Acarus siro and to evaluate the degree of co-sensitization to various other astigmatid mites in a population in southwestern Ohio. METHODS: Serum samples from 600 people randomly selected from a 1-day submission of approximately 3,000 samples to a clinical diagnostic laboratory were screened for IgE to allergens of L destructor and A siro. Proteins in the extracts of each mite were electrophoretically separated, transferred to membranes, and incubated in the serum samples, and the slot blots were probed for IgE binding using radiolabeled anti-human IgE and autoradiography. RESULTS: Thirty-two (5.3%) of the 600 serum samples screened had IgE to allergens from at least 1 of the 2 mite species; 14 (2.3%) and 20 (3.3%) had serum IgE to proteins of the mites A siro and L destructor, respectively. Additional analysis revealed that most serum samples also had IgE that bound to proteins in extracts prepared from a variety of other astigmatid mite species, but IgE binding profiles suggested little cross-reactivity. CONCLUSIONS: Sensitization to the mites L destructor and A siro is significant in this region of southwestern Ohio. Further studies are needed to determine the importance of these and other storage mites in occupationally exposed and urban populations of the United States.

Effects of wet cleaning with disodium octaborate tetrahydrate on dust mites (Acari: Pyroglyphidae) in carpet.

In a controlled laboratory study, disodium octaborate tetrahydrate (DOT) applied to carpets with a carpet-cleaning machine at a rate of 509 ml DOT/8.15 liter H2O/100 m2 (two cups DOT/2 gal H2O/100 feet2) reduced survival and population growth of live Dermatophagoides farinae and Dermatophagoides pteronyssinus by > or = 98% compared with water-cleaned and uncleaned carpets at 8 wk postcleaning. Cleaning with DOT was more effective against D. pteronyssinus than D. farinae.

Mite and mite allergen removal during machine washing of laundry.

BACKGROUND: Few studies have investigated live house dust mite and mite allergen removal from clothing and bedding by washing machines. No studies have investigated the transfer of mites from infested to uninfested clothing and bedding during washing. OBJECTIVE: The purpose of this study was to wash different types of clothing and bedding in residential washing machines to determine the live Dermatophagoides farinae mite and allergen removal and the mite transfer from mite-infested items to mite-free items. METHODS: Clothing and bedding items were machine washed in 6- and 8-lb loads in warm (36 degrees C-38 degrees C) or cold (22 degrees C-27 degrees C) water with and without recommended concentrations of laundry detergent and sodium hypochlorite bleach. Live mites and allergen present in washed versus unwashed and washed mite-infested versus washed mite-free items were compared. RESULTS: Washing clothing and bedding in water alone, detergent, or detergent plus bleach removed 60% to 83% of the live mites. Washing removed more mites from some items than from others. When mite-infested items were washed with identical sets of mite-free items, many live mites were transferred to the previously mite-free items. Overall, 84% of Der f 1 was removed from items washed in water alone or in detergent and 98% from items washed in detergent plus bleach. CONCLUSIONS: Washing clothing and bedding in cold or warm water with detergent or detergent plus bleach removed most allergen and a significant (P <.05) portion of live mites. Repeated washing is required to further reduce mite levels. Live mites were transferred from mite-infested to mite-free items during washing.

Effects of laundry detergents on Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Euroglyphus maynei.

BACKGROUND: House-dust mites in clothing and bedding are the source of major allergens. Based on studies of Dermatophagoides pteronyssinus only, weekly washing in hot water is recommended to kill dust mites and remove allergens from clothing and bedding. However, in the United States, washing is most often done in warm or cold water, and other mite species are involved. OBJECTIVE: The purpose of this study was to investigate the lethal effects of various temperatures of hot water alone and hot, warm, and cold water containing detergents and chlorine bleach on Dermatophagoidesfarinae, D. pteronyssinus, and Euroglyphus maynei. METHODS: Mites were soaked in test solutions at various temperatures and for various lengths of time, allowed time to recover, and then analyzed for survival. RESULTS: D. farinae was the most temperature-sensitive and chlorine bleach-sensitive of the three species. In 50 degrees C water alone, 100% mortality for D. farinae was obtained in 10 minutes, whereas most D. pteronyssinus and E. maynei survived. However, 53 degrees C-soaks for 12 and 5 minutes were needed to kill all D. pteronyssinus and E. maynei, respectively. Laundry detergents at their recommended and doubled concentrations and chlorine bleach generally increased mite mortalities over water alone for the three species. Soaking for 4 hours in warm water containing various detergents alone induced mortalities of 19 to 50%, 2 to 35%, and 14 to 46% for D. farinae, D. pteronyssinus, and E. maynei, respectively. CONCLUSIONS: Washing bed linens weekly in warm water with a 4-hour presoak containing most detergents and bleach will kill most D. farinae and, depending on the detergent brand, moderate numbers of D. pteronyssinus. Four-hour soaks in warm water containing the recommended concentrations of various detergents alone also kills moderate numbers of D. farinae, D. pteronyssinus, and E. maynei. Therefore, the cumulative effect of weekly washing with long presoaks should significantly reduce mite levels over time in bed linens, particularly when mattresses and pillows are encased to prevent reinfestation.